Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

Axions (A0) and Other
Very Light Bosons, Searches for
See the related review(s):Axions and Other Similar Particles
A0 (Axion) MASS LIMITS from Astrophysics and Cosmology
These bounds depend on model-dependent assumptions (i.e. — on a combination ofaxion parameters).
VALUE (MeV)

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •
>0.2
>0.25
>0.2

BARROSO
1 RAFFELT
2 DICUS

82
82
78C
78
78
78

ASTR
ASTR
ASTR
ASTR
ASTR
ASTR

Standard Axion
Standard Axion
Standard Axion
Stellar emission
Standard Axion
Standard Axion

MIKAELIAN
2 SATO>0.3>0.2
VYSOTSKII
1 Lower bound from 5.5 MeV γ-ray line from the sun.
2 Lower bound from requiring the red giants’ stellar evolution not be disrupted by axion
emission.

A0 (Axion) and Other Light Boson (X 0 ) Searches in Hadron Decays
Limits are for branching ratios.
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ADACHI<4 × 10−8
95
23K BEL2 B + → K + X 0−82<9 × 1095
ADACHI
23K BEL2 B 0 → K ∗ (892)0 X 0(K ∗ (892)0 → K + π − )−103+<3.7 × 10
95
CORTINA-GIL 23B NA62 K → π + A0 A0 , A0 →
e+ e−
−8
4
±
<4.2 × 10
90
LEES
22B BABR B → K ± A0 (A0 → γ γ)
−135
<7 × 1095
ABRATENKO 21 MCBN K + → π + X 0 (X 0 → e + e − )−76<1.5 × 10
90
CORTINA-GIL 21 NA62 K + → µ+ ν X 0−11
7<5 × 1090
CORTINA-GIL 21A NA62 K + → π + X 0
8 CORTINA-GIL 21C NA62 K + → π + X 0<9 × 10−10 90−8
9<1.5 × 1090
PARK
21 BELL B 0 → X 0 X 0 (X 0 → e + e − ,µ+ µ− , π + π − )−9100<2.4 × 1090
AHN
19 KOTO K → π 0 X 0 , m 0 = 135 MeV
L
X
11 AAIJ<2 × 10−10 95
17AQ LHCB B + → K + X 0 (X 0 → µ+ µ− )12 AHN<3.7 × 10−890
17 KOTO K 0 → π 0 X 0 , m 0 = 135 MeV
L
X
−11
13
<6 × 1090
BATLEY
17 NA48 K ± → π ± X 0 (X 0 → µ+ µ− )14 WON
16 BELL η → γ X 0 (X 0 → π + π − )−915<1 × 1095
AAIJ
15AZ LHCB B 0 → K ∗0 X 0 (X 0 → µ+ µ− )−6
16<1.5 × 10
90
ADLARSON
13 WASA π 0 → γ X 0 (X 0 → e + e − ),m 0 = 100 MeVX−817<2 × 1090
BABUSCI
13B KLOE φ → η X 0 (X 0 → e + e − )https://pdg.lbl.gov

Page 1Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)<2 × 10−15<3 × 10−14<7 × 10−10<7.3 × 10−11<4.5 × 10−11<4 × 10−5<4.9 × 10−5
<5.3 × 10−5

90
90
90
90
90
90
90
90

18 ARCHILLI
12
19 GNINENKO
12A
20 GNINENKO
12B
21 ADLER
04
22 ANISIMOVSK...04
23 ADLER
02C
24 ADLER
01
AMMAR
AMMAR

01B
01B

90

25 ALTEGOER

98

90
90
90

26 KITCHING
27 ADLER
28 AMSLER

97
96
96B

90

28 AMSLER

96B

90

28 AMSLER

96B

90

28 AMSLER

94B

90

28 AMSLER

94B

90

29 MEIJERDREES94

90

29 MEIJERDREES94<2 × 10−7<3 × 10−13<1.1 × 10−8
<5 × 10−4<1 × 10−12

90
90
90
95

30 ATIYA
31 NG
32 ALLIEGRO
33 ATIYA
34 BARABASH

93B
93
92
92
92

<1

× 10−1295

35 BARABASH

92<1

× 10−1195

36 BARABASH

92<1

× 10−1495

37 BARABASH

92<4

× 10−690

38 MEIJERDREES92<1 × 10−790−8<1.3 × 10
90<1 × 10−990<2 × 10−590<(1.5–4) × 10−6 90

39 ATIYA
90B
40 KORENCHE... 87
41 EICHLER
86
42 YAMAZAKI
84
42 YAMAZAKI
84<3.3 × 10−5<5.0 × 10−8
<5.2 × 10−10<2.8 × 10−4
<3

<4
<6
<6
<7
<2

× 10−4× 10−5× 10−5× 10−5× 10−3× 10−343 ASANO82
44 ASANO
81B
45 ZHITNITSKII 79

KLOE φ → η X 0 , X 0 → e + e −BDMP π 0 → γ X 0 (X 0 → e + e − )BDMP η(η ′ ) → γ X 0 (X 0 → e + e − )B787 K + → π + X 0
B949 K + → π + X 0
B787 K + → π + X 0
B787 K + → π + π 0 A0CLEO B ± → π ± (K ± )X 0
CLEO B 0 → K 0 X 0S
NOMD π 0 → γ X 0 , m 0 < 120 MeV
X
B787 K + → π + X 0 (X 0 → γ γ)
B787 K + → π + X 0
CBAR π 0 → γ X 0 , m 0 < 65 MeV
X
CBAR η → γ X 0 , m 0 = 50–200 MeV
X
CBAR η ′ → γ X 0 , m 0 = 50–925 MeV
X
CBAR π 0 → γ X 0 , m 0 =65–125 MeV
X
CBAR η → γ X 0 , m 0 =200–525 MeV
X
CNTR π 0 → γ X 0 , m 0 =25 MeV
X
CNTR π 0 → γ X 0 , m 0 =100 MeV
X
B787 Sup. by ADLER 04
COSM π 0 → γ X 0SPEC K + → π + X 0 (X 0 → e + e − )B787 π 0 → γ X 0
BDMP π ± → e ± ν X 0 (X 0 → e + e − ,γ γ), m 0 = 8 MeV
X±
BDMP K → π ± X 0 (X 0 → e + e − ,γ γ), m 0 = 10 MeV
X
0BDMP K → π 0 X 0 (X 0 → e + e − ,Lγ γ), m 0 = 10 MeV
X′
BDMP η → η X 0 (X 0 → e + e − , γ γ),
m 0 = 10 MeV
X
0SPEC π → γ X 0 (X 0 → e + e − ),m 0 = 100 MeV
X
B787 Sup. by KITCHING 97
SPEC π + → e + ν A0 (A0 → e + e − )SPEC Stopped π + → e + ν A0
SPEC For 160<m<260 MeV
SPEC K decay, m 0 ≪ 100 MeV
X
CNTR Stopped K + → π + X 0
CNTR Stopped K + → π + X 0
Heavy axion

1 ADACHI 23K quoted limit is for m≃ 3 GeV, cτ 0 = 1 cm, and the decay channel
X0X
X 0 → e + e − . See their Fig. 2 for limits with different lifetimes and decay channels,
X 0 → µ+ µ− , π + π − , K + K − .

https://pdg.lbl.gov

Page 2Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

2 ADACHI 23K quoted limit is for m≃ 2 GeV, cτ 0 = 1 cm, and the decay channel
X0X
X 0 → e + e − . See their Fig. 2 for limits with different lifetimes and decay channels,
X 0 → µ+ µ− , π + π − , K + K − .
3 CORTINA-GIL 23B limit extends over 10–170 MeV in mass. Quoted limit is at 155 MeV.
4 LEES 22B quoted limit is for m= 3.9 GeV, assuming the promptly decaying axion.
A0−7
Limits of O(10 ) are obtained for m 0 = 0.175–4.78 GeV. See their Figs.3 and 4 forAmass and lifetime dependent limits.
5 ABRATENKO 21 quoted limit is for m= 150 MeV and the lifetime cτ 0 = 80 m.
X0
X
See their Fig. 4 for the limits in the range of m 0 = 10–210 MeV.
X
6 CORTINA-GIL 21 quoted limit is for m= 370 MeV. Limits from O(10−5 ) and0X
O(10−6 ) are obtained for m 0 = 10–370 MeV (see their Fig. 7).
X
7 CORTINA-GIL 21A quoted limit is for m= 160–250 MeV. Limits between 5 × 10−11
X0
and 2 × 10−10 are obtained in the range of m 0 = 0–110 and 154–260 MeV, assumingXstable or invisibly decaying X 0 . See their Fig. 4 for mass- and lifetime-dependent limits.
8 CORTINA-GIL 21C quoted limit is for m= 130–140 MeV, and limits of 9×10−10 –6×
X0
10−7 are obtained in the mass range of m 0 = 110–155 MeV, assuming X 0 escapesX
detection. See their Fig. 6 for mass- and lifetime-dependent limits.
9 PARK 21 look for dark photons produced by decays of B 0 through off-shell Higgs-dark
Higgs mixing. See their Fig. 5 for limits in the range of m 0 = 0.01–2.62 GeV.
X
10 AHN 19 is an update of AHN 17 from a new data set. See their Fig. 4 for the limits in
the range of m 0 = 0–250 MeV.
X
11 AAIJ 17AQ limit is for τ= 10 ps. See their Fig. 4 for limits in the range of m 0 =X
X0
250–4700 MeV and τ 0 = 0.1–1000 ps.
X
12 AHN 17 limit as a function of mfrom 0 to 250 MeV is provided in their Fig. 5.
X0
13 BATLEY 17 limit is for m= 216 MeV and τ 0 ≤ 10 ps. See their Fig. 4(c) for
X0
X
limits in the range of m 0 = 211–354 MeV and longer lifetimes.
X
14 WON 16 look for a vector boson coupled to baryon number. Derived limits on α′< 10−3 –10−2 for m 0 = 290–520 MeV at 95% CL. See their Fig. 4 for massX
dependent limits.
15 AAIJ 15AZ limit is for τ= 10 ps and m 0 = 214–4350 MeV. See their Fig. 4 for
X0
X
mass- and lifetime-dependent limits.
16 ADLARSON 13 limits between 2.0 × 10−5 and 1.5 × 10−6 are obtained for m=
X0
20–100 MeV (see their Fig. 8). Angular momentum conservation requires that X 0 has
spin ≥ 1.
17 BABUSCI 13B limit is for B(φ → η X 0 )·B(X 0 → e + e − ) and applies to m
= 410
X0
MeV. It is derived by analyzing η → π 0 π 0 π 0 and π − π + π 0 . Limits between 1 × 10−6
and 2 × 10−8 are obtained for m 0 ≤ 450 MeV (see their Fig. 6).
X
18 ARCHILLI 12 analyzed η → π + π − π 0 decays. Derived limits on α′ /α < 2 × 10−5
for m 0 = 50–420 MeV at 90% CL. See their Fig. 8 for mass-dependent limits.
X
19 GNINENKO 12A limit is for B(π 0 → γ X 0 )·B(X 0 → e + e − ) and applies for m
=
X0
−8
−8
−15
90 MeV and τ 0 ≃ 1 × 10
sec. Limits between 10
and 2 × 10
are obtainedX−11
for m 0 = 3–120 MeV and τ 0 = 1 × 10
–1 sec. See their Fig. 3 for limits at
X
X
different masses and lifetimes.
20 GNINENKO 12B limit is for B(η → γ X 0 )·B(X 0 → e + e − ) and applies for m
=
X0
−9
−5
−14
100 MeV and τ 0 ≃ 6 × 10
sec. Limits between 10
and 3 × 10
are obtainedX

https://pdg.lbl.gov

Page 3Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

for m 0 . 550 MeV and τ 0 = 10−10 –10 sec. See their Fig. 5 for limits at different
X
X
mass and lifetime and for η ′ decays.
21 ADLER 04 limit applies for a mass near 180 MeV. For other masses in the range m=
X0
150–250 MeV the limit is less restrictive, but still improves ADLER 02C and ATIYA 93B.
22 ANISIMOVSKY 04 bound is for m =0.
X0
23 ADLER 02C bound is for m<60
MeV. See Fig. 2 for limits at higher masses.
X0
24 The quoted limit is for m= 0–80 MeV. See their Fig. 5 for the limit at higher mass.
X0
The branching fraction limit assumes pure phase space decay distributions.
25 ALTEGOER 98 looked for X 0 from π 0 decay which penetrate the shielding and convert
to π 0 in the external Coulomb field of a nucleus.
26 KITCHING 97 limit is for B(K + → π + X 0 )·B(X 0 → γ γ) and applies for m
≃ 50
X0
−8
−10
MeV, τ 0 < 10
s. Limits are provided for 0<m 0 < 100 MeV, τ 0 < 10s.
XXX
27 ADLER 96 looked for a peak in missing-mass distribution. This work is an update of
ATIYA 93. The limit is for massless stable X 0 particles and extends to m 0 =80 MeV
X
at the same level. See paper for dependence on finite lifetime.
28 AMSLER 94B and AMSLER 96B looked for a peak in missing-mass distribution.
29 MEIJERDREES 94 limit is based on inclusive photon spectrum and is independent of
X 0 decay modes. It applies to τ (X 0 )> 10−23 sec.
30 ATIYA 93B looked for a peak in missing mass distribution. The bound applies for stable
X 0 of m 0 =150–250 MeV, and the limit becomes stronger (10−8 ) for m 0 =180–240
X
X
MeV.
31 NG 93 studied the production of X 0 via γ γ → π 0 → γ X 0 in the early universe at T≃ 1
MeV. The bound on extra neutrinos from nucleosynthesis ∆Nν < 0.3 (WALKER 91) is
employed. It applies to m 0 ≪ 1 MeV in order to be relativistic down to nucleosynthesisX
temperature. See paper for heavier X 0 .
32 ALLIEGRO 92 limit applies for m =150–340 MeV and is the branching ratio times theX0decay probability. Limit is < 1.5 × 10−8 at 99%CL.
33 ATIYA 92 looked for a peak in missing mass distribution. The limit applies tom 0 =0–130 MeV in the narrow resonance limit. See paper for the dependence on
Xlifetime. Covariance requires X 0 to be a vector particle.
34 BARABASH 92 is a beam dump experiment that searched for a light Higgs. Limits
between 1 × 10−12 and 1 × 10−7 are obtained for 3 < m 0 < 40 MeV.
X
35 Limits between 1 × 10−12 and 1 are obtained for 4 < m< 69 MeV.
X0
36 Limits between 1 × 10−11 and 5 × 10−3 are obtained for 4 < m< 63 MeV.
X0
37 Limits between 1 × 10−14 and 1 are obtained for 3 < m< 82 MeV.
X0
38 MEIJERDREES 92 limit applies for τ
−23
−11
= 10
–10
sec. Limits between 2× 10−4
X0
and 4 × 10−6 are obtained for m 0 = 25–120 MeV. Angular momentum conservationX
requires that X 0 has spin ≥ 1.
39 ATIYA 90B limit is for B(K + → π + X 0 )·B(X 0 → γ γ) and applies for m= 50 MeV,
X0−10
τ 0 < 10s. Limits are also provided for 0 < m 0 < 100 MeV, τ 0 < 10−8 s.
XX
X
40 KORENCHENKO 87 limit assumes m−12 s, and B(A0 →
=
1.7
MeV,
τ
.
10
A0
A0
e + e − ) = 1.
41 EICHLER 86 looked for π + → e + ν A0 followed by A0 → e + e − . Limits on the
branching fraction depend on the mass and and lifetime of A0 . The quoted limits arevalid when τ (A0 ) & 3. × 10−10 s if the decays are kinematically allowed.
42 YAMAZAKI 84 looked for a discrete line in K + → π + X. Sensitive to wide mass range(5–300 MeV), independent of whether X decays promptly or not.

https://pdg.lbl.gov

Page 4Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

43 ASANO 82 at KEK set limits for B(K + →π + X 0 ) for m 0 <100 MeV as BRX< 4. × 10−8 for τ (X 0 → n γ ’s) > 1. × 10−9 s, BR < 1.4 × 10−6 for τ < 1. × 10−9 s.
44 ASANO 81B is KEK experiment. Set B(K + → π + X 0 ) < 3.8 × 10−8 at CL = 90%.
45 ZHITNITSKII 79 argue that a heavy axion predicted by YANG 78 (3 <m <40 MeV)
contradicts experimental muon anomalous magnetic moments.

A0 (Axion) Searches in Quarkonium Decays
Decay or transition of quarkonium. Limits are for branching ratio.
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ABLIKIM<8.3 × 10−8 95
23E BES3 J/ψ → A0 γ (A0 → γ γ)
−72<3.1 × 10
90
JIA
22 BELL Υ(1S) → A0 γ(A0 → µ+ µ− )3 ABLIKIM<2.8 × 10−8 90
16E BES3 J/ψ → A0 γ (A0 → µ+ µ− )−74<4 × 1090
ABLIKIM
12 BES3 J/ψ → A0 γ (A0 → µ+ µ− )−55<4.0 × 10
90
ANTREASYAN 90C CBAL Υ(1S) → A0 γ
−56<5 × 1090
DRUZHININ 87 ND
φ → A0 γ (A0 → e + e − )7 DRUZHININ 87 ND<2 × 10−3 90
φ → A0 γ (A0 → γ γ)
−68
<7 × 1090
DRUZHININ 87 ND
φ → A0 γ (A0 → missing)−5
9<1.4 × 10
90
EDWARDS
82 CBAL J/ψ → A0 γ

1 ABLIKIM 23E obtained limits in the range of 8.3 × 10−8 –1.8 × 10−6 for 0.165 GeV ≤m 0 ≤ 2.84 GeV. See their Fig. 5 for mass-dependent limits.
A
2 JIA 22 limits between 3.1 × 10−7 –1.6 × 10−5 were obtained for 0.22 GeV < m<
A0
9.2 GeV. See their Fig. 4 for mass-dependent limits.
3 ABLIKIM 16E limits between 2.8–495.3 × 10−8 were obtained for 0.212 GeV < m<
A0
3.0 GeV. See their Fig. 5 for mass-dependent limits.
4 ABLIKIM 12 derived limits between 4 × 10−7 –2.1 × 10−5 for 0.212 GeV < m< 3.0
A0
GeV. See their Fig. 2(c) for mass-dependent limits.
5 ANTREASYAN 90C assume that A0 does not decay in the detector.
6 The first DRUZHININ 87 limit is valid when τ /m
< 3 × 10−13 s/MeV and
A0
A0m 0 < 20 MeV.
A
7 The second DRUZHININ 87 limit is valid when τ /m
< 5 × 10−13 s/MeV and
A0
A0m 0 < 20 MeV.
A
8 The third DRUZHININ 87 limit is valid when τ /m
> 7 × 10−12 s/MeV and
A0
A0m 0 < 200 MeV.
A
9 EDWARDS 82 looked for J/ψ → γ A0 decays by looking for events with a singleγ of energy ∼ 1/2 the J/ψ(1S) mass , plus nothing else in the detector. The limit isinconsistent with the axion interpretation of the FAISSNER 81B result.

A0 (Axion) Searches in Positronium Decays
Decay or transition of positronium. Limits are for branching ratio.
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 BADERT... 02 CNTR o-Ps → γ X X , m +m<4.4 × 10−5
90
1 2
X1
X2 ≤
900 keV<2 × 10−4
90
MAENO
95 CNTR o-Ps → A0 γ m 0 =850–1013 keVA
2 ASAI<3.0 × 10−4
90
94 CNTR o-Ps → A0 γ m 0 =30–500 keVAhttps://pdg.lbl.gov

Page 5Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)<2.8 × 10−590

3 AKOPYAN

91<1.1 × 10−6
<3.8 × 10−490

4 ASAI

91

90−4<(1–5) × 10
95
−5
<6.4 × 10
90

GNINENKO 90
5 TSUCHIAKI 90
6 ORITO
89
7 AMALDI
8 CARBONI

85
83

CNTR o-Ps → A0 γ (A0 → γ γ),
m 0 < 30 keVA
CNTR o-Ps → A0 γ, m 0 < 800 keVA
CNTR o-Ps → A0 γ, m 0 < 30 keVA
CNTR o-Ps → A0 γ, m 0 = 300–900 keVA
CNTR o-Ps → A0 γ, m 0 < 30 keVA
CNTR Ortho-positronium
CNTR Ortho-positronium

1 BADERTSCHER 02 looked for a three-body decay of ortho-positronium into a photon
and two penetrating (neutral or milli-charged) particles.
2 The ASAI 94 limit is based on inclusive photon spectrum and is independent of A0 decay
modes.
3 The AKOPYAN 91 limit applies for a short-lived A0 with τ< 10−13 m 0 [keV] s.
A0A
4 ASAI 91 limit translates to g2−11 (90% CL) for m
< 800
/4π
<
1.1
×
10
A0
A0 e + e −keV.
5 The TSUCHIAKI 90 limit is based on inclusive photon spectrum and is independent of
A0 decay modes.
6 ORITO 89 limit translates to g2/4π < 6.2 × 10−10 . Somewhat more sensitive
A0 e elimits are obtained for larger m 0 : B < 7.6 × 10−6 at 100 keV.
A
7 AMALDI 85 set limits B(A0 γ) / B(γ γ γ) < (1–5) × 10−6 for m= 900–100 keV
A0which are about 1/10 of the CARBONI 83 limits.
8 CARBONI 83 looked for orthopositronium → A0 γ. Set limit for A0 electron couplingsquared, g(e e A0 )2 /(4π) < 6. × 10−10 –7. × 10−9 for m 0 from 150–900 keV (CL =A
99.7%). This is about 1/10 of the bound from g−2 experiments.

A0 (Axion) Search in Photoproduction
VALUE

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ADHIKARI
22C GLUX m 0 = 180–480, 600–720 MeV
A
2 BASSOMPIE... 95m 0 = 1.8 ± 0.2 MeV
A
1 ADHIKARI 22C search for A0 → γ γ and A0 → π + π − π 0 decays, and set limits off 0 . 0.5–14 GeV at 90% CL. See their Fig. 4 for mass-dependent limits.
A
2 BASSOMPIERRE 95 is an extension of BASSOMPIERRE 93. They looked for a peakin the invariant mass of e + e − pairs in the region m + − = 1.8 ± 0.2 MeV. Theye eobtained bounds on the production rate A0 for τ (A0 ) = 10−18 –10−9 sec. They also
found an excess of events in the range m + − = 2.1–3.5 MeV.
e e

A0 (Axion) Production in Hadron Collisions
Limits are for σ(A0 ) / σ(π 0 ).
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ACCIARRI
23 ARNT A0 → µ+ µ−
2 BERTUZZO
23 ARNT A0 → µ+ µ−
3 AAD
22J ATLS H → A0 A0 , Z A0
(A0 → µ+ µ− )https://pdg.lbl.gov

Page 6Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

4 TUMASYAN<2. × 10−11<1. × 10−139090<1. × 10−8
<1. × 10−149090<1. × 10−8
<1. × 10−3
<1. × 10−8
<6. × 10−9<1.5 × 10−8
<5.4 × 10−14

90
95
90
95
90
90

https://pdg.lbl.gov

H → A0 A0 , A0 →e + e − , µ+ µ−
5 TUMASYAN 22R CMS p p → A∗0 → Z Z , Z H
6 AAD
21F ATLS Monojet + missing pT
7 AAD
21K ATLS Mono-γ + missing pT
8 AAD
21N ATLS γ γ scatt. in Pb+Pb
9 CARRA21 ATLS p p → A∗0 → W W ,Zγ
10 AAIJ
20AL LHCB p p → X 0 → µ+ µ−
11 GAVELA
20 CMS p p → A∗0 → γ γ, Z Z
12 SIRUNYAN
19BQ CMS X 0 → µ+ µ−
13 JAIN
07 CNTR A0 → e + e −14 AHMAD
97 SPEC e + production
15 LEINBERGER 97 SPEC A0 → e + e −16 GANZ
96 SPEC A0 → e + e −17 KAMEL
96 EMUL 32 S emulsion, A0 →e+ e−
18 BLUEMLEIN 92 BDMP A0 N → ℓ+ ℓ− N
Z
Z
19 MEIJERDREES92 SPEC π − p → n A0 , A0 →e+ e−
20 BLUEMLEIN 91 BDMP A0 → e + e − , 2γ
21 FAISSNER
89 OSPK Beam dump,
A0 → e + e −22 DEBOER
88 RVUE A0 → e + e −23 EL-NADI
88 EMUL A0 → e + e −24 FAISSNER
88 OSPK Beam dump, A0 → 2γ
25 BADIER
86 BDMP A0 → e + e −26 BERGSMA
85 CHRM CERN beam dump
26 BERGSMA
85 CHRM CERN beam dump
27 FAISSNER
83 OSPK Beam dump, A0 → 2γ
28 FAISSNER
83B RVUE LAMPF beam dump
29 FRANK
83B RVUE LAMPF beam dump
30 HOFFMAN
83 CNTR π p → n A0
(A0 → e + e − )31 FETSCHER
82 RVUE See FAISSNER 81B
32 FAISSNER
81 OSPK CERN PS ν wideband
33 FAISSNER
81B OSPK Beam dump, A0 → 2γ
34 KIM
81 OSPK 26 GeV p N → A0 X
35 FAISSNER
80 OSPK Beam dump,
A0 → e + e −36 JACQUES80 HLBC 28 GeV protons
36 JACQUES80 HLBC Beam dump
37 SOUKAS
80 CALO 28 GeV p beam dump
38 BECHIS
79 CNTR
39 COTEUS
79 OSPK Beam dump
40 DISHAW
79 CALO 400 GeV p p
ALIBRAN78 HYBR Beam dump
ASRATYAN
78B CALO Beam dump
41 BELLOTTI
78 HLBC Beam dump
41 BELLOTTI
78 HLBC m 0 =1.5 MeV
APage 7

22AH CMS

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)<4.1 × 10−9
<1. × 10−890<0.5 × 10−890

90

41 BELLOTTI

78

HLBC m 0 =1 MeV
A
78B HYBR Beam dump
78
HANSL
78D WIRE Beam dump
44 MICELMAC... 78
45 VYSOTSKII
78
42 BOSETTI
43 DONNELLY

1 ACCIARRI 23 search for axions in the NuMI neutrino beam target, which are produced
through mixings with mesons due to the coupling with gluons, and exclude f 0 aroundA
tens of TeV for m 0 = 0.2–0.9 GeV. They assume a slightly suppressed axion couplingA
to muons. See their Fig. 4 for the limits.
2 BERTUZZO 23 employs an analysis analogous to ACCIARRI 23. They search for leptophilic axions primarily produced via τ → µ A0 and τ → e A0 , and exclude f 0 aroundA
1 × 106 –6 × 107 GeV for m 0 = 0.2–1.7 GeV. See their Fig. 2 for the limits.
A
3 AAD 22J set upper limits for the cross sections of H → A0 A0 → 4µ and H → Z A0 →2ℓ 2µ. See their Figs. 14 and 17 for the respective mass-dependent limits.
4 TUMASYAN 22AH set the limits of O(10−6 ) with respect to the product of the branching
fractions of H → A0 A0 and A0 → e + e − , µ+ µ− . They also derive limits on theeffective axion couplings contributing to H → A0 A0 and H → Z A0 . See their Figs.
5 and 7 for the limits.
5 TUMASYAN 22R is analogous to GAVELA 20, and set a limit on the products of theaxion couplings to gluons and Z bosons as GAZ Z GAg g < 6.64 × 10−7 GeV−2 at
95% CL for f 0 = 3 TeV and m 0 < 100 GeV. Here we use c e = GAg g f 0 /4 andAAAGc e = GAZ Z f 0 /4 to translate their limits. They also set a limit on the product of theAZaxion couplings to gluons and Z H. See their Fig. 9 for the f 0 -dependent limits.
A
6 AAD 21F look for axion production with an energetic jet and large missing p , and set
Ta limit on the axion coupling to gluons, c e /f 0 < 8 × 10−6 GeV−1 at 95 % CL for
G A
m 0 = 1 MeV. Using c e = αs /8π, we interpret the limit as f 0 > 0.4 TeV for αs ≃
A
A
G
0.08.
7 AAD 21K look for axion production with an energetic photon and large missing p , andT
set a limit on the axion coupling to a Z boson and photon, GAZ γ < 5.1×10−4 GeV−1
at 95 % CL for m 0 = 1 MeV and assuming GAγ γ = 0.
A
8 AAD 21N look for axion production using the measurement of light-by-light scattering based on Pb+Pb collision data. They set the limit on the axion-photon coupling,GAγ γ < 5.3 × 10−5 –3.4 × 10−4 GeV−1 at 95 % CL for m 0 = 6–100 GeV. Here weAuse Λa =GAγ γ −1 to translate their limits. See their Fig. 9 for mass-dependent limits.
9 CARRA 21 is analogous to GAVELA 20, and they use the differential cross sections for
W W and Z γ production measured with the ATLAS detector to set limits on the productof the axion couplings to gauge bosons as GAW W GAg g < 6.2 × 10−7 GeV−2 andGAZ γ GAg g < 3.7 × 10−7 GeV−2 at 95 % CL for m 0 . 100 GeV.
A
10 AAIJ 20AL look for a light new boson decaying into a pair of muons using the LHCb
data with an integrated luminosity of 5.1 fb−1 , and set limits on the cross section overa range of m 0 = 0.22–3 and 20–60 GeV. See Figs. 8 and 9 for mass-dependent limits.
X
11 GAVELA 20 focus on the axion production as an s-channel off shell mediator, and use
the Run 2 CMS public data to set limits on the product of the axion couplings to gluons
and photons as well as Z bosons as GAγ γ GAg g < 2.8 × 10−7 GeV−2 and GAZ Z
GAg g < 9.8 × 10−7 GeV−2 for m 0 . 200 GeV. See their Fig.3 for the limits.
A
12 SIRUNYAN 19BQ look for the pair production of a new light boson decaying into a pairof muons, and set limits on the product of the production cross section times branchinghttps://pdg.lbl.gov

Page 8Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

fraction to dimuons squared times acceptance over a range of m 0 = 0.25–8.5 GeV.
X
See the right panel of their Fig. 1 for mass-dependent limits.
13 JAIN 07 claims evidence for A0 → e + e − produced in 207 Pb collision on nuclear
emulsion (Ag/Br) for m(A0 ) = 7 ± 1 or 19 ± 1 MeV and τ (A0 ) ≤ 10−13 s.
14 AHMAD 97 reports a result of APEX Collaboration which studied positron production in
238 U+232 Ta and 238 U+181 Ta collisions, without requiring a coincident electron. No
narrow lines were found for 250 <E + < 750 keV.
e
15 LEINBERGER 97 (ORANGE Collaboration) at GSI looked for a narrow sum-energye + e − -line at ∼ 635 keV in 238 U+181 Ta collision. Limits on the production probability for a narrow sum-energy e + e − line are set. See their Table 2.
16 GANZ 96 (EPos II Collaboration) has placed upper bounds on the production cross section of e + e − pairs from 238 U+181 Ta and 238 U+232 Th collisions at GSI. See Table 2
for limits both for back-to-back and isotropic configurations of e + e − pairs. These limits rule out the existence of peaks in the e + e − sum-energy distribution, reported by anearlier version of this experiment.
17 KAMEL 96 looked for e + e − pairs from the collision of 32 S (200 GeV/nucleon) andemulsion. No evidence of mass peaks is found in the region of sensitivity m e e >2 MeV.
18 BLUEMLEIN 92 is a proton beam dump experiment at Serpukhov with a secondary
target to induce Bethe-Heitler production of e + e − or µ+ µ− from the produce A0 .
See Fig. 5 for the excluded region in m 0 -x plane. For the standard axion, 0.3 <x<25
A
is excluded at 95% CL. If combined with BLUEMLEIN 91, 0.008<x<32 is excluded.
19 MEIJERDREES 92 give Γ(π − p → n A0 )·B(A0 → e + e − )Γ(π − p → all) < 10−5(90% CL) for m 0 = 100 MeV, τ 0 = 10−11 –10−23 sec. Limits ranging from 2.5 ×AA
10−3 to 10−7 are given for m 0 = 25–136 MeV.
A
20 BLUEMLEIN 91 is a proton beam dump experiment at Serpukhov. No candidate event
for A0 → e + e − , 2γ are found. Fig. 6 gives the excluded region in m 0 -x plane (x =Atanβ = v2 /v1 ). Standard axion is excluded for 0.2 < m 0 < 3.2 MeV for mostAx > 1, 0.2–11 MeV for most x < 1.
21 FAISSNER 89 searched for A0 → e + e − in a proton beam dump experiment at SIN. No
excess of events was observed over the background. A standard axion with mass 2m e –20
MeV is excluded. Lower limit on f 0 of ≃ 104 GeV is given for m 0 = 2m e –20 MeV.
A
A
22 DEBOER 88 reanalyze EL-NADI 88 data and claim evidence for three distinct stateswith mass ∼ 1.1, ∼ 2.1, and ∼ 9 MeV, lifetimes 10−16 –10−15 s decaying to e + e −and note the similarity of the data with those of a cosmic-ray experiment by Bristol group(B.M. Anand, Proc. of the Royal Society of London, Section A A22 183 (1953)). For a
criticism see PERKINS 89, who suggests that the events are compatible with π 0 Dalitz
decay. DEBOER 89B is a reply which contests the criticism.
23 EL-NADI 88 claim the existence of a neutral particle decaying into e + e − with mass
1.60 ± 0.59 MeV, lifetime (0.15 ± 0.01) × 10−14 s, which is produced in heavy ion
interactions with emulsion nuclei at ∼ 4 GeV/c/nucleon.
24 FAISSNER 88 is a proton beam dump experiment at SIN. They found no candidate event
for A0 → γ γ. A standard axion decaying to 2γ is excluded except for a region x≃ 1.
Lower limit on f 0 of 102 –103 GeV is given for m 0 = 0.1–1 MeV.
A
A
25 BADIER 86 did not find long-lived A0 in 300 GeV π − Beam Dump Experiment thatdecays into e + e − in the mass range m 0 = (20–200) MeV, which excludes the A0 decayA
constant f (A0 ) in the interval (60–600) GeV. See their figure 6 for excluded region onf (A0 )-m 0 plane.
A
26 BERGSMA 85 look for A0 → 2γ, e + e − , µ+ µ− . First limit above is for m= 1
A0
MeV; second is for 200 MeV. See their figure 4 for excluded region on f 0 −m 0 plane,AA

https://pdg.lbl.gov

Page 9Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

where f 0 is A0 decay constant. For Peccei-Quinn PECCEI 77 A0 , m 0 <180 keV andAAτ >0.037 s. (CL = 90%). For the axion of FAISSNER 81B at 250 keV, BERGSMA 85
expect 15 events but observe zero.
27 FAISSNER 83 observed 19 1-γ and 12 2-γ events where a background of 4.8 and 2.3
respectively is expected. A small-angle peak is observed even if iron wall is set in frontof the decay region.
28 FAISSNER 83B extrapolate SIN γ signal to LAMPF ν experimental condition. Resulting
370 γ’s are not at variance with LAMPF upper limit of 450 γ’s. Derived from LAMPF
limit that dσ(A0 )/dω at 90◦ m 0 /τ 0 < 14 × 10−35 cm2 sr− 1 MeV ms− 1 . See
AAcomment on FRANK 83B.
29 FRANK 83B stress the importance of LAMPF data bins with negative net signal. Bystatistical analysis say that LAMPF and SIN-A0 are at variance when extrapolation byphase-space model is done. They find LAMPF upper limit is 248 not 450 γ’s. See
comment on FAISSNER 83B.
30 HOFFMAN 83 set CL = 90% limit dσ/dt B(e + e − ) < 3.5 × 10−32 cm2 /GeV2 for 140<m 0 <160 MeV. Limit assumes τ (A0 ) < 10−9 s.
A
31 FETSCHER 82 reanalyzes SIN beam-dump data of FAISSNER 81. Claims no evidence
for axion since 2-γ peak rate remarkably decreases if iron wall is set in front of the decay
region.
32 FAISSNER 81 see excess µ e events. Suggest axion interactions.
33 FAISSNER 81B is SIN 590 MeV proton beam dump. Observed 14.5 ± 5.0 events of 2γ
decay of long-lived neutral penetrating particle with m 2γ . 1 MeV. Axion interpretation with η-A0 mixing gives m 0 = 250 ± 25 keV, τ(2γ) = (7.3 ± 3.7) × 10−3 s fromA
above rate. See critical remarks below in comments of FETSCHER 82, FAISSNER 83,
FAISSNER 83B, FRANK 83B, and BERGSMA 85. Also see in the next subsection ALEKSEEV 82B, CAVAIGNAC 83, and ANANEV 85.
34 KIM 81 analyzed 8 candidates for A0 → 2γ obtained by Aachen-Padova experiment at
CERN with 26 GeV protons on Be. Estimated axion mass is about 300 keV and lifetime
is (0.86∼ 5.6) × 10−3 s depending on models. Faissner (private communication), says
axion production underestimated and mass overestimated. Correct value around 200
keV.
35 FAISSNER 80 is SIN beam dump experiment with 590 MeV protons looking for A0 →e + e − decay. Assuming A0 /π 0 = 5.5 × 10−7 , obtained decay rate limit 20/(A0 mass)
MeV/s (CL = 90%), which is about 10−7 below theory and interpreted as upper limit
to m 0 <2m − .
Ae
36 JACQUES 80 is a BNL beam dump experiment. First limit above comes from nonobser
vation of excess neutral-current-type events σ(production)σ(interaction) < 7. × 10−68
cm4 , CL = 90% . Second limit is from nonobservation of axion decays into 2γ’s ore + e − , and for axion mass a few MeV.
37 SOUKAS 80 at BNL observed no excess of neutral-current-type events in beam dump.
38 BECHIS 79 looked for the axion production in low energy electron Bremsstrahlung andthe subsequent decay into either 2γ or e + e − . No signal found. CL = 90% limits formodel parameter(s) are given.
39 COTEUS 79 is a beam dump experiment at BNL.
40 DISHAW 79 is a calorimetric experiment and looks for low energy tail of energy distributions due to energy lost to weakly interacting particles.
41 BELLOTTI 78 first value comes from search for A0 → e + e − . Second value comesfrom search for A0 → 2γ, assuming mass <2m − . For any mass satisfying this,elimit is above value×(mass− 4 ). Third value uses data of PL 60B 401 and quotes
σ(production)σ(interaction) < 10−67 cm4 .
42 BOSETTI 78B quotes σ(production)σ(interaction) < 2. × 10−67 cm4 .

https://pdg.lbl.gov

Page 10Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

43 DONNELLY 78 examines data from reactor neutrino experiments of REINES 76 andGURR 74 as well as SLAC beam dump experiment. Evidence is negative.
44 MICELMACHER 78 finds no evidence of axion existence in reactor experiments of
REINES 76 and GURR 74. (See reference under DONNELLY 78 below).
45 VYSOTSKII 78 derived lower limit for the axion mass 25 keV from luminosity of the sunand 200 keV from red supergiants.

A0 (Axion) Searches in Reactor Experiments
VALUE

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 CHANG
07
Primakoff or Compton
2 ALTMANN
95 CNTR Reactor; A0 → e + e −3 KETOV
86 SPEC Reactor, A0 → γ γ
4 KOCH
86 SPEC Reactor; A0 → γ γ
5 DATAR82 CNTR Light water reactor
6 VUILLEUMIER 81 CNTR Reactor, A0 → 2γ

1 CHANG 07 looked for monochromatic photons from Primakoff or Compton conversionof axions from the Kuo-Sheng reactor due to axion coupling to photon or electron,
respectively. The search places model-independent limits on the products GAγ γ GAN N
and GAe e GAN N for m(A0 ) less than the MeV range.
2 ALTMANN 95 looked for A0 decaying into e + e − from the Bugey 5 nuclear reactor. They obtain an upper limit on the A0 production rate of ω(A0 )/ω(γ) ×B(A0 →e + e − )< 10−16 for m 0 = 1.5 MeV at 90% CL. The limit is weaker for heavier A0 . InA
the case of a standard axion, this limit excludes a mass in the range 2m e <m 0 < 4.8
A
MeV at 90% CL. See Fig. 5 of their paper for exclusion limits of axion-like resonances
Z 0 in the (m 0 ,f 0 ) plane.
X X
3 KETOV 86 searched for A0 at the Rovno nuclear power plant. They found an upper
limit on the A0 production probability of 0.8 100 keV/m 0 6 × 10−6 per fission. In
A
the standard axion model, this corresponds to m 0 >150 keV. Not valid for m 0 &AA
1 MeV.
4 KOCH 86 searched for A0 → γ γ at nuclear power reactor Biblis A. They found an
upper limit on the A0 production rate of ω(A0 )/ω(γ(M1)) < 1.5 × 10−10 (CL=95%).
Standard axion with m 0 = 250 keV gives 10−5 for the ratio. Not valid for m 0 >1022
AA
keV.
5 DATAR 82 looked for A0 → 2γ in neutron capture (n p → d A0 ) at Tarapur 500 MWreactor. Sensitive to sum of I = 0 and I = 1 amplitudes. With ZEHNDER 81 (I = 0)− (I = 1) result, assert nonexistence of standard A0 .
6 VUILLEUMIER 81 is at Grenoble reactor. Set limit m<280 keV.
A0

A0 (Axion) and Other Light Boson (X 0 ) Searches in Nuclear Transitions
Limits are for branching ratio.
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 DERBIN< 8.89 × 10−690
23 CNTR M1 transition of 169 Tm−62< 8.5 × 10
90
DERBIN
02 CNTR 125m Te decay

https://pdg.lbl.gov

Page 11Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)< 5.5 × 10−10< 1.2 × 10−6
< 2
× 10−4< 1.5 × 10−9<(0.4–10) × 10−3

95
95
90
95
95

3 DEBOER
4 TSUNODA
5 MINOWA
6 HICKS
7 ASANUMA
8 DEBOER<(0.2–1) × 10−390

9 BINI

89

CNTR

10 AVIGNONE

88

CNTR
CNTR

97C
95
93
92
90
90

RVUE
CNTR
CNTR
CNTR
CNTR
CNTR

< 1.5 × 10−4

90

11 DATAR88< 5× 10−390

12 DEBOER

88C CNTR

< 3.4
< 4
< 3
<10.6
<10.8
< 2.2
< 4

× 10−5× 10−4× 10−3× 10−2

95
95
95
90
90
90
90

13 DOEHNER
14 SAVAGE
14 SAVAGE
15 HALLIN
15 HALLIN
15 HALLIN
16 SAVAGE
17 ANANEV
18 CAVAIGNAC

88
88
88
86
86
86
86B
85
83

19 ALEKSEEV82B CNTR

20 LEHMANN
21 ZEHNDER
22 ZEHNDER
23 CALAPRICE

82
82
81
79

× 10−4

SPEC
CNTR
CNTR
SPEC
SPEC
SPEC
CNTR
CNTR
CNTR

CNTR
CNTR
CNTR

M1 transitions
252 Cf fission, A0 → e e
139 La∗ → 139 La A0
35 S decay, A0 → γ γ
241 Am decay
8 Be∗ → 8 Be A0 ,A0 → e + e −16 O∗ → 16 O X 0 ,X 0 → e+ e−
Cu∗ → Cu A0 (A0 → 2γ,
A0 e → γ e, A0 Z → γ Z )12 C∗ → 12 CA0 ,A0 → e + e −16 O∗ → 16 O X 0 ,X 0 → e+ e−
2 H∗ , A0 → e + e −Nuclear decay (isovector)
Nuclear decay (isoscalar)
6 Li isovector decay
10 B isoscalar decays
14 N isoscalar decays
14 N∗
Li∗ , deut∗ A0 → 2γ
97 Nb∗ , deut∗ transition
A0 → 2γ∗Li , deut∗ transition
A0 → 2γ∗
Cu → Cu A0 (A0 → 2γ)
Li∗ , Nb∗ decay, n-capt.
Ba∗ → Ba A0 (A0 → 2γ)

Carbon1 DERBIN 23 use a thallium garnet bolometric detector to search for the 8.4 keV solar axion
line emitted from the M1 nuclear transition of 169 Tm. Their limits are equivalent to an
upper bound on the KSVZ and DFSZ axion masses of 141 eV and 244 eV, respectively.
2 DERBIN 02 looked for the axion emission in an M1 transition in 125m Te decay. Theylooked for a possible presence of a shifted energy spectrum in gamma rays due to theundetected axion.
3 DEBOER 97C reanalyzed the existent data on Nuclear M1 transitions and find that a
9 MeV boson decaying into e + e − would explain the excess of events with large opening
angles. See also DEBOER 01 for follow-up experiments.
4 TSUNODA 95 looked for axion emission when 252 Cf undergoes a spontaneous fission,
with the axion decaying into e + e − . The bound is for m 0 =40 MeV. It improves toA
2.5 × 10−5 for m 0 =200 MeV.
A
5 MINOWA 93 studied chain process, 139 Ce → 139 La∗ by electron capture and M1
transition of 139 La∗ to the ground state. It does not assume decay modes of A0 . The
bound applies for m 0 < 166 keV.
A
6 HICKS 92 bound is applicable for τ< 4 × 10−11 sec.
X0
7 The ASANUMA 90 limit is for the branching fraction of X 0 emission per 241 Amα decay
and valid for τ 0 < 3 × 10−11 s.
Xhttps://pdg.lbl.gov

Page 12Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

8 The DEBOER 90 limit is for the branching ratio 8 Be∗ (18.15 MeV, 1+ ) → 8 Be A0 ,A0 → e + e − for the mass range m 0 = 4–15 MeV.
A
9 The BINI 89 limit is for the branching fraction of 16 O∗ (6.05 MeV, 0+ ) → 16 O X 0 ,X 0 → e + e − for m X = 1.5–3.1 MeV. τ 0 . 10−11 s is assumed. The spin-parity
Xof X is restricted to 0+ or 1− .
10 AVIGNONE 88 looked for the 1115 keV transition C∗ → Cu A0 , either from A0 →2γ in-flight decay or from the secondary A0 interactions by Compton and by Primakoff
processes. Limits for axion parameters are obtained for m 0 < 1.1 MeV.
A
11 DATAR 88 rule out light pseudoscalar particle emission through its decay A0 → e + e −in the mass range 1.02–2.5 MeV and lifetime range 10−13 –10−8 s. The above limit isfor τ = 5 × 10−13 s and m = 1.7 MeV; see the paper for the τ -m dependence of thelimit.
12 The limit is for the branching fraction of 16 O∗ (6.05 MeV, 0+ ) → 16 O X 0 , X 0 →e + e − against internal pair conversion for m 0 = 1.7 MeV and τ 0 < 10−11 s.
X
X
Similar limits are obtained for m 0 = 1.3–3.2 MeV. The spin parity of X 0 must beXeither 0+ or 1− . The limit at 1.7 MeV is translated into a limit for the X 0 -nucleon
coupling constant: g2 0
/4π < 2.3 × 10−9 .
X NN
13 The DOEHNER 88 limit is for m= 1.7 MeV, τ (A0 ) < 10−10 s. Limits less thanA0
10−4 are obtained for m 0 = 1.2–2.2 MeV.
A
14 SAVAGE 88 looked for A0 that decays into e + e − in the decay of the 9.17 MeV J P =2+ state in 14 N, 17.64 MeV state J P = 1+ in 8 Be, and the 18.15 MeV state J P =1+ in 8 Be. This experiment constrains the isovector coupling of A0 to hadrons, if m 0
A= (1.1 → 2.2) MeV and the isoscalar coupling of A0 to hadrons, if m 0 = (1.1 →A
2.6) MeV. Both limits are valid only if τ (A0 ) . 1 × 10−11 s.
15 Limits are for Γ(A0 (1.8 MeV))/Γ(πM1); i.e., for 1.8 MeV axion emission normalized
to the rate for internal emission of e + e − pairs. Valid for τ 0 < 2 × 10−11 s. 6 LiA
isovector decay data strongly disfavor PECCEI 86 model I, whereas the 10 B and 14 N
isoscalar decay data strongly reject PECCEI 86 model II and III.
16 SAVAGE 86B looked for A0 that decays into e + e − in the decay of the 9.17 MeV J P =2+ state in 14 N. Limit on the branching fraction is valid if τ 0 . 1. × 10−11 s for m 0
AA= (1.1–1.7) MeV. This experiment constrains the iso-vector coupling of A0 to hadrons.
17 ANANEV 85 with IBR-2 pulsed reactor exclude standard A0 at CL = 95% masses below
470 keV (Li∗ decay) and below 2m e for deuteron* decay.
18 CAVAIGNAC 83 at Bugey reactor exclude axion at any m
97 Nb∗ decay and axion with
m 0 between 275 and 288 keV (deuteron* decay).
A
19 ALEKSEEV 82 with IBR-2 pulsed reactor exclude standard A0 at CL = 95% mass-ranges
m 0 <400 keV (Li∗ decay) and 330 keV <m 0 <2.2 MeV. (deuteron* decay).
A
A
20 LEHMANN 82 obtained A0 → 2γ rate < 6.2 × 10−5 /s (CL = 95%) excluding m
A0
between 100 and 1000 keV.
21 ZEHNDER 82 used Gosgen 2.8GW light-water reactor to check A0 production. No2γ peak in Li∗ , Nb∗ decay (both single p transition) nor in n capture (combined withprevious Ba∗ negative result) rules out standard A0 . Set limit m 0 <60 keV for any
AA0 .
22 ZEHNDER 81 looked for Ba∗ → A0 Ba transition with A0 → 2γ. Obtained 2γ
coincidence rate < 2.2 × 10−5 /s (CL = 95%) excluding m 0 >160 keV (or 200 keVAdepending on Higgs mixing). However, see BARROSO 81.

https://pdg.lbl.gov

Page 13Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

23 CALAPRICE 79 saw no axion emission from excited states of carbon. Sensitive to axion
mass between 1 and 15 MeV.

A0 (Axion) Limits from Its Electron Coupling
Limits are for τ (A0 → e + e − ).

VALUE (s)CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ANDREEV
21 NA64 e N → e A0 N
(A0 → invisibles)
2 ANDREEV
21B NA64 e N → e A0 N
(A0 → e e)
3 BROSSnone 4 × 10−16 –4.5 × 10−12 90
91 BDMP e N → e A0 N
(A0 → e e)
4 GUO
90 BDMP e N → e A0 N
(A0 → e e)
5 BJORKEN
88 CALO A → e + e − or2γ
6 BLINOV
88 MD1 e e → e e A0
(A0 → e e)
−14
−10
7
none 1 × 10
–1 × 1090
RIORDAN
87 BDMP e N → e A0 N
(A0 → e e)
−14
−11
8
none 1 × 10
–1 × 1090
BROWN
86 BDMP e N → e A0 N
(A0 → e e)
−14
−11
9
none 6 × 10
–9 × 1095
DAVIER86 BDMP e N → e A0 N
(A0 → e e)
−13
−7
10
none 3 × 10
–1 × 1090
KONAKA86 BDMP e N → e A0 N
(A0 → e e)
1 ANDREEV 21 look for invisible decays of axions coupled to electrons, and set limits on
gAe e < 4.6 × 10−6 –3.1 × 10−3 for m 0 = 10−3 –1 GeV. This limits the axion contriA
bution to the electron g−2 to an order of magnitude less than the current experimental
uncertainty. See their Figs. 3 and 4 for mass-dependent limits.
2 ANDREEV 21B set limits on g
−6
−3 for m=
Ae e in the range of 6.3 × 10 –1.6 × 10
A0
2–17 MeV at 90% CL. This excludes 6.6 × 10−5 < gAe e < 1 × 10−4 at m 0 =A
16.7 MeV corresponding to the ATOMKI anomaly. See their Fig. 2 for mass-dependent
limits.
3 The listed BROSS 91 limit is for m= 1.14 MeV. B(A0 → e + e − ) = 1 assumed.
A0
Excluded domain in the τ 0 –m 0 plane extends up to m 0 ≈ 7 MeV (see Fig. 5).
AAA
Combining with electron g – 2 constraint, axions coupling only to e + e − ruled out form 0 < 4.8 MeV (90% CL).
A
4 GUO 90 use the same apparatus as BROWN 86 and improve the previous limit in the
shorter lifetime region. Combined with g – 2 constraint, axions coupling only to e + e −are ruled out for m 0 < 2.7 MeV (90% CL).
A
5 BJORKEN 88 reports limits on axion parameters (f , m , τ ) for m< 200 MeVA
A A
A0from electron beam-dump experiment with production via Primakoff photoproduction,bremsstrahlung from electrons, and resonant annihilation of positrons on atomic electrons.
6 BLINOV 88 assume zero spin, m = 1.8 MeV and lifetime < 5 × 10−12 s and findΓ(A0 → γ γ)B(A0 → e + e − ) < 2 eV (CL=90%).
7 Assumes A0 γ γ coupling is small and hence Primakoff production is small. Their figure
2 shows limits on axions for m 0 < 15 MeV.
A

https://pdg.lbl.gov

Page 14Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

8 Uses electrons in hadronic showers from an incident 800 GeV proton beam. Limits form 0 < 15 MeV are shown in their figure 3.
A9m= 1.8 MeV assumed. The excluded domain in the τ 0 −m 0 plane extends up to
A0AA
m 0 ≈ 14 MeV, see their figure 4.
A
10 The limits are obtained from their figure 3.
Also given is the limit on the
A0 γ γ−A0 e + e − coupling plane by assuming Primakoff production.

Search for A0 (Axion) Resonance in Bhabha Scattering
The limit is for Γ(A0 )[B(A0 → e + e − )]2 .

VALUE (10−3 eV)

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 HALLIN<
1.3
97
92 CNTR m 0 = 1.75–1.88 MeVA
2none 0.0016–0.47
90
HENDERSON 92C CNTR m 0 = 1.5–1.86 MeV
A
3 WU
<
2.0
90
92 CNTR m 0 = 1.56–1.86 MeV
A
<
0.013
95
TSERTOS91 CNTR m 0 = 1.832 MeV
A
4 WIDMANN
none 0.19–3.3
95
91 CNTR m 0 = 1.78–1.92 MeV
A
<
5
97
BAUER
90 CNTR m 0 = 1.832 MeV
A
5 JUDGEnone 0.09–1.5
95
90 CNTR m 0 = 1.832 MeV,A
elastic
6<
1.9
97TSERTOS89 CNTR m 0 = 1.82 MeV
A
6 TSERTOS<(10–40)
97
89 CNTR m 0 = 1.51–1.65 MeV
A
6 TSERTOS<(1–2.5)
97
89 CNTR m 0 = 1.80–1.86 MeV
A
< 31
95
LORENZ
88 CNTR m 0 = 1.646 MeV
A
< 94
95
LORENZ
88 CNTR m 0 = 1.726 MeV
A
< 23
95
LORENZ
88 CNTR m 0 = 1.782 MeV
A
< 19
95
LORENZ
88 CNTR m 0 = 1.837 MeV
A
7 TSERTOS<
3.8
97
88 CNTR m 0 = 1.832 MeV
A
8 VANKLINKEN 88 CNTR
9 MAIER
87 CNTR
<2500
90
MILLS
87 CNTR m 0 = 1.8 MeV
A
10 VONWIMMER...87 CNTR
1 HALLIN 92 quote limits on lifetime, 8 × 10−14 – 5 × 10−13 sec depending on mass,
assuming B(A0 → e + e − ) = 100%. They say that TSERTOS 91 overstated their
sensitivity by a factor of 3.
2 HENDERSON 92C exclude axion with lifetime τ =1.4 × 10−12 – 4.0 × 10−10 s, asA00+−suming B(A → e e )=100%. HENDERSON 92C also exclude a vector boson with
τ =1.4 × 10−12 – 6.0 × 10−10 s.
3 WU 92 quote limits on lifetime > 3.3 × 10−13 s assuming B(A0 → e + e − )=100%.
They say that TSERTOS 89 overestimate the limit by a factor of π/2. WU 92 also quotea bound for vector boson, τ > 8.2 × 10−13 s.
4 WIDMANN 91 bound applies exclusively to the case B(A0 → e + e − )=1, since thedetection efficiency varies substantially as Γ(A0 )total changes. See their Fig. 6.
5 JUDGE 90 excludes an elastic pseudoscalar e + e − resonance for 4.5× 10−13 s < τ (A0 )< 7.5 × 10−12 s (95% CL) at m 0 = 1.832 MeV. Comparable limits can be set forA
m 0 = 1.776–1.856 MeV.
A
6 See also TSERTOS 88B in references.

https://pdg.lbl.gov

Page 15

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

7 The upper limit listed in TSERTOS 88 is too large by a factor of 4. See TSERTOS 88B,
footnote 3.
8 VANKLINKEN 88 looked for relatively long-lived resonance (τ = 10−10 –10−12 s). The
sensitivity is not sufficient to exclude such a narrow resonance.
9 MAIER 87 obtained limits RΓ . 60 eV (100 eV) at m
≃ 1.64 MeV (1.83 MeV) forA0
energy resolution ∆E cm ≃ 3 keV, where R is the resonance cross section normalized
to that of Bhabha scattering, and Γ = Γ2 /Γtotal . For a discussion implying thatee
∆E cm ≃ 10 keV, see TSERTOS 89.
10 VONWIMMERSPERG 87 measured Bhabha scattering for E
cm = 1.37–1.86 MeV andR
found a possible peak at 1.73 with σdE cm = 14.5 ± 6.8 keV·b. For a comment anda reply, see VANKLINKEN 88B and VONWIMMERSPERG 88. Also see CONNELL 88.

Search for A0 (Axion) Resonance in e + e − → γ γ

The limit is for Γ(A0 → e + e − )·Γ(A0 → γ γ)/Γtotal

VALUE (10−3 eV)

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •< 0.1895

VO

94

CNTR m 0 =1.1 MeV
A
< 1.5
95
VO
94 CNTR m 0 =1.4 MeV
A
<12
95
VO
94 CNTR m 0 =1.7 MeV
A
1 TRZASKA< 6.6
95
91 CNTR m 0 = 1.8 MeV
A
< 4.4
95
WIDMANN91 CNTR m 0 = 1.78–1.92 MeV
A
2 FOX
89 CNTR
3 MINOWA< 0.1195
89 CNTR m 0 = 1.062 MeV
A<33
97
CONNELL
88 CNTR m 0 = 1.580 MeV
A<42
97
CONNELL
88 CNTR m 0 = 1.642 MeV
A<73
97
CONNELL
88 CNTR m 0 = 1.782 MeV
A<79
97
CONNELL
88 CNTR m 0 = 1.832 MeV
A
1 TRZASKA 91 also give limits in the range (6.6–30) × 10−3 eV (95%CL) for m=
A0
1.6–2.0 MeV.
2 FOX 89 measured positron annihilation with an electron in the source material into two
photons and found no signal at 1.062 MeV (< 9 × 10−5 of two-photon annihilation atrest).
3 Similar limits are obtained for m= 1.045–1.085 MeV.
A0

Search for X 0 (Light Boson) Resonance in e + e − → γ γ γThe limit is for Γ(X 0 → e + e − )·Γ(X 0 → γ γ γ)/Γtotal . C invariance forbids spin-0
X 0 coupling to both e + e − and γ γ γ.

VALUE (10−3 eV)

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •
1 VO
< 0.2
95
94 CNTR m 0 =1.1–1.9 MeV
X
2 VO
< 1.0
95
94 CNTR m 0 =1.1 MeV
X
2 VO
< 2.5
95
94 CNTR m 0 =1.4 MeV
X
2 VO
<120
95
94 CNTR m 0 =1.7 MeV
X
3 SKALSEY< 3.8
95
92 CNTR m 0 = 1.5 MeV
X
1 VO 94 looked for X 0 → γ γ γ decaying at rest. The precise limits depend on m . See
X0
Fig. 2(b) in paper.

https://pdg.lbl.gov

Page 16Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

2 VO 94 looked for X 0 → γ γ γ decaying in flight.
3 SKALSEY 92 also give limits 4.3 for m= 1.54 and 7.5 for 1.64 MeV. The spin of X 0
X0
is assumed to be one.

Light Boson (X 0 ) Search in Nonresonant e + e − Annihilation at Rest
Limits are for the ratio of n γ + X 0 production relative to γ γ.

VALUE (units 10−6 )CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 MITSUI< 4.2
90
96 CNTR γ X 0
2 SKALSEY< 4
6895 CNTR γ X 0
3<4068
SKALSEY
95 RVUE γ X 0
4< 0.1890
ADACHI
94 CNTR γ γ X 0 , X 0 → γ γ
5< 0.2690
ADACHI
94 CNTR γ γ X 0 , X 0 → γ γ
6 ADACHI< 0.3390
94 CNTR γ X 0 , X 0 → γ γ γ

1 MITSUI 96 looked for a monochromatic γ. The bound applies for a vector X 0 with
C=− 1 and m 0 <200 keV. They derive an upper bound on e e X 0 coupling and henceXon the branching ratio B(o-Ps → γ γ X 0 )< 6.2 × 10−6 . The bounds weaken for heavier
X 0.
2 SKALSEY 95 looked for a monochromatic γ without an accompanying γ in e + e −annihilation. The bound applies for scalar and vector X 0 with C = − 1 and m 0 =X
100–1000 keV.
3 SKALSEY 95 reinterpreted the bound on γ A0 decay of o-Ps by ASAI 91 where 3% of
delayed annihilations are not from 3S1 states. The bound applies for scalar and vector
X 0 with C = − 1 and m 0 = 0–800 keV.
X
4 ADACHI 94 looked for a peak in the γ γ invariant mass distribution in γ γ γ γ production
from e + e − annihilation. The bound applies for m 0 = 70–800 keV.
X
5 ADACHI 94 looked for a peak in the missing-mass mass distribution in γ γ channel, usingγ γ γ γ production from e + e − annihilation. The bound applies for m 0 <800 keV.
X
6 ADACHI 94 looked for a peak in the missing mass distribution in γ γ γ channel, usingγ γ γ γ production from e + e − annihilation. The bound applies for m 0 = 200–900
X
keV.

Searches for Goldstone Bosons (X 0 )(Including Horizontal Bosons and Majorons.) Limits are for branching ratios.
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ADACHI
23A BEL2 τ − → e − X 0 , Familon
2 ADACHI
23A BEL2 τ − → µ− X 0 , Familon
3 FIORILLO
23 ASTR Majoron, SN 1987A
4 SANDNER
23 COSM Majoron, CMB
5 COLOMA
22A BORX ν e non-standard interactions
6 AGUILAR-AR...21A PIEN π → µ ν X 0 , Majoron<4.3 × 10−690
7 AGUILAR-AR...21A PIEN π → e ν X 0 , Majoron<5.2 × 10−890
−68
<9 × 1090
AGUILAR-AR...20 PIEN µ+ → e + X 0 , Familon−129<7 × 1090
BALDINI
20 MEG µ+ → e + X 0 (X 0 → γ γ),
Familon10 BAYES<9 × 10−690
15 TWST µ+ → e + X 0 , Familon

https://pdg.lbl.gov

Page 17Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

11 LATTANZI12 LESSA
13 FARZAN
14 DIAZCOSM Majoron dark matter decay
RVUE Meson, ℓ decays to Majoron
ASTR Majoron, SN cooling
THEO H 0 → X 0 X 0 , A0 →X 0 X 0 X 0 , Majoron
15 BOBRAKOV 91
Electron quasi-magnetic interaction
16 ALBRECHT<3.3 × 10−2
95
90E ARGτ → µ X 0 . Familon
16 ALBRECHT<1.8 × 10−2
95
90E ARGτ → e X 0 . Familon−917<6.4 × 10
90ATIYA
90 B787 K + → π + X 0 . Familon−5
18<1.4 × 1090
BALKE
88 CNTR µ+ → e + X 0 . Familon
19 BOLTON<1.1 × 10−990
88 CBOX µ+ → e + γ X 0 . Familon
20 CHANDA
88 ASTR Sun, Majoron
21 CHOI
88 ASTR Majoron, SN 1987A
22 PICCIOTTO 88 CNTR π → e ν X 0 , Majoron<5 × 10−690−923 GOLDMAN<1.3 × 1090
87 CNTR µ → e γ X 0 . Familon
24 BRYMAN<3 × 10−4
90
86B RVUE µ → e X 0 . Familon−1025<1 × 1090
EICHLER86 SPEC µ+ → e + X 0 . Familon−6
26<2.6 × 10
90
JODIDIO
86 SPEC µ+ → e + X 0 . Familon
27 BALTRUSAIT...85 MRK3 τ → ℓ X 0 . Familon
28 DICUS
83 COSM ν (hvy) → ν (light) X 0
1 ADACHI 23A set limits in the range of 1.1 × 10−3 –9.7 × 10−3 for 0 < m< 1.6 GeV
X0
−
−
0
−
−
on B(τ → e X )/B(τ → e ν e ντ ). See their Fig. 2 for mass-dependent limits.
2 ADACHI 23A set limits in the range of 7 × 10−4 –1.22 × 10−2 for 0 < m< 1.6 GeV
X0
−
−
0
−
−
on B(τ → µ X )/B(τ → µ ν µ ντ ). See their Fig. 2 for mass-dependent limits.
3 FIORILLO 23 used data from Kamiokande-II and IMB on the neutrino flux from SN1987A
to constrain the universal neutrino Majoron Yukawa coupling, g. They set an upper limitof g m 0 . 10−9 MeV for Majoron masses 100 eV . m 0 . 100 MeV, using
X
X
neutrino coalescence as production of Majorons which then decay back to neutrinos. See
their Fig. 1 for the mass-dependent limits.
4 SANDNER 23 study Majoron production via neutrino inverse decay and use Planck datato constrain the neutrino Majoron Yukawa coupling to g . 2 × 10−13 –1 × 10−12 forMajoron masses m 0 = 1–10 eV. See their Fig. 1 for mass-dependent limits.
X
5 COLOMA 22A used the spectral data of Borexino Phase II to constrain the neutrino
non-standard interaction with electrons mediated by a scalar or a pseudoscalar. Limits
on the universal coupling to neutrinos and electrons between 2 × 10−6 and 10−4 areobtained for m 0 . 30–40 MeV. See their Fig. 6 for mass-dependent limits.
X
6 AGUILAR-AREVALO 21A quoted limit applies to m
= 33.9 MeV. Limits between
X0−6−5
4.3 × 10and 7.5 × 10
are obtained for 0 < m 0 < 33.9 MeV. The lifetime ofX0
X is assumed to be long enough. See their Fig. 6 for mass-dependent limits.
7 AGUILAR-AREVALO 21A quoted limit applies to m
= 85 MeV. Limits between 5.2 ×
X0
−8
−6
10
and 1.4 × 10
are obtained for 0 < m 0 < 120 MeV, which improve the limits
Xof PICCIOTTO 88 by an order of magnitude. The lifetime of X 0 is assumed to be longenough. See their Fig. 4 for mass-dependent limits.
8 AGUILAR-AREVALO 20 obtained limits of order 10−5 for m= 47.8–95.1 MeV. The
X0quoted limit applies to m 0 = 75 MeV. See their Fig. 1 for mass-dependent limits.
X
9 BALDINI 20 obtained limits for m= 20–45 MeV and τ 0 < 40 ps, and supersedes
X0
X
BOLTON 88 for m 0 = 20–40 MeV. See their Fig. 17 for mass-dependent limits.
X

https://pdg.lbl.gov

Page 18

13
07
03
98

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

10 BAYES 15 limits are the average over m= 13–80 MeV for the isotropic decay distriX0
bution of positrons. See their Fig. 4 and Table II for the mass-dependent limits as wellas the dependence on the decay anisotropy. In particular, they find a limit < 58 × 10−6
at 90% CL for massless familons and for the same asymmetry as normal muon decay, acase not covered by JODIDIO 86.
11 LATTANZI 13 use WMAP 9 year data as well as X-ray and γ-ray observations to derive
limits on decaying majoron dark matter. A limit on the decay width Γ(X 0 → ν ν)
< 6.4 × 10−19 s−1 at 95% CL is found if majorons make up all of the dark matter.
12 LESSA 07 consider decays of the form Meson → ℓ ν Majoron and ℓ → ℓ′ ν ν Majoron
and use existing data to derive limits on the neutrino-Majoron Yukawa couplings gαβ(α,β = e, µ,τ ). Their best limits are ge α 2 < 5.5 × 10−6 , gµ α 2 < 4.5 × 10−5 ,gτ α 2 < 5.5 × 10−2 at CL = 90%.
13 FARZAN 03 set limits on the neutrino Majoron Yukawa coupling, g−7e e < 4 × 10 ,by considering the SN cooling due to the massless Majoron emission via neutrino coalescence. They also exclude values around 10−5 for both ge µ and gµ µ using the processν ν → X 0 X 0 . See also their Figs. 3 and 4 for mass-dependent limits.
14 DIAZ 98 studied models of spontaneously broken lepton number with both singlet andtriplet Higgses. They obtain limits on the parameter space from invisible decay Z →H 0 A0 → X 0 X 0 X 0 X 0 X 0 and e + e − → Z H 0 with H 0 → X 0 X 0 .
15 BOBRAKOV 91 searched for anomalous magnetic interactions between polarized electrons expected from the exchange of a massless pseudoscalar boson (arion). A limit−4x2
e < 2 × 10√ (95%CL) is found for the effective anomalous magneton parametrized
as xe (GF /8π 2)1/2 .
16 ALBRECHT 90E limits are for B(τ → ℓ X 0 )/B(τ → ℓ ν ν). Valid for m< 100
X0
MeV. The limits rise to 7.1% (for µ), 5.0% (for e) for m 0 = 500 MeV.
X
17 ATIYA 90 limit is for m= 0. The limit B < 1 × 10−8 holds for m 0 < 95 MeV.
0X
X
For the reduction of the limit due to finite lifetime of X 0 , see their Fig. 3.
18 BALKE 88 limits are for B(µ+ → e + X 0 ). Valid for m< 80 MeV and τ 0 > 10−8
X0
X
sec.
19 BOLTON 88 limit corresponds to F > 3.1 × 109 GeV, which does not depend on thechirality property of the coupling.
20 CHANDA 88 find v
T < 10 MeV for the weak-triplet Higgs vacuum expectation valuein Gelmini-Roncadelli model, and vS > 5.8 × 106 GeV in the singlet Majoron model.
21 CHOI 88 used the observed neutrino flux from the supernova SN 1987A to exclude theneutrino Majoron Yukawa coupling h in the range 2 × 10−5 < h < 3 × 10−4 for thecinteraction Lint = 1
2 ihψ ν γ5 ψν φX . For several families of neutrinos, the limit applies for(Σh4 )1/4 .
i
22 PICCIOTTO 88 limit applies when m< 55 MeV and τ 0 > 2ns, and it decreases
X0
X−7
to 4 × 10
at m 0 = 125 MeV, beyond which no limit is obtained.
X
23 GOLDMAN 87 limit corresponds to F > 2.9 × 109 GeV for the family symmetry breaking
scale from the Lagrangian Lint = (1/F)ψ µ γ µ (a+bγ5 ) ψe ∂ µ φ 0 with a2 +b2 = 1.
X
This is not as sensitive as the limit F > 9.9 × 109 GeV derived from the search for µ+ →e + X 0 by JODIDIO 86, but does not depend on the chirality property of the coupling.
24 Limits are for Γ(µ → e X 0 )/Γ(µ → e ν ν). Valid when m= 0–93.4, 98.1–103.5
X0
MeV.
25 EICHLER 86 looked for µ+ → e + X 0 followed by X 0 → e + e − . Limits on the
branching fraction depend on the mass and and lifetime of X 0 . The quoted limits arevalid when τ 0 . 3. × 10−10 s if the decays are kinematically allowed.
X

https://pdg.lbl.gov

Page 19

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

26 JODIDIO 86 corresponds to F > 9.9 × 109 GeV for the family symmetry breaking scalewith the parity-conserving effective Lagrangian Lint = (1/F) ψ µ γ µ ψe ∂ µ φ 0 .
X
27 BALTRUSAITIS 85 search for light Goldstone boson(X 0 ) of broken U(1). CL = 95%limits are B(τ → µ+ X 0 ) B(τ → µ+ ν ν) <0.125 and B(τ → e + X 0 ) B(τ → e + ν ν)
<0.04. Inferred limit for the symmetry breaking scale is m >3000 TeV.
28 The primordial heavy neutrino must decay into ν and familon, f , early so that theA
red-shifted decay products are below critical density, see their table. In addition, K →π fA and µ → e fA are unseen. Combining these excludes m heavyν between 5 × 10−5
and 5 × 10−4 MeV (µ decay) and m heavyν between 5 × 10−5 and 0.1 MeV (K -decay).

Majoron Searches in Neutrinoless Double β Decay
Limits are for the half-life of neutrinoless β β decay with a Majoron emission.
No experiment currently claims any such evidence. Only the best or comparable limits
for each isotope are reported.
t1/2 (1021 yr)

CL% ISOTOPE

TRANSITION METHODDOCUMENT ID

1 BERNATOW... 92
90 128 Te
>7200
CNTR
• • • We do not use the following data for averages, fits, limits, etc. • • •2 AZZOLINI> 120
90 82 Se
0ν1χ
CUPID-0
23
3 AGOSTINI> 640
90 76 Ge
0ν1χ
GERDA
22
136
4
>4300
90
Xe
0ν1χ
EXO-200
AL-KHARUSI 21
5 ARNOLD>
4.4
90 100 Mo
0ν1χ
NEMO-319
6 ARNOLD> 37
90 82 Se
0ν1χ
NEMO-318
7 AGOSTINI> 420
90 76 Ge
0ν1χ
GERDA
15A
100
8
> 400
90
Mo
0ν1χ
NEMO-3
ARNOLD15
9 ALBERT>1200
90 136 Xe0ν1χ
EXO-200
14A
10 GANDO>2600
90 136 Xe
0ν1χ
KamLAND-Zen
12
130
11
> 16
90
Te
0ν1χ
NEMO-3
ARNOLD11
12 ARGYRIADES 10>
1.9
90 96 Zr
2ν1χ
NEMO-313 ARGYRIADES 09>
1.52
90 150 Nd
0ν1χ
NEMO-3
100
14
> 27
90
Mo
0ν1χ
NEMO-3
ARNOLD
06
82
15
> 15
90
Se
0ν1χ
NEMO-3
ARNOLD06
16 ARNOLD> 14
90 100 Mo
0ν1χ
NEMO-304
17 ARNOLD> 12
90 82 Se
0ν1χ
NEMO-304
18 ARNABOLDI 03>
2.2
90 130 Te
0ν1χ
Cryog. det.
19 ARNABOLDI 03>
0.9
90 130 Te
0ν2χ
Cryog. det.
116
20 DANEVICH
>
8
90
Cd
0ν1χ
CdWO4 scint.
03
116
21
>
0.8
90
Cd
0ν2χ
CdWO4 scint.
DANEVICH03> 500
90 136 Xe
0ν1χ
Liquid Xe Scint. 22 BERNABEI
02D
100
23 FUSHIMI
>
5.8
90
Mo
0ν1χ
ELEGANT V
02
24 ASHITKOV>
0.32
90 100 Mo
0ν1χ
Liq. Ar ioniz.
01
160
160
25
>
0.003590
Gd
0ν1χ
Gd2 SiO5 :Ce
DANEVICH
01
160
160
26
>
0.013
90
Gd
0ν2χ
Gd2 SiO5 :Ce
DANEVICH
01
27 ARNOLD>
2.3
90 82 Se
0ν1χ
NEMO 200
28 ARNOLD>
0.31
90 96 Zr
0ν1χ
NEMO 2
00
82
29
>
0.63
90
Se
0ν2χ
NEMO 2ARNOLD00
29 ARNOLD>
0.063
90 96 Zr
0ν2χ
NEMO 200
29 ARNOLD>
0.16
90 100 Mo
0ν2χ
NEMO 2
00
82
30
>
2.4
90
Se
0ν1χ
NEMO 2ARNOLD98

https://pdg.lbl.gov

Page 20

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

31 LUESCHER>
7.2
90 136 Xe
0ν2χ
TPC
98
32 GUENTHER 96>
7.91
90 76 GeSPEC
> 17
90 76 Ge
CNTR
BECK
93
1 BERNATOWICZ 92 studied double-β decays of 128 Te and 130 Te, and found the ratioτ (130 Te)/τ (128 Te) = (3.52 ± 0.11) × 10−4 in agreement with relatively stable theoretical predictions. The bound is based on the requirement that Majoron-emitting decay
cannot be larger than the observed double-beta rate of 128 Te of (7.7 ± 0.4) × 1024 year.
We calculated 90% CL limit as (7.7–1.28 × 0.4=7.2) × 1024 .
2 AZZOLINI 23 use 9.95 kg·yr of data, collected by the CUPID-0 experiment, to place alimit on the single Majoron mode of the 0νβ β decay of 82 Se. Various limits on modes
involving the emission of multiple Majorons are given too. The resulting constraint on
the Majoron-neutrino coupling constant is gν χ < 1.8–4.4 × 10−5 . The range is due tothe variability of the used nuclear matrix elements.
3 AGOSTINI 22 use 32.8 kg·yr of GERDA phase 2 data to derive a limit of gνχ <−5
1.8–4.4 × 10
on the neutrino-Majoron coupling. The range reflects the author’s
evaluation of the spread of nuclear matrix elements.
4 AL-KHARUSI 21 utilize the complete dataset of the EXO-200 experiment, corresponding
to an exposure of 234 kg yr, to place a limit on the one Majoron mode of the neutrinolessdouble beta decay of 136 Xe. Several limits are reported, the one given here corresponds
to a spectral index of 1, resulting in a limit of gν χ < 0.4–0.9 × 10−5 on the Majoronneutrino coupling constant. The range reflects the spread of the nuclear matrix elements.
5 ARNOLD 19 uses the NEMO-3 tracking calorimeter to determine limits for the Majoron
emitting double beta decay, with spectral index n = 3. The limit corresponds to therange of the gee coupling of 0.013–0.035; dependimg on the nuclear matrix elements
used.
6 ARNOLD 18 use the NEMO-3 tracking detector. The limit corresponds to gee <3.2–8.0 × 10−5 ; the range corresponds to different nuclear matrix element calculations.
7 AGOSTINI 15A analyze a 20.3 kg yr of data set of the GERDA calorimeter to determinegν χ < 3.4–8.7 × 10−5 on the Majoron-neutrino coupling constant. The range reflects
the spread of the nuclear matrix elements.
8 ARNOLD 15 use the NEMO-3 tracking calorimeter with 3.43 kg yr exposure to determine
the limit on Majoron emission. The limit corresponds to gν χ < 1.6–3.0 × 10−4 . The
spread reflects different nuclear matrix elements. Supersedes ARNOLD 06.
9 ALBERT 14A utilize 100 kg yr of exposure of the EXO-200 tracking calorimeter to placea limit on the gν χ < 0.8–1.7 × 10−5 on the Majoron-neutrino coupling constant. The
range reflects the spread of the nuclear matrix elements.
10 GANDO 12 use the KamLAND-Zen detector to obtain the limit on the 0νχ decay withMajoron emission. It implies that the coupling constant gν χ < 0.8–1.6 × 10−5 depending on the nuclear matrix elements used.
11 ARNOLD 11 use the NEMO-3 detector to obtain the reported limit on Majoron emission.
It implies that the coupling constant gν χ < 0.6–1.6 × 10−4 depending on the nuclear
matrix element used. Supercedes ARNABOLDI 03.
12 ARGYRIADES 10 use the NEMO-3 tracking detector and 96 Zr to derive the reported
limit. No limit for the Majoron electron coupling is given.
13 ARGYRIADES 09 use 150 Nd data taken with the NEMO-3 tracking detector. The
reported limit corresponds to gν χ < 1.7–3.0 × 10−4 using a range of nuclear matrix
elements that include the effect of nuclear deformation.
14 ARNOLD 06 use 100 Mo data taken with the NEMO-3 tracking detector. The reported
limit corresponds to gν χ < (0.4–1.8) × 10−4 using a range of matrix element calculations. Superseded by ARNOLD 15.

https://pdg.lbl.gov

Page 21

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

15 NEMO-3 tracking calorimeter is used in ARNOLD 06 . Reported half-life limit for 82 Se
corresponds to gν χ < (0.66–1.9)×10−4 using a range of matrix element calculations.
Supersedes ARNOLD 04.
16 ARNOLD 04 use the NEMO-3 tracking detector. The limit corresponds to gνχ <(0.5–0.9)10−4 using the matrix elements of SIMKOVIC 99, STOICA 01 and CIVITARESE 03. Superseded by ARNOLD 06.
17 ARNOLD 04 use the NEMO-3 tracking detector. The limit corresponds to gνχ <−4
(0.7–1.6)10
using the matrix elements of SIMKOVIC 99, STOICA 01 and CIVITARESE 03.
18 Supersedes ALESSANDRELLO 00. Array of TeO crystals in high resolution cryogenic
2
calorimeter. Some enriched in 130 Te. Derive gν χ < 17–33 × 10−5 depending on
matrix element.
19 Supersedes ALESSANDRELLO 00. Cryogenic calorimeter search.
20 Limit for the 0ν χ decay with Majoron emission of 116 Cd using enriched CdWO scin4
tillators. gν χ < 4.6–8.1 × 10−5 depending on the matrix element. Supersedes
DANEVICH 00.
21 Limit for the 0ν2χ decay of 116 Cd. Supersedes DANEVICH 00.
22 BERNABEI 02D obtain limit for 0ν χ decay with Majoron emission of 136 Xe using liquid
Xe scintillation detector. They derive gν χ < 2.0–3.0 × 10−5 with several nuclear
matrix elements.
23 Replaces TANAKA 93. FUSHIMI 02 derive half-life limit for the 0ν χ decay by meansof tracking calorimeter ELEGANT V. Considering various matrix element calculations, a
range of limits for the Majoron-neutrino coupling is given: gν χ <(6.3–360) × 10−5 .
24 ASHITKOV 01 result for 0ν χ of 100 Mo is less stringent than ARNOLD 00.
25 DANEVICH 01 obtain limit for the 0ν χ decay with Majoron emission of 160 Gd using
Gd2 SiO5 :Ce crystal scintillators.
26 DANEVICH 01 obtain limit for the 0ν 2χ decay with 2 Majoron emission of 160 Gd.
27 ARNOLD 00 reports limit for the 0ν χ decay with Majoron emission derived from tracking
calorimeter NEMO 2. Using 82 Se source: gν χ < 1.6 × 10−4 . Matrix element fromGUENTHER 96.
28 Using 96 Zr source: g−4ν χ < 2.6 × 10 . Matrix element from ARNOLD 99.
29 ARNOLD 00 reports limit for the 0ν 2χ decay with two Majoron emission derived fromtracking calorimeter NEMO 2.
30 ARNOLD 98 determine the limit for 0ν decay with Majoron emission of 82 Se using theχ< 2.3–4.3 × 10−4 with several nuclear
NEMO-2 tracking detector. They derive gνχmatrix elements.
31 LUESCHER 98 report a limit for the 0ν decay with Majoron emission of 136 Xe using Xe
TPC. This result is more stringent than BARABASH 89. Using the matrix elements of
ENGEL 88, they obtain a limit on gν χ of 2.0 × 10−4 .
32 See Table 1 in GUENTHER 96 for limits on the Majoron coupling in different models.

Invisible A0 (Axion) MASS LIMITS from Astrophysics and Cosmology
v1 = v2 is usually assumed (vi = vacuum expectation values). For a review of theselimits, see RAFFELT 91 and TURNER 90. In the comment lines below, D and K refer
to DFSZ and KSVZ axion types, discussed in the above minireview.
VALUE (eV)CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 CHENG
23 ASTR BH superradiance−192> 3.2 × 10
95
DELLA-MON... 23 ASTR Ultralight DM soliton
halo core

https://pdg.lbl.gov

Page 22

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)<141< 0.2490
95

none 10−24 –5 × 10−23 95

none 0.15–1.5 × 10−12> 1.4 × 10−21< 1.9 × 104

none 1.3–2.7 × 10−13> 2
× 10−20none 0.8–6.5 × 10−13> 2
× 10−17

95
95

95
95

> 2.1 × 10−21
none 6.4–8.0 × 10−13
95
none 2.9–4.6 × 10−21
none 10−21 –6 × 10−20
none 1.1–4 × 10−1395< 0.06< 0.67none 0.7–3 × 105
<105

95

<

95

0.72

<191
<334
< 1.02< 1.2< 0.42< 1.053
to 20< 0.007< 4<(0.5–6) × 10−3
< 0.018< 0.010

90

90
95
95
95
95
95

3 DERBIN
4 NOTARI
5 ROGERS
6 SMARRA

7 XIA
23
8 LAGUE
22
9 YUAN
22A
10 BANIK
21
11 BAUMHOLZ... 21
12 CROON
21
13 FUJIKURA
21
14 MARTINCAM...2115 NG
21
16 ROGERS
21
17 TSUKADA
21
18 IRSIC
20
19 PODDAR
20
20 SCHUTZ
20
21 SUN20
22 DAVOUDIASL 19
23 MARSH
19
24 PALOMBA
19
25 CHANG
18
26 PORAYKO
1827 ARCHIDIACO...13A
28 CADAMURO 11
29 DERBIN
11A
30 ANDRIAMON...10
31 HANNESTAD 10
32 ANDRIAMON...09
33 DERBIN
09A
34 KEKEZ
09
35 HANNESTAD 08
36 HANNESTAD 07
37 MELCHIORRI 07A
38 HANNESTAD 05A
39 MOROI
98
40 BORISOV
97
41 KACHELRIESS 97
42 KEIL
97
43 RAFFELT
95
44 ALTHERR
94
45 CHANG< 0.01< 0.03none 3–8

https://pdg.lbl.gov

23
23
23
23

WANG
WANG
46 BERSHADY

Page 23

93
92
92C
91

CNTR K, solar axions
COSM K, Hot dark matter
COSM Ultra-light axion DM
EPTA Ultralight DM masslimit
ASTR Fuzzy DM
COSM Ultralight axion DM
ASTR BH superradiance
ASTR Fuzzy DM
COSM warm dark matter
ASTR SN 1987A, axion-muon
coupling
ASTR Microlensing
ASTR SN 1987A, Λ decay
ASTR BH superradiance
COSM Lyman-αASTR BH superradiance
COSM Isocurvature fluctuations
ASTR Compact binary systems
COSM Fuzzy DM
ASTR BH superradiance
ASTR BH superradiance
ASTR Fuzzy DM
ASTR BH superradiance
ASTR K, SN 1987A
PPTA Fuzzy DM
COSM K, hot dark matter
COSM D abundance
CNTR D, solar axion
CAST K, solar axions
COSM K, hot dark matter
CAST K, solar axions
CNTR K, solar axions
HPGE K, solar axions
COSM K, hot dark matter
COSM K, hot dark matter
COSM K, hot dark matter
COSM K, hot dark matter
COSM K, hot dark matter
ASTR D, neutron star
ASTR D, neutron star cooling
ASTR SN 1987A
ASTR D, red giant
ASTR D, red giants, whitedwarfsASTR K, SN 1987A
ASTR D, white dwarf
ASTR D, C-O burning
ASTR D, K,
intergalactic light

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

47 KIM< 10< 1
× 10−3−3none 10 –3< 0.02< 1
× 10−3<(1.4–10) × 10−3
< 3.6 × 10−4
< 12
< 1
× 10−3< 0.07< 0.7< 2–5< 0.01< 0.06< 0.7< 0.03< 1< 0.003–0.02> 1
× 10−5× 10−5

>

1

<
>

0.04
1
× 10−548 RAFFELT
49 RESSELL
BURROWS
50 ENGEL
51 RAFFELT
52 BURROWS
53 ERICSON
54 MAYLE
CHANDARAFFELT55 RAFFELTFRIEMAN56 RAFFELTTURNER
57 DEARBORN
RAFFELT58 RAFFELTRAFFELT59 KAPLAN
IWAMOTOABBOTTDINEELLISPRESKILL

91C COSM D, K, mass density of
the universe, supersymmetry
91B ASTR D,K, SN 1987A
91 ASTR K, intergalactic light
90 ASTR D,K, SN 1987A
90 ASTR D,K, SN 1987A
90D ASTR D, red giant
89 ASTR D,K, SN 1987A
89 ASTR D,K, SN 1987A
89 ASTR D,K, SN 1987A
88 ASTR D, Sun
88 ASTR D,K, SN 1987A
88B ASTR red giant
87 ASTR D, red giant
87 ASTR K, red giant
87 COSM K, thermal production
86 ASTR D, red giant
86 ASTR D, red giant
86 ASTR K, red giant
86B ASTR D, white dwarf
85 ASTR K, red giant
84 ASTR D, K, neutron star
83 COSM D,K, mass density of
the universe
83 COSM D,K, mass density of
the universe
83B ASTR D, red giant
83 COSM D,K, mass density of
the universe
82 ASTR D, red giant
82 ASTR D, stellar cooling
82B ASTR D, red giant< 0.1
BARROSO
60 FUKUGITA< 1< 0.07FUKUGITA
1 CHENG 23 employ an improved approximation of the boson cloud eigenfrequency to
calculate the superradiance rate. They find that sensitivity depends on initial spin distribution and the merger timescale, and identify two preferred ranges for boson masscentered at 1.78 × 10−12 and 7.94 × 10−13 eV.
2 DELLA-MONICA 23 consider the solitonic core implied by ultralight scalar dark matter inthe centre of the Milky Way and the effect its presence would have on the precisely tracked
orbits of the stars orbiting our galaxy’s central supermassive black hole, Sagittarius A∗ .
3 DERBIN 23 employ a thulium garnet crystal bolometer to search for the 8.4 keV solar
axion line emitted from the M1 nuclear transition of thulium-169, 169 Tm. Mass boundapplies to KSVZ axions, value for DFSZ is 244 eV.
4 NOTARI 23 improved the evaluation of axion production from pion scatterings by using
pion-pion scattering data and incorporating the momentum dependence of the Boltzmann
equation. The limit is based on the Planck 2018, BAO, and Pantheon SN Ia data.
5 ROGERS 23 use the CMB and BOSS galaxy-clustering data to set limits on the abundance of ultralight axion DM. They obtained Ω 0 < 0.002 for m 0 = 10−30 –10−28AA
eV and set upper limits ranging from 0.002 to 0.07 for m 0 = 10−32 –10−25 eV. See
Atheir Fig. 22 for mass-dependent limits.

https://pdg.lbl.gov

Page 24

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

6 SMARRA 23 is the European Pulsar Timing Array’s constraint on the contribution ofultralight DM to the DM density in our local galactic neighbourhood. Ultralight DM
cannot saturate the known DM density of 0.3 GeV/cc for masses inside this mass intervalof 10−24 –5 × 10−23 eV.
7 XIA 23 is analogous to PORAYKO 18 and use the Fermi-LAT pulsar timing array. They
set a bound on the local density as ρ 0 . 8 GeV/cm3 for m 0 . 10−23 eV at 95%
AA
CL, with weaker constraints up to 10−22 eV. See their Fig. 1 for the mass-dependent
limits.
8 LAGUE 22 used the BOSS galaxy-clustering data to set limits on the abundance of ultralight axion dark matter. When combined with the CMB data, they obtained Ω 0 h2 <A
0.004 for m 0 = 10−31 –10−26 eV. See their Figs. 1 and 15 for mass-dependent limits.
A
9 YUAN 22A use the data of Advanced LIGO and Advanced Virgo’s first three observing
runs to search for stochastic GW background produced by scalar bosonic clouds formedby the BH superradiant instability. They set the limit, taking into account all the unstablemodes.
10 BANIK 21 use the subhalo mass function inferred from the analyses of the GD-1 andPal 5 stellar streams. The limit is strengthened to 2.2 × 10−21 eV when adding dwarf
satellite counts.
11 BAUMHOLZER 21 study the freeze-in production of axion dark matter through couplings
to photons, and set the limit using Lyman-α forest data and the observed number ofMilky Way subhalos.
12 CROON 21 study the supernova cooling effect of the axion-muon coupling, taking account of semi-Compton scattering and muon-proton bremsstrahlung, as well as the loopinduced axion-photon coupling, and exclude the range of gAµ µ ≃ 7× 10−3 –2× 10−10
for m 0 < 0.5 GeV. See their Fig. 8 for mass-dependent limits.
A
13 FUJIKURA 21 use the EROS-2 survey and the Subaru HSC observation to set limits
on spherically symmetric axion clumps, taking account of the finite lens and source size
effects. f 0 & 1012 GeV can be constrained depending on the fraction of the axionAdark matter collapsed into clumps, and the clump densities. See their Figs. 7–10 for thelimits.
14 MARTINCAMALICH 21 considered axion emission from a supernova core through theΛ hyperon decay, and set the limit on B(Λ → n A0 ) . 8 × 10−9 , or equivalently,
f 0 /Csd & 2.6 × 109 GeV in terms of the flavor-violating axion coupling to the downAand strange quarks.
15 NG 21 use the binary black holes reported by LIGO and Virgo to determine the blackhole spin distribution at formation and the scalar boson mass simultaneously, neglecting
the boson self-interaction.
16 ROGERS 21 set the limit by using a framework involving Bayesian emulator optimizationto accurately forward-model the Lyman-α flux power spectrum, and comparing this withsmall-scale data to constrain the predicted suppression of cosmic structure growth.
17 TSUKADA 21 look for a stochastic GW background produced by extragalactic BH-hidden
photon cloud systems through the superradiant instability. They assume a uniform spin
distribution at birth of isolated BHs from 0 to 1.
18 IRSIC 20 used the Lyman-α forest constraint on small-scale isocurvature perturbation toderive limits on the axion mass and decay constant, assuming that the axion makes up
all dark matter in the post-inflationary scenario. See their Fig. 1 for other astrophysicallimits as well as the limits on the case of the temperature-dependent axion mass.
19 PODDAR 20 used the observed decay in orbital period of four compact binary systems
to derive a limit on the emission of axions with m 0 < 1 × 10−19 eV, assuming theyA
couple to nucleons and the strong CP phase vanishes at the potential minimum. They
exclude f 0 . 1011 GeV for such axions.
A
20 SCHUTZ 20 set a limit on fuzzy dark matter based on the existing limits for warm dark
matter derived from the inferred subhalo mass function.

https://pdg.lbl.gov

Page 25

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

21 SUN 20 look for quasimonochromatic gravitational waves emitted from boson clouds
around the Cygnus X-1 black hole. The quoted limit assume the black hole age of
5 × 106 years. A mass range of 9.6–15.5 × 10−13 eV is disfavored when repeatedinduction of bosenova for string axions with decay constant f 0 ≃ 1015 GeV preventsA
the superradiance from being saturated.
22 DAVOUDIASL 19 used the observed data of M87* by the Event Horizon Telescope to
set the limit. A mass range of 0.85–4.6 × 10−21 eV is disfavored for a spin-1 boson.
23 MARSH 19 considered heating of star clusters due to the stochastic oscillations of thecore and granular quasiparticles in the outer halo. The limit was derived by requiring thesurvival of the old star cluster in Eridanus II, where the lower end is set by the validity ofdiffusion approximation. The effect of tidal stripping is also discussed for lower masses.
24 PALOMBA 19 used the LIGO O2 dataset to derive limits on nearly monochromatic
gravitational waves emitted by boson clouds formed around a stellar-mass black hole.
They exclude boson masses in a range of 1.1 × 10−13 and 4 × 10−13 eV for high initial
black hole spin, and 1.2 × 10−13 and 1.8 × 10−13 eV for moderate spin. See their Figs.
2 and 3 for limits based on various values of black hole initial spin, boson cloud age, anddistance.
25 CHANG 18 update axion bremsstrahlung emission rates in nucleon-nucleon collisions,shifting the excluded mass range to higher values. They rule out the hadronic axion withmass up to a few hundred eV, closing the hadronic axion window. See their Fig. 11 forresults based on several different choices of the temperature and density profile of the
proto-neutron star.
26 PORAYKO 18 look for time-dependent oscillations in the gravitational potential generated by ultralight scalar dark matter, and set a bound on its local density as ρ 0 . 6
A
GeV/cm3 for m 0 . 10−23 eV at 95% CL. See their Fig. 4 for the limits.
A
27 ARCHIDIACONO 13A is analogous to HANNESTAD 05A. The limit is based on the CMB
temperature power spectrum of the Planck data, the CMB polarization from the WMAP
9-yr data, the matter power spectrum from SDSS-DR7, and the local Hubble parametermeasurement by the Carnegie Hubble program.
28 CADAMURO 11 use the deuterium abundance to show that the mrange 0.7 eV –A0
300 keV is excluded for axions, complementing HANNESTAD 10.
29 DERBIN 11A look for solar axions produced by Compton and bremsstrahlung processes,
in the resonant excitation of 169 Tm, constraining the axion-electron × axion nucleon
couplings.
30 ANDRIAMONJE 10 search for solar axions produced from 7 Li (478 keV) and D(p,γ)3 He(5.5 MeV) nuclear transitions. They show limits on the axion-photon coupling for two
reference values of the axion-nucleon coupling for m A < 100 eV.
31 This is an update of HANNESTAD 08 including 7 years of WMAP data.
32 ANDRIAMONJE 09 look for solar axions produced from the thermally excited 14.4 keVlevel of 57 Fe. They show limits on the axion-nucleon × axion-photon coupling assumingm A < 0.03 eV.
33 DERBIN 09A look for Primakoff-produced solar axions in the resonant excitation of
169 Tm, constraining the axion-photon × axion-nucleon couplings.
34 KEKEZ 09 look at axio-electric effect of solar axions in HPGe detectors. The one-loop
axion-electron coupling for hadronic axions is used.
35 This is an update of HANNESTAD 07 including 5 years of WMAP data.
36 This is an update of HANNESTAD 05A with new cosmological data, notably WMAP (3years) and baryon acoustic oscillations (BAO). Lyman-α data are left out, in contrast to
HANNESTAD 05A and MELCHIORRI 07A, because it is argued that systematic errors
are large. It uses Bayesian statistics and marginalizes over a possible neutrino hot dark
matter component.
37 MELCHIORRI 07A is analogous to HANNESTAD 05A, with updated cosmological data,
notably WMAP (3 years). Uses Bayesian statistics and marginalizes over a possible

https://pdg.lbl.gov

Page 26

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

neutrino hot dark matter component. Leaving out Lyman-α data, a conservative limit is
1.4 eV.
38 HANNESTAD 05A puts an upper limit on the mass of hadronic axion because in this mass
range it would have been thermalized and contribute to the hot dark matter componentof the universe. The limit is based on the CMB anisotropy from WMAP, SDSS large
scale structure, Lyman α, and the prior Hubble parameter from HST Key Project. A χ2statistic is used. Neutrinos are assumed not to contribute to hot dark matter.
39 MOROI 98 points out that a KSVZ axion of this mass range (see CHANG 93) can be a
viable hot dark matter of Universe, as long as the model-dependent gAγ is accidentally
small enough as originally emphasized by KAPLAN 85; see Fig. 1.
40 BORISOV 97 bound is on the axion-electron coupling g < 1 × 10−13 from the photoae
production of axions off of magnetic fields in the outer layers of neutron stars.
41 KACHELRIESS 97 bound is on the axion-electron coupling g < 1 × 10−10 from theaeproduction of axions in strongly magnetized neutron stars. The authors also quote astronger limit, gae < 9 × 10−13 which is strongly dependent on the strength of themagnetic field in white dwarfs.
42 KEIL 97 uses new measurements of the axial-vector coupling strength of nucleons, aswell as a reanalysis of many-body effects and pion-emission processes in the core of theneutron star, to update limits on the invisible-axion mass.
43 RAFFELT 95 reexamined the constraints on axion emission from red giants due to theaxion-electron coupling. They improve on DEARBORN 86 by taking into proper accountdegeneracy effects in the bremsstrahlung rate. The limit comes from requiring the red
giant core mass at helium ignition not to exceed its standard value by more than 5%(0.025 solar masses).
44 ALTHERR 94 bound is on the axion-electron coupling g < 1.5 × 10−13 , from energy
aeloss via axion emission.
45 CHANG 93 updates ENGEL 90 bound with the Kaplan-Manohar ambiguity in z=m /mud(see the Note on the Quark Masses in the Quark Particle Listings). It leaves the windowfA =3×105 –3×106 GeV open. The constraint from Big-Bang Nucleosynthesis is satisfied
in this window as well.
46 BERSHADY 91 searched for a line at wave length from 3100–8300 Å expected from 2γ
decays of relic thermal axions in intergalactic light of three rich clusters of galaxies.
47 KIM 91C argues that the bound from the mass density of the universe will change drastically for the supersymmetric models due to the entropy production of saxion (scalarcomponent in the axionic chiral multiplet) decay. Note that it is an upperbound rather
than a lowerbound.
48 RAFFELT 91B argue that previous SN 1987A bounds must be relaxed due to corrections
to nucleon bremsstrahlung processes.
49 RESSELL 91 uses absence of any intracluster line emission to set limit.
50 ENGEL 90 rule out 10−10 . g−3AN . 10 , which for a hadronic axion with EMC
motivated axion-nucleon couplings corresponds to 2.5 × 10−3 eV . m 0 . 2.5 ×A
104 eV. The constraint is loose in the middle of the range, i.e. for g AN ∼ 10−6 .
51 RAFFELT 90D is a re-analysis of DEARBORN 86.
52 The region m& 2 eV is also allowed.
A0
53 ERICSON 89 considered various nuclear corrections to axion emission in a supernova
core, and found a reduction of the previous limit (MAYLE 88) by a large factor.
54 MAYLE 89 limit based on naive quark model couplings of axion to nucleons. Limit basedon couplings motivated by EMC measurements is 2–4 times weaker. The limit fromaxion-electron coupling is weak: see HATSUDA 88B.
55 RAFFELT 88B derives a limit for the energy generation rate by exotic processes in heliumburning stars ǫ < 100 erg g−1 s− 1 , which gives a firmer basis for the axion limits basedon red giant cooling.
56 RAFFELT 87 also gives a limit g−10 GeV− 1 .
Aγ < 1 × 10
57 DEARBORN 86 also gives a limit g−11 GeV− 1 .
Aγ < 1.4 × 10

https://pdg.lbl.gov

Page 27

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

58 RAFFELT 86 gives a limit g−10 GeV− 1 from red giants and < 2.4×10−9
Aγ < 1.1×10

GeV− 1 from the sun.
59 KAPLAN 85 says m< 23 eV is allowed for a special choice of model parameters.
A0
60 FUKUGITA 82 gives a limit g−10 GeV− 1 .
Aγ < 2.3 × 10

Search for Relic Invisible Axions

VALUE

Limits are for the dimensionless quantity [GAγ γ /m 0 ]2 ρA where GAγ γ denotes theAGeµν = GB , and ρA isaxion two-photon coupling, Lint = − A4γ γ φA Fµ ν F
Aγ γ φA E ·B
the axion energy density near the earth, unless otherwise stated. Notice that for QCD
axions GAγ γ /m 0 does not depend on m 0 . For the reference values m 0 = 1 µeV,AAAGAγ γ = 3.9 × 10−16 GeV−1 (that would apply to KSVZ axions at that mass), andρA = 300 MeV/cm3 one finds [GAγ γ /m 0 ]2 ρA = 3.5 × 10−43 .
A
CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ADACHI<1.3 × 10−3 95
23D CMB m 0 = 0.096–2.2 × 10−20 eVA−432<7.5 × 10
90
DI-VORA
23 QUAX m 0 = 42.8178–42.8190 µeV
A
3 JEWELL<2.3 × 10−42 90
23 HYST m 0 =18.44–18.71 µeV
A
4 JEWELL<2.0 × 10−42 90
23 HYST m 0 = 16.96–17.12,
A
17.14–17.28 µeV−425<2.5 × 10
90
KIM
23 CASK m 0 = 9.39–9.51 µeVA
6 OSHIMA<3.0 × 10−4 95
23 DANC m 0 = 4.1 × 10−16 –2.0 ×
A
10−12 eV
7 THOMSON<2.56 × 10−24 95
23 UPLD m 0 = 1.12–1.20 µeV
A
8 YANG<6.09 × 10−43 90
23 CAPP m 0 = 19.883–19.926 µeVA
9 YI<6.6 × 10−44 90
23 CASK m 0 = 4.51–4.59 µeVA−44
10<2.6 × 10
90
YI
23A CASK m 0 = 4.51–4.59 µeVA
11 ADE<4.7 × 10−5 95
22 CMB m 0 = 0.16–4.8 × 10−20 eVA−41
12<1.0 × 10
90
ALESINI
22 QUAX m 0 = 42.8210–42.8223 µeVA
13 BATTYE<7
× 10−33 95
22 ASTR m 0 = 4.2–60 µeVA
14 CHANG<5.8 × 10−41 95
22 TASE m 0 = 19.4687–19.8436 µeVA−615 FERGUSON<3.2 × 1095
22 CMB m 0 = 0.047–4.7 × 10−20 eVA
16 LEE<8.4 × 10−43 90
22 CASK m 0 = 19.764–19.890 µeVA
17 QUISKAMP<4.9 × 10−39 95
22 ORGN m 0 = 63.2–67.1 µeVA
18 YOON<3.6 × 10−43 90
22 CASK m 0 = 19.764–19.890 µeV
A
19 ZHOU<1.03 × 10−35 95
22 ASTR m 0 = 3.18–4.35 µeVA
20 ADE<2.8 × 10−4 95
21 CMB m 0 = 0.16–4.8 × 10−20 eV
A
21 ALESINI<1.1 × 10−41 90
21 QUAX m 0 = 43 µeVA
22 BARTRAM<1× 10−44 90
21A ADMX m 0 = 3.3–4.2 µeVA
23 DEVLIN<1.6 × 10−29 95
21 TRAP m 0 = 2.7906–2.7914 neV
A
24 GRAMOLIN<1.4 × 10−23 95
21 SHFT m 0 = 0.012–12 neVA
25 KWON<7× 10−43 90
21 CASK m 0 = 10.7126–10.7186 µeVA
26 MELCON<4.6 × 10−40 95
21 RADE m 0 = 34.6738–34.6771 µeVA
27 SALEMI<3.5 × 10−28 95
21 ABRA m 0 = 0.41–8.27 neV
A
28 THOMSON<3
× 10−3 95
21m 0 = 7.44–19.38 neVA

https://pdg.lbl.gov

Page 28

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)<1

× 10−295

28 THOMSON21

m 0 = 74.4–74.5 µeVA
21 ASTR m 0 = 10−20 –10−17 eVA
30 BRAINE<1.9 × 10−44 90
20 ADMX m 0 = 2.81–3.31 µeV
A
31 CRISOSTO<2× 10−35 90
20 SLICm 0 = 180.07–180.15 neV
A
32 DARLING<4
× 10−37 95
20A ASTR m 0 = 4.2–165.6 µeVA
33 FOSTER<3.2 × 10−36 95
20 ASTR m 0 = 5–7, 10–11µeVA
34 JEONG<5.7 × 10−41 90
20 CASK m 0 = 13.0–13.9 µeVA
35 KENNEDY20m 0 = 10−19 –10−17 eVS
36 LEE<4.8 × 10−42 90
20A CASK m 0 = 6.62–6.82 µeVA
37 ALESINI<2.6 × 10−39 95
19 QUAX m 0 = 37.5 µeVA
38 FUJITA<6
× 10−519 ASTR m 0 < 10−21 eVA
39 OUELLET<2
× 10−27 95
19A ABRA m 0 = 0.31–8.3 neV
A
40 BOUTAN<7.3 × 10−40 90
18 ADMX m 0 = 17.38–17.57 µeVA
40 BOUTAN<1.8 × 10−39 90
18 ADMX m 0 = 21.03–23.98 µeV
A
40 BOUTAN<3.4 × 10−39 90
18 ADMX m 0 = 29.67–29.79 µeVA
41 DU<1.4 × 10−44 90
18 ADMX m 0 =2.66–2.81 µeV
A
42 ZHONG<2.87 × 10−42 90
18 HYST m 0 =23.15–24 µeVA
43 BRANCA
17 AURG m 0 = 3.5–3.9 peVS
44 BRUBAKER<3
× 10−42 90
17 HYST m 0 = 23.55–24.0 µeVA
45 CHOI<1.0 × 10−29 95
17 CASK m 0 = 24.7–29.1 µeVA
46 MCALLISTER 17 ORGN at m
<5.9 × 10−36 90= 110 µeVA0−4247<8.6 × 10
90
HOSKINS
16 ADMX m 0 =3.36–3.52 orA
3.55–3.69 µeV
48 BECK13m 0 = 0.11 meVA
49 HOSKINS<3.5 × 10−43
11 ADMX m 0 = 3.3–3.69 × 10−6 eVA
50 ASZTALOS<2.9 × 10−43 90
10 ADMX m 0 = 3.34–3.53 × 10−6 eVA
51 DUFFY<1.9 × 10−43 97.7
06 ADMX m 0 = 1.98–2.17 × 10−6 eVA
52 ASZTALOS<5.5 × 10−43 90
04 ADMX m 0 = 1.9–3.3 × 10−6 eVA
53 KIM
98 THEO
54 HAGMANN<2
× 10−4190 CNTR m 0 = (5.4–5.9)10−6 eVA
55 WUENSCH<6.3 × 10−42 95
89 CNTR m 0 = (4.5–10.2)10−6 eVA
55 WUENSCH<5.4 × 10−41 95
89 CNTR m 0 = (11.3–16.3)10−6 eVA
1 ADACHI 23D is analogous to ADE 21. They used POLARBEAR data, and take accountof a stochastic local axion field amplitude with the time-averaged local axion density ρA= 0.3 GeV/cm3 . Limits are set at GAγ γ < 2.4 × 10−11 GeV−1 (m 0 /10−21 eV),A
which is 2.2 times larger than the deterministic case. See Fig. 5 for mass-dependent
limits.
2 DI-VORA 23 searches for axions in a narrow mass window using an 8T haloscope and a
travelling wave parametric amplifier to achieve noise close to the quantum limit. This is
an improvement on their previous scan at the same mass, ALESINI 21. See Fig. 7 formass-dependent limits and a comparison.
3 JEWELL 23 is an update of BRUBAKER 17. See their Fig. 11 for the mass-dependent
limits.
4 JEWELL 23 correct an underestimation of intermediate frequency noise in BACKES 21.
See their Fig. 11 for the mass-dependent limits.

https://pdg.lbl.gov

29 YUAN

Page 29

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

5 KIM 23 is an update of KWON 21 on the CAPP-PACE experiment. See their Fig. 4 formass-dependent limits.
6 OSHIMA 23 report first limits from the DANCE experiment. This experiment is basedon a novel bow-tie cavity design that searches for the oscillating rotation of polarised
laser light driven by the DM axion-photon mixing at low frequencies. See their Fig. 6
for mass-dependent limits.
7 THOMSON 23 used an AC microwave cavity to search for dark matter axions. Theaxion signal is resonantly enhanced when the axion mass matches the difference betweena cavity which is pumped with power and another resonant mode close in frequency thatis used to read out the signal. See their Fig. 7 for the mass-dependent limits.
8 YANG 23 extends the first phase of CAPP 18T to KSVZ axions between 4.8077 and4.8181 GHz. They used an 18T high-temperature superconducting magnet haloscope.
See their Fig. 5 for mass-dependent limits. Quoted value is for their limit derived witha Bayesian method.
9 YI 23 is analogous to LEE 20A, using the CAPP-12TB haloscope. See their Fig. 4 formass-dependent limits.
10 YI 23A used the same data as YI 23, but instead of the standard halo model, they
searched for axion dark matter in the Sagittarius tidal stream with a velocity v = 300
km/sec and a velocity dispersion δv = 20 km/sec. See their Fig. 4 for mass-dependent
limits.
11 ADE 22 is an update of ADE 21 based on the expanded data of the 2012–2015 observing
seasons. See their Fig. 3 for mass-dependent limits over the extended mass range
1 × 10−23 –6 × 10−19 eV.
12 ALESINI 22 is an update of ALESINI 21, using the TM030 mode of the cylindricaldielectric cavity. See their Fig. 8 for mass-dependent limits.
13 BATTYE 22 is analogous to DARLING 20A, and use plasma ray tracing technique toanalyze the propagation of radio photons converted from axion dark matter in the magnetosphere of PSR J1745-2900. The quoted limit assumes ρA = 6.5 × 104 GeV/cm3 inthe vicinity of the magnetar. See their Fig. 1 for mass-dependent limits.
14 CHANG 22 used a microwave cavity detector to search for dark matter axions. See Fig.
3 for the mass-dependent limits.
15 FERGUSON 22 is analogous to ADE 21. They use the data of the SPT-3G’s 2019
observing season. See their Fig. 5 for mass-dependent limits over the extended mass
range 0.047–9.5 × 10−20 eV.
16 LEE 22 is analogous to LEE 20A. They used an 18T high-temperature superconducting
magnet haloscope. See their Fig. 5 for mass-dependent limits.
17 QUISKAMP 22 is a 15.28 to 16.23 GHz microwave cavity haloscope with 11.5 T B-field.
See Fig. 4 for mass-dependent limits.
18 YOON 22 analyzed the data from LEE 22 and changed from a frequentist to a Bayesian
method to set limits. See their Fig. 27 for mass-dependent limits.
19 ZHOU 22 is analogous to DARLING 20A, and they use the data from the MeerKAT radio
telescope’s observation of the neutron star J0806.4-4123, which is 250 pc from Earth.
See their Fig.3 for mass-dependent limits.
20 ADE 21 looks for a time-variable global rotation of the CMB polarization induced by
the harmonic oscillations of local axion-like dark matter and uses data from the 2012
observing season of the Keck Array, part of the BICEP program. The limits get 25%
weaker for m 0 = 4.8 × 10−20 –5.7 × 10−19 eV. See their Eq. (80) and Fig. 6 forA
mass-dependent limits.
21 ALESINI 21 is an update of ALESINI 19. See their Figs. 5 and 6 for the mass-dependent
limits.
22 BARTRAM 21A is analogous to DU 18. See their Fig.4 for mass-dependent limits.
23 DEVLIN 21 use the superconducting resonant detection circuit of a cryogenic Penning
trap with a single antiproton. See their Fig. 3 for mass-dependent limits.
24 GRAMOLIN 21 use two detection channels, each consisting of two stacked toroids tolook for the axion-induced oscillating magnetic field. The quoted limit applies at m 0
A= 0.02 neV. See their Fig. 4 for mass-dependent limits.

https://pdg.lbl.gov

Page 30

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

25 KWON 21 is analogous to LEE 20A. They also obtain weaker limits in the range of m

A0
= 10.16–11.37 µeV. See their Fig. 4 for mass-dependent limits.
26 MELCON 21 use a radio frequency cavity consisting of 5 sub-cavities coupled by inductive
irises installed inside the CAST dipole magnet to look for higher axion masses. See theirFig. 9 for mass-dependent limits.
27 SALEMI 21 is an update of OUELLET 19A. See their Fig. 4 for mass-dependent limits.
28 THOMSON 21 use a resonant cavity supporting two spatially overlapping microwave
modes, which is sensitive to the axion mass corresponding to the sum or difference ofthe two resonant frequencies. The original limit was retracted due to a sign error. See
their Fig. 2 in the erratum for the corrected limits.
29 YUAN 21 use polarimetric observations of Sgr A∗ taken by the Event Horizon Telescope
to search for periodic oscillation of the polarization induced by axion dark matter, assuming a solitonic core near the Galactic center. They obtained limits in the range ofGAγ γ = 8 × 10−13 –3 × 10−11 GeV−1 .
30 BRAINE 20 is analogous to DU 18. See Fig. 4 for their mass-dependent limits.
31 CRISOSTO 20 used a resonant LC circuit to look for lighter axion dark matter. Theyobtained a similar, slightly weaker limit for m 0 = 174.98–175.19 and 177.34–177.38
A
neV. See their Fig. 4 for mass-dependent limits.
32 DARLING 20A use VLA data to look for radio-frequency radiation converted from axion
dark matter in the magnetosphere of the Galactic Center magnetar PSR J1745-2900.
They extended the results of DARLING 20, which used only data with the highest angularresolution, by adding sub-optimal data. They use ρA = 6.5×104 GeV/cm3 in the vicinityof the magnetar. See their Fig. 2 for mass-dependent limits.
33 FOSTER 20 look for radio-frequency radiation converted from axion dark matter in themagnetic field around neutron stars. They use the observed data of isolated local neutronstars and in the Galactic center. The quoted limit applies to m 0 ≃ 7 µeV. See theirA
Fig. 2 for mass-dependent limits.
34 JEONG 20 is analogous to LEE 20A, and they use a double-cell cavity to look for axions
with mass > 10 µeV. See their Fig. 5 for mass-dependent limits.
35 KENNEDY 20 is analogous to BRANCA 17, and they compare the frequency ratios of
the Si cavity measured by a Sr optical lattice clock and by a H maser. Assuming the
local density of moduli dark matter, ρS = 0.3 GeV/cm3 , they obtain a limit GS γ γ <5.8 × 10−24 GeV−1 at m 0 = 2 × 10−19 eV. See their Fig. 2 for mass-dependent
Slimits as well as limits on the modulus coupling to electrons.
36 LEE 20A used a microwave cavity detector at the IBS/CAPP to search for dark matteraxions. See Fig. 3 for the mass-dependent limits.
37 ALESINI 19 used a superconducting resonant cavity made of NbTi to increase the quality
factor. The limit applies to a mass range of 0.2 neV around m 0 = 37.5 µeV.
A
38 FUJITA 19 look for photon birefringence under the oscillating axion background using
the polarimetric imaging observation of a protoplanetary disk, AB Aur. See their Fig. 2
for a more conservative limit taking account of possible systematic effects.
39 OUELLET 19A look for the axion-induced oscillating magnetic field generated by atoroidal magnetic field. The quoted limit applies at m 0 = 8 neV. See their Fig. 3
Afor the mass-dependent limits.
40 BOUTAN 18 use a small high frequency cavity installed above the main ADMX cavity
to look for heavier axion dark matter. See their Fig. 4 for mass-dependent limits.
41 DU 18 is analogous to DUFFY 06. They upgraded a dilution refrigerator to reduce thesystem noise. The quoted limit is around m 0 = 2.69 µeV for the boosted MaxwellianAaxion line shape. See Fig. 4 for their mass-dependent limits.
42 ZHONG 18 is analogous to BRUBAKER 17. The quoted limit applies at m
= 23.76
A0µeV. See Fig. 4 for their mass-dependent limits.
43 BRANCA 17 look for modulations of the fine-structure constant and the electron massdue to moduli dark matter by using the cryogenic resonant-mass AURIGA detector. The

https://pdg.lbl.gov

Page 31

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

limit on the assumed dilatonic coupling implies GS γ γ < 1.5 × 10−24 GeV−1 for thescalar to two-photon coupling. See Fig. 5 for the mass-dependent limits.
44 BRUBAKER 17 used a microwave cavity detector at the Yale Wright Laboratory to searchfor dark matter axions. See Fig. 3 for the mass-dependent limits.
45 CHOI 17 used a microwave cavity detector with toroidal geometry. See Fig. 4 for theirmass-dependent limits.
46 MCALLISTER 17 used a high-frequency microwave cavity haloscope at 26.6 GHz in a 7
T magnetic field. See Fig. 4 for mass-dependent limits.
47 HOSKINS 16 is analogous to DUFFY 06. See Fig. 12 for mass-dependent limits in termsof the local dark matter density.
48 BECK 13 argues that dark-matter axions passing through Earth may generate a small
observable signal in resonant S/N/S Josephson junctions. A measurement by HOFFMANN 04 [Physical Review B70 180503 (2004)] is interpreted in terms of subdominant
dark matter axions with m 0 = 0.11 meV.
A
49 HOSKINS 11 is analogous to DUFFY 06. See Fig. 4 for the mass-dependent limit interms of the local density.
50 ASZTALOS 10 used the upgraded detector of ASZTALOS 04 to search for halo axions.
See their Fig. 5 for the m 0 dependence of the limit.
A
51 DUFFY 06 used the upgraded detector of ASZTALOS 04, while assuming a smaller
velocity dispersion than the isothermal model as in Eq. (8) of their paper. See Fig. 10of their paper on the axion mass dependence of the limit.
52 ASZTALOS 04 looked for a conversion of halo axions to microwave photons in magnetic field. At 90% CL, the KSVZ axion cannot have a local halo density more than
0.45 GeV/cm3 in the quoted mass range. See Fig. 7 of their paper on the axion massdependence of the limit.
53 KIM 98 calculated the axion-to-photon couplings for various axion models and compared them to the HAGMANN 90 bounds. This analysis demonstrates a strong model
dependence of GAγ γ and hence the bound from relic axion search.
54 HAGMANN 90 experiment is based on the proposal of SIKIVIE 83.
55 WUENSCH 89 looks for condensed axions near the earth that could be converted tophotons in the presence of an intense electromagnetic field via the Primakoff effect,
following the proposal of SIKIVIE 83. The theoretical prediction with [GAγ γ /m 0 ]2 =A
2 × 10−14 MeV− 4 (the three generation DFSZ model) and ρA = 300 MeV/cm3 thatmakes up galactic halos gives (GAγ γ /m 0 )2 ρA = 4 × 10−44 . Note that our definitionAof GAγ γ is (1/4π) smaller than that of WUENSCH 89.

Invisible A0 (Axion) Limits from Photon Coupling
Limits are for the modulus of the axion-two-photon coupling GAγ γ defined by
L = −GAγ γ φA E · B . For scalars S 0 the limit is on the coupling constant in
E 2 −B
B 2 ). The relation between GAγ γ and m 0 is not used unless
L = GS γ γ φS (EAstated otherwise, i.e., many of these bounds apply to low-mass axion-like particles(ALPs), not to QCD axions.
VALUE (GeV− 1 )CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 PANT<3× 10−1195
24 ASTR m 0 = 0.3–1 neVA−11
2<5.5 × 1095
BATTYE23 DM
m 0 = 3.9–4.7 µeVA
3 BEAUFORT<2
× 10−1395
23 ASTR m 0 = 3–38 keV
A
4 BERNAL<2
× 10−1299
23 COSM m 0 = 8–25 eVA
5 CAPOZZI<4
× 10−1499
23 COSM m 0 = 30–800 eVA

https://pdg.lbl.gov

Page 32

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)<1.3 × 10−7
<5
× 10−12<1.7 × 10−10<6
× 10−29<4.5 × 10−12<3
× 10−12

95
95
95
95
95

<2.7 × 10−11<2
× 10−11<3.0 × 10−12

99

<5
<8

95
95

<5

× 10−11× 10−26
× 10−9<7.9 × 10−12<3.8 × 10−22<5
× 10−10<1.45 × 10−9
× 10−11
3–6 × 10−11<7<3.76 × 10−11<2
× 10−10<3<6

× 10−14× 10−12<5.4 × 10−12<2.1 × 10−11<1
× 10−11<1.14 × 10−5
<2
× 10−16

× 10−12<1.3 × 10−11<1
× 10−5<6<9.2 × 10−11<1.8 × 10−10<1.6 × 10−10<5
× 10−11

99.7
95
95

95
90
95
95
95
95
95
90
95
95
95
95
95
95
95
95
95
95

<1.2 × 10−4
<1.2 × 10−11

95

× 10−13<1.8 × 10−11<7
× 10−495<1<2
× 10−4<1.0 × 10−11<5
× 10−10

https://pdg.lbl.gov

95

95
95
90
95

6 CAPOZZI7 DAVIES

23A DUMP m 0 = 103 –2 × 108 eVA
23 ASTR m 0 = 5–200 neV
A
8 DIAMOND
23 ASTR m 0 = 2–56 MeV
A
9 FILZINGER
23
Dilaton-like dark matter
10 HOOF23 ASTR m 0 = 4 × 10−10 eVA
11 HOOF23 ASTR m 0 = 60 MeV
A
12 JACOBSEN
23 ASTR m 0 < 3 × 10−7 eVA
13 LI
23H ASTR m 0 = 1–100 neV
A
14 NOORDHUIS 23 ASTR m= 10−9 –10−5 eV
A0
15 PANT
23 ASTR m 0 = 0.1–1000 neV
A
16 SHERRILL
23 DM
Dilaton-like dark matter
17 SULAI
23 DM
m 0 = 0.25–2 × 10−14AeV
18 YAO
23 ASTR m 0 . 10−13 eVA
19 ZHANG
23A
Dilaton-like dark matter
20 APRILE
22B XENT Solar axions
21 ARNQUIST22 MAJD m 0 < 100 eVA
22 ARZA
22 DM
m 0 =0.2–7 × 10−17 eVA
23 BERNAL
22 COSM m 0 = 8–20 eV
A
24 CALORE
22 ASTR m 0 < 10−11 eVA
25 CAPUTO
22 ASTR m 0 = 1–500 MeV
A
26 CASTILLO
22 ASTR m 0 = 3 × 10−23 eVA
27 DEROCCO
22 ASTR m 0 = 5–30 keV
A
28 DESSERT
22A ASTR m 0 . 3 × 10−7 eVA
29 ECKNER
22 ASTR m 0 < 2 × 10−7 eV
A
30 FOSTER
22 ASTR m 0 = 16.5–32.5 µeVA
31 KIRITA
22 SAPH m 0 = 0.5–500 meVA
32 LANGHOFF
22 COSM m 0 = 0.1–3×104 keVA
33 LI
22 ASTR m 0 = 0.2–20 neV
A
34 LI
22C ASTR m 0 = 8–200 neV
A
35 LUCENTE
22 ASTR m 0 . 0.4 MeV
A
36 BASU
21 ASTR m 0 = 3.6 × 10−21 eVA
37 BI
21 ASTR m 0 = 2–6 × 10−7 eVA
38 DOLAN
21A ASTR m 0 = 1–570 keVA
39 GUO
21 ASTR m 0 = 8–23 neVA
40 HOMMA
21 SAPH m 0 = 0.4–600 meVA
41 LI
21B ASTR m 0 = 0.5–500 neV
A
42 LLOYD
21 ASTR Magnetars
43 REGIS
21 ASTR m 0 = 2.7–5.3 eVA
44 XIAO
21 ASTR m 0 < 3.5×10−11 eVA
45 ABUDINEN
20 BEL2 m 0 = 0.2–1 GeV
A
46 BANERJEE
20A NA64 m 0 < 55 MeV
A
47 BUEHLER
20 ASTR m 0 < 3 neV
A
48 CALORE
20 ASTR m 0 . 10−11 eVAPage 33

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

49 CARENZA
50 DENT
51 DEPTA
52 DESSERT

20
20A
20
20A

95

57 MEYER

20

99

2–4 × 10−1095<3.6 × 10−1295

4–6 × 10−10<2.8 × 10−11
none 6.0 × 10−9 –1.3 ×
10−5<2.6 × 10−11<8.4 × 10−89095ASTR Globular clusters
ASTR Solar axions
COSM Axion-like particles
ASTR m 0 < 5 × 10−11 eV
A
53 ESTEBAN
20 ANIT Axion-like particles
54 GAO
20 ASTR Solar axions
55 KOROCHKIN 20 ASTR m= 25 eVA0
56 LUCENTE
20A ASTR m 0 < 270 MeV
A

× 10−3<1.4 × 10−14<9.6 × 10−14

95

58 YAMAMOTO 20
59 ALONI
19

95

60 CAPUTO

19

95

61 FEDDERKE

1995

62 IVANOV

19

<4

95

63 LIANG

19

64 FORTIN
65 JAECKEL

18
18

90

66 YAMAJI

18

99.9

67 ZHANG<1<7

× 10−13× 10−11× 10−12<5.0 × 10−3
<1
× 10−11<3<6.6 × 10−1195

18
68 ADE17
69 ANASTASSO... 17<2.51 × 10−4
>1.5 × 10−11

95

70 DOLAN
71 INADA

17
17

95

72 KOHRI

17

95

73 MARSH

17

74 TIWARI

17<2.6 × 10−12<6
× 10−13<5
× 10−12<1.2 × 10−7
<7.2 × 10−8
<8
× 10−495

16
76 DELLA-VALLE 16

95

77 DELLA-VALLE 16<1.47 × 10−10<3.5 × 10−895

16
80 ANASTASSO... 15
81 ARIK
15

95

82 BALLOU

15

83 BRAX

15

<6

95

75 AJELLO

78 JAECKEL

16

79 LEEFER

× 10−2184 HASEBE<5.42 × 10−495

<4.1 × 10−10<3.3 × 10−10

99.7

15
85 MILLEA
15
86 VANTILBURG 15
87 VINYOLES
1595

88 ARIK<6.6 × 10−11<1.4 × 10−7
<8

× 10−8https://pdg.lbl.gov

95
95
95

14
89 AYALA
1490 DELLA-VALLE 1491 EJLLI

14

92 PUGNAT

14

Page 34m 0 < 3 × 10−10 eVA
COSM m 0 < 4 × 10−6 eVA
PRMX m 0 = 0.16 GeV
A
ASTR m 0 = 5 × 10−24 eVA
CMB m 0 = 10−22 eVA
ASTR m 0 = 5 × 10−23 eVA
ASTR m 0 = 1.2 × 10−7 eVAASTR Axion-like particles
ASTR m 0 = 30–100 MeV
A
LSW m 0 = 46–1020 eV
A
ASTR m 0 = 0.6–4 neVA
CMB Axion-like particles
CAST m 0 < 0.02 eVA
RVUE Axion-like particles
LSW m 0 < 0.1 eVA
ASTR m 0 = 0.7–50 neV
A
ASTR m 0 ≤ 10−13 eVA
COSM m 0 ≤ 10−15 eV
A
ASTR m 0 = 0.5–5 neV
A
LASR m 0 = 1.3 meV
A
LASR m 0 < 0.5 meVA
ALPS m 0 = 0.1–100 GeV
A
m 0 < 10−18 eVS
CAST Chameleons
CAST m 0 = 0.39–0.42 eVA
LSW m 0 < 2 × 10−4 eVAASTR m 0 < 4 × 10−12 eVS
LASR m 0 = 0.15 eVA
COSM Axion-like particles
Dilaton-like dark matter
ASTR m 0 = 0.6–185 eVA
CAST m 0 = 0.64–1.17 eV
A
ASTR Globular clusters
LASR m 0 = 1 meVA
COSM m 0 = 2.66–48.8 µeVA
LSW m 0 < 0.3 meVA
FLAT

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

× 10−11<2.1 × 10−11<2.15 × 10−9

93 REESMANASTR m 0 < 1 × 10−10 eVA
94 ABRAMOWSKI13A IACT m
95= 15–60 neV
A09595
ARMENGAUD 13 EDEL m 0 < 200 eVA
96 BETZ<4.5 × 10−895
13 LSW m 0 = 7.2 × 10−6 eV
A
97 FRIEDLAND 13 ASTR Red giants<8× 10−1198 MEYER>2× 10−11
13 ASTR m 0 < 1 × 10−7 eVA
99 WOUTERS<8.3 × 10−1295
13 ASTR m 0 < 7 × 10−12 eV
A
100 CADAMURO 12 COSM Axion-like particles
101 PAYEZ<2.5 × 10−1395
12 ASTR m 0 < 4.2 × 10−14 eVA
102 ARIK<2.3 × 10−1095
11 CAST m 0 = 0.39–0.64 eVA
103 EHRET<6.5 × 10−8
95
10 ALPS m 0 < 0.7 meVA
104 AHMED<2.4 × 10−9
95
09A CDMS m 0 < 100 eV
A
−10
105
< 1.2–2.8 × 10
95
ARIK
09 CAST m 0 = 0.02–0.39 eVA
106 CHOU
09
Chameleons
107 GONDOLO<7
× 10−10
09 ASTR m 0 < few keVA−6108<1.3 × 10
95
AFANASEV08m 0 < 1 meVS<3.5 × 10−7
99.7 109 CHOU
08
m 0 < 0.5 meVA<1.1 × 10−6
99.7 110 FOUCHE
08
m 0 < 1 meVA
111 INOUE< 5.6–13.4 × 10−109508m 0 = 0.84–1.00 eVA
112 ZAVATTINI<5
× 10−708m 0 < 1 meVA
113 ANDRIAMON...07 CAST m<8.8 × 10−1195< 0.02 eV
A0
114 ROBILLIARD 07<1.25 × 10−695
m 0 < 1 meVA
115 ZAVATTINI
2–5 × 10−606m 0 = 1–1.5 meVA
116 INOUE<1.1 × 10−99502m 0 = 0.05–0.27 eVA−9117<2.78 × 1095
MORALES02B
m 0 <1 keVA
118 BERNABEI<1.7 × 10−99001B
m 0 <100 eVA
119 ASTIER<1.5 × 10−4
9000B NOMD m 0 <40 eVA
120 MASSO
00 THEO induced γ coupling−9
121<2.7 × 10
95
AVIGNONE98 SLAX m 0 < 1 keV
A
−10
122
<6.0 × 10
95
MORIYAMA 98
m 0 < 0.03 eVA
123 CAMERON<3.6 × 10−795
93m 0 < 10−3 eV,A
optical rotation
124 CAMERON<6.7 × 10−795
93m 0 < 10−3 eV,Aphoton regeneration<3.6 × 10−9
99.7 125 LAZARUS
92m 0 < 0.03 eVA<7.7 × 10−9
99.7 125 LAZARUS
92m 0 = 0.03–0.11 eVA
126 RUOSO<7.7 × 10−799
92
m 0 < 10−3 eVA
127 SEMERTZIDIS 90<2.5 × 10−6
m 0 < 7 × 10−4 eVA
1 PANT 24 searches for the imprint of axion-photon oscillations in the very-high-energy
gamma-ray spectrum of the quasar QSO B1420+326 observed by the MAGIC telescope.
Three small disconnected regions of mass-coupling parameter space below 1 neV are
ruled out. See Fig. 4 for the limits.
<1

https://pdg.lbl.gov

Page 35

14

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

2 BATTYE 23 look for dark-matter axions falling into pulsar magnetospheres and converting into narrow radio lines. Unlike the earlier FOSTER 22 they search for evidence of
conversion in the time-domain signal of a single pulsar, using 1 hour of MeerKAT dataon the pulsar PSR J2144-3933. The quoted limit applies to an assumed magnetic fieldof 2 × 1012 G and a dark matter density of 0.45 GeV/cm3 .
3 BEAUFORT 23 extends DEROCCO 22 who searched for the X-ray decay of axions thatbuild up in the gravitational well of the Sun over its lifetime, the ’solar basin’. They use
data from NuSTAR and SphinX telescopes and extends the previous study by accounting
for the axion production via photon coalescence.
4 BERNAL 23 use gamma-ray data from 739 blazars observed by FermiLAT and 38 blazars
by Cherenkov observatories. They estimate optical depth, subtract the astrophysicalcomponent, and attribute the residual to axion two-photon decay. The quoted limit isfor m 0 ≃ 25 eV. See their Fig. 3 for the mass-dependent limits.
A
5 CAPOZZI 23 use Planck CMB and Lyman-alpha observations to set limits on earlyenergy injection by decaying dark matter axions that would affect CMB anisotropies andthe reionisation history of the Universe. The quoted limit applies to m 0 = 100 eV andA
the reionization model of Fauchere-Giguere. See Fig.4 for mass-dependent constraints
from different reionization models.
6 CAPOZZI 23A search for axions produced in electromagnetic showers in proton beam
dumps and fixed target experiments. In this case, they reinterpret MiniBoone data.
Quoted limit applies at 100 MeV but the limit does not extend to arbitrarily large couplings. See Fig. 7 for mass-dependent limits.
7 DAVIES 23 is analogous to AJELLO 16, and use the Fermi-LAT data from three quasars(3C454.3, CTA 102, and 3C279), considering the blazer jets as the regions where theaxion-photon oscillations occur. See Fig. 8 for the mass-dependent limits.
8 DIAMOND 23 demonstrate that a window of decaying 10-MeV-mass ALP parameter
space previously thought to be excluded by the lack of gamma-ray emission from the
SN 1987A explosion is actually unconstrained because of the formation of a fireball thatwould prevent decay photons from escaping. They nevertheless re-exclude this window
by considering the non-detection of the sub-MeV emission by the Pioneer Venus Orbiter.
The quoted limit is at m 0 = 56 MeV. See their Fig. 2 for mass-dependent limits.
A
9 FILZINGER 23 searched for oscillations in the fine structure constant induced by dilatonlike dark matter by measuring the frequency ratio between the E3 and E2 transitions of
171 Yb+ . They assume the local dark matter density ρ = 0.4 GeV/cm3 . The quoted
S
limit is set at m 0 ≃ 4 × 10−23 eV. See their Fig. 4 for the limits over m 0 =SS
1 × 10−24 –1 × 10−17 eV.
10 HOOF 23 consider axions emitted from SN1987A converting to gamma rays in Galacticmagnetic fields, using temporal information of the Solar Maximum Mission data. They
set a limit GAγ γ . 5 × 10−12 for masses m 0 . 2 × 10−10 eV. See left panel inA
Fig. 3 for mass-dependent limits.
11 HOOF 23 look for gamma rays resulting from the decay of axions produced from
SN1987A, using the Solar Maximum Mission data. See right panel in Fig. 3 for massdependent limits.
12 JACOBSEN 23 search for the imprints of axion-photon mixing on the TeV spectra ofseveral blazars using data from the HAWC air shower detector.
13 LI 23H look for gamma-ray spectral irregularities induced by axion-photon oscillations
from AGN VER J0521+211, using the Fermi-LAT and VERITAS data. See their Fig. 4
for mass-dependent limits.
14 NOORDHUIS 23 places strong constraints on the axion-photon coupling over a broad
mass window using the fact that the polar cap regions of pulsars can generate a populationof axions, which would then convert into an observable outgoing radio flux in the presenceof the neutron star’s B-field. They search for this signal in 27 pulsars and set massdependent limits shown in their Fig. 2.

https://pdg.lbl.gov

Page 36

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

15 PANT 23 study the effect of axion-photon oscillations on the gamma-ray spectrum fromthe extragalactic neutrino source, TXS 0506+056. The quoted limit is at m 0 ≃A
2.7 × 10−7 eV. See their Fig. 2 for mass-dependent limits.
16 SHERRILL 23 search for scalar dilaton-like dark matter via oscillations in the fundamental
constants. Their most competitive constraint is on the scalar photon coupling (Fig. 6,
upper panel) that affects the fine-structure constant, which they extract using an opticalto-optical clock comparison between 171 Yb+ and 87 Sr. Quoted limit applies at thesmallest mass in their search window for this case of 10−20 eV.
17 SULAI 23 looked for ultralight axion dark matter using the “Earth as a transducer”
concept over the 0.5 to 5 Hz frequency range. They situate several magnetometers
at magnetically quiet places and search for spatially-correlated magnetic field patterns
induced by axion dark matter interacting in the effective cavity formed between the
Earth’s surface and the ionosphere. See their Fig. 12 for mass-dependent limits incontext. This limit extends to higher-frequencies than their previous limit using archival
geomagnetic field data collected by the SuperMAG collaboration, see ARZA 22
18 YAO 23 study an optical circular polarization in blazers induced by the axion-photon
mixing. The quoted limit assumes the transverse magnetic field at the jet’s emission
site, with BT = 1 G, and this limit inversely scales with BT . See their Fig. 3 for thelimits’ dependence on BT and electron density.
19 ZHANG 23A searched for oscillations in the fine structure constant induced by dilatonlike dark matter by measuring the frequencies of a hyperfine-structure transition in 87 Rb
and an electronic transition in 164 Dy, and by comparing them with that of a quartz
oscillator. They assume the local dark matter density ρS ≃ 0.4 GeV/cm3 . The quoted
limit is set at m 0 ≃ 1 × 10−17 eV. See their Fig. 3 for the limits over m 0 =SS
1 × 10−17 –8.3 × 10−13 eV.
20 APRILE 22B is an update of APRILE 20 based on a similar solar axion modeling to
DENT 20A and GAO 20. They exclude the XENON1T excess found in APRILE 20. The
quoted limit holds for small gAe e . See Fig. 6 for correlation between GAγ γ and gAe e .
21 ARNQUIST 22 is analogous to AVIGNONE 98, and supersedes ANASTASSOPOULOS 17
for m 0 & 1.2 eV.
A
22 ARZA 22 search for low-mass axions as dark matter using the Earth as a transducer foraxion-photon conversion. The concept works because the region between the Earth andthe ionosphere forms an insulating cavity that parametrically enhances the axion signalby the radius of the Earth. The result is an oscillating and spatially correlated magnetic
field induced via the interaction between axion dark matter and the geomagnetic field,
which they searched for using archival magnetometer field data over 20 years compiledby the SuperMAG collaboration. Quoted limit applies for masses 3–4 × 10−17 eV, seeFig. 1 for mass-dependent limits.
23 BERNAL 22 explored the possibility that the excess in the cosmic optical backgroundmeasured by New Horizonss Long Range Reconnaisance Imager was due to axion dark
matter decaying into monoenergetic photons. See their Fig. 2 for the axion-photon
coupling to explain the excess.
24 CALORE 22 update CALORE 20 by evaluating axion fluxes from progenitors of various
masses and performing a template-based analysis using 12 years of Fermi-LAT data inthe energy range from 50 MeV to 500 GeV. See their Fig. 10 for mass-dependent limits.
25 CAPUTO 22 study the effect of energy deposition by radiative decay of axions produced
via the Primakoff process and photon coalescence in the supernova core, and set thelimits by the radiative energy deposition < 1050 erg and progenitor radius = 5 × 1013
cm. The quoted limit is at m 0 = 150 MeV. See their Fig. 2 for mass-dependent limits.
A

https://pdg.lbl.gov

Page 37

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

26 CASTILLO 22 update CAPUTO 19 using the polarization measurements of the CrabPulsar by the QUIJOTE MFI instrument and 20 Galactic pulsars from the PPTA project.
See their Table 1 for the assumed local axion energy density ρA for each pulsar and theirFig. 7 for the mass-dependent limits in the range of 3 × 10−23 eV ≤ m 0 ≤ 10−19AeV.
27 DEROCCO 22 uses the NuSTAR data to search for monochromatic X-ray lines producedby the decay of solar axions trapped on bound orbits. The quoted limit applies to m 0 ≃A
9 keV. They also derive limits in the plane of gAe e and GAγ γ . See their Figs. 2 and 4
for mass-dependent limits.
28 DESSERT 22A look for an axion-induced linear polarization using data from multiple
magnetic white dwarf stars. See their Figs. 1 and 8 for the mass-dependent limits.
29 ECKNER 22 set limits by using sub-PeV diffuse gamma-ray data from HAWC and Tibet
ASγ by assuming that gamma rays produced simultaneously with high-energy neutrinos
from extragalactic sources suggested by IceCube are converted to axions in the magnetic
field at the source and reconverted to gamma rays in the Galactic magnetic field. See
their Fig. 4 for mass-dependent limits.
30 FOSTER 22 is an update of FOSTER 20 in the list of limits on relic invisible axions.
They search for axion-photon transitions generated by neutron stars in the Galactic centerregion. They use improved population models of the Galactic center neutron stars and a
Navarro-Frenk-White (NFW) model of the galactic dark matter distribution. The quoted
limit applies to m 0 ≃ 17–25 µeV. See their Fig. 1 for mass-dependent limits.
A
31 KIRITA 22 update HOMMA 21 by increasing the laser energy and developing a background discrimination method using the beam cross-section dependence of the background originated from optical elements. The quoted limits applies to m 0 = 0.18 eV.
A
See their Fig. 11 for mass-dependent limits.
32 LANGHOFF 22 set limits by considering the freeze-in production of axions coupled only
to photons. The quoted limit applies to m 0 = 2 MeV for the reheating temperatureA
equal to 5 MeV. See their Fig. 1 for mass-dependent limits.
33 LI 22 is analogous to LI 21B, and use the spectra of the blazar FSRQ 4C+21.35 measured
by MAGIC, VERITAS, and Fermi-LAT. The quoted limit applies to m 0 ≃ 8 × 10−10A
eV. See their Fig. 1 for mass-dependent limits.
34 LI 22C is analogous to LI 21B, and use the spectra of the blazars Mrk 421 and PG
1553+113 measured by MAGIC and Fermi-LAT. The quoted limit applies to m 0 ≃A
1 × 10−8 eV. See their Fig. 4 for mass-dependent limits.
35 LUCENTE 22 developed a method to correctly incorporate the effects of axions decaying
into photons inside the core of horizontal-branch stars. They update CARENZA 20 byevaluating axion energy transfer in the range of axion mean free path where the diffusive
energy transport and free streaming approximations are not applicable. See their Fig. 1
for the limits.
36 BASU 21 searched for birefringence induced by axion dark matter using multiple imagesof the polarized source in the strongly gravitationally lensed system CLASS B1152+199.
They assume the axion makes up all dark matter, and used the axion density in theemitting region, ρA = 20 GeV/cm3 . Limits between 9.2 × 10−11 –7.7 × 10−8 GeV−1
are obtained for m 0 = 3.6×10−21 –4.6×10−18 eV. See their Fig. 2 for mass-dependentA
limits.
37 BI 21 look for the gamma-ray spectral distortions induced by axion-photon oscillations in
the presence of the Galactic magnetic field, using the measurements of sub-PeV gammarays from the Crab Nebula by the Tibet ASγ and HAWC experiments, together withMAGIC and HEGRA gamma-ray data. See their Fig. 3 for mass-dependent limits.
38 DOLAN 21A study the effect of axion production on the evolution of asymptotic giant
branch stars, and use the white-dwarf initial-final mass relation to set the limits. See
their Fig. 1 for mass-dependent limits.
39 GUO 21 is analogous to AJELLO 16, and use the Fermi-LAT and H.E.S.S. II measurements of PG 1553+113 and PKS 2155-304. See their Fig. 6 for mass-dependent limits.

https://pdg.lbl.gov

Page 38

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

40 HOMMA 21 look for the production of axion resonance states and their subsequent
stimulated decays by combining linearly polarized creation laser pulses and circularly
polarized inducing laser pulses. The quoted limit is at m 0 ≃ 0.178 eV. See their Fig.
A
14 for mass-dependent limits.
41 LI 21B is analogous to AJELLO 16, and use the spectra of the blazar Mrk 421 measured
by ARGO-YBJ and Fermi-LAT. They consider ALP-photon mixing in the magnetic fields
of both the blazar jet and the Galaxy. The quoted limit applies to m 0 ≃ 1 × 10−9A
eV. See their Fig. 5 for mass-dependent limits.
42 LLOYD 21 is analogous to FORTIN 18, and set limits on the product of the axion
couplings to photons and nucleons as gAN N GAγ γ . 4.6×10−19 GeV−1 for m 0 .
A
10−5 eV by using the quiescent soft gamma-ray flux upper limits in five magnetars. We
use gAN N = GAN 2m N to translate their limits. See their Table II and Fig. 3 for thelimits.
43 REGIS 21 look for monochromatic photons from axion decay, using the MUSE spectroscopic data on the Leo T dwarf spheroidal galaxy. They assume that axions makeup all of dark matter and use the integrated dark matter density along the line of sightdetermined by observations.
44 XIAO 21 use X-ray data from Betelgeuse to look for signals from axions produced in thestellar core that were converted to X-rays by the Galactic magnetic field. See their Fig.
1 for the mass-dependent limit.
45 ABUDINEN 20 look for the process e + e − → γ A0 (A0 → γ γ) and set upper limitsof around 10−3 over the mass range. The quoted limit is at m 0 = 0.3 GeV. See theirA
Fig. 5 for mass dependent limits.
46 BANERJEE 20A look for axions produced from high-energy bremsstrahlung photons
through the Primakoff effect with the electric field of the target nuclei. They exclude
GAγ γ = 2 × 10−4 –5 × 10−2 GeV−1 for m 0 < 55 MeV. See their Fig. 5 for massA
dependent limits.
47 BUEHLER 20 look for the γ-ray transparency due to axion-photon oscillations using highenergy photon events from 79 sources in the Second Fermi-LAT Catalog of High-Energy
Sources. The quoted limit is for the intergalactic magnetic field strength and coherence
length of B = 1 nG and s = 1 Mpc. See their Figs. 4 and 5 for mass-dependent limits
and for different magnetic-field parameters.
48 CALORE 20 use the isotropic diffuse γ-ray background measured by the Fermi-LAT toconstrain the γ-ray flux converted in the Galactic magnetic field from axions produced
from past core-collapse supernovae. They also derive a limit on a heavier axion withm 0 & keV decaying into two photons of GAγ γ . 5 × 10−11 GeV−1 for m 0
AA= 5 keV. See their Figs. 5 and 7 for the limits as well as limits in the presence ofaxion-nucleon couplings.
49 CARENZA 20 extend the globular cluster bound of AYALA 14 to heavier masses (m≤A0a few 100 keV) by taking account of the coalescence process γ + γ → A0 as well as
the decay of the ALP inside the stellar core. See their Fig.4 for mass-dependent limits.
50 DENT 20A is analogous to GAO 20. The quoted limit is from their arXiv:2006.15118v3(v2 is their published version), using the relativistic Hartree-Fock form factor. The limit
is up to two times weaker than the published one. See Fig. 4 in their arXiv version 3
for the correlation between GAγ γ and gAe e corresponding to the excess reported in
APRILE 20.
51 DEPTA 20 correct the underestimated D abundance in MILLEA 15, and derive robust
cosmological bounds by allowing the reheating temperature, Neff , and neutrino chemical
potential to vary. See their Fig. 6 for mass-dependent limits.
52 DESSERT 20A use the NuSTAR data of the Quintuplet and Westerlund 1 super starclusters to look for X-rays converted in the Galactic magnetic field from the axions
produced in stellar cores. See their Fig. 3 for the mass-dependent limits.
53 ESTEBAN 20 show that the two anomalous ANITA events can be explained by thereflected radio pulses that are resonantly produced in the ionosphere via axion-photon

https://pdg.lbl.gov

Page 39

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

conversion for m 0 . 1 × 10−7 eV , if an axion clump passes the Earth about onceA
a month. See their Fig.5 for the region consistent with this interpretation for different
values of the axion density inside the clumps.
54 GAO 20 correct the limit of APRILE 20 by including inverse Primakoff scattering in
the XENON1T detector. The quoted limit is from their arXiv:2006.14598v4 (v3 is their
published version), taking account of the atomic form factor of Xe as pointed out in
ABE 20J. The limit is weaker by a factor of 1.5–2 than the published one. See Fig. 3
in their arXiv version 4 for correlation between GAγ γ and gAe e corresponding to theexcess reported in APRILE 20.
55 KOROCHKIN 20 assume the axion makes up all dark matter, and look for a dip in theobserved gamma-ray spectrum of the blazer 1ES 1218+304 by Fermi/LAT and VERITAS
due to the extragalactic background light produced by the axion decay. Their analysis
favors nonzero axion-induced absorption with GAγ γ = 3 × 10−11 –2 × 10−10 GeV−1
over a range of m 0 = 2–18 eV. See their Fig. 1 for mass-dependent limits between
A
0.25 < m 0 < 25 eV.
A
56 LUCENTE 20A study the SN 1987A energy-loss argument on the axion-like particle
production. In addition to the Primakoff process, they take account of photon coalescenceas well as gravitational trapping that become relevant at m 0 > 100 MeV. See theirA
Fig. 12 for the mass-dependent limit.
57 MEYER 20 look for prompt γ-rays converted in the Galactic magnetic fields from axions produced via the Primakoff process in a sample of 20 extragalactic core-collapse
supernovae. The limits assume a progenitor mass of 10 times the solar mass and certain
models for the optical emission and the galactic magnetic field. See their Figs. 2 and 6
in the erratum for mass- and model-dependent limits.
58 YAMAMOTO 20 look for X-ray photons converted by the Earth’s magnetic field fromthe axions produced by the two-body decay of dark matter, and set the limits by using
the Suzaku data. The quoted limit is for the monochromatic X-ray line from the galactic
dark matter with lifetime τ = 4.32 × 1017 sec. They also derive limits on the continuum
spectrum from the extragalactic component. See their Fig. 7 for the limits.
59 ALONI 19 used the data collected by the PRIMEX experiment to derive a limit based ona data-driven method. See their Fig. 2 for mass-dependent limits.
60 CAPUTO 19 look for an oscillating variation of the polarization angle of the pulsar
J0437-4715, where they assume the local axion energy density ρA = 0.3 GeV/cm3 . See
their Fig. 2 for mass-dependent limits for 5 × 10−24 eV ≤ m 0 ≤ 2 × 10−19 eV.
A
61 FEDDERKE 19 look for a uniform reduction of the CMB polarization at large scales,
which is induced by the oscillating axion background during CMB decoupling. The quoted
limit is based on the assumption that axions make up all of the dark matter. See theirFig. 3 for mass-dependent limits for m 0 = 10−22 –10−19 eV.
A
62 IVANOV 19 look for the axion-induced periodic changes in the polarization angle ofparsec-scale jets in active galactic nuclei observed by the MOJAVE program, where they
use the axion energy density ρA = 20 GeV/cm3 . See their Fig. 6 for mass-dependent
limits for 5 × 10−23 eV ≤ m 0 ≤ 1.2 × 10−21 eV.
A
63 LIANG 19 look for spectral irregularities in the spectrum of 10 bright H.E.S.S. sourcesin the Galactic plane, assuming photon-ALP mixing in the Galactic magnetic fields. See
their Fig. 2 for mass-dependent limits with different Galactic magnetic field models.
64 FORTIN 18 studied the conversion of axion-like particles produced in the core of amagnetar to hard X-rays in the magnetosphere. See their Fig. 5 for mass-dependent
limits with different values of the magnetar core temperature.
65 JAECKEL 18 study axions produced through the Primakoff process from SN 1987A,
which subsequently decay into photon pairs. See their Fig. 1 for the mass-dependent
limits in the range of m 0 = 0.01–100 MeV.
A

https://pdg.lbl.gov

Page 40

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

66 YAMAJI 18 search for axions with an x-ray LSW at Spring-8, using the Laue-case conversion in a silicon crystal. They also obtain GAγ γ < 4.2 × 10−3 GeV−1 for m 0 <A
10 eV. See their Fig. 5 for mass-dependent limits.
67 ZHANG 18 look for spectral irregularities in the spectrum of PKS 2155-304 measured
by Fermi LAT, assuming photon-ALP mixing in the intercluster and Galactic magnetic
fields. See their Figs. 2 and 3 for mass-dependent limits with different values of theintercluster magnetic field parameters.
68 ADE 17 look for cosmic birefringence from axion-like particles using CMB polarization
data taken by the BICEP2 and Keck Array experiments. They set a limit GAγ γ HI
< 7.2 × 10−2 at 95 %CL for m 0 < 10−28 eV, where HI is the Hubble parameterAduring inflation.
69 ANASTASSOPOULOS 17 looked for solar axions by the CAST axion helioscope in thevacuum phase, and supersedes ANDRIAMONJE 07.
70 DOLAN 17 update existing limits on G
Aγ γ for axion-like particles. The limits from theproton beam dump experiments in their Fig. 2 contained an error, and the correctedversion is shown in Fig. 1 of DOLAN 21.
71 INADA 17 search for axions with an x-ray LSW at Spring-8. See their Fig. 4 for massdependent limits.
72 KOHRI 17 attributed to axion-photon oscillations the excess of cosmic infrared background observed by the CIBER experiment. See their Fig. 5 for the region preferred bytheir scenario.
73 MARSH 17 is similar to WOUTERS 13, using Chandra observations of M87. See theirFig. 6 for mass-dependent limits.
74 TIWARI 17 use observed limits of the cosmic distance-duality relation to constrain thephoton-ALP mixing based on 3D simulations of the magnetic field configuration. The
quoted value is for the averaged magnetic field of 1nG with a coherent length of 1 Mpc.
See their Fig. 5 for mass-dependent limits.
75 AJELLO 16 look for irregularities in the energy spectrum of the NGC1275 measured
by Fermi LAT, assuming photon-ALP mixing in the intra-cluster and Galactic magnetic
fields. See their Fig. 2 for mass-dependent limits.
76 DELLA-VALLE 16 look for the birefringence induced by axion-like particles. See theirFig. 14 for mass-dependent limits.
77 DELLA-VALLE 16 look for the dichroism induced by axion-like particles. See their Fig.
14 for mass-dependent limits.
78 JAECKEL 16 use the LEP data of Z → 2γ and Z → 3γ to constrain the ALP production
via e + e − → Z → A0 γ (A0 → γ γ), assuming the ALP coupling with two hyperchargebosons. See their Fig. 4 for mass-dependent limits.
79 LEEFER 16 derived limits by using radio-frequency spectroscopy of dysprosium andatomic clock measurements. See their Fig. 1 for mass-dependent limits as well as
limits on Yukawa-type couplings of the scalar to the electron and nucleons.
80 ANASTASSOPOULOS 15 search for solar chameleons with CAST and derived limits on
the chameleon coupling to photons and matter. See their Fig. 12 for the exclusion
region.
81 ARIK 15 is analogous to ARIK 09, and search for solar axions for maround 0.2 andA0
0.4 eV. See their Figs. 1 and 3 for the mass-dependent limits.
82 Based on OSQAR photon regeneration experiment. See their Fig. 6 for mass-dependent
limits on scalar and pseudoscalar bosons.
83 BRAX 15 derived limits on conformal and disformal couplings of a scalar to photons bysearching for a chaotic absorption pattern in the X-ray and UV bands of the Hydra A
galaxy cluster and a BL lac object, respectively. See their Fig. 8.
84 HASEBE 15 look for an axion via a four-wave mixing process at quasi-parallel colliding
laser beams. They also derived limits on a scalar coupling to photons GS γ γ < 2.62 ×
10−4 GeV−1 at m 0 = 0.15 eV. See their Figs. 11 and 12 for mass-dependent limits.
Shttps://pdg.lbl.gov

Page 41

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

85 MILLEA 15 is similar to CADAMURO 12, including the Planck data and the latest
inferences of primordial deuterium abundance. See their Fig. 3 for mass-dependent
limits.
86 VANTILBURG 15 look for harmonic variations in the dyprosium transition frequency
data, induced by coherent oscillations of the fine-structure constant due to dilaton-likedark matter, and set the limits, GS γ γ < 6 × 10−27 GeV−1 at m 0 = 6 × 10−23 eV.
S
See their Fig. 4 for mass-dependent limits between 1 × 10−24 < m 0 < 1 × 10−15 eV.
S
87 VINYOLES 15 performed a global fit analysis based on helioseismology and solar neutrino
observations. See their Fig. 9.
88 ARIK 14 is similar to ARIK 11. See their Fig. 2 for mass-dependent limits.
89 AYALA 14 derived the limit from the helium-burning lifetime of horizontal-branch stars
based on number counts in globular clusters.
90 DELLA-VALLE 14 use the new PVLAS apparatus to set a limit on vacuum magnetic
birefringence induced by axion-like particles. See their Fig. 6 for the mass-dependent
limits.
91 EJLLI 14 set limits on a product of primordial magnetic field and the axion mass using
CMB distortion induced by resonant axion production from CMB photons. See theirFig. 1 for limits applying specifically to the DFSZ and KSVZ axion models.
92 PUGNAT 14 is analogous to EHRET 10. See their Fig. 5 for mass-dependent limits on
scalar and pseudoscalar bosons.
93 REESMAN 14 derive limits by requiring effects of axion-photon interconversion on
gamma-ray spectra from distant blazars to be no larger than errors in the best-fit opticaldepth based on a certain extragalactic background light model. See their Fig. 5 formass-dependent limits.
94 ABRAMOWSKI 13A look for irregularities in the energy spectrum of the BL Lac object
PKS 2155–304 measured by H.E.S.S. The limits depend on assumed magnetic fieldaround the source. See their Fig. 7 for mass-dependent limits.
95 ARMENGAUD 13 is analogous to AVIGNONE 98. See Fig. 6 for the limit.
96 BETZ 13 performed a microwave-based light shining through the wall experiment. See
their Fig. 13 for mass-dependent limits.
97 FRIEDLAND 13 derived the limit by considering blue-loop suppression of the evolutionof red giants with 7–12 solar masses.
98 MEYER 13 attributed to axion-photon oscillations the observed excess of very high-energy
γ-rays with respect to predictions based on extragalactic background light models. See
their Fig.4 for mass-dependent lower limits for various magnetic field configurations.
99 WOUTERS 13 look for irregularities in the X-ray spectrum of the Hydra cluster observedby Chandra. See their Fig. 4 for mass-dependent limits.
100 CADAMURO 12 derived cosmological limits on G
Aγγ for axion-like particles. See theirFig. 1 for mass-dependent limits.
101 PAYEZ 12 derive limits from polarization measurements of quasar light (see their Fig. 3).
The limits depend on assumed magnetic field strength in galaxy clusters. The limits
depend on assumed magnetic field and electron density in the local galaxy supercluster.
102 ARIK 11 search for solar axions using 3 He buffer gas in CAST, continuing from the 4 He
version of ARIK 09. See Fig. 2 for the exact mass-dependent limits.
103 ALPS is a photon regeneration experiment. See their Fig. 4 for mass-dependent limits
on scalar and pseudoscalar bosons.
104 AHMED 09A is analogous to AVIGNONE 98.
105 ARIK 09 is the 4 He filling version of the CAST axion helioscope in analogy to INOUE 02
and INOUE 08. See their Fig. 7 for mass-dependent limits.

https://pdg.lbl.gov

Page 42

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

106 CHOU 09 use the GammeV apparatus in the afterglow mode to search for chameleons,(pseudo)scalar bosons with a mass depending on the environment. For pseudoscalars
they exclude at 3σ the range 2.6 × 10−7 GeV−1 < GAγγ < 4.2 × 10−6 GeV−1 forvacuum m 0 roughly below 6 meV for density scaling index exceeding 0.8.
A
107 GONDOLO 09 use the all-flavor measured solar neutrino flux to constrain solar interiortemperature and thus energy losses.
108 LIPSS photon regeneration experiment, assuming scalar particle S 0 . See Fig. 4 for massdependent limits.
109 CHOU 08 perform a variable-baseline photon regeneration experiment. See their Fig. 3
for mass-dependent limits. Excludes the PVLAS result of ZAVATTINI 06.
110 FOUCHE 08 is an update of ROBILLIARD 07. See their Fig. 12 for mass-dependent
limits.
111 INOUE 08 is an extension of INOUE 02 to larger axion masses, using the Tokyo axion
helioscope. See their Fig. 4 for mass-dependent limits.
112 ZAVATTINI 08 is an upgrade of ZAVATTINI 06, see their Fig. 8 for mass-dependent
limits. They now exclude the parameter range where ZAVATTINI 06 had seen a positive
signature.
113 ANDRIAMONJE 07 looked for Primakoff conversion of solar axions in 9T superconducting magnet into X-rays. Supersedes ZIOUTAS 05.
114 ROBILLIARD 07 perform a photon regeneration experiment with a pulsed laser andpulsed magnetic field. See their Fig. 4 for mass-dependent limits. Excludes the PVLAS
result of ZAVATTINI 06 with a CL exceeding 99.9%.
115 ZAVATTINI 06 propagate a laser beam in a magnetic field and observe dichroism andbirefringence effects that could be attributed to an axion-like particle. This result is now
excluded by ROBILLIARD 07, ZAVATTINI 08, and CHOU 08.
116 INOUE 02 looked for Primakoff conversion of solar axions in 4T superconducting magnet
into X ray.
117 MORALES 02B looked for the coherent conversion of solar axions to photons via thePrimakoff effect in Germanium detector.
118 BERNABEI 01B looked for Primakoff coherent conversion of solar axions into photons
via Bragg scattering in NaI crystal in DAMA dark matter detector.
119 ASTIER 00B looked for production of axions from the interaction of high-energy photons
with the horn magnetic field and their subsequent re-conversion to photons via theinteraction with the NOMAD dipole magnetic field.
120 MASSO 00 studied limits on axion-proton coupling using the induced axion-photon coupling through the proton loop and CAMERON 93 bound on the axion-photon coupling
using optical rotation. They obtained the bound g2 /4π < 1.7 × 10−9 for the couplingp
gp pγ5 pφA .
121 AVIGNONE 98 result is based on the coherent conversion of solar axions to photons via
the Primakoff effect in a single crystal germanium detector.
122 Based on the conversion of solar axions to X-rays in a strong laboratory magnetic field.
123 Experiment based on proposal by MAIANI 86.
124 Experiment based on proposal by VANBIBBER 87.
125 LAZARUS 92 experiment is based on proposal found in VANBIBBER 89.
126 RUOSO 92 experiment is based on the proposal by VANBIBBER 87.
127 SEMERTZIDIS 90 experiment is based on the proposal of MAIANI 86. The limit isobtained by taking the noise amplitude as the upper limit. Limits extend to m 0 =A
4 × 10−3 where GAγ γ < 1 × 10−4 GeV− 1 .

https://pdg.lbl.gov

Page 43

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

Limit on Invisible A0 (Axion) Electron Coupling
The limit is for gAe e φA e(i γ5 )e, or equivalently, the dipole-dipole potential
g2
σ 1 ·σσ 2 ) − 3(σσ 1 ·nn ) (σσ 2 ·nn ))/r3 where n =rr /r and the sign of the potential− A e e2 ((σ16πm ewas corrected based on DAIDO 17.
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 AALBERS<2.35 × 10−1290
23A LZ
Solar axions−142<1.3 × 10
90
AALBERS
23A LZm 0 = 1–17 keV
A
3 ADHIKARI<1.61 × 10−1190
23 C100 Solar axions
4 ADHIKARI<6
× 10−1390
23A C100 m 0 =10–1000 keV
A
−14
5
<8
× 10
90
AGNES
23A DS50 m 0 = 0.03–20 keVA
6 APRILE
23B XE1T Neutron star merger
7 CAPOZZI<3
× 10−995
23A DUMP m 0 = 104 –2 × 107 eVA
8 WADEKAR<6
× 10−15
23 ASTR m 0 = 100 keVA
9 APRILE<4
× 10−1290
22 XE1T m 0 = 0.01–0.4 keVA
10 APRILE<9
× 10−1590
22B XENT m 0 = 1–39, 44–140 keVA
11 APRILE<2
× 10−1290
22B XENT Solar axions
12 DESSERT
22 ASTR Magnetic white dwarf
13 IKEDA<2.6 × 10−69522m 0 =33.117–33.130 µeVA−1814<2.5 × 10
LANGHOFF
22 COSM m 0 = 20–3 × 104 keVA
15 WANG22C
m 0 ≤ 0.47 meVA
16 XIAO
22 ASTR Betelgeuse
17 CALORE
21 ASTR Core-collapse SNe
18 LUCENTE<2.5 × 10−10
21 ASTR SN 1987A
19 AGOSTINI<5.1 × 10−1290
20 HPGE m 0 = 0.06–1 MeV
A
−9
20
<1
× 10
90
AMARAL20 SCDM m 0 = 1.2–50 eVA
21 APRILE<2
× 10−1490
20 XE1T m 0 = 1 keVA
22 APRILE
2.6–3.7 × 10−1290
20 XE1T Solar axions
23 ARALIS<6× 10−1390
20 SCDM m 0 = 0.04–500 keVA−13
24<1.3 × 10
95
CAPOZZI
20 ASTR Tip of the Red Giant
Branch25 CRESCINI<1.7 × 10−11
95
20 QUAX m 0 = 42.4–43.1 µeVA
26 GHOSH<1.8 × 10−9
20A COSM m 0 . 0.5 MeV
A
27 STRANIERO 20 ASTR Tip of the Red Giant<1.48 × 10−13
95
Branch28 WANG<2.48 × 10−1190
20A CDEX Solar axions
29 WANG<4× 10−1390
20A CDEX m 0 = 1.5 keV
A−1130<1.7 × 10
90
ADHIKARI
19B C100 Solar axions
31 APRILE<2.3 × 10−14
90
19D XE1T m 0 = 0.186–1 keV
A
32 DESSERT
19 ASTR Magnetic white dwarf
33 TERRANO<2.6 × 10−1095
19Torsion pendulum−1334<1.5 × 10
90
ABE
18F XMAS m 0 = 40–120 keVA
35 ARMENGAUD 18 EDE3 Solar axions<1.1 × 10−11
90
36 ARMENGAUD 18 EDE3 m<4× 10−1390= 0.8–500 keV
A0
−10
37
<4.9 × 10
95
CRESCINI
18 QUAX m 0 = 58 µeVA
38 FICEK
18 THEO m 0 < 10 keVAhttps://pdg.lbl.gov

Page 44

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)<4.5 × 10−13<3.5 × 10−12<4.2 × 10−13<2.3 × 10−13<4
× 10−4<4.35 × 10−12<4.3 × 10−14<5
× 10−13<2.5 × 10−11<0.15<3.3 × 10−13<7
× 10−13<1.39 × 10−11<7.4 × 10−9

× 10−13<7.7 × 10−12<8< 0.96–8.2 × 10−8
<2.8 × 10−13<5.4 × 10−11<1.07 × 10−1290

39 ABGRALL

17

90
90

40 AKERIB
41 AKERIB

17B
17B

90

42 APRILE

17B

90

43 FICEK

17

90
90

44 FU
45 FU

17A
17A

90

46 LIU

17A

90
95

47 LIU
48 LUO

17A
17

68
90
95

49 BATTICH
50 CORSICO
51 YOON
52 TERRANO

16
16
16
15

90

53 ABE

14F

90

54 APRILE
55 APRILE

14B
14B

90

56 DERBIN

99
90
90

14
57 MILLER-BER... 1458 ABE
13D
59 ARMENGAUD 13<2.59 × 10−1190< 1.4–9.7 × 10−7
<1.5 × 10−8

90

60 ARMENGAUD 13
61 BARTH
1362 DERBIN
13

68

63 HECKEL

13

95
95
90
90

64 VIAUX
65 CORSICO
66 DERBIN
67 AALSETH

13A
12
12
11

<1.4 × 10−12<4
× 10−9<2.7 × 10−890

68 AHMED<4.3 × 10−13<7
× 10−13<2.2 × 10−10< 0.02–1 × 10−10

66

09A
69 DAVOUDIASL 09
70 NI
94
70 CHUI
93
71 PAN92
70 BOBRAKOV 91
72 WINELAND
91
71 RITTER
90
70 VOROBYOV 88

HPGE m 0 = 11.8 keVA
LUX
Solar axions
LUX
m 0 = 1–16 keV
A
X100 m 0 = 6 keV
A
THEO m 0 < 1 keVA
PNDX Solar axions
PNDX m 0 = 2 keVA
CDEX m 0 = 13 keVA
CDEX Solar axions
m 0 = 300 eVA
ASTR White dwarf cooling
ASTR White dwarf cooling
KIMS Solar axions
m 0 < 30 µeVA
XMAS m 0 = 60 keVA
X100 Solar axions
X100 m 0 = 5–7 keVA
CNTR m 0 = 0.1–1 MeV
A
ASTR White dwarf cooling
XMAS Solar axions
EDEL m 0 = 12.5 keVAEDEL Solar axions
CAST Solar axions
CNTR m 0 = 0.1–1 MeVAm 0 ≤ 0.1 µeVAASTR Low-mass red giants
ASTR White dwarf cooling
CNTR Solar axions
CNTR m 0 = 0.3–8 keVA
CDMS m 0 = 2.5 keVAASTR Earth cooling
Induced magnetism
Induced magnetism
Torsion pendulum
Induced magnetism
NMR
Torsion pendulum
Induced magnetism<3.6 × 10−7
66
<2.9 × 10−8
95
<1.9 × 10−6
66
<7
× 10−766<6.6 × 10−895
1 AALBERS 23A look for solar axions from the ABC processes. See their Fig. 6 for thelimits.
2 AALBERS 23A look for absorption of axion dark matter. The quoted limit is for m
A0≃ 1.4 keV. The local density ρA = 0.3 GeV/cm3 is assumed. See their Fig. 7 formass-dependent limits.
3 ADHIKARI 23 is an update of ADHIKARI 19B.
4 ADHIKARI 23A look for absorption and Compton-like processes of axion dark matter.
The quoted limit is for m 0 ≃ 37 keV. See their Fig. 4 for mass-dependent limits.
A

https://pdg.lbl.gov

Page 45

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

5 AGNES 23A look for absorption of axion dark matter. The quoted limit is for m
A03≃ 0.25 keV. The local density ρA = 0.3 GeV/cm is assumed. See their Fig. 2 formass-dependent limits.
6 APRILE 23B look for an absorption signal of axions within ± 500 seconds of the GW
signals, including the neutron star merger GW170817. They set a 90% CL upper limiton the product of coincident fluence and cross section of axions to be less than 10−29
cm2 /cm2 in the recoil energy range of 5.5–210 keVee .
7 CAPOZZI 23A search for axions produced in electromagnetic showers in proton beam
dumps and fixed target experiments. In this case, they reinterpret MiniBoone data.
Quoted limit applies at 1 MeV. See Fig. 8 for mass-dependent limits.
8 WADEKAR 23 use the Leo T dwarf galaxy’s interstellar medium to derive limits, requiring
the heating rate from axion dark matter absorption into hydrogen atoms and two-photon
decay to be less than the astrophysical cooling rate. See Fig. 2 for limits over m 0 =A
1–100 keV, which loosen for lighter masses.
9 APRILE 22 extend APRILE 19D to lower masses by removing the background of ionization
signals correlated with high-energy events. The quoted limit applies to m 0 = 0.1 keV.
A
See their Fig. 15 for mass-dependent limits.
10 APRILE 22B is an update of APRILE 20, and set the limit, g−15 –3 ×Ae e . 9 × 10
10−13 . The quoted limit applies to m 0 = 2 keV. They exclude the XENON1T excess
Afound in APRILE 20. See their Fig. 6 for mass-dependent limits.
11 APRILE 22B is an update of APRILE 20. They exclude the XENON1T excess found in
APRILE 20. The quoted limit holds for small GAγ γ . See their Fig. 6 for correlation
between gAe e and GAγ γ .
12 DESSERT 22 is an update of DESSERT 19. They used the Chandra observation of themagnetic white dwarf RE J0317-853 to look for converted X-rays in the magnetospherefrom axions produced in the core through electron bremsstrahlung. They obtained thelimit, gAe e · GAγ γ < 1.3 × 10−25 GeV−1 at 95% CL for m 0 . 10−5 eV. See
Atheir Fig. 1 for mass-dependent limits.
13 IKEDA 22 look for magnons excited by dark matter axions, using data taken with a hybrid
quantum system consisting of a superconducting qubit and a spherical ferrimagnetic
crystal. The quoted limit assumes the local dark matter density ρA = 0.45 GeV/cm3
and the velocity v = 220 km/sec. See their Fig. 4 for the limits.
14 LANGHOFF 22 set limits by considering the freeze-in production of axions coupled toelectrons without anomalous coupling to photons. The quoted limit applies to m 0 = 15
A
MeV for the reheating temperature equal to 5 MeV. See their Fig. 2 for mass-dependent
limits.
15 WANG 22C use the spin-amplifier based on hyperpolarized 129 Xe to set limits on the
product of the axion couplings to electrons and nucleons as gAe e gAn n < 4 × 102(95 % CL) at m 0 = 0.1 meV. Here gAn n is the dimensionless axion-neutron coupling.
A
See their Fig. 4 for the mass-dependent limits.
16 XIAO 22 extend XIAO 21 in the list of photon coupling limits by including the productionof axions from Compton and bremsstrahlung processes, and set limits on the product of
the axion couplings to electrons and photons as GAγ γ gAe e < 0.4–2.8 × 10−24
GeV−1 (95 % CL) for m 0 < 3.5 × 10−11 eV. See their Fig. 5 for the limits. TheyA
are comparable to those of DESSERT 19 and more restrictive than the CAST bounds of
BARTH 13.
17 CALORE 21 consider the production of axions from Galactic and extragalactic SNe via
nucleon-nucleon bremsstrahlung and their subsequent decay into electron-positron pairs,
and exclude the range of gAe e ≃ 10−19 –10−11 at gAp p = 10−9 for m 0 = 3–30
A
MeV. See their Fig. 7 for the limits.
18 LUCENTE 21 study the axion production in a supernova via electron-proton bremsstrahlung and electron-positron fusion, and exclude the range of gAe e ≃ 10−10 –10−8 forhttps://pdg.lbl.gov

Page 46

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

m 0 = 1–160 MeV. The quoted limit is at m 0 = 120 MeV. See their Fig. 12 for theAAmass-dependent limits.
19 AGOSTINI 20 is analogous to AHMED 09A. The quoted limit applies to m
= 150
A0
keV. Their limits in their Fig. 3 were later found to be incorrect due to an error of theirEqs. (1) and (2). See Fig. 3 in AGOSTINI 22A for the corrected limits.
20 AMARAL 20 use a second-generation SuperCDMS high-voltage eV-resolution detector
to set limits on dark-matter axion absorption. The quoted limit is for m 0 ≃ 17 eV.
A
The local density ρA = 0.3 GeV/cm3 is assumed. See their Fig. 3 for mass-dependent
limits.
21 APRILE 20 is an update of APRILE 17B where they look for an absorption signal of axion
dark matter. They obtained the limit, gAe e . 2 × 10−14 –1 × 10−12 at 90%CL form 0 = 1–200 keV. They also found an excess over known backgrounds, which favors theAmass m 0 = 2.3 ± 0.2 keV with a 3 σ significance. See their Fig. 10 for mass-dependentA
limits.
22 APRILE 20 look for solar axions from the ABC interactions, the Primakoff conversion,and the 14.4 keV M1 transition of 57 Fe, and set limits on gAe e , GAγ γ , gAN N , andtheir products. An excess is observed at low energies between 2 and 3 keV. See theirFig.8 for correlation between the couplings. The quoted limit applies to the case ofvanishing GAγ γ and gAN N .
23 ARALIS 20 is analogous to AHMED 09A. The quoted limit applies to m
= 0.3 keV.
A0
The limits at masses above 3 keV in their Fig. 9 was later found to be incorrect due toan error in their analysis. See Fig. 2 in ARALIS 21 for the corrected limits.
24 CAPOZZI 20 obtains a limit on the axion-electron coupling from the brightness of the
tip of the red-giant branch in ω Centauri. A similar limit of < 1.6 × 10−13 is obtainedin NGC 4258.
25 CRESCINI 20 is an update of CRESCINI 18. They assume a local axion dark matter
density, ρA = 0.3 GeV/cm3 . See their Fig.4 for the limits.
26 GHOSH 20A study thermal production of axion via coupling to leptons in the early
universe and estimate its contribution to ∆Neff . The quoted limit is for ∆Neff < 0.5.
See their Fig. 7 for their mass-dependent limits.
27 STRANIERO 20 is analogous to CAPOZZI 20, with 22 galactic globular clusters used toderive the limit.
28 WANG 20A is an update of LIU 17A. See their Fig. 9.
29 WANG 20A is an update of LIU 17A. They assume a local axion dark matter density, ρA= 0.3 GeV/cm3 . See their Fig. 10 for limits between 0.185 < m 0 < 10 keV.
A
30 ADHIKARI 19B is analogous to LIU 17A.
31 APRILE 19D is analogous to APRILE 17B, but they use only ionization signals. The
quoted limit applies to m 0 = 0.7 keV. See their Fig. 5(e) for mass-dependent limits.
A
32 DESSERT 19 used the Suzaku observations of a magnetic white dwarf (RE J0317-853)
to look for X-ray signatures converted from axions in the surrounding magnetic fields.
They obtained the limit, gAe e · GAγ γ < 1.6 × 10−24 GeV−1 at 95%CL for m 0 .
A
10−5 eV. See their Fig. 2 for mass-dependent limits.
33 TERRANO 19 look for the axion-induced oscillating magnetic field acting on the electron
spin, using data taken with a rotating torsion pendulum containing polarized electrons.
The quoted limit applies to m 0 = 10−23 –10−18 eV and assumes a local axion darkAmatter density, ρA = 0.45 GeV/cm3 . See their Fig. 5 for mass-dependent limits.
34 ABE 18F is an update of ABE 14F. The quoted limit applies to m
= 60 keV. See their
A0
Fig. 5 for mass-dependent limits.
35 ARMENGAUD 18 is analogous to LIU 17A.
36 ARMENGAUD 18 is analogous to AHMED 09A. See the left panel of Fig. 5 for massdependent limits.

https://pdg.lbl.gov

Page 47

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

37 CRESCINI 18 look for collective excitations of the electron spins caused by dark matteraxions. The quoted limit assumes the local dark matter density, ρA = 0.45 GeV/cm3 .
38 FICEK 18 use the measurements of the hyperfine structure of antiprotonic helium toconstrain a dipole-dipole potential between electron and antiproton. See their Fig. 3 forlimits on various spin- and velocity-dependent potentials.
39 ABGRALL 17 is analogous to AHMED 09A using the MAJORANA DEMONSTRATOR.
See their Fig. 2 for limits between 6 keV < m 0 < 97 keV.
A
40 AKERIB 17B is analogous to LIU 17A.
41 AKERIB 17B is analogous to AHMED 09A. See their Fig. 7 for mass-dependent limits.
42 APRILE 17B is analogous to AHMED 09A. They found a bug in their code and needed
to correct the limits in Fig. 7 of APRILE 14B. See their Fig. 1 for the corrected limits
between 1 keV < m 0 < 40 keV.
A
43 FICEK 17 look for spin-dependent interactions between electrons by comparing precision
spectroscopic measurements in 4 He with theoretical calculations. See their Fig. 1 forlimits up to m 0 = 10 keV.
A
44 FU 17A is analogous to LIU 17A. See their Fig. 3 for mass-dependent limits.
45 FU 17A is analogous to AHMED 09A. See their Fig. 4 for mass-dependent limits.
46 LIU 17A is analogous to AHMED 09A. See their Fig. 9 for limits between 0.25 keV <m 0 < 20 keV.
A
47 LIU 17A look for solar axions produced from Compton, bremsstrahlung, atomicrecombination and deexcitation channels, and set a limit for m 0 < 1 keV.
A
48 LUO 17 use a recent measurement of the dipole-dipole interaction between two ironatoms at the nanometer scale and set a limit for m 0 < 1 keV. See their Fig. 3 forA
mass-dependent limits.
49 BATTICH 16 is analogous to CORSICO 16 and used the pulsating DB white dwarf PG
1351+489.
50 CORSICO 16 studied the cooling rate of the pulsating DA white dwarf L19-2 based on
an asteroseismic model.
51 YOON 16 look for solar axions with the axio-electric effect in CsI(Tl) crystals and set alimit for m 0 < 1 keV.
A
52 TERRANO 15 used a torsion pendulum and rotating attractor with 20-pole electron-spin
distributions. See their Fig. 4 for a mass-dependent limit up to m 0 = 500 µeV.
A
53 ABE 14F set limits on the axioelectric effect in the XMASS detector assuming the pseudoscalar constitutes all the local dark matter. See their Fig. 3 for limits between m 0
A= 40–120 keV.
54 APRILE 14B look for solar axions using the XENON100 detector.
55 APRILE 14B is analogous to AHMED 09A. Their Fig. 7 was later found to be incorrect
due to a bug in their code. See Fig. 1 in APRILE 17B for the corrected limits.
56 DERBIN 14 is an update of DERBIN 13 with a BGO scintillating bolometer. See theirFig. 3 for mass-dependent limits.
57 MILLER-BERTOLAMI 14 studied the impact of axion emission on white dwarf coolingin a self-consistent way.
58 ABE 13D is analogous to DERBIN 12, using the XMASS detector.
59 ARMENGAUD 13 is similar to AALSETH 11. See their Fig. 10 for limits between 3 keV< m 0 < 100 keV.
A
60 ARMENGAUD 13 is similar to DERBIN 12, and take account of axio-recombination andaxio-deexcitation effects. See their Fig. 12 for mass-dependent limits.
61 BARTH 13 search for solar axions produced by axion-electron coupling, and obtained thelimit, gAe e · GAγ γ < 8.1 × 10−23 GeV−1 at 95%CL.
62 DERBIN 13 looked for 5.5 MeV solar axions produced in p d → 3 He A0 in a BGO
detector through the axioelectric effect. See their Fig. 4 for mass-dependent limits.

https://pdg.lbl.gov

Page 48

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

63 HECKEL 13 studied the influence of 2 or 4 stationary sources each containing 6.0 × 1024
polarized electrons, on a rotating torsion pendulum containing 9.8 × 1024 polarized
electrons. See their Fig. 4 for mass-dependent limits.
64 VIAUX 13A constrain axion emission using the observed brightness of the tip of the
red-giant branch in the globular cluster M5.
65 CORSICO 12 attributed the excessive cooling rate of the pulsating white dwarf R548 toemission of axions with gAee ≃ 4.8 × 10−13 .
66 DERBIN 12 look for solar axions with the axio-electric effect in a Si(Li) detector. The
solar production is based on Compton and bremsstrahlung processes.
67 AALSETH 11 is analogous to AHMED 09A. See their Fig. 4 for mass-dependent limits.
68 AHMED 09A assume keV-mass pseudoscalars are the local dark matter and constrain theaxio-electric effect in the CDMS detector. See their Fig. 5 for mass-dependent limits.
69 DAVOUDIASL 09 use geophysical constraints on Earth cooling by axion emission.
70 These experiments measured induced magnetization of a bulk material by the spindependent potential generated from other bulk material with aligned electron spins,
where the magnetic field is shielded with superconductor. The sign of the limit set by
CHUI 93 is opposite to that of the axion-mediated dipole-dipole potential.
71 These experiments used a torsion pendulum to measure the potential between two bulk
matter objects where the spins are polarized but without a net magnetic field in eitherof them. The limits reflect the corrected sign of the dipole-dipole potential.
72 WINELAND 91 looked for an effect of bulk matter with aligned electron spins on atomic
hyperfine splitting using nuclear magnetic resonance.

Invisible A0 (Axion) Limits from Nucleon Coupling
Limits are for the axion mass in eV.
VALUE (eV)CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 LELLA< 0.0195
24 ASTR SN1987A
2 KARANTH
23
Deuteron EDM
3 LEE
23Axion dark matter
4 BUSCHMANN 22 ASTR Neutron star cooling< 0.01695
5 GAVRILYUK 22 CNTR Solar axion<320
90
6 SCHULTHESS 22
Neutron EDM
7 AYBAS
21 CASP Nucleon EDM
8 BHUSAL
21
Solar axion
9 JIANG
21 NMR Axion dark matter10 ROUSSY21
Molecular EDM
11 ZHANG
21B ASTR Neutron star inspiral
12 ABDELHAME...20 CNTR Solar axion< 24
90
13 ABDELHAME...20 CNTR Solar axion
14 APRILE
20 XE1T Solar axion
15 KLIMCHITSK...20
Casimir effect
16 WANG< 7.3
90
20A CDEX Solar axion
17 LEINSON< 0.0319 ASTR Neutron star cooling−3
18 LLOYD< 9.6 × 10
95
19 ASTR γ-rays from NS
19 SMORRA
p g-factor
19
20 WU
19 NMR Axion dark matter
21 AKHMATOV 18 CNTR Solar axion< 65
95
22 ARMENGAUD 18 EDE3 Solar axion< 6.6
90
23 BEZNOGOV 18 ASTR Neutron star cooling< 0.08590https://pdg.lbl.gov

Page 49

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)< 12.7< 0.01

95

< 93
< 4

90
90

<177
< 0.079
<100

90
95
95

<250
<155
< 8.6
< 1.4
<145

95
90
90
90
95

× 103
× 104

24 GAVRILYUK 18
25 HAMAGUCHI 18
26 ABEL17
27 ABGRALL
17
28 FU
17A
29 KLIMCHITSK...17A
30 LIU
17A
31 BERENJI
16
32 GAVRILYUK 15
33 KLIMCHITSK...15
34 BEZERRA
1435 BEZERRA
14A
36 BEZERRA
14B
37 BEZERRA
14C
38 BLUM14
39 LEINSON
1440 ALESSANDRIA13
41 ARMENGAUD 13
42 BELLI
1243 BELLINI
12B
44 DERBIN
1145 BELLINI
08
46 ADELBERGER 07

CNTR Solar axion
ASTR Neutron star cooling
Neutron EDM
HPGE Solar axion
PNDX Solar axion
Casimir effect
CDEX Solar axion
ASTR γ-rays from NS
CNTR Solar axion
Casimir-lessCasimir effectCasimir effectCasimir effectCasimir effect
COSM 4 He abundance
ASTR Neutron star cooling
CNTR Solar axion
EDEL Solar axion
CNTR Solar axion
BORX Solar axion
CNTR Solar axion
CNTR Solar axion
Test of Newton’s law

1 LELLA 24 update constraints on the axion-proton coupling from supernova 1987A basedon the SN cooling argument (including a treatment of the trapping regime) as well as thenon-observation of any coincident axion-induced events in the Kamiokande II neutrino
detector. They exclude QCD axion models above 0.01 eV, and axion-like particles in awindow that extends up to 300 MeV. See their Fig. 3 for mass-dependent limits.
2 KARANTH 23 utilized an in-plane polarized deuteron beam in a storage ring to constrain the axion-induced oscillating EDM of the deuteron for m 0 = 0.496–0.502 neV.
A
Assuming axions account for all dark matter with ρA ≃ 0.55 GeV/cm3 , they derived
constraints on axion couplings to the deuteron EDM operator, gluons, and the deuteronspin. For detailed limits, see their Figs. 19–21.
3 LEE 23 analyzed data from a K−3 He comagnetometer, accounting for stochastic effects,
to limit the axion-neutron coupling gAn n < 2.4 × 10−10 GeV−1 at 95% CL for m 0
A= 0.4–4 feV. They assumed axions form all dark matter with a density of 0.3 GeV/cm3 .
See their Fig. 5 for the limits.
4 BUSCHMANN 22 studied the axion emission from five neutron stars with ages ∼105 –106 years, comparing the simulation with axions to age and luminosity measurements. The mass bound assumes the KSVZ axion model with Cp = − 0.47 and Cn =− 0.02. See their Fig. 3 for the limits on the DFSZ axion model.
5 GAVRILYUK 22 look for solar axions from the ABC interactions with the experimental
setup similar to GAVRILYUK 15. The mass bound assumes the KSVZ axion model, S =0.5, and m u /m d = 0.56.
6 SCHULTHESS 22 look for a time-oscillating neutron EDM caused by the coupling between axion dark matter and gluons, using a Ramsey-type apparatus for a cold neutron
beam. See their Fig. 4 for limits in the range of m 0 = 10−19 –4 × 10−12 eV.
A
7 AYBAS 21 limits the axion couplings to the nucleon EDM and the nucleons as g
AN γ <−4−2−1
9.5 × 10
GeV
and gAN N /2m N < 0.28 GeV(95 % CL) for m 0 = 162–166
A
207
neV, based on a measurement of
Pb solid-state NMR in a polarized ferroelecrtriccrystal. Here m N is the nucleon mass and gAN N is the dimensionless axion-nucleon

https://pdg.lbl.gov

Page 50

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

coupling. They assume that axions make up all the dark matter with ρA ≃ 0.46
GeV/cm3 . See their Fig. 3 for the limits.
8 BHUSAL 21 looked for 5.5 MeV solar axions produced by p d → 3 He A0 through theaxion-induced dissociation of deuterons by using SNO data, and set a limit on the isovec< 2×10−5 GeV−1 , which is equivalent to gAnn −tor axion-nucleon coupling, g3
aN
gApp < 4 × 10−5 in terms of the dimensionless axion-nucleon couplings.
9 JIANG 21 use the spin-amplifier based on hyperpolarized 129 Xe gas to set limits on theaxion couplings to nucleons as gAN N /2m N < 3.2 × 10−9 GeV−1 (95 % CL) at
m 0 = 52.94 feV, and comparable limits in the mass range of 8.3–744 feV. Here m N isA
the nucleon mass and gAN N is the dimensionless axion-nucleon coupling. They assume
that axions make up all the dark matter with ρA ≃ 0.4 GeV/cm3 . See their Fig. 4b
for the limits.
10 ROUSSY 21 look for a time-oscillating EDM of molecular ions HfF+ induced by axion
dark matter couplings to gluons. See their Fig. 3 for limits in the range of m 0 =A
10−22 –10−15 eV.
11 ZHANG 21B use the gravitational waves from the binary neutron star inspiral GW170817
to look for a type of axion whose mass is suppressed due to cancellation with additional
contributions. They exclude 1.6 × 1016 < fA < 1018 GeV at 3 σ for m 0 . 10−13
A
eV. See their Fig. 1 for mass-dependent limits.
12 ABDELHAMEED 20 look for the resonant excitation of 169 Tm (8.41 keV) by solar
axions produced via the Primakoff effect. The mass bound assumes the KSVZ axion
model, S = 0.5, and m u /m d = 0.56. They set a limit on the product of axion couplings
to photons and nucleons as GAγ γ · gAp p < 1.44 × 10−14 GeV−1 (90 % CL).
13 ABDELHAMEED 20 look for the resonant excitation of 169 Tm (8.41 keV) by solar
axions produced via the axion-electron coupling. They set a limit on the product ofaxion couplings to electrons and nucleons as gAe e · gAp p < 2.81 × 10−16 (90 %CL).
14 APRILE 20 look for solar axions from the ABC interactions, the Primakoff conversion,and the 14.4 keV M1 transition of 57 Fe. An excess is observed at low energies between
2 and 3 keV. See their Fig.8 for correlation between the couplings.
15 KLIMCHITSKAYA 20 use the measurement of the Casimir force between a Au-coatedmicrosphere and a SiC plate to constrain the force due to two-axion exchange for 17.8
< m 0 < 100 eV. See their Fig. 2 for mass-dependent limits.
A
16 WANG 20A is an update of LIU 17A. The limit assumes the DFSZ axion. See their Fig.
7 for the limit on product of axion couplings to electrons and nucleons.
17 LEINSON 19 is analogous to BEZNOGOV 18, but estimating the axion luminosity basedon the Tolman’s analytic solution to the Einstein equations of spherical fluids in hydrostatic equilibrium. The dimensionless axion-neutron coupling is constrained as gAnn <1.0 × 10−10 .
18 LLOYD 19 is analogous to BERENJI 16. They highlight that the limit obtained withthis technique strongly depends on the assumed NS core temperature.
19 SMORRA 19 look for spin-precession effects from ultra-light axion dark matter in the pspin-flip resonance data. Assuming ρA = 0.4 GeV/cm3 , they constrain the dimensionlessaxion-antiproton coupling as gAp p < 2–9 at 95% CL for m 0 = 2× 10−23 –4× 10−17
A
eV. See the right panel of their Fig. 3.
20 WU 19 look for axion-induced time-oscillating features of the NMR spectrum ofacetonitrile-2-13 C. Assuming Cp = Cn and ρA = 0.4 GeV/cm3 , they constrain
the dimensionless axion-nucleon coupling as gANN
< 6 × 10−5 for m 0 =A
10−21 –1.3 × 10−17 eV. Note that the limits for m 0 < 10−21 eV in their Fig. 3(a)Ashould be weaker than those for heavier masses. See ADELBERGER 19 and WU 19C on
this issue.

https://pdg.lbl.gov

Page 51

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

21 AKHMATOV 18 is an update of GAVRILYUK 15.
22 ARMENGAUD 18 is analogous to ALESSANDRIA 13. The quoted limit assumes the
DFSZ axion model. See their Fig. 4 for the limit on product of axion couplings toelectrons and nucleons.
23 BEZNOGOV 18 constrain the axion-neutron coupling by assuming that thermal evolutionof the hot neutron star HESS J1731-347 is dominated by the lowest possible neutrino
emission. The quoted limit assumes the KSVZ axion with the effective Peccei-Quinn
charge of the neutron Cn = − 0.02. The dimensionless axion-neutron couling is constrained as gAnn < 2.8 × 10−10 .
24 GAVRILYUK 18 look for the resonant excitation of 83 Kr (9.4 keV) by solar axions produced via the Primakoff effect. The mass bound assumes m u /m d = 0.56 and S =0.5.
25 HAMAGUCHI 18 studied the axion emission from the neutron star in Cassiopeia A basedon the minimal cooling scenario which explains the observed rapid cooling rate. The
quoted limit corresponds to fA > 5 × 108 GeV obtained for the KSVZ axion with Cp= − 0.47 and Cn = − 0.02.
26 ABEL 17 look for a time-oscillating neutron EDM and an axion-wind spin-precession
effect respectively induced by axion dark matter couplings to gluons and nucleons. See
their Fig. 4 for limits in the range of m 0 = 10−24 –10−17 eV.
A
27 ABGRALL 17 limit assumes the hadronic axion model used in ALESSANDRIA 13. See
their Fig. 4 for the limit on product of axion couplings to electrons and nucleons.
28 FU 17A look for the 14.4 keV 57 Fe solar axions. The limit assumes the DFSZ axion model.
See their Fig. 3 for mass-dependent limits on the axion-electron coupling. Notice thatin this figure the DFSZ and KSVZ lines should be interchanged.
29 KLIMCHITSKAYA 17A use the differential measurement of the Casimir force between
a Ni-coated sphere and Au and Ni sectors of the structured disc to constrain the axion
coupling to nucleons for 2.61 meV < m 0 < 0.9 eV. See their Figs. 1 and 2 for massA
dependent limits.
30 LIU 17 is analogous to ALESSANDRIA 13. The limit assumes the hadronic axion model.
See their Fig. 6(b) for the limit on product of axion couplings to electrons and nucleons.
31 BERENJI 16 used the Fermi LAT observations of neutron stars to look for photons fromaxion decay. They assume the effective Peccei-Quinn charge of the neutron Cn = 0.1
and a neutron-star core temperature of 20 MeV.
32 GAVRILYUK 15 look for solar axions emitted by the M1 transition of 83 Kr (9.4 keV).
The mass bound assumes m u /m d = 0.56 and S = 0.5.
33 KLIMCHITSKAYA 15 use the measurement of differential forces between a test mass androtating source masses of Au and Si to constrain the force due to two-axion exchange
for 1.7 × 10−3 < m 0 < 0.9 eV. See their Figs. 1 and 2 for mass dependent limits.
A
34 BEZERRA 14 use the measurement of the thermal Casimir-Polder force between a BoseEinstein condensate of 87 Rb atoms and a SiO2 plate to constrain the force mediated byexchange of two pseudoscalars for 0.1 meV < m 0 < 0.3 eV. See their Fig. 2 for theAmass-dependent limit on pseudoscalar coupling to nucleons.
35 BEZERRA 14A is analogous to BEZERRA 14. They use the measurement of the Casimirpressure between two Au-coated plates to constrain pseudoscalar coupling to nucleons
for 1 × 10−3 eV < m 0 < 15 eV. See their Figs. 1 and 2 for the mass-dependent limit.
A
36 BEZERRA 14B is analogous to BEZERRA 14. BEZERRA 14B use the measurementof the normal and lateral Casimir forces between sinusoidally corrugated surfaces of asphere and a plate to constrain pseudoscalar coupling to nucleons for 1 eV < m 0 <A
20 eV. See their Figs. 1–3 for mass-dependent limits.
37 BEZERRA 14C is analogous to BEZERRA 14. They use the measurement of the gradientof the Casimir force between Au- and Ni-coated surfaces of a sphere and a plate toconstrain pseudoscalar coupling to nucleons for 3 × 10−5 eV < m A < 1 eV. See their0
Figs. 1, 3, and 4 for the mass-dependent limits.

https://pdg.lbl.gov

Page 52

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

38 BLUM 14 studied effects of an oscillating strong CP phase induced by axion dark matteron the primordial 4 He abundance. See their Fig. 1 for mass-dependent limits.
39 LEINSON 14 attributes the excessive cooling rate of the neutron star in Cassiopeia A toaxion emission from the superfluid core, and found C2 m 2 0 ≃ 5.7 × 10−6 eV2 , wheren A
Cn is the effective Peccei-Quinn charge of the neutron.
40 ALESSANDRIA 13 used the CUORE experiment to look for 14.4 keV solar axions produced from the M1 transition of thermally excited 57 Fe nuclei in the solar core, using
the axio-electric effect. The limit assumes the hadronic axion model. See their Fig. 4
for the limit on product of axion couplings to electrons and nucleons.
41 ARMENGAUD 13 is analogous to ALESSANDRIA 13. The limit assumes the hadronic
axion model. See their Fig. 8 for the limit on product of axion couplings to electrons
and nucleons.
42 BELLI 12 looked for solar axions emitted by the M1 transition of 7 Li∗ (478 keV) after theelectron capture of 7 Be, using the resonant excitation 7 Li in the LiF crystal. The mass
bound assumes m u /m d = 0.55, m u /m s = 0.029, and the flavor-singlet axial vector
matrix element S = 0.4.
43 BELLINI 12B looked for 5.5 MeV solar axions produced in the p d → 3 He A0 .The limit
assumes the hadronic axion model. See their Figs. 6 and 7 for mass-dependent limits on
productsof axion couplings to photons, electrons, and nucleons.
44 DERBIN 11 looked for solar axions emitted by the M1 transition of thermally excited
57 Fe nuclei in the Sun, using their possible resonant capture on 57 Fe in the laboratory.
The mass bound assumes m u /m d = 0.56 and the flavor-singlet axial vector matrix
element S = 3F − D ≃ 0.5.
45 BELLINI 08 consider solar axions emitted in the M1 transition of 7 Li∗ (478 keV) andlook for a peak at 478 keV in the energy spectra of the Counting Test Facility (CTF), a
Borexino prototype. For m 0 < 450 keV they find mass-dependent limits on productsAof axion couplings to photons, electrons, and nucleons.
46 ADELBERGER 07 use precision tests of Newton’s law to constrain a force contribution
from the exchange of two pseudoscalars. See their Fig. 5 for limits on the pseudoscalar
coupling to nucleons, relevant for m 0 below about 1 meV.
A

Axion Limits from T-violating Medium-Range Forces
The limit is for the coupling g = gp gs in a T-violating potential between nucleons,g h̄2 σ r̂nucleon and electron, or electrons of the form V = 8πm (σ·r̂ ) ( 12 + 1 ) e−r /λ ,λrrpwhere gs and gp are dimensionless scalar and pseudoscalar coupling constants, m p is
the fermion mass with the pseudoscalar coupling (whereas the mass m s of the fermion
with the scalar coupling does not explicitly appear), and λ = h̄/(m A c) is the range ofthe force.
VALUE

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 AYRES
23 EDM ultracold neutrons
2 PODDAR
23 ASTR solar system
3 ZHANG
23 NMR polarized 129 Xe and 131 Xe
4 CRESCINI
22 SQID paramagnetic GSO crystal
5 FENG
22 NMR polarized 129 Xe and 131 Xe
6 AFACH
21 GNME Optical magnetometers
7 DZUBA
18 THEO atomic EDM
8 STADNIK
18 THEO atomic and molecular EDMs
9 CRESCINI
17 SQID paramagnetic GSO crystal
10 AFACH
15
ultracold neutrons
11 STADNIK
15 THEO nucleon spin contributions for nuclei

https://pdg.lbl.gov

Page 53

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

12 TERRANO
15
13 BULATOWICZ 13
14 CHU
13
15 TULLNEY
13
16 RAFFELT
1217 HOEDL
11
18 PETUKHOV 10
19 SEREBROV
1020 IGNATOVICH 09
21 SEREBROV
09
22 BAESSLER
07
23 HECKEL
06
24 NI
99
25 POSPELOV
98
26 YOUDIN
96
27 RITTER
93
28 VENEMA
92
29 WINELAND
91

torsion pendulum
polarized 129 Xe and 131 Xepolarized 3 He
SQID polarized 3 He and 129 Xe
stellar energy loss
torsion pendulum
polarized 3 He
ultracold neutrons
RVUE ultracold neutrons
RVUE ultracold neutrons
ultracold neutrons
torsion pendulum
paramagnetic Tb F3
THEO neutron EDM
NMR

torsion pendulum
nuclear spin-precession frequencies
NMR

1 AYRES 23 at PSI use their neutron EDM setup to look for a mm to micron-range spindependent force between ultracold spin-polarized neutrons stored in vacuum and theunpolarised nucleons in the surrounding apparatus. They constrain a nucleon-neutronmonopole-dipole interaction parameterised by the coupling g N g n . They set a limit ofs p
g N g n < 10−20 (95% CL) for a 1 meV mass axion, see Fig. 6.
s p
2 PODDAR 23 search for long-range monopole-dipole forces between the polarized population of electrons inside the Earth and the unpolarised nucleons in the Sun, which
would affect the precession of orbital perihelion. However, the most competitive limit isobtained by combining the monopole-monopole force constraints on g N from planetarys
precession with the strongest stellar bound on the pseudoscalar electron coupling (g e ),pshown in Fig. 5.
3 ZHANG 23 look for changes of the ratio of precession frequencies between 129 Xe and
131 Xe as the bias field is flipped in Earth’s gravitational field after Earth roation effectis subtracted. They find g n g N < 1 × 10−26 –3.7 × 10−36 for λ = 0.3–1 × 1010 m.
p s
See their Fig. 4 for limits as a function of λ.
4 CRESCINI 22 is an update of CRESCINI 17, and find g e g N ≤ 5.7 × 10−32 and
p s
e
e
−31
g g
≤ 1.6 × 10
for λ & 10 cm at 95% CL. See their Fig. 4 for limits as ap sfunction of λ.
5 FENG 22 look for changes of the ratio of precession frequencies between 129 Xe and
131 Xe when a BGO crystal is positioned near the atomic cell. They find g n g N <
p s
−20
−24
2 × 10–3 × 10for λ = 0.11–0.55 mm. See their Fig. 4 for limits as a functionof λ.
6 AFACH 21 look for axion domain walls coupled to atomic spins by using the global
network of optical magnetometers. Assuming that the axion domain walls make up all
dark matter, they exclude the effective decay constant below 4 × 105 GeV for m 0 inA
the range of 10−15 –10−11 eV. See their Fig. 4 for the mass-dependent limits.
7 DZUBA 18 used atomic EDM measurements to derive limits on the product of thepseudoscalar coupling to nucleon and the scalar coupling to electron, which improved on
the laboratory bounds for m 0 > 0.01 eV. See their Fig. 1 for mass-dependent limits.
A
8 STADNIK 18 used atomic and molecular EDM experiments to derive limits on the productof the pseudoscalar couplings to electron and the scalar coupling to nucleon and electron.

https://pdg.lbl.gov

Page 54

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

See their Fig. 2 for mass-dependent limits, which improved on the laboratory bounds form 0 > 0.01 eV.
A
9 CRESCINI 17 use the QUAX-g g experiment to look for variation of a paramagnetic
p s
GSO crystal magnetization when rotating lead disks are positioned near the crystal, andfind g = g e g N < 4.3 × 10−30 for λ = 0.1–0.2 m at 95% CL. See their Fig. 6 forp slimits as a function of λ.
10 AFACH 15 look for a change of spin precession frequency of ultracold neutrons when amagnetic field with opposite directions is applied, and find g < 2.2 × 10−27 (m/λ)2
at 95% CL for 1 µm < λ < 5 mm. See their Fig. 3 for their limits.
11 STADNIK 15 studied proton and neutron spin contributions for nuclei and derive thelimits g < 10−28 –10−23 for λ > 3 × 10−4 m using the data of TULLNEY 13. See
their Figs. 1 and 2 for λ-dependent limits.
12 TERRANO 15 used a torsion pendulum and rotating attractor, and derived a restrictive
limit on the product of the pseudoscalar coupling to electron and the scalar coupling to
nucleons, g < 9 × 10−29 –5 × 10−26 for m 0 < 1.5–400 µeV. See their Fig. 5 forA
mass-dependent limits.
13 BULATOWICZ 13 looked for NMR frequency shifts in polarized 129 Xe and 131 Xe whena zirconia rod is positioned near the NMR cell, and find g < 1 × 10−19 –1 × 10−24 for
λ = 0.01–1 cm. See their Fig. 4 for their limits.
14 CHU 13 look for a shift of the spin precession frequency of polarized 3 He in the presenceof an unpolarized mass, in analogy to YOUDIN 96. See Fig. 3 for limits on g in theapproximate m 0 range 0.02–2 meV.
A
15 TULLNEY 13 look for a shift of the precession frequency difference between the colocated3 He and 129 Xe in the presence an unpolarized mass, and derive limits g < 3×10−29 –2×
10−22 for λ > 3 × 10−4 m. See their Fig. 3 for λ-dependent limits.
16 RAFFELT 12 show that the pseudoscalar couplings to electron and nucleon and thescalar coupling to nucleon are individually constrained by stellar energy-loss arguments
and searches for anomalous monopole-monopole forces, together providing restrictive
constraints on g. See their Figs. 2 and 3 for results.
17 HOEDL 11 use a novel torsion pendulum to study the force by the polarized electrons ofan external magnet. In their Fig. 3 they show restrictive limits on g in the approximate
m 0 range 0.03–10 meV.
A
18 PETUKHOV 10 use spin relaxation of polarized 3 He and find g < 3 × 10−23 (cm/λ)2
at 95% CL for the force range λ = 10−4 –1 cm.
19 SEREBROV 10 use spin precession of ultracold neutrons close to bulk matter and findg < 2 × 10−21 (cm/λ)2 at 95% CL for the force range λ = 10−4 –1 cm.
20 IGNATOVICH 09 use data on depolarization of ultracold neutrons in material traps.
They show λ-dependent limits in their Fig. 1.
21 SEREBROV 09 uses data on depolarization of ultracold neutrons stored in material
traps and finds g < 2.96 × 10−21 (cm/λ)2 for the force range λ = 10−3 –1 cm andg < 3.9 × 10−22 (cm/λ)2 for λ = 10−4 –10−3 cm, each time at 95% CL, significantly
improving on BAESSLER 07.
22 BAESSLER 07 use the observation of quantum states of ultracold neutrons in the Earth’s
gravitational field to constrain g for an interaction range 1 µm–a few mm. See their Fig. 3
for results.
23 HECKEL 06 studied the influence of unpolarized bulk matter, including the laboratory’s
surroundings or the Sun, on a torsion pendulum containing about 9 × 1022 polarized
electrons. See their Fig. 4 for limits on g as a function of interaction range.
24 NI 99 searched for a T-violating medium-range force acting on paramagnetic Tb F salt.
3
See their Fig. 1 for the result.
25 POSPELOV 98 studied the possible contribution of T-violating Medium-Range Force tothe neutron electric dipole moment, which is possible when axion interactions violate

https://pdg.lbl.gov

Page 55

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

CP. The size of the force among nucleons must be smaller than gravity by a factor of
2 × 10−10 (1 cm/λA ), where λA =h̄/m A c.
26 YOUDIN 96 compared the precession frequencies of atomic 199 Hg and Cs when a large
mass is positioned near the cells, relative to an applied magnetic field. See Fig. 3 fortheir limits.
27 RITTER 93 studied the influence of bulk mass with polarized electrons on an unpolarized
torsion pendulum, providing limits in the interaction range from 1 to 100 cm.
28 VENEMA 92 looked for an effect of Earth’s gravity on nuclear spin-precession frequencies
of 199 Hg and 201 Hg atoms.
29 WINELAND 91 looked for an effect of bulk matter with aligned electron spins on atomic
hyperfine resonances in stored 9 Be+ ions using nuclear magnetic resonance.

Hidden Photons: Kinetic Mixing Parameter Limits
Limits are on the kinetic mixing parameter χ which is defined by the Lagrangianm2 ′ ′ ′
′µ ν
′
′µ ν
χ
1
1
µ
ν
L = − 4 Fµ ν F
F−4 F− 2 Fµ ν F+ 2γ A A µ ,µνµwhere Aµ and A′ are the photon and hidden-photon fields with field strengths Fµ νµ′
, respectively, and m ′ is the hidden-photon mass.
and F
µν
γ
VALUE

CL%

DOCUMENT ID

TECNCOMMENT• • • We do not use the following data for averages, fits, limits, etc. • • •1 ABREU< 4
× 10−690
24 FASR m ′ ≃ 50 MeV
γ
−3
2
< 1
× 10
90
AAD
23BO ATLS m ′ = 5–40 GeV
γ
3 AAD
< 1.3
× 10−890
23I ATLS m ′ = 0.017–15 GeVγ
4 AAD
23T ATLS m ′ . 40 GeV
γ
5 AALBERS< 1
× 10−16 90
23A LZm ′ = 1–17 keVγ
6 ABLIKIM< 1.6
× 10−390
23AF BES3 m ′ = 1.5–2.9 GeVγ
7 ABUDINEN
23B BEL2 m ′ = 4–9.7 GeVγ
8 ADHIKARI< 1.61× 10−14 90
23 C100 m ′ = 215 eVγ
9 ADHIKARI< 6
× 10−14 90
23A C100 m ′ = 10–1000 keVγ
10 ADRIAN< 2.1
× 10−395
23 HPSm ′ = 19–81 MeV
γ
11 AGNES< 1.1
× 10−16 90
23A DS50 m ′ = 0.03–20 keV
γ
12 AN
< 2
× 10−12 95
23Am ′ = 4.1–6.2 µeVγ
13 ANDREEV< 5
× 10−690
23 NA64 m ′ = 10−3 –1.5 GeV
γ
14 BAJJALI< 5.0
× 10−14 68
23 BRAS m ′ = 49.63–74.44 µeVγ
15 CORTINA-GIL 23C NA62 m = 10–700 MeV< 2
× 10−7
90
γ′
−3
16
< 2.2
× 10
90
HAYRAPETY...23G CMS m ′ = 1.1–7.9 GeV
γ
−11
17
< 3
× 10
95
KOTAKA
23 DORR m ′ = 74–110 µeV
γ
18 LI
< 2
× 10−15
23I ASTR m ′ = 10−3 –105 eVγ
19 RAMANATH... 23 QULP m = 19.7–30.5 µeV< 7.9
× 10−13 95
γ′
20 ROMANENKO 23 LSW m = 0.21–5.7 µeV< 1.6
× 10−995
γ′
21 XIA
23 ASTR m ′ . 10−23 eVγ
22 AAD
22J ATLS m ′ = 1–60 GeVγ

https://pdg.lbl.gov

Page 56

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

23 AAD

< 2
< 2
< 5
< 1

× 10−15 90
× 10−15 90
× 10−17 90
× 10−290+ 0.5 ) × 10−15 68(4.6 −
0.4
< 1
< 1
< 8.7

< 7.97< 6.86
< 3

< 8
< 2.3
< 1.6
< 3
< 1.68
< 2
< 1.8
< 3
< 2
< 3
< 1

< 4.1
< 3.3
< 1.2
< 6.72< 1< 9

× 10−13 90
× 10−12 90
× 10−11 95
× 10−9
95
−11
× 10
90
−2
× 10
95

× 10−6× 10−4× 10−4× 10−5

90
90
95
90

× 10−15 90
× 10−16 90
× 10−13× 10−12 95
× 10−295
× 10−8× 10−490
90

× 10−12 90
× 10−14 90
× 10−14 90

× 10−13 95
× 10−16 90
× 10−16 90

https://pdg.lbl.gov

m ′ . 10 GeV
γ
22 XE1T m ′ = 0.9 keVγ
25 APRILE
22 XE1T m ′ = 0.01–0.4 keVγ
26 APRILE
22B XENT m ′ = 1–39,44–140 keVγ
27 BATTAGLIERI 22 BDMP m = 3–100 MeV
γ′
28 BOLTON
22 ASTR m ′ = (8.4 ± 0.6) ×γ
10−14 eV29 CERVANTES 22 ORPH m = 65.5–69.3 µeVγ′
30 CHILES
22m ′ = 0.7–0.8 eVγ
31 HOCHBERG 22 SNSP m = 0.73–30 eVγ′
32 LEES
22 BABR m ′ = 1 × 10−3 –3.16
γ
GeV
33 LU
22 ASTR m ′ . 3 × 10−5 eVγ
34 MANENTI
22 MDHI m ′ = 1.61 eVγ
35 THOMAS
22m ′ = 1–80 GeVγ
36 TUMASYAN 22AH CMS m = 4–62.5 GeVγ′
37 TUMASYAN 22N CMS m = 0.6–49 GeVγ′
38 WU
22A PPTA m ′ . 10−23 eVγ
39 ANDREEV
21 NA64 m ′ = 1 × 10−3 –1 GeVγ
40 ANDREEV
21A NA64 m ′ = 0.1–0.35 GeVγ
41 BI
21 ASTR m ′ = 0.03–0.06 eVγ
42 CAZZANIGA 21 NA64 m = 10–390 MeV
γ′
43 DIXIT
21 CNTR m ′ = 24.86 µeVγ
44 GHOSH
21 RVUE m ′ = 2–30 µeVγ
45 GODFREY
21
m ′ =
γ
0.2637–0.2648 µeV
46 KOPYLOV
21A CNTR m ′ = 9–40 eVγ
47 KRIBS
21m ′ . 10 GeVγ
48 SCHMIDT
21 THEO m ′ < 0.6 GeV
γ
49 TSAI
21 BDMP m ′ = 0.78 GeV
γ
50 AAIJ
20C LHCB m ′ = 214 MeV
γ
51 AAIJ
20C LHCB m ′ = 218–315 MeV
γ
52 ABLIKIM
20AB BES3 m ′ = 0.2–2.1 GeV
γ
53 AGOSTINI
20 HPGE m ′ = 60 keV – 1 MeVγ
54 AMARAL
20 SCDM m ′ = 1.2–50 eVγ
55 AN
20 XE1T m ′ = 200 eVγ
56 ANDRIANAV... 20 FUNK m = 1.95–8.55 eVγ′
57 APRILE
20 XE1T m ′ = 1–200 keVγ
58 ARALIS
20 SCDM m ′ = 0.04–500 keVγ
22S ATLS

24 APRILE

Page 57

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

< 3
< 7
< 8.2

× 10−5
90
−14
× 10
90
× 10−590< 7

× 10−15 90< 1.4

× 10−14 90
× 10−15 90
× 10−3
90

< 1.3
< 1
< 4.3

× 10−10 95< 9

× 10−16 90< 6

× 10−3× 10−3

< 3.4
< 8
< 9
< 7.5

90
90

× 10−15 90
× 10−17 90
× 10−690< 2

× 10−11< 5

× 10−12 95
× 10−490
× 10−5
95

< 4.4
< 3
< 6
< 1
< 1.5

× 10−9
95
−11
× 10
95
−9
× 10

< 3

× 10−14 95< 4.5

× 10−14 90
× 10−3
95
−4
× 10
90

< 2.5
< 4.4
< 4

× 10−15 90< 1.8

× 10−5× 10−890

× 10−4

90

< 1
< 3.1
< 6
< 7
< 1.2

90
−14
× 10
90
−4
× 10
90
× 10−15 90

https://pdg.lbl.gov

59 ARGUELLES

20

THEO m ′ = 0.01 GeV
γ
20 EDEL m ′ = 1–40 eVγ
61 BANERJEE
20 NA64 m ′ = 1.5–24 MeV
γ62 BARAK
20 SENS m ′ = 1.2–12.8 eVγ
63 KRASNIKOV 20 RVUE m = 16.7 MeV
γ′
64 SHE
20 CDEX m ′ = 10–300 eVγ
65 SHE
20 CDEX m ′ = 0.1–4 keVγ
66 SIRUNYAN
20AQ CMS m ′ = 11.5–75 GeV,γ
110–200 GeV
67 TOMITA
20
m ′ =
γ
115.79–115.85 µeV
68 WANG
20A CDEX m ′ = 0.185–10 keVγ
69 AABOUD
19G ATLS m ′ = 20–60 GeV
γ
70 ABLIKIM
19A BES3 m ′ = 0.01–2.4 GeV
γ
71 ABLIKIM
19H BES3 m ′ = 0.1–2.1 GeV
γ
72 AGUILAR-AR...19A DAMC m = 1.2–30 eVγ′
73 APRILE
19D XE1T m ′ = 0.186–5 keVγ
74 BANERJEE
19 NA64 m ′ = 1–200 MeV
γ
75 BHOONAH
19 ASTR m ′ = 10−22 –10−10γeV
76 BRUN
19 SHUK m ′ = 20.8–28.3 µeVγ
77 CORTINA-GIL 19 NA62 m = 60–110 MeV
γ′
78 DANILOV
19 TEXO m ′ = 20 eV - 1 MeVγ
79 HOCHBERG 19
m ′ = 0.8–4 eVγ
80 KOPYLOV
19 CNTR m ′ = 9–40 eVγ
81 KOVETZ
19 COSM m ′ = 10−23 –10−13γeV
82 NGUYEN
19 WDMX m ′ = 6 neV – 2.07γ
µeV
83 ABE
18F XMAS m ′ = 40–120 keVγ
84 ADRIAN
18 HPSm ′ = 19–81 MeV
γ
85 ANASTASI18B KLOE m ′ = 519–987 MeVγ
86 ARMENGAUD 18 EDE3 m = 0.8–500 keVγ′
87 BANERJEE
18 NA64 m ′ = 1–23 MeV
γ88 BANERJEE
18A NA64 m ′ = 1–100 MeV
γ
89 KNIRCK18m ′ = 0.67–0.92 meVγ
90 ABGRALL
17 HPGE m ′ = 11.8 keVγ
91 ABLIKIM
17AA BES3 m ′ = 1.5–3.4 GeVγ
92 ANGLOHER
17 CRES m ′ = 0.3–0.7 keVγ
93 BANERJEE
17 NA64 m ′ = 0.002–0.4 GeV
γ
60 ARNAUD

Page 58

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

< 2
< 4.5
< 4
< 4.4
< 1.7
< 4
< 1.4

< 1.7
< 4.2
< 3
< 6
< 2.3
< 2
< 1.8
< 9.0

< 1.3
< 3
< 3.5
< 9
< 3
< 7
< 8
< 2
< 2.2
< 8.06< 2< 1.7< 5.32
< 1
< 8
< 1
< 1
< 9

× 10−11× 10−390
× 10−490
× 10−4× 10−6× 10−2× 10−3× 10−3× 10−4

90
95
95
90

90
90

× 10−13× 10−12× 10−13 99.7
× 10−13× 10−3× 10−490
90

× 10−795−18
× 10

× 10−4× 10−490
95

× 10−15
× 10−14× 10−4× 10−390−13× 10
× 10−595
× 10−10 95

× 10−7× 10−15

× 10−15
× 10−890
× 10−790

× 10−3× 10−8https://pdg.lbl.gov

9095

94 CHANG

17

ASTR m ′ = 15 MeV
γ
17 EMUL m ′ = 1.1–24 MeV
γ
96 LEES17E BABR m ′ = 4.7 GeVγ
97 AAD
16AG ATLS m ′ = 0.1–2 GeVγ
98 ANASTASI
16 KLOE m ′ = 527–987 MeVγ
99 KHACHATRY...16 CMS m = 2 GeV
γ′
100 AAD
15CD ATLS m ′ = 15–55 GeVγ101 ADARE
15m ′ = 30–90 MeV
γ
102 AN15A
m ′ = 12 eV - 40 keVγ
103 ANASTASI
15 KLOE m ′ = 2m µ - 1 GeVγ
104 ANASTASI
15A KLOE m ′ = 5–320 MeV
γ105 BATLEY
15A NA48 m ′ = 36 MeV
γ106 JAEGLE
15 BELL m ′ = 0.1–3.5 GeVγ107 KAZANAS
15 ASTR m ′ = 2m e – 100 MeV
γ
108 SUZUKI
15m ′ = 1.9–4.3 eVγ
109 VINYOLES
15 ASTR m ′ = 8 eVγ
110 ABE
14F XMAS m ′ = 40–120 keVγ
111 AGAKISHIEV 14 HDES m = 63 MeVγ′112 BABUSCI
14 KLOE m ′ = 969 MeV
γ113 BATELL
14 BDMP m ′ = 10−3 –1 GeVγ114 BLUEMLEIN 14 BDMP m = 0.6 GeV
γ′
115 FRADETTE
14 COSM m ′ = 50–300 MeV
γ116 LEES
14J BABR m ′ = 0.2 GeVγ117 MERKEL
14 A1
m ′ = 40–300 MeV
γ
118 AN13B ASTR m ′ = 2 keVγ
119 AN
13C XE10 m ′ = 100 eVγ
120 DIAMOND
13 BDMP m ′ = 30–250 MeV
γ
121 GNINENKO
13 BDMP m ′ = 25–120 MeV
γ122 HORVAT
13 HPGE m ′ = 230 eVγ
123 INADA
13 LSW m ′ = 0.04 eV−26 keVγ
124 MIZUMOTO 13
m ′ = 1 eVγ
125 PARKER
13 LSW m ′ = 53 µeVγ
126 PARKER
13m ′ = 53 µeVγ
127 REDONDO
13 ASTR m ′ = 2 keVγ
128 GNINENKO
12A BDMP m ′ = 1–135 MeV
γ129 GNINENKO
12B CHRM m ′ = 1–500 MeV
γ
130 ABRAHAMY... 11m ′ = 175–250 MeV
γ131 BLUEMLEIN 11 BDMP m = 70 MeV
γ′
95 DUBININA

Page 59

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

< 1
< 5

× 10−7× 10−9132 BJORKEN

09

133 BJORKEN

09

BDMP m ′ = 2–400 MeVγASTR m ′ = 2–50 MeV
γ

1 ABREU 24 look for hidden photons produced from the p p collision in the decay channel
γ ′ → e + e − , and exclude at 90% CL the region of χ = 4 × 10−6 –2 × 10−4 and m ′γ= 10–80 MeV, with the newly excluded region near the higher values of χ. See theirFig. 7 for mass-dependent limits.
2 AAD 23BO look for rare decays of the Z boson, Z → γ ′ + H ′ , with dark Higgs decaying
into a pair of hidden photons, assuming that at least two of the hidden photons decay intoe + e − or µ+ µ− . The quoted limit assumes the hidden fine structure constant αD = 0.1
and the dark Higgs mass ranging 20 to 70 GeV. See their Fig.5 for the mass-dependent
limits.
3 AAD 23I look for exotic decays of the SM-like Higgs boson, H → γ ′ γ ′ with hidden
photons decaying into displaced lepton or light quark pairs, and set limits on the kinetic
mixing within 1 × 10−4 –1 × 10−8 for the given mass range. The quoted limit is for m 0
A≃ 13 GeV with a branching fraction of 0.1 for the Higgs decaying into hidden photon
pairs. See their Fig. 13 for the mass-dependent limits.
4 AAD 23T is analogous to AAD 22S, but using the Z H production mode, and set theupper limit on the branching ratio B(H → γ γ ′ ) within 0.0219–0.0252 (95% CL).
5 AALBERS 23A look for an absorption of hidden photon dark matter. The quoted limit
is for m ′ = 1.4 keV. The local density ρ ′ = 0.3 GeV/cm3 is assumed. See their Fig.
γγ
7 for mass-dependent limits.
6 ABLIKIM 23AF look for invisible decays of hidden photons produced in the reactione + e − → γ γ ′ . They set limits within the 1.6 × 10−3 –5.7 × 10−3 . See their Fig. 3 formass-dependent limits.
7 ABUDINEN 23B look for hidden photons in the dark Higgsstrahlung process, e + e − →γ ′ H ′ (γ ′ → µ+ µ− ) with H ′ being invisible. They set upper limits on the product of the
kinetic mixing and the hidden gauge coupling, χ2 · αD , in the range of 1.7 × 10−8 –2 ×
10−6 at 90% CL for a 1 GeV dark Higgs mass. See their Fig. 3 for the mass-dependent
limits.
8 ADHIKARI 23 look for the annual modulation signal induced by solar flux of hidden
photons. See their Fig. 10 for mass-dependent limits.
9 ADHIKARI 23A look for absorption and Compton-like processes of hidden photon dark
matter. The quoted limit is for m ′ ≃ 12 keV. Limits between 6 × 10−14 –3 × 10−11γ
are obtained. See their Fig. 4 for mass-dependent limits.
10 ADRIAN 23 is an update of ADRIAN 18, and use the data from the 2016 engineering
run at 2.3 GeV. The quoted limit is at m ′ ≃ 74 MeV. See their Fig. 28 for theγ
mass-dependent limits.
11 AGNES 23A look for an absorption of hidden photon dark matter. The quoted limit isfor m ′ = 0.03 keV. The local density ρ ′ = 0.3 GeV/cm3 is assumed. See their Fig. 2γ
γ
for mass-dependent limits.
12 AN 23A look for absorption of hidden photon dark matter at radio telescopes, setting
limits based on data from the FAST telescope. The local density ρ ′ = 0.3 GeV/cm3 isγ
assumed. See their Fig. 1 for mass-dependent limits.
13 ANDREEV 23 is an update of ANDREEV 21 and ANDREEV 21A. The quoted limit
applies to m ′ = 1 MeV. See their Fig. 3 for mass-dependent limits.
γ

https://pdg.lbl.gov

Page 60

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

14 BAJJALI 23 look for hidden photon dark matter by using a 12–18 GHz dish antenna at U.
Hamburg that is sensitive to vertically aligned hidden photon polarizations. They assume
a local density of ρ ′ = 0.3 GeV/cm3 . See their Figure 12 for mass-dependent limitsγ
in the range of m ′ = 50–75 µeV under the assumption of randomly aligned hidden
γ
photon polarizations, defined as ”1 sigma sensitivity”. The run is labelled BRASS-p.
15 CORTINA-GIL 23C NA62 beam dump experiment searches for hidden photons decaying
to µ+ µ− , extending their previous search CORTINA-GIL 19. The quoted limit applies
at 300 MeV but does not extend to arbitrarily large kinetic mixing parameters. See Fig.
4 for mass-dependent limits.
16 HAYRAPETYAN 23G search for kinetically mixed hidden photons in proton-proton collisions at the LHC that would generate a narrow peak in the mass spectrum of dimuon
events. The mass window between 2.6 and 4.2 GeV is left unconstrained to avoid J/ψ
and ψ(2S) resonances. Mass dependent limits given in their Fig. 6.
17 KOTAKA 23 is an update of TOMITA 20, and set limits χ < 0.3–2 × 10−10 for thequoted mass range. The local density ρ ′ = 0.39 GeV/cm3 is assumed. See their Fig.
γ
5 for mass-dependent limits.
18 LI 23I set cooling bounds on the emission of hidden photons from the Sun, red giant,and horizontal branch stars, including emission of both the transverse and longitudinalmodes. Cooling bounds are computed assuming a static model as opposed to considering
the impact on stellar evolution. The result is comparable to earlier estimates of the same
bound e.g. REDONDO 13. Limit applies at the most constraining mass around 200 eV
for the solar bound.
19 RAMANATHAN 23 look for hidden photon dark matter using a gold-plated copper dishantenna cooled to 20 mK. The local density ρ ′ = 0.45 GeV/cm3 is assumed. Limitsγ
between 7.9×10−13 and 3.81×10−12 are obtained. See their Fig. 5 for mass-dependent
limits.
20 ROMANENKO 23 employed two superconducting radio frequency cavities with a highquality factor, optimized for detecting the longitudinal polarization of the hidden photon.
The quoted limit is set at m ′ ≃ 5µeV. See their Fig. 4 for the mass-dependent limits.
γ
21 XIA 23 is analogous to WU 22A and use the Fermi-LAT pulsar timing array. They set abound on the local density as ρ ′ . 7 GeV/cm3 for m ′ . 10−23 eV at 95% CL,γγ−22with weaker constraints up to 10
eV. See their Fig. 1 for the mass-dependent limits.
22 AAD 22J look for exotic decays of the SM-like Higgs boson, H → γ ′ γ ′ → 4ℓ and H →Z γ ′ → 4ℓ, and set limits on the kinetic mixing and the Higgs portal coupling. See theirFigs. 19 and 20 for the mass-dependent limits.
23 AAD 22S look for decays of a Higgs boson into γ and γ ′ using the VBF production mode,and set the upper limit on the branching ratio at 0.018 (95% CL) for the 125 GeV Higgs
boson. For the quoted mass range, the signal acceptance changes by less than 1%.
24 APRILE 22 is analogous to AN 20, and set limits χ < 3 × 10−13 (eV/m ) for m<γ′γ′
3 eV (90% C.L.). For m ′ > 3 eV, see their Fig. 16 for mass-dependent limits.
γ
25 APRILE 22 extend APRILE 19 to lower masses by removing the background of ionization
signals correlated with high-energy events. The quoted limit applies to m ′ = 0.09 keV.
γ
See their Fig. 15 for mass-dependent limits.
26 APRILE 22B is an update of APRILE 20, and set limits χ . 5 × 10−17 –2 × 10−13 .
The quoted limit applies to m ′ = 1 keV. They exclude the XENON1T excess found inγ
APRILE 20. See their Fig. 6 for mass-dependent limits.
27 BATTAGLIERI 22 is analogous to BATELL 14, and derived limits from the electron beam
dump experiment at Jefferson Lab (BDX-MINI). Limits at the level of 7×10−5 –1×10−2
are obtained for the dark matter mass m ′ /3 and the hidden gauge coupling αD = 0.1.
γ
See their Fig. 11.

https://pdg.lbl.gov

Page 61

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

28 BOLTON 22 use the Ly-α forest at z ≃ 0.1 as a calorimeter for heating in the intergalactic medium by the resonant conversion of hidden photon dark matter to photons,
which is assumed to be responsible for the tension between the predicted and observed
Ly-α absorption linewidths.
29 CERVANTES 22 use a dielectrically loaded Fabry-Perot open cavity to look for hidden
photon dark matter. The local density ρ ′ = 0.45 GeV/cm3 is assumed. See their Fig.
γ
5 for mass-dependent limits.
30 CHILES 22 look for hidden photon dark matter by using a layered dielectric target and asuperconducting nanowire single-photon detector. The local density ρ ′ = 0.4 GeV/cm3γ
is assumed. See their Fig. 4 for mass-dependent limits.
31 HOCHBERG 22 update HOCHBERG 19. The quoted limit applies to m
≃ 11 eV.
A0
See their Fig. 5 for mass-dependent limits.
32 LEES 22 look for a hidden fermion-fermion bound state decaying into three hidden
photons, which subsequently decay into e + e − , µ+ µ− , or π + π − . For the bound-state
mass in the range of 0.05–9.5 GeV, limits at the level of 5×10−5 –1×10−3 are obtained.
See their Fig. 6 for mass-dependent limits.
33 LU 22 derive the limit by studying the effect of photons oscillating into hidden photons
on the surface luminosity of the neutron star RX J1856.6-3754.
34 MANENTI 22 look for hidden photon dark matter by using a multilayer dielectric haloscope. Limits between 6.86 × 10−11 and 5 × 10−8 are obtained for m ′ ≃ 1.1–3.1γeV. See their Fig. 11 for mass-dependent limits.
35 THOMAS 22 improved KRIBS 21 by taking account of the changes in the parton distribution functions due to the inclusion of hidden photons. The quoted limit is at m ′ ≃γ
4 GeV. Limits in the range of 3 × 10−2 –9 × 10−2 are obtained for m ′ = 1–80 GeV.
γ
See their Fig. 1 for the limits.
36 TUMASYAN 22AH look for exotic decays of the SM-like Higgs boson, H → Z γ ′ → 4ℓ,
and set limits on the Higgs portal coupling. See their Fig. 6 for the limits.
37 TUMASYAN 22N look for exotic decays of the SM-like Higgs boson, H → γ ′ γ ′ (γ ′ →µ+ µ− ), and set limits on the branching fraction product. See their Fig. 7 for massand lifetime-dependent limits.
38 WU 22A look for direction-dependent oscillations in the gravitational potential generated
by ultralight hidden photon dark matter, and set a bound on its local density as ρ ′ .
γ
5 GeV/cm3 for m ′ . 10−23 eV at 95% CL.
γ
39 ANDREEV 21 is analogous to BANERJEE 18A. The quoted limit applies to m = 1γ′MeV. See their Fig. 3 for mass-dependent limits.
40 ANDREEV 21A extends the limits of BANERJEE 19 by taking account of production
through the resonant annihilation of secondary positrons with atomic electrons. The
quoted limit is at m ′ = 0.23 GeV, assuming the fermion dark matter of mass m ′ /3γγ
and the hidden gauge coupling αD = 0.1. See their Fig.3 for mass-dependent limits.
41 BI 21 look for the gamma-ray spectral attenuation due to scattering with hidden photons
constituting all dark matter, using the measurements of sub-PeV gamma-rays from the
Crab Nebula by the Tibet ASγ and HAWC experiments, together with MAGIC andHEGRA gamma-ray data. See their Fig. 4 for mass-dependent limits.
42 CAZZANIGA 21 look for semi-visible decays of hidden photons, γ ′ → χ χ (χ →1 22
χ1 e + e − ), where χ1 and χ2 are hidden fermions. They exclude 3 × 10−5 . χ .
2 × 10−2 assuming the hidden gauge coupling αD = 0.1, and the fermion masses m χ1= m ′ /3, (m χ − m χ )/m χ = 0.4. See their Fig. 4 for mass-dependent limits.
γ
2
1
1

https://pdg.lbl.gov

Page 62

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

43 DIXIT 21 look for hidden photon dark matter by using a superconducting transmon qubit
dispersively coupled to a high Q storage cavity. The local density ρ ′ = 0.4 GeV/cm3γ
is assumed. See their Fig.4 for mass-dependent limits.
44 GHOSH 21 use existing haloscope axion search limits to set limits on hidden photon dark
matter, considering the polarization of hidden photons. The quoted limit is at m ′ ≃ 3γµeV. See their Fig. 1 for mass-dependent limits.
45 GODFREY 21 look for hidden photon dark matter by using a wideband antenna, andset 5σ limits on χ. The local density ρ ′ = 0.38 GeV/cm3 is assumed. See theirγ
updated Fig. 12 in arXiv:2101.02805v4 for mass-dependent limits in the range of m ′γ= 0.207–1.24 µeV.
46 KOPYLOV 21A is an update of KOPYLOV 19, but use Ne gas instead of Ar. The quoted
limit applies to m ′ = 12 eV. See their Fig. 4 for mass-dependent limits.
γ
47 KRIBS 21 used the HERA data on neutral current deep inelastic e p scattering to derive
the limits, which become weaker for heavier masses. See their Fig. 3 for mass-dependent
limits.
48 SCHMIDT 21 use the microscopic Parton-Hadron-String Dynamics approach to extract
limits by comparing the theoretically calculated dilepton spectra with the HADES dataon the search for γ ′ → e + e − . See their Fig. 5 for the mass-dependent limits forvarious allowed surplus of the hidden photon contribution over the standard model yield.
49 TSAI 21 update the limits from the CHARM and NuCal experiments, taking account ofadditional production channels from proton bremsstrahlung and η meson decays, respectively. Limits between 3 × 10−8 and 1 × 10−4 are obtained for 0.01 < m ′ < 0.8 GeVγ(see their Fig. 1).
50 AAIJ 20C look for hidden photons produced from the p p collision in the decay channel
γ ′ → µ+ µ− . For prompt decaying hidden photons, limits at the level of 10−4 –10−3
are obtained for m ′ = 0.214–30 GeV. See their Fig. 2 for mass-dependent limits.
γ
51 AAIJ 20C look for hidden photons produced from the p p collision in the decay channel
γ ′ → µ+ µ− . For hidden photons with lifetimes of order ps, limits at the level of 10−5
are obtained for m ′ = 218–315 MeV. See their Fig. 4 for mass-dependent limits.
γ
52 ABLIKIM 20AB search for J/ψ → η ′ γ ′ (γ ′ → γ π 0 ), and set the upper limit on the
product branching fraction of order 10−7 . See their Fig. 7 for mass-dependent limits.
53 AGOSTINI 20 is analogous to ABE 14F. The quoted limit applies to m = 150 keV.
γ′
3The local density ρ ′ = 0.3 GeV/cm is assumed. Their limits in their Fig. 3 wereγ
later found to be incorrect due to an error of their Eqs. (1) and (2). See Fig. 3 in
AGOSTINI 22A for the corrected limits.
54 AMARAL 20 use a second-generation SuperCDMS high-voltage eV-resolution detector
to set limits on dark-matter hidden photon absorption. The quoted limit is for m ′ ≃γ
17 eV. The local density ρ ′ = 0.3 GeV/cm3 is assumed. See their Fig. 3 for massγ
dependent limits.
55 AN 20 updates the direct detection limit of AN 13C on solar flux of hidden photons;
χ < 1.6 × 10−12 (eV/m ′ ) for m ′ < 6 eV (90% C.L.). For m ′ > 6 eV, see theirγγγ
Fig. 1 for mass-dependent limits.
56 ANDRIANAVALOMAHEFA 20 is analogous to SUZUKI 15, but uses a mirror that isabout one order of magnitude larger than in similar studies in the past. Limits at thelevel of 10−12 are obtained for m ′ = 2.5–7 eV. See their Fig.23 and Table III forγ
mass-dependent limits.
57 APRILE 20 is analogous to ABE 14F, and set limits χ . 10−16 –10−12 . The quoted
limit applies to m ′ = 1 keV. They also found an excess over known backgrounds, whichγ

https://pdg.lbl.gov

Page 63

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

favors the mass m ′ = 2.3 ± 0.2 keV with a 3 σ significance. See their Fig. 10 forγ
mass-dependent limits.
58 ARALIS 20 is analogous to ABE 14F. The quoted limit applies to m = 0.1 keV. Theγ′local density ρ ′ = 0.3 GeV/cm3 is assumed. The limits at masses above 3 keV in theirγFig. 10 was later found to be incorrect due to an error in their analysis. See Fig. 3 in
ARALIS 21 for the corrected limits.
59 ARGUELLES 20 examine hidden-photon production in atmospheric cosmic-ray showers
and its decay in IceCube and Super-Kamiokande. The quoted limit assumes a lifetimeof cτ = 0.1 km. See their Fig. 16 for mass- and lifetime-dependent limits.
60 ARNAUD 20 look for the absorption signal of hidden photon dark matter in a Ge detector.
The quoted limit applies to m ′ ≃ 9 eV. The local density ρ ′ = 0.3 GeV/cm3 isγγ
assumed. See their Fig. 3 for mass-dependent limits.
61 BANERJEE 20 is an update of BANERJEE 18. They exclude 8.2 × 10−5 . χ .
1×10−2 for m ′ = 1.5–24 MeV. In particular, they exclude χ = 1.2×10−4 –6.8×10−4γ
for the 16.7 MeV gauge boson. See their Fig. 5 for mass-dependent limits.
62 BARAK 20 is analogous to AGUILAR-AREVALO 19A, and look for hidden photon dark
matter by using the Skipper CCD. The quoted limit applies to m ′ = 12.8 eV. See theirγFig. 4 for mass-dependent limits.
63 KRASNIKOV 20 showed that the limit of BANERJEE 20 combined with the measured
anomalous magnetic moment of the electron exclude the 16.7 MeV gauge boson suggested by the ATOMKI (KRASZNAHORKAY 16) experiment if it has pure vector oraxial-vector interactions.
64 SHE 20 look for solar hidden photons. The quoted limit applies to m = 180 eV. Seeγ′their Fig. 4 for mass-dependent limits.
65 SHE 20 look for hidden photon dark matter and set limits χ < 1.3×10−15 –2.8×10−14
for the quoted mass range. The local density ρ ′ = 0.3 GeV/cm3 is assumed. See theirγFig. 6 for mass-dependent limits.
66 SIRUNYAN 20AQ look for a narrow resonance decaying into a pair of muons. For mγ′< 45 GeV, they use dedicated high-rate dimuon triggers to reduce the muon transverse
momentum thresholds. The quoted limit applies to m ′ = 50 GeV, and limits of orderγ10−3 are obtained for the quoted mass range. See their Fig. 3 for mass-dependent
limits.
67 TOMITA 20 look for hidden photon dark matter using a planar metal plate and cryogenic
receiver and set limits χ < 1.8–4.3 × 10−10 for the quoted mass range. The local
density ρ ′ = 0.39 GeV/cm3 is assumed. See their Fig. 7 for mass-dependent limits.
γ
68 WANG 20A is analogous to ABE 14F. The quoted limit applies to m = 185 eV. Theγ′
3
local density ρ ′ = 0.3 GeV/cm is assumed. See their Fig. 11 for mass-dependentγ
limits.
69 AABOUD 19G look for h → γ ′ γ ′ (γ ′ → µ+ µ− ) and exclude a kinetic mixing around10−9 –10−8 for B(h → γ ′ γ ′ ) = 0.01 and 0.1. See their Fig. 9 for mass-dependent
limits.
70 ABLIKIM 19A look for J/ψ → γ ′ η (γ ′ → e + e − ). Limits between 6 × 10−3 and5 × 10−2 are obtained (see their Fig. 8).
71 ABLIKIM 19H look for J/ψ → γ ′ η ′ (γ ′ → e + e − ). Limits between 3.4 × 10−3 and2.6 × 10−2 are obtained. See their Fig. 5 for mass-dependent limits.
72 AGUILAR-AREVALO 19A look for the absorption signal of hidden photon dark matterby using a CCD. The quoted limit applies to m ′ = 17 eV. The local density ρ ′ = 0.3γγ
GeV/cm3 is assumed. See their Fig. 4 for mass-dependent limits.

https://pdg.lbl.gov

Page 64

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

73 APRILE 19D is analogous to ABE 14F. The quoted limit applies to mγ′

= 0.7 keV. See

their Fig. 5(f) for mass-dependent limits.
74 BANERJEE 19 is an update of BANERJEE 18A. The quoted limit is at mγ′

= 1 MeV.

See their Fig. 3 for mass-dependent limits.
75 BHOONAH 19 examine heating of Galactic Center gas clouds by hidden photon dark
matter. The quoted limit applies to m ′ ≃ 10−12 eV. See their Fig. 2 for massγ
dependent limits.
76 BRUN 19 is analogous to SUZUKI 15. The limit is derived under an assumption that
hidden photons constitute the local dark matter density ργ ′ = 0.3 GeV/cm3 .
77 CORTINA-GIL 19 look for an invisible hidden photon in the reaction K + → π + π 0(π 0 → γ γ ′ ). The quoted limit applies to m ′ = 62.5–65 MeV. See their Figs. 6 andγ
7 for mass-dependent limits.
78 DANILOV 19 examined the hidden photon production in nuclear reactors, correctly taking
account of the effective photon mass in the reactor and detector. The limit gets weakerfor m ′ less than the effective photon mass in proportion to 1/m 2 ′ . See their Fig. 1 forγγ
mass-dependent limits.
79 HOCHBERG 19 look for the absorption signal of hidden photon dark matter by using
superconducting-nanowire single-photon detectors. The quoted limit applies to m ′ ≃γ
1 eV. The local density ρ ′ = 0.3 GeV/cm3 is assumed. See their Fig. 4 for massγ
dependent limits.
80 KOPYLOV 19 look for hidden-photon dark matter using a counter with an aluminum
cathode and derive limits assuming it constitute all the local dark matter. The quoted
limit applies to m ′ = 12 eV. See their Fig. 7 for mass-dependent limits.
γ
81 KOVETZ 19 examine heating of the early Universe plasma by hidden photon dark matter,and derive the limits by requiring that the cosmic mean 21 cm brightness temperature
relative to the CMB temperature satisfy T21 > − 100 mK. The quoted limit applies tom ′ ≃ 2 × 10−14 eV. See their Fig. 3 for mass-dependent limits.
γ
82 NGUYEN 19 look for hidden photon dark matter with a resonant cavity, and set limits∼ 10−12 for m ′ = 0.2–2.07µeV. The quoted limit applies to m ′ = 1.3 µeV. The localγγ
density ρ ′ = 0.3 GeV/cm3 is assumed. See their Fig. 19 for mass-dependent limits.
γ
83 ABE 18F is an update of ABE 14F. The quoted limit applies to m ≃ 40 keV. See theirγ′Fig. 5 for mass-dependent limits.
84 ADRIAN 18 look for a hidden photon resonance in the reaction e − Z → e − Z γ ′ (γ ′ →e + e − ). The quoted limit applies to m ′ = 40 MeV. See their Fig. 4 for mass-dependentγ
limits.
85 ANASTASI 18B look for a hidden photon resonance in the reaction e + e − → γ ′ γ (γ ′ →µ+ µ− ). The quoted limit is obtained by combining the result of ANASTASI 16 and it
applies to m ′ ≃ 519–987 MeV. See their Fig. 9 for mass-dependent limits.
γ
86 ARMENGAUD 18 is analogous to ABE 14F. The quoted limits applies to m = 1.6
γ′keV. See the right panel of Fig. 5 for mass-dependent limits.
87 BANERJEE 18 look for hidden photons produced in the reaction e − Z → e − Z γ ′ (γ ′ →e + e − ), and exclude 9.2×10−5 . χ . 1×10−2 for m ′ = 1–23 MeV. They also setγa limit on the electron coupling to a 16.7 MeV gauge boson suggested by the ATOMKI(KRASZNAHORKAY 16) experiment. See their Fig. 3 for mass-dependent limits.
88 BANERJEE 18A look for invisible decays of hidden photons produced in the reactione − Z → e − Z γ ′ . The quoted limit is at m ′ = 1 MeV. See their Fig. 15 for massγ
dependent limits.

https://pdg.lbl.gov

Page 65

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

89 KNIRCK 18 is analogous to SUZUKI 15. See their Fig. 5 for mass-dependent limits.
90 ABGRALL 17 is analogous to ABE 14F using the MAJORANA DEMONSTRATOR. See
their Fig. 3 for limits between 6 keV < m ′ < 97 keV.
γ
91 ABLIKIM 17AA look for e + e − → γ γ ′ (γ ′ → e + e − or µ+ µ− ) . Limits between
10−3 and 10−4 are obtained (see their Fig. 3).
92 ANGLOHER 17 is analogous to ABE 14F. The quoted limit is at m = 0.7 keV. Seeγ′their Fig. 8 for mass-dependent limits.
93 BANERJEE 17 look for invisible decays of hidden photons produced in the reactione − Z → e − Z γ ′ . The quoted limit applies to m ′ = 2 MeV. See their Fig. 3 forγ
mass-dependent limits.
94 CHANG 17 examine the hidden photon emission from SN1987A, including the effects offinite temperature and density on χ and obtain limits χ (m ′ /MeV) . 3 × 10−9 forγ−9for m ′ = 15–120 MeV.
m ′ < 15 MeV and χ . 10γγ
95 DUBININA 17 look for µ+ → e + ν ν γ ′ (γ ′ → e + e − ) in a nuclear photoemulsion.
µ e
The quoted limit applies to m ′ = 1.1 MeV. Limits between 4.5 × 10−3 and 10−2 areγ
obtained (see their Fig. 3).
96 LEES 17E look for invisible decays of hidden photons produced in the reaction e + e − →γ γ ′ . See their Fig. 5 for limits in the mass range m ′ ≤ 8 GeV.
γ97 AAD 16AG look for hidden photons promptly decaying into collimated electrons and/or
muons, assuming that they are produced in the cascade decays of squarks or the Higgs
boson. See their Fig. 10 and Fig.13 for their limits on the cross section times branching
fractions.
98 ANASTASI 16 look for the decay γ ′ → π + π − in the reaction e + e − → γ γ ′ . Limits
between 4.3 × 10−3 and 4.4 × 10−4 are obtained for 527 < m ′ < 987 MeV (see theirγFig. 9).
99 KHACHATRYAN 16 look for γ ′ → µ+ µ− in a dark SUSY scenario where the SM-like
Higgs boson decays into a pair of the visible lightest neutralinos with mass 10 GeV, bothof which decay into γ ′ and a hidden neutralino with mass 1 GeV. See the right panel in
their Fig. 2.
100 AAD 15CD look for H → Z γ ′ → 4ℓ with the ATLAS detector at LHC and find
χ < 4–17 × 10−2 for m ′ = 15–55 GeV. See their Fig. 6.
γ
101 ADARE 15 look for a hidden photon in π 0 , η 0 → γ e + e − at the PHENIX experiment.
See their Fig. 4 for mass-dependent limits.
102 AN 15A derived limits from the absence of ionization signals in the XENON10 and
XENON100 experiments, assuming hidden photons constitute all the local dark matter.
Their best limit is χ < 1.3×10−15 at m ′ = 18 eV. See their Fig. 1 for mass-dependentγ
limits.
103 ANASTASI 15 look for a production of a hidden photon and a hidden Higgs boson with
the KLOE detector at DAΦNE, where the hidden photon decays into a pair of muonsand the hidden Higgs boson lighter than m ′ escape detection. See their Figs. 6 andγ
7 for mass-dependent limits on a product of the hidden fine structure constant and the
kinetic mixing.
104 ANASTASI 15A look for the decay γ ′ → e + e − in the reaction e + e − → e + e − γ.
Limits between 1.7 × 10−3 and 1 × 10−2 are obtained for m ′ = 5–320 MeV (see theirγFig. 7).
105 BATLEY 15A look for π 0 → γ γ ′ (γ ′ → e + e − ) at the NA48/2 experiment. Limits
between 4.2 × 10−4 and 8.8 × 10−3 are obtained for m ′ = 9–120 MeV (see their Fig.
γ
4).

https://pdg.lbl.gov

Page 66

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

106 JAEGLE 15 look for the decay γ ′ → e + e − , µ+ µ− , or π + π − in the dark Higgstrahlung
channel, e + e − → γ ′ H ′ (H ′ → γ ′ γ ′ ) at the BELLE experiment. They set limits on a
product of the branching fraction and the Born cross section as well as a product of thehidden fine structure constant and the kinetic mixing. See their Figs. 3 and 4.
107 KAZANAS 15 set limits by studying the decay of hidden photons γ ′ → e + e − inside
and near the progenitor star of SN1987A. See their Fig. 6 for mass-dependent limits.
108 SUZUKI 15 looked for hidden-photon dark matter with a dish antenna and derived limits
assuming they constitute all the local dark matter. Their limits are χ < 6 × 10−12 form ′ = 1.9–4.3 eV. See their Fig. 7 for mass-dependent limits.
γ
109 VINYOLES 15 performed a global fit analysis based on helioseismology and solar neutrino
observations, and set the limits χm ′ < 1.8 × 10−12 eV for m ′ = 3 × 10−5 –8 eV.
γγ
See their Fig. 11.
110 ABE 14F look for the photoelectric-like interaction in the XMASS detector assuming thehidden photon constitutes all the local dark matter. Limits between 2 × 10−13 and1 × 10−12 are obtained, where the relation χ2 = α’/α is used to translate the original
bound on the ratio of the hidden and EM fine-structure constants. See their Fig. 3 formass-dependent limits.
111 AGAKISHIEV 14 look for hidden photons γ ′ → e + e − at the HADES experiment, andset limits on χ for m ′ = 0.02–0.6 GeV. See their Fig. 5 for mass-dependent limits.
γ
112 BABUSCI 14 look for the decay γ ′ → µ+ µ− in the reaction e + e − → µ+ µ− γ.
Limits between 4 × 10−3 and 9.0 × 10−4 are obtained for 520 MeV < m ′ < 980 MeVγ(see their Fig. 7).
113 BATELL 14 derived limits from the electron beam dump experiment at SLAC (E-137)
by searching for events with recoil electrons by sub-GeV dark matter produced from thedecay of the hidden photon. Limits at the level of 10−4 –10−1 are obtained for m ′ =γ
10−3 –1 GeV, depending on the dark matter mass and the hidden gauge coupling (seetheir Fig. 2).
114 BLUEMLEIN 14 analyzed the beam dump data taken at the U-70 accelerator to lookfor γ ′ -bremsstrahlung and the subsequent decay into muon pairs and hadrons. See theirFig. 4 for mass-dependent excluded region.
115 FRADETTE 14 studied effects of decay of relic hidden photons on BBN and CMB to
set constraints on very small values of the kinetic mixing. See their Figs. 4 and 7 formass-dependent excluded regions.
116 LEES 14J look for hidden photons in the reaction e + e − → γ γ ′ (γ ′ → e + e − , µ+ µ− ).
Limits at the level of 10−4 –10−3 are obtained for 0.02 GeV < m ′ < 10.2 GeV. Seeγtheir Fig. 4 for mass-dependent limits.
117 MERKEL 14 look for γ ′ → e + e − at the A1 experiment at the Mainz Microtron(MAMI). See their Fig. 3 for mass-dependent limits.
118 AN 13B examined the stellar production of hidden photons, correcting an important errorof the production rate of the longitudinal mode which now dominates. See their Fig. 2
for mass-dependent limits based on solar energy loss.
119 AN 13C use the solar flux of hidden photons to set a limit on the atomic ionization ratein the XENON10 experiment. They find χ m ′ < 3 × 10−12 eV for m ′ < 1 eV. Seeγγ
their Fig. 2 for mass-dependent limits.
120 DIAMOND 13 analyzed the beam dump data taken at the SLAC millicharge experiment
to constrain a hidden photon invisibly decaying into lighter long-lived particles, which
undergo elastic scattering off nuclei in the detector. Limits between 8 × 10−4 –2 × 10−2
are obtained. The quoted limit is applied when the dark gauge coupling is set equal tothe electromagnetic coupling. See their Fig.4 for mass-dependent limits.
121 GNINENKO 13 used the data taken at the SINDRUM experiment to constrain the decay,
π 0 → γ γ ′ (γ ′ → e + e − ) to derive limits. See their Fig. 2 for their mass-dependentexcluded region.

https://pdg.lbl.gov

Page 67

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

122 HORVAT 13 look for hidden-photo-electric effect in HPGe detectors induced by solar
hidden photons. See their Fig. 3 for mass-dependent limits.
123 INADA 13 search for hidden photons using an intense X-ray beamline at SPring-8. See
their Fig. 4 for mass-dependent limits.
124 MIZUMOTO 13 look for solar hidden photons. See their Fig. 5 for mass-dependent
limits.
125 PARKER 13 look for hidden photons using a cryogenic resonant microwave cavity. See
their Fig.5 for mass-dependent limits.
126 PARKER 13 derived a limit for the hidden photon CDM with a randomly oriented hidden
photon field.
127 REDONDO 13 examined the solar emission of hidden photons including the enhancement
factor for the longitudinal mode pointed out by AN 13B, and also updated stellar-energy
loss arguments. See their Fig.3 for mass-dependent limits, including a review of thecurrently best limits from other arguments.
128 GNINENKO 12A obtained bounds on B(π 0 → γ γ ′ ) · B(γ ′ → e + e − ) from the NOMAD
and PS191 neutrino experiments, and derived limits between 8 × 10−8 –2 × 10−4 . See
their Fig.4 for mass-dependent excluded regions.
129 GNINENKO 12B used the data taken at the CHARM experiment to constrain the decay,η(η ′ ) → γ γ ′ (γ ′ → e + e − ), and derived limits between 1 × 10−7 –1 × 10−4 . See
their Fig.4 for mass-dependent excluded region.
130 ABRAHAMYAN 11 look for γ ′ → e + e − in the electron-nucelon fixed-target experimentat the Jefferson Laboratory (APEX). See their Fig. 5 for mass-dependent limits.
131 BLUEMLEIN 11 analyzed the beam dump data taken at the U-70 accelerator to look for
π 0 → γ γ ′ (γ ′ → e + e − ). See their Fig. 5 for mass-dependent limits.
132 BJORKEN 09 analyzed the beam dump data taken at E137, E141, and E774 to constraina hidden photon produced by bremsstrahlung, subsequently decaying into e + e − , andderived limits between 10−7 and 10−2 . See their Fig. 1 for mass-dependent excluded
region.
133 BJORKEN 09 required the energy loss in the γ ′ emission from the core of SN1987A not
to exceed 1053 erg/s, and derived limits between 5 × 10−9 and 2 × 10−6 . See theirFig. 1 for mass-dependent excluded region.

REFERENCES FOR Searches for Axions (A0 ) and Other Very Light Bosons
ABREU
LELLA
PANT
AAD
AAD
AAD
AALBERSABLIKIMABLIKIMABUDINEN
ACCIARRI
ADACHI
ADACHI
ADACHIADHIKARIADHIKARIADRIANAGNES
AN
ANDREEVAPRILEAYRESAZZOLINIBAJJALIBATTYEBEAUFORT24
PL B848 138378
24
PR D109 023001
24
PR D109 023011
23BO PRL 131 251801
23I
JHEP 2306 153
23T JHEP 2307 133
23A PR D108 072006
23AF PL B839 137785
23E PL B838 137698
23B PRL 130 071804
23
PRL 130 221802
23A PRL 130 181803
23D PR D108 043017
23K PR D108 L111104
23
PR D107 122004
23A PR D108 L041301
23
PR D108 012015
23A PRL 130 101002
23A PRL 130 181001
23
PRL 131 161801
23B PR D108 072015
23
NJP 25 103012
23
PR D107 032006
23
JCAP 2308 077
23
PR D108 063001
23
PR D108 L081302

https://pdg.lbl.gov

H. Abreu et al.
A. Lella et al.
B.P. Pant
G. Aad et al.
G. Aad et al.
G. Aad et al.
J. Aalbers et al.
M. Ablikim et al.
M. Ablikim et al.
F. Abudinen et al.
R. Acciarri et al.
I. Adachi et al.
S. Adachi et al.
I. Adachi et al.
G. Adhikari et al.
G. Adhikari et al.
P.H. Adrian et al.
P. Agnes et al.
H. An et al.
Yu.M. Andreev et al.
E. Aprile et al.
N.J. Ayres et al.
O. Azzolini et al.
F. Bajjali et al.
R. Battye et al.
C. Beaufort et al.

Page 68(FASER Collab.)(BARI, STOH, INFNL, +)(IITJ)(ATLAS Collab.)(ATLAS Collab.)(ATLAS Collab.)(LZ Collab.)(BESIII Collab.)(BESIII Collab.)(BELLE II Collab.)(ArgoNeuT Collab.)(BELLE II Collab.)(POLARBEAR Collab.)(BELLE II Collab.)(COSINE-100 Collab.)(COSINE-100 Collab.)(HPS Collab.)(DarkSide-50 Collab.)(NA64 Collab.)(XENON Collab.)(CUPID-0 Collab.)(BRASS Collab.)

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

BERNAL23
BERTUZZO23
CAPOZZI23
CAPOZZI
23A
CHENG
23
CORTINA-GIL 23B
CORTINA-GIL 23C
DAVIES
23
DELLA-MON... 23
DERBIN23
DIAMOND
23
DI-VORA23
FILZINGER
23
FIORILLO
23
HAYRAPETY... 23G
HOOF
23
JACOBSEN
23JEWELL23
KARANTH
23
KIM
23
KOTAKA
23
LEE
23
LI
23H
LI
23I
NOORDHUIS 23
NOTARI
23
OSHIMA
23
PANT
23
PODDAR
23
RAMANATH... 23
ROGERS
23
ROMANENKO 23
SANDNER23
SHERRILL
23
SMARRA
23
SULAI
23
THOMSON
23
WADEKAR
23
XIA
23
YANG
23
YAO
23
YI
23
YI
23A
ZHANG
23
ZHANG
23A
AAD
22J
AAD
22S
ADE
22
ADHIKARI
22C
AGOSTINI
22
AGOSTINI
22A
ALESINI22
APRILE
22
APRILE
22B
ARNQUIST22
ARZA
22
BATTAGLIERI 22
BATTYE
22
BERNAL
22
BOLTON
22
BUSCHMANN 22
CALORE
22
CAPUTO
22
CASTILLO
22
CERVANTES 22
CHANG
22
CHILES
22
COLOMA
22A
CRESCINI
22
DEROCCO22
DESSERT22

PR D107 103046
PRL 130 171801
JCAP 2306 060
PR D108 075019
PR D107 063021
PL B846 138193
JHEP 2309 035
PR D107 083027
PR D108 L101303
JETPL 118 160
PR D108 049902
PR D108 062005
PRL 130 253001
PRL 131 021001
JHEP 2312 070
JCAP 2303 054
JCAP 2310 009
PR D107 072007
PR X13 031004
PRL 130 091602
PRL 130 071805
PR X13 011050
PR D107 063031
JCAP 2309 009
PRL 131 111004
PRL 131 011004
PR D108 072005
PR D108 023016
PR D108 103024
PRL 130 231001
JCAP 2306 023
PRL 130 261801
EPJ C83 709
NJP 25 093012
PRL 131 171001
PR D108 096026
PR D107 112003
PR D107 083011
PR D107 L121302
PRL 131 081801
PR D107 043031
PRL 130 071002
PR D108 L021304
PRL 130 201401
PRL 130 251002
JHEP 2203 041
EPJ C82 105
PR D105 022006
PR D105 052007
JCAP 2212 012
PRL 129 089901
PR D106 052007
PR D106 022001
PRL 129 161805
PRL 129 081803
PR D105 095007
PR D106 072011
PR D105 L021305
PRL 129 231301
PRL 129 211102
PRL 128 091102
PR D105 063028
PRL 128 221103
JCAP 2206 014
PRL 129 201301
PRL 129 111802
PRL 128 231802
JHEP 2207 138
PR D105 022007
PRL 129 101101
PRL 128 071102

https://pdg.lbl.gov

J.L. Bernal et al.
(JHU, TELA, REHO+)
E. Bertuzzo et al.
(SPAUL)
F. Capozzi et al.
F. Capozzi et al.
L.-d. Cheng, H. Zhang, S.-s. Bao(SHDNQ)
E. Cortina-Gil et al.
(NA62 Collab.)
E. Cortina Gil et al.
(NA62 Collab.)
J. Davies, M. Meyer, G. Cotter(OXF, HAMB)
R. Della Monica, I. de Martino
A.V. Derbin et al.
(PNPI)
M. Diamond et al.
R. Di Vora et al.
(QUAX Collab.)
M. Filzinger et al.
D.F.G. Fiorillo, G.G. Raffelt, E. Vitagliano(NBI+)
A. Hayrapetyan et al.
(CMS Collab.)
S. Hoof, L. Schulz(KIT, GOET)
S. Jacobsen, T. Linden, K. Freese(STOH, TEXA+)
M.J. Jewell et al.
(HAYSTAC Collab.)
S. Karanth et al.
(JEDI Collab.)
J. Kim et al.
(KAIST, RIKEN, TOKY)
S. Kotaka et al.
(DOSUE-RR Collab.)
J. Lee et al.
(ASTAR, PRIN)
H.-J. Li, W. Chao
(BNORM)
S.-P. Li, X.-J. Xu(BHEP)
D. Noordhuis et al.
(AMST, PRIN, STAN+)
A. Notari, F. Rompineve, G. Villadoro(ICCUB+)Y. Oshima et al.
(DANCE Collab.)
B.P. Pant et al.
(IITJ)
T.K. Poddar, D. Pachhar
K. Ramanathan et al.
(CIT, JPL)
K.K. Rogers et al.
A. Romanenko et al.
(FNAL)
S. Sandner, M. Escudero, S.J. Witte(VALE, CERN+)
N. Sherrill et al.
(SUSS, NPLT)
C. Smarra et al.
(EPTA Collab.)
I. Sulai et al.
(SNIPE Hunt Collab.)
C.A. Thomson et al.
(UPLOAD Collab.)
D. Wadekar, Z. Wang
(IAS, NYU)
Z.-Q. Xia et al.
B. Yang et al.
(CAPP18T Collab.)
R.-M. Yao et al.
A.K. Yi et al.
(CASK Collab.)
A.K. Yi et al.
(CASK Collab.)
S.-B. Zhang et al.
(CST)
X. Zhang et al.
(MAINZ, REHO, UCB, +)G. Aad et al.
(ATLAS Collab.)
G. Aad et al.
(ATLAS Collab.)
P.A.R. Ade et al.
(BICEP/Keck Collab.)
S. Adhikari et al.
(GLUEX Collab.)
M. Agostini et al.
(GERDA Collab.)
M. Agostini et al.
(GERDA Collab.)
D. Alesini et al.
(QUAX Collab.)
E. Aprile et al.
(XENON1T Collab.)
E. Aprile et al.
(XENONnT Collab.)
I.J. Arnquist et al.
(MAJORANA Collab.)
A. Arza et al.
(ITEP, JHU, STAN, CSEB)
M. Battaglieri et al.
(BDX-MINI Collab.)
R.A. Battye et al.
J.L. Bernal, G. Sato-Polito, M. Kamionkowski(JHU)
J.S. Bolton et al.
M. Buschmann et al.
(PRIN, MICH, UCB+)
F. Calore et al.
(LAPTH, STOH, BARI, WROC+)
A. Caputo et al.
A. Castillo et al.
R. Cervantes et al.
(ADMX Collab.)
H. Chang et al.
(TASEH Collab.)
J. Chiles et al.
P. Coloma et al.
(IFT, CNYIT, ICC, ICREA+)
N. Crescini et al.
W. DeRocco et al.
C. Dessert, A.J. Long, B.R. Safdi(MICH, UCB+)

Page 69

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

DESSERT
22A PR D105 103034
C. Dessert, D. Dunsky, B.R. Safdi(UCB, LBL+)ECKNER22
PR D106 083020
C. Eckner, F. Calore(LAPTH)
FENG
22
PRL 128 231803
Y.-K. Feng et al.
FERGUSON
22
PR D106 042011
K.R. Ferguson et al.
(SPT-3G Collab.)
FOSTER22
PRL 129 251102
J.W. Foster et al.
GAVRILYUK22
JETPL 116 11
Yu.M. Gavrilyuk et al.
HOCHBERG
22
PR D106 112005
Y. Hochberg et al.
(SNSPD Collab.)
IKEDA
22
PR D105 102004
T. Ikeda et al.
JIA22
PRL 128 081804
S. Jia et al.
(BELLE Collab.)
KIRITA
22
JHEP 2210 176
Y. Kirita et al.
(SAPPHIRES Collab.)
LAGUE
22
JCAP 2201 049
A. Lague et al.
LANGHOFF22
PRL 129 241101
K. Langhoff, N.J. Outmezguine, N.L. Rodd
(UCB+)LEE22
PRL 128 241805
Y. Lee et al.
(CAPP18T Collab.)
LEES
22
PRL 128 021802
J.P. Lees et al.
(BABAR Collab.)
LEES
22B PRL 128 131802
J.P. Lees et al.
(BABAR Collab.)LI
22
PL B829 137047
H.-J. Li(BNORM)LI
22C CP C46 085105
H.-J. Li, X.-J. Bi, P.-F. Yin
LU
22
PR D105 123017
B.-Q. Lu, C.-W. Chiang
LUCENTE22
PRL 129 011101
G. Lucente et al.
MANENTI
22
PR D105 052010
L. Manenti et al.
(MuDHI Collab.)
QUISKAMP
22
SADV 8 27
A. Quiskamp et al.
(ORGAN Collab.)
SCHULTHESS 22
PRL 129 191801
I. Schulthess et al.
(BERN, ILLG)
THOMAS
22
PR D105 L031901
A.W. Thomas, X.G. Wang, A.G. Williams(ADLD)TUMASYAN
22AH EPJ C82 290
A. Tumasyan et al.
(CMS Collab.)
TUMASYAN
22N JHEP 2204 062
A. Tumasyan et al.
(CMS Collab.)
TUMASYAN
22R JHEP 2204 087
A. Tumasyan et al.
(CMS Collab.)
WANG
22C PRL 129 051801
Y. Wang et al.
WU
22A PR D106 L081101
Y.M. Wu et al.
(PPTA Collab.)
XIAO
22
PR D106 123019
M. Xiao et al.
YOON
22
PR D106 092007
H. Yoon et al.
YUAN
22A PR D106 023020
C. Yuan, Y. Jiang, Q.-G. Huang
ZHOU
22
PR D106 083006
Y.-F. Zhou et al.
(MeerKAT-Axion Collab.)
AAD
21F PR D103 112006
G. Aad et al.
(ATLAS Collab.)
AAD
21K JHEP 2102 226
G. Aad et al.
(ATLAS Collab.)
AAD
21N JHEP 2103 243
G. Aad et al.
(ATLAS Collab.)
Also
JHEP 2111 050 (errat.) G. Aad et al.
(ATLAS Collab.)
ABRATENKO 21
PRL 127 151803
P. Abratenko et al.
(MicroBooNE Collab.)
ADE
21
PR D103 042002
P.A.R. Ade et al.
(BICEP/Keck Collab.)
AFACH
21
NATP 17 1396
S. Afach et al.
(GNOME Collab.)
AGUILAR-AR... 21A PR D103 052006
A. Aguilar-Arevalo et al.
(PIENU Collab.)
ALESINI21
PR D103 102004
D. Alesini et al.
(QUAX Collab.)
AL-KHARUSI 21
PR D104 112002
S. Al Kharusi et al.
(EXO-200 Collab.)
ANDREEV21
PRL 126 211802
Yu.M. Andreev et al.
(NA64 Collab.)
ANDREEV
21A PR D104 L091701
Yu.M. Andreev et al.
(NA64 Collab.)
ANDREEV
21B PR D104 L111102
Yu.M. Andreev et al.
(NA64 Collab.)
ARALIS
21
PR D103 039901 (errat.) T. Aralis et al.
(SuperCDMS Collab.)
AYBAS
21
PRL 126 141802
D. Aybas et al.
(CASPEr Collab.)
BACKES21
NAT 590 238
K.M. Backes et al.
(HAYSTAC Collab.)
BANIK
21
JCAP 2110 043
N. Banik et al.
BARTRAM
21A PRL 127 261803
C. Bartram et al.
(ADMX Collab.)
BASU
21
PRL 126 191102
A. Basu et al.
(BIEL, NAGO)BAUMHOLZ... 21
JCAP 2105 004
S. Baumholzer, V. Brdar, E. Morgante (MAINZ, FNAL+)
BHUSAL21
PRL 126 091601
A. Bhusal, N. Houston, T. Li(BEIJ)BI
21
PR D103 043018
X.-J. Bi et al.
(BHEP, TSIN)CALORE21
PR D104 043016
F. Calore et al.
(HEID)CARRA
21
PR D104 092005
S. Carra et al.
CAZZANIGA21
EPJ C81 959
C. Cazzaniga et al.
(NA64 Collab.)
CORTINA-GIL 21
PL B816 136259
E. Cortina Gil et al.
(NA62 Collab.)
CORTINA-GIL 21A JHEP 2103 058
E. Cortina Gil et al.
(NA62 Collab.)
CORTINA-GIL 21C JHEP 2102 201
E. Cortina Gil et al.
(NA62 Collab.)
CROON
21
JHEP 2101 107
D. Croon et al.
(TRIU, WASH, MIT, FNAL)DEVLIN21
PRL 126 041301
J.A. Devlin et al.
(BASE Collab.)
DIXIT
21
PRL 126 141302
A.V. Dixit et al.
(CHIC, RUTG, UCB+)DOLAN
21JHEP 2103 190 (errat.) M.J. Dolan et al.
(MELB, BRCO, DESY)
DOLAN
21A JCAP 2109 010
M.J. Dolan, F.J. Hiskens, R.R. Volkas(MELB)
FUJIKURA
21
PR D104 123012
K. Fujikura et al.
GHOSH
21
PR D104 092016
S. Ghosh et al.
GODFREY21
PR D104 012013
B. Godfrey et al.
(UCD, CSUS, STAN)
GRAMOLIN
21
NATP 17 79
A.V. Gramolin et al.
(SHAFT Collab.)
GUO
21
CP C45 025105
J.-G. Guo et al.
(BHEP)HOMMA
21
JHEP 2112 108
K. Homa et al.
(SAPPHIRES Collab.)https://pdg.lbl.gov

Page 70

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

JIANG
21
NATP 17 1402
M. Jiang et al.
KOPYLOV
21A PPN 52 31
A.V. Kopylov, I.V. Orekhov, V.V. Petukhov(INRM)KRIBS21
PRL 126 011801
G.D. Kribs, D. McKeen, N. Raj(OREG, TRIU)
KWON
21PRL 126 191802
O. Kwon et al.
(CAPP-ACTION Collab.)LI
21B PR D103 083003
H.-J. Li et al.
(BHEP)LLOYD
21
PR D103 023010
S.J. Lloyd et al.
(DURH, OKLA)
LUCENTE21
PR D104 103007
G. Lucente, P. Carenza(BARI)MARTINCAM... 21
PR D103 L121301
J.M. Camalich et al.
MELCON21
JHEP 2110 075
A.A. Melcon et al.
(CAST-RADES Collab.)NG
21
PRL 126 151102
K.K.Y. Ng et al.
(MIT, ANIK, UTRE, LEUV)PARK21JHEP 2104 191
S.-H. Park et al.
(BELLE Collab.)
REGIS
21
PL B814 136075
M. Regis et al.
(MUSE Collab.)
ROGERS21
PRL 126 071302
K.K. Rogers, H.V. Peiris(STOH, LOUC)ROUSSY21
PRL 126 171301
T.S. Roussy et al.
(COLO, MAINZ)SALEMI21
PRL 127 081801
C.P. Salemi et al.
(ABRACADABRA Collab.)
SCHMIDT21
PR D104 015008
I. Schmidt et al.
(FRAN, GSI, +)THOMSON21
PRL 126 081803
C.A. Thomson et al.
(WAUS)Also
PRL 127 019901 (errat.) C.A. Thomson et al.
(WAUS)TSAI21
PRL 126 181801
Y.-D. Tsai, P. deNiverville, M.X. Liu(FNAL+)TSUKADA21
PR D103 083005
L. Tsukada et al.
(ROMA, TOKY, WATER)
XIAO
21
PRL 126 031101
M. Xiao et al.
YUAN
21
JCAP 2103 018
G.-W. Yuan et al.
(CST)
ZHANG
21B PRL 127 161101
J. Zhang et al.
AAIJ
20AL JHEP 2010 156
R. Aaij et al.
(LHCb Collab.)
AAIJ
20C PRL 124 041801
R. Aaij et al.
(LHCb Collab.)
ABDELHAME... 20
EPJ C80 376
A.H. Abdelhameed et al.
ABE
20J PL B815 136174
T. Abe, K. Hamaguchi, N. Nagata(TOKY)ABLIKIM
20AB PR D102 052005
M. Ablikim et al.
(BESIII Collab.)
ABUDINEN20
PRL 125 161806
F. Abudinen et al.
(BELLE II Collab.)
AGOSTINI20
PRL 125 011801
M. Agostini et al.
(GERDA Collab.)
AGUILAR-AR... 20
PR D101 052014
A. Aguilar-Arevalo et al.
(PIENU Collab.)
AMARAL20
PR D102 091101
D.W. Amaral et al.
(SuperCDMS Collab.)AN
20
PR D102 115022
H. An et al.
(VIEN, MINN, VICT, TSIN)
ANDRIANAV... 20
PR D102 042001
A. Andrianavalomahefa et al.
(FUNK Collab.)
APRILE20
PR D102 072004
E. Aprile et al.
(XENON Collab.)
ARALIS
20
PR D101 052008
T. Aralis et al.
(SuperCDMS Collab.)Also
PR D103 039901 (errat.) T. Aralis et al.
(SuperCDMS Collab.)
ARGUELLES
20
JHEP 2002 190
C. Arguelles et al.
(MIT, VALE)
ARNAUD20
PRL 125 141301
Q. Arnaud et al.
(EDELWEISS Collab.)
BALDINI20EPJ C80 858
A.M. Baldini et al.
(MEG Collab.)
BANERJEE20
PR D101 071101
D. Banerjee et al.
(NA64 Collab.)
BANERJEE
20A PRL 125 081801
D. Banerjee et al.
(NA64 Collab.)
BARAK
20
PRL 125 171802
L. Barak et al.
(SENSEI Collab.)
BRAINE20
PRL 124 101303
T. Braine et al.
(ADMX Collab.)
BUEHLER
20
JCAP 2009 027
R. Buehler et al.
(DESY, MADU)CALORE20
PR D102 123005
F. Calore et al.
(LAPP, BARI, HEID, +)CAPOZZI20
PR D102 083007
F. Capozzi, G. Raffelt(MPIM)CARENZA
20
PL B809 135709
P. Carenza et al.
CRESCINI20
PRL 124 171801
N. Crescini et al.
(QUAX Collab.)
CRISOSTO
20
PRL 124 241101
N. Crisosto et al.
(ADMX SLIC Collab.)
DARLING20
PRL 125 121103
J. Darling(COLO)DARLING
20A APJ 900 L28
J. Darling(COLO)DENT
20A PRL 125 131805
J.B. Dent et al.
DEPTA
20
JCAP 2005 009
P.F. Depta, M. Hufnagel, K. Schmidt-Hoberg(DESY)
DESSERT
20A PRL 125 261102
C. Dessert, J.W. Foster, B.R. Safdi(MICH)ESTEBAN20
EPJ C80 259
I. Esteban et al.
FOSTER20
PRL 125 171301
J.W. Foster et al.
(MICH, ILL, TOKY+)
GAO
20
PRL 125 131806
C. Gao et al.
(FNAL, EFI, CHIC, ANL+)GAVELA20
PRL 124 051802
M.B. Gavela et al.
GHOSH
20A JCAP 2010 060
D. Ghosh, D. Sachdeva
IRSIC
20
PR D101 123518
V. Irsic, H. Xiao, M. McQuinn
JEONG
20
PRL 125 221302
J. Jeong et al.
KENNEDY20
PRL 125 201302
C.J. Kennedy et al.
(COLO, STAN)
KLIMCHITSK... 20
PR D101 056013
G.L. Klimchitskaya, P. Kuusk, V.M. Mostepanenko
KOROCHKIN 20
JCAP 2003 064
A. Korochkin, A. Neronov, D. Semikoz
KRASNIKOV20
MPL A35 2050116
N.V. Krasnikov
LEE
20A PRL 124 101802
S .Lee et al.
(CULTASK Collab.)
LUCENTE
20A JCAP 2012 008
G. Lucente et al.
MEYER
20
PRL 124 231101
M. Meyer, T. Petrushevska(Fermi-LAT Collab.)
Also
PRL 125 119901 (errat.) M. Meyer, T. Petrushevska(Fermi-LAT Collab.)
PODDAR20
PR D101 083007
T.K. Poddar, S. Mohanty, S. Jana

https://pdg.lbl.gov

Page 71

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

SCHUTZ20
PR D101 123026
K. Schutz
(MIT)
SHE
20
PRL 124 111301
Z. She et al.
(CDEX Collab.)
SIRUNYAN
20AQ PRL 124 131802
A.M. Sirunyan et al.
(CMS Collab.)
STRANIERO
20
AA 644 A166
O. Straniero et al.
(SASSO, BGNA, GRAN)
SUN20
PR D101 063020
L. Sun, R. Brito, M. Isi(CIT, ROMAI, MIT)TOMITA20
JCAP 2009 012
N. Tomita et al.
WANG
20A PR D101 052003
Y. Wang et al.
(CDEX Collab.)
YAMAMOTO 20
JCAP 2002 011
R. Yamamoto et al.
AABOUD
19G PR D99 012001
M. Aaboud et al.
(ATLAS Collab.)
ABLIKIM
19A PR D99 012006
M. Ablikim et al.
(BESIII Collab.)Also
PR D104 099901 (errat.) M. Ablikim et al.
(BESIII Collab.)
ABLIKIM
19H PR D99 012013
M. Ablikim et al.
(BESIII Collab.)
ADELBERGER 19
PRL 123 169001
E.G. Adelberger, W.A. Terrano(WASH, PRIN)ADHIKARI
19B ASP 114 101
P. Adhikari et al.
(COSINE-100 Collab.)
AGUILAR-AR... 19A PRL 123 181802
A. Aguilar-Arevalo et al.
(DAMIC Collab.)
AHN
19
PRL 122 021802
J.K. Ahn et al.
(KOTO Collab.)
ALESINI19
PR D99 101101
D. Alesini et al.
(QUAX Collab.)
ALONI
19
PRL 123 071801
D. Aloni et al.
(REHO, MIT, CERN, HAIF)APRILE19
PRL 122 071301
E. Aprile et al.
(XENON1T Collab.)
APRILE
19D PRL 123 251801
E. Aprile et al.
(XENON1T Collab.)
ARNOLD19
EPJ C79 440
R. Arnold et al.
(NEMO-3 Collab.)
BANERJEE19
PRL 123 121801
D. Banerjee et al.
(NA64 Collab.)
BHOONAH
19
PR D100 023001
A. Bhoonah et al.
BRUN
19
PRL 122 201801
P. Brun, L. Chevalier, C. Flouzat(SACL)CAPUTO
19
PR D100 063515
A. Caputo et al.
CORTINA-GIL 19
JHEP 1905 182
E. Cortina Gil et al.
(NA62 Collab.)
DANILOV19
PRL 122 041801
M. Danilov, S. Demidov, D. Gorbunov (LEBD, INRM+)DAVOUDIASL 19
PRL 123 021102
H. Davoudiasl, P.B. Denton(BNL)
DESSERT19
PRL 123 061104
C. Dessert, A.J. Long, B.R. Safdi(MICH)FEDDERKE19
PR D100 015040
M.A. Fedderke, P.W. Graham, S. Rajendran(STAN+)
FUJITA19
PRL 122 191101
T. Fujita, R. Tazaki, K. Toma (KYOT, GEVA, TOHO)HOCHBERG19
PRL 123 151802
Y. Hochberg et al.
(HEBR, MIT, NIST)IVANOV19
JCAP 1902 059
M.M. Ivanov et al.
KOPYLOV19
JCAP 1907 008
A. Kopylov, I. Orekhov, V. Petukhov(INRM)KOVETZ19
PR D99 123511
E.D. Kovetz, I. Cholis, D.E. Kaplan(JHU)
LEINSON
19
JCAP 1911 031
L.B. Leinson
LIANG
19
JCAP 1906 042
Y-F. Liang et al.
LLOYD
19
PR D100 063005
S.J. Lloyd et al.
MARSH
19
PRL 123 051103
D.J.E. Marsh, J.C. Niemeyer(GOET)NGUYEN19
JCAP 1910 014
L.H. Nguyen, A. Lobanov, D. Horns (WISPDMX Collab.)
OUELLET
19A PRL 122 121802
J.L. Ouellet et al.
(ABRACADABRA Collab.)
PALOMBA19
PRL 123 171101
C. Palomba et al.
SIRUNYAN
19BQ PL B796 131
A.M. Sirunyan et al.
(CMS Collab.)
SMORRA19
NAT 575 310
C. Smorra et al.
TERRANO19
PRL 122 231301
W. Terrano et al.
(WASH)WU
19
PRL 122 191302
T. Wu et al.
(CASPEr-ZULF Collab.)
WU
19C PRL 123 169002
T. Wu et al.
(CASPEr-ZULF Collab.)
ABE
18F PL B787 153
K. Abe et al.
(XMASS Collab.)
ADRIAN18
PR D98 091101
P.H. Adrian et al.
(HPS Collab.)
AKHMATOV18
PPN 49 599
Z.A. Akhmatov et al.
ANASTASI
18B PL B784 336
A. Anastasi et al.
(KLOE-2 Collab.)
ARMENGAUD 18
PR D98 082004
E. Armengaud et al.
(EDELWEISS-III Collab.)
ARNOLD18
EPJ C78 821
R. Arnold et al.
(NEMO-3 Collab.)
BANERJEE18
PRL 120 231802
D. Banerjee et al.
(NA64 Collab.)
BANERJEE
18A PR D97 072002
D. Banerjee et al.
(NA64 Collab.)
BEZNOGOV18
PR C98 035802
M.V. Beznogov et al.
BOUTAN18
PRL 121 261302
C. Boutan et al.
(ADMX Collab.)
CHANG
18
JHEP 1809 051
J.C. Chang, R. Essig, S.D. McDermott
CRESCINI18
EPJ C78 703
N. Crescini et al.
(QUAX Collab.)
DU
18
PRL 120 151301
N. Du et al.
(ADMX Collab.)
DZUBA
18
PR D98 035048
V.A. Dzuba et al.
FICEK18
PRL 120 183002
F. Ficek et al.
FORTIN18
JHEP 1806 048
J.-F. Fortin, K. Sinha(LAVL, OKLA)GAVRILYUK18
JETPL 107 589
Yu.M. Gavrilyuk et al.
HAMAGUCHI 18
PR D98 103015
K. Hamaguchi et al.
JAECKEL18
PR D98 055032
J. Jaeckel, P. C. Malta, J. Redondo
KNIRCK18
JCAP 1811 031
S. Knirck et al.
PORAYKO18
PR D98 102002
N.K. Porayako et al.
(PPTA Collab.)
STADNIK18
PRL 120 013202
Y.V. Stadnik, V.A. Dzuba, V.V. Flambaum
YAMAJI18
PL B782 523
T. Yamaji et al.
(TOKY, RIKEN, KEK)
ZHANG
18PR D97 063009
C. Zhang et al.

https://pdg.lbl.gov

Page 72

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

ZHONG
18
PR D97 092001
L. Zhong et al.
(HAYSTAC Collab.)
AAIJ
17AQ PR D95 071101
R. Aaij et al.
(LHCb Collab.)
ABEL
17
PR X7 041034
C. Abel et al.
(nEDM Collab.)
ABGRALL17
PRL 118 161801
N. Abgrall et al.
(MAJORANA Collab.)
ABLIKIM
17AA PL B774 252
M. Ablikim et al.
(BESIII Collab.)
ADE
17
PR D96 102003
P.A.R. Ade et al.
(BICEP2/Keck Array Collab.)
AHN
17
PTEP 2017 021C01
J.K. Ahn et al.
(KOTO Collab.)
AKERIB17B PRL 118 261301
D.S. Akerib et al.
(LUX Collab.)
ANASTASSO... 17
NATP 13 584
V. Anastassopoulos et al.
(CAST Collab.)
ANGLOHER
17
EPJ C77 299
G. Angloher et al.
(CRESST-II Collab.)
APRILE
17B PR D95 029904
E. Aprile et al.
(XENON100 Collab.)
BANERJEE17
PRL 118 011802
D. Banerjee et al.
(NA64 Collab.)
BATLEY17
PL B769 67
J.R. Batley et al.
(NA48/2 Collab.)
BRANCA17
PRL 118 021302
A. Branca et al.
(AURIGA Collab.)
BRUBAKER17
PRL 118 061302
B.M. Brubaker et al.
(YALE, UCB, NIST+)CHANG
17JHEP 1701 107
J.H. Chang, R. Essig, S.D. McDermott(STON)CHOI
17
PR D96 061102
J. Choi et al.
(CAPP-ACTION Collab.)
CRESCINI17
PL B773 677
N. Crescini et al.
(QUAX-gpgs Collab.)
DAIDO
17
PL B772 127
R. Daido, F. Takahashi
DOLAN
17JHEP 1712 094
M.J. Dolan et al.
Also
JHEP 2103 190 (errat.) M.J. Dolan et al.
(MELB, BRCO, DESY)
DUBININA17
PAN 80 461
V.V. Dubinina et al.
FICEK17
PR A95 032505
F. Ficek et al.
FU
17A PRL 119 181806
C. Fu et al.
(PandaX-II Collab.)
INADA
17
PRL 118 071803
T. Inada et al.
KLIMCHITSK... 17A PR D95 123013
G.L. Klimchitskaya, V.M. Mostepanenko
KOHRI
17
PR D96 051701
K. Kohri, H. Kodama(KEK, KYOT)
LEES
17E PRL 119 131804
J.P. Lees et al.
(BABAR Collab.)
LIU
17
PL B766 117
X.-H. Liu
(TINT)LIU
17A PR D95 052006
S.K. Liu et al.
(CDEX Collab.)
LUO
17
PR D96 055028
P. Luo et al.
MARSH
17
JCAP 1712 036
M.C.D. Marsh et al.
MCALLISTER 17
PDU 18 67
B.T. McAllister et al.
(WAUS)TIWARI17
PR D95 023005
P. Tiwari(Technion)
AAD
16AG JHEP 1602 062
G. Aad et al.
(ATLAS Collab.)
ABLIKIM
16E PR D93 052005
M. Ablikim et al.
(BESIII Collab.)
AJELLO16
PRL 116 161101
M. Ajello et al.
(Fermi-LAT Collab.)
ANASTASI
16
PL B757 356
A. Anastasi et al.
(KLOE-2 Collab.)
BATTICH
16
JCAP 1608 062
T. Battich et al.
BERENJI16
PR D93 045019
B. Berenji et al.
CORSICO16
JCAP 1607 036
A.H. Corsico et al.
DELLA-VALLE 16
EPJ C76 24
F. Della Valle et al.
(PVLAS Collab.)
HOSKINS16
PR D94 082001
J. Hoskins et al.
(ADMX Collab.)
JAECKEL16
PL B753 482
J. Jaeckel, M. Spannowsky(HEID, DURH)
KHACHATRY... 16
PL B752 146
V. Khachatryan et al.
(CMS Collab.)
KRASZNAHO... 16
PRL 116 042501
A.J. Krasznahorkay et al.
(HINR, ANIK+)LEEFER16
PRL 117 271601
N. Leefer et al.
(MAINZ, BONN, LBL, UCB+)
WON
16
PR D94 092006
E. Won et al.
(BELLE Collab.)
YOON
16
JHEP 1606 011
Y.S. Yoon et al.
(KIMS Collab.)
AAD
15CD PR D92 092001
G. Aad et al.
(ATLAS Collab.)
AAIJ
15AZ PRL 115 161802
R. Aaij et al.
(LHCb Collab.)
ADARE
15
PR C91 031901
A. Adare et al.
(PHENIX Collab.)
AFACH
15
PL B745 58
S. Afach et al.
(ETH, PSI, CAEN, +)AGOSTINI
15A EPJ C75 416
M. Agostini et al.
(GERDA Collab.)AN
15A PL B747 331
H. An et al.
(CIT, VICT, VIEN)
ANASTASI
15
PL B747 365
A. Anastasi et al.
(KLOE-2 Collab.)
ANASTASI
15A PL B750 633
A. Anastasi et al.
(KLOE-2 Collab.)
ANASTASSO... 15
PL B749 172
V. Anastassopoulos et al.
(CAST Collab.)
ARIK
15
PR D92 021101
M. Arik et al.
(CAST Collab.)
ARNOLD15
PR D92 072011
R. Arnold et al.
(NEMO-3 Collab.)
BALLOU15
PR D92 092002
R. Ballou et al.
(OSQAR Collab.)
BATLEY
15A PL B746 178
J.R. Batley et al.
(NA48/2 Collab.)
BAYES
15
PR D91 052020
R. Bayes et al.
(TWIST Collab.)
BRAX
15
PR D92 083501
P. Brax, P. Brun, D. Wouters(SACL, SACL5)GAVRILYUK15
JETPL 101 664
Yu.M. Gavrilyuk et al.
Translated from ZETFP 101 739.
HASEBE
15
PTEP 2015 073C01
T. Hasebe et al.
JAEGLE15
PRL 114 211801
I. Jaegle et al.
(BELLE Collab.)
KAZANAS
15
NP B890 17
D. Kazanas et al.
KLIMCHITSK... 15
EPJ C75 164
G.L. Klimchitskaya, V.M. Mostepanenko
MILLEA15
PR D92 023010
M. Millea, L. Knox, B. Fields(UCD, ILL)

https://pdg.lbl.gov

Page 73

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

STADNIK15SUZUKI15
TERRANO
15
VANTILBURG 15
VINYOLES
15ABE
14F
AGAKISHIEV 14
ALBERT
14A
APRILE
14B
ARIK
14
AYALA
14
BABUSCI
14
BATELL14
BEZERRA14
BEZERRA
14A
BEZERRA
14B
BEZERRA
14C
BLUEMLEIN
14
BLUM
14
DELLA-VALLE 14
DERBIN
14EJLLI
14FRADETTE
14
LEES
14J
LEINSON
14
MERKEL14
MILLER-BER... 14
PUGNAT
14
REESMAN
14
ABE
13D
ABRAMOWSKI 13A
ADLARSON
13
ALESSANDRIA 13
AN
13B
AN
13C
ARCHIDIACO... 13A
ARMENGAUD 13
BABUSCI
13B
BARTH
13
BECK
13
BETZ
13
BULATOWICZ 13
CHU13
DERBIN
13
DIAMOND
13
FRIEDLAND
13
GNINENKO
13
HECKEL
13
HORVAT
13
INADA
13
LATTANZI
13
MEYER
13
MIZUMOTO
13
PARKER
13
REDONDO
13
TULLNEY
13
VIAUX
13A
WOUTERS13
ABLIKIM
12
ARCHILLI
12
BELLI
12
BELLINI
12B
CADAMURO 12
CORSICO12
DERBIN12GANDOGNINENKOGNINENKOPAYEZ
RAFFELT

12
12A
12B
12
12

EPJ C75 110
Y.V. Stadnik, V.V. Flambaum(SYDN)
JCAP 1509 042
J. Suzuki et al.
PRL 115 201801
W.A. Terrano et al.
(WASH)
PRL 115 011802
K. Van Tilburg et al.
JCAP 1510 015
N. Vinyoles et al.
PRL 113 121301
K. Abe et al.
(XMASS Collab.)
PL B731 265
G. Agakishiev et al.
(HADES Collab.)
PR D90 092004
J.B. Albert et al.
(EXO-200 Collab.)
PR D90 062009
E. Aprile et al.
(XENON100 Collab.)
PRL 112 091302
M. Arik et al.
(CAST Collab.)
PRL 113 191302
A. Ayala et al.
PL B736 459
D. Babusci et al.
(KLOE-2 Collab.)
PRL 113 171802
B. Batell, R. Essig, Z. Surujon(EFI, STON)PR D89 035010
V.B. Bezerra et al.
EPJ C74 2859
V.B. Bezerra et al.
PR D90 055013
V.B. Bezerra et al.
PR D89 075002
V.B. Bezerra et al.
PL B731 320
J. Bluemlein, J. Brunner(CPPM, DESY)
PL B737 30
K. Blum et al.
(IAS, PRIN)PR D90 092003
F. Della Valle et al.
(PVLAS Collab.)
EPJ C74 3035
A.V. Derbin et al.
PR D90 123527
D. Ejlli
PR D90 035022
A. Fradette et al.
PRL 113 201801
J.P. Lees et al.
(BABAR Collab.)
JCAP 1408 031
L. Leinson
PRL 112 221802
H. Merkel et al.
(A1 at MAMI)
JCAP 1410 069
M.M. Miller Bertolami et al.
EPJ C74 3027
P. Pugnat et al.
(OSQAR Collab.)
JCAP 1408 021
R. Reesman et al.
(OSU)
PL B724 46
K. Abe et al.
(XMASS Collab.)
PR D88 102003
A. Abramowski et al.
(H.E.S.S. Collab.)
PL B726 187
P. Adlarson et al.
(WASA-at-COSY Collab.)
JCAP 1305 007
F. Alessandria et al.
(CUORE Collab.)
PL B725 190
H. An, M. Pospelov, J. Pradler
PRL 111 041302
H. An, M. Pospelov, J. Pradler
JCAP 1310 020
M. Archidiacono et al.
JCAP 1311 067
E. Armengaud et al.
(EDELWEISS-II Collab.)
PL B720 111
D. Babusci et al.
(KLOE-2 Collab.)
JCAP 1305 010
K. Barth et al.
(CAST Collab.)
PRL 111 231801
C. Beck
PR D88 075014
M. Betz et al.
(CROWS Collab.)
PRL 111 102001
M. Bulatowicz et al.
PR D87 011105
P.-H. Chu et al.
(DUKE, IND, SJTU)EPJ C73 2490
A. V. Derbin et al.
PRL 111 221803
M.D. Diamond, P. Schuster
PRL 110 061101
A. Friedland, M. Giannotti, M. WisePR D87 035030
S.N. Gninenko(INRM)
PRL 111 151802
B. R. Heckel et al.
PL B721 220
R. Horvat et al.
PL B722 301
T. Inada et al.
PR D88 063528
M. Lattanzi et al.
PR D87 035027
M. Meyer, D. Horns, M. Raue
JCAP 1307 013
T. Mizumoto et al.
PR D88 112004
S. Parker et al.
JCAP 1308 034
J. Redondo, G. Raffelt
PRL 111 100801
K. Tullney et al.
PRL 111 231301
N. Viaux et al.
APJ 772 44
D. Wouters, P. Brun
(SACL)
PR D85 092012
M. Ablikim et al.
(BESIII Collab.)
PL B706 251
F. Archilli et al.
(KLOE-2 Collab.)
PL B711 41
P. Belli et al.
(DAMA-KIEV)PR D85 092003
G. Bellini et al.
(Borexino Collab.)
JCAP 1202 032
D. Cadamuro et al.
(MPIM)
JCAP 1212 010
A.H. Corsico et al.
(LAPL, RGSUL, WASH+)JETPL 95 339
A.V. Derbin et al.
(PNPI)
Translated from ZETFP 95 379.
PR C86 021601
A. Gando et al.
(KamLAND-Zen Collab.)
PR D85 055027
S.N. Gninenko(INRM)PL B713 244
S.N. Gninenko(INRM)
JCAP 1207 041
A. Payez et al.
(LIEG)
PR D86 015001
G. Raffelt(MPIM)

https://pdg.lbl.gov

Page 74

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

AALSETHABRAHAMY...
ARIK
ARNOLD
BLUEMLEINCADAMURO
DERBIN

11
11
11
11
11
11
11

PRL 106 131301
C.E. Aalseth et al.
(CoGeNT Collab.)
PRL 107 191804
S. Abrahamyan et al.
PRL 107 261302
M. Arik et al.
(CAST Collab.)
PRL 107 062504
R. Arnold et al.
(NEMO-3 Collab.)
PL B701 155
J. Bluemlein, J. Brunner(DESY)
JCAP 1102 003
D. Cadamuro et al.
(MPIM, AARHUS)
PAN 74 596
A.V. Derbin et al.
(PNPI)
Translated from YAF 74 620.
DERBIN
11A PR D83 023505
A.V. Derbin et al.
(PNPI)HOEDL
11
PRL 106 041801
S.A. Hoedl et al.
(WASH)HOSKINS11
PR D84 121302
J. Hoskins et al.
(ADMX Collab.)
ANDRIAMON... 10
JCAP 1003 032
S. Andriamonje et al.
(CAST Collab.)
ARGYRIADES 10
NP A847 168
J. Argyriades et al.
(NEMO-3 Collab.)
ASZTALOS10PRL 104 041301
S.J. Asztalos et al.
(ADMX Collab.)
EHRET
10
PL B689 149
K. Ehret et al.
(ALPS Collab.)
HANNESTAD 10
JCAP 1008 001
S. Hannestad et al.
PETUKHOV10
PRL 105 170401
A.K. Petukhov et al.
SEREBROV10JETPL 91 6
A.P. Serebrov et al.
Translated from ZETFP 91 8.
AHMED
09A PRL 103 141802
Z. Ahmed et al.
(CDMS Collab.)
ANDRIAMON... 09
JCAP 0912 002
S. Andriamonje et al.
ARGYRIADES 09
PR C80 032501
J. Argyriades et al.
(NEMO-3 Collab.)
ARIK
09
JCAP 0902 008
E. Arik et al.
(CAST Collab.)
BJORKEN09
PR D80 075018
J. Bjorken et al.
CHOU
09
PRL 102 030402
A.S. Chou et al.
(GammeV Collab.)
DAVOUDIASL 09
PR D79 095024
H. Davoudiasl, P. Huber
DERBIN
09A PL B678 181
A.V. Derbin et al.
GONDOLO09
PR D79 107301
P. Gondolo, G. Raffelt(UTAH, MPIM)
IGNATOVICH 09
EPJ C64 19
V.K. Ignatovich, Y.N. Pokotilovski(JINR)KEKEZ
09
PL B671 345
D. Kekez et al.
SEREBROV09
PL B680 423
A.P. Serebrov(PNPI)AFANASEV08
PRL 101 120401
A. Afanasev et al.
BELLINI08
EPJ C54 61
G. Bellini et al.
(Borexino Collab.)
CHOU
08
PRL 100 080402
A.S. Chou et al.
(GammeV Collab.)
FOUCHE08
PR D78 032013
M. Fouche et al.
HANNESTAD 08
JCAP 0804 019
S. Hannestad et al.
INOUE
08
PL B668 93
Y. Inoue et al.
ZAVATTINI08
PR D77 032006
E. Zavattini et al.
(PVLAS Collab.)
ADELBERGER 07
PRL 98 131104
E.G. Adelberger et al.
ANDRIAMON... 07
JCAP 0704 010
S. Andriamonje et al.
(CAST Collab.)
BAESSLER07
PR D75 075006
S. Baessler et al.
CHANG07
PR D75 052004
H.M. Chang et al.
(TEXONO Collab.)
HANNESTAD 07
JCAP 0708 015
S. Hannestad et al.
JAIN
07
JP G34 129
P.L. Jain, G. Singh
LESSA
07
PR D75 094001
A.P. Lessa, O.L.G. Peres
MELCHIORRI 07A PR D76 041303
A. Melchiorri, O. Mena, A. Slosar
ROBILLIARD 07
PRL 99 190403
C. Robilliard et al.
ARNOLD06
NP A765 483
R. Arnold et al.
(NEMO-3 Collab.)
DUFFY
06
PR D74 012006
L.D. Duffy et al.
HECKEL06
PRL 97 021603
B.R. Heckel et al.
ZAVATTINI06
PRL 96 110406
E. Zavattini et al.
(PVLAS Collab.)
HANNESTAD 05A JCAP 0507 002
S. Hannestad, A. Mirizzi, G. Raffelt
ZIOUTAS05
PRL 94 121301
K. Zioutas et al.
(CAST Collab.)
ADLER
04
PR D70 037102
S. Adler et al.
(BNL E787 Collab.)
ANISIMOVSK... 04
PRL 93 031801
V.V. Anisimovsky et al.
(BNL E949 Collab.)
ARNOLD
04
JETPL 80 377
R. Arnold et al.
(NEMO-3 Collab.)
Translated from ZETFP 80 429.
ASZTALOS04
PR D69 011101
S.J. Asztalos et al.
HOFFMANN04
PR B70 180503
C. Hoffmann et al.
ARNABOLDI 03
PL B557 167
C. Arnaboldi et al.
CIVITARESE
03
NP A729 867
O. Civitarese, J. Suhonen
DANEVICH03
PR C68 035501
F.A. Danevich et al.
FARZAN03
PR D67 073015
Y. Farzan(SLAC, SISSA)ADLER
02C PL B537 211
S. Adler et al.
(BNL E787 Collab.)
BADERT...
02
PL B542 29
A. Badertscher et al.
BERNABEI
02D PL B546 23
R. Bernabei et al.
(DAMA Collab.)
DERBIN02
PAN 65 1302
A.V. Derbin et al.
Translated from YAF 65 1335.

https://pdg.lbl.gov

Page 75

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

FUSHIMIINOUEMORALESADLER
AMMAR
ASHITKOV

02
02
02B
01
01B
01

BERNABEI
01B
DANEVICH
01
DEBOER
01
STOICA
01
ALESSAND... 00
ARNOLD00
ASTIER00B
DANEVICH
00
MASSO
00
ARNOLD99
NI
99
SIMKOVIC
99
ALTEGOER98
ARNOLD98
AVIGNONE
98
DIAZ
98
KIM
98
LUESCHER98
MORIYAMA
98
MOROI
98
POSPELOV
98
AHMAD
97
BORISOV97
DEBOER
97C
KACHELRIESS 97
KEIL
97
KITCHING
97
LEINBERGER 97
ADLER
96
AMSLER
96B
GANZ
96GUENTHER
96
KAMEL
96
MITSUI96
YOUDIN96
ALTMANN95
BASSOMPIE... 95
MAENO
95
RAFFELT95
SKALSEY95
TSUNODA95
ADACHI
94
ALTHERR
94
AMSLER
94B
ASAI
94
MEIJERDREES 94
NI
94
VO
94
ATIYA
93
Also
ATIYA
93B
BASSOMPIE... 93
BECK93
CAMERON
93
CHANG
93
CHUI
93
MINOWA
93
NG
93
RITTER93
TANAKA
93
ALLIEGRO
92
ATIYA
92
BARABASH
92
BERNATOW... 92

PL B531 190
K. Fushimi et al.
(ELEGANT V Collab.)
PL B536 18
Y. Inoue et al.
ASP 16 325
A. Morales et al.
(COSME Collab.)PR D63 032004
S. Adler et al.
(BNL E787 Collab.)
PRL 87 271801
R. Ammar et al.
(CLEO Collab.)
JETPL 74 529
V.D. Ashitkov et al.
Translated from ZETFP 74 601.
PL B515 6
R. Bernabei et al.
(DAMA Collab.)
NP A694 375
F.A. Danevich et al.
JP G27 L29
F.W.N. de Boer et al.
NP A694 269
S. Stoica, H.V. Klapdor-Kleingrothous
PL B486 13
A. Alessandrello et al.
NP A678 341
R. Arnold et al.
PL B479 371
P. Astier et al.
(NOMAD Collab.)
PR C62 045501
F.A. Danevich et al.
PR D61 011701
E. Masso
NP A658 299
R. Arnold et al.
(NEMO Collab.)
PRL 82 2439
W.-T. Ni et al.
PR C60 055502
F. Simkovic et al.
PL B428 197
J. Altegoer et al.
NP A636 209
R. Arnold et al.
(NEMO-2 Collab.)
PRL 81 5068
F.T. Avignone et al.
(Solar Axion Experiment)
NP B527 44
M.A. Diaz et al.
PR D58 055006
J.E. Kim
PL B434 407
R. Luescher et al.
PL B434 147
S. Moriyama et al.
PL B440 69
T. Moroi, H. Murayama
PR D58 097703
M. Pospelov
PRL 78 618
I. Ahmad et al.
(APEX Collab.)
JETP 83 868
A.V. Borisov, V.Y. Grishinia(MOSU)JP G23 L85
F.W.N. de Boer et al.
PR D56 1313
M. Kachelriess, C. Wilke, G. Wunner(BOCH)PR D56 2419
W. Keil et al.
PRL 79 4079
P. Kitching et al.
(BNL E787 Collab.)
PL B394 16
U. Leinberger et al.
(ORANGE Collab.)
PRL 76 1421
S. Adler et al.
(BNL E787 Collab.)
ZPHY C70 219
C. Amsler et al.
(Crystal Barrel Collab.)
PL B389 4
R. Ganz et al.
(GSI, HEID, FRAN, JAGL+)PR D54 3641
M. Gunther et al.
(MPIK, SASSO)
PL B368 291
S. Kamel(SHAMS)EPL 33 111
T. Mitsui et al.
(TOKY)
PRL 77 2170
A.N. Youdin et al.
(AMHT, WASH)
ZPHY C68 221
M. Altmann et al.
(TUM, LAPP, CPPM)
PL B355 584
G. Bassompierre et al.
(LAPP, LCGT, LYON)
PL B351 574
T. Maeno et al.
(TOKY)PR D51 1495
G. Raffelt, A. Weiss(MPIM, MPIG)PR D51 6292
M. Skalsey, R.S. Conti(MICH)EPL 30 273
T. Tsunoda et al.
(TOKY)PR A49 3201
S. Adachi et al.
(TMU)
ASP 2 175
T. Altherr, E. Petitgirard, T. del Rio Gaztelurrutia
PL B333 271
C. Amsler et al.
(Crystal Barrel Collab.)
PL B323 90
S. Asai et al.
(TOKY)
PR D49 4937
M.R. Drees et al.
(BRCO, OREG, TRIU)
Physica B194 153
W.T. Ni et al.
(NTHU)PR C49 1551
D.T. Vo et al.
(ISU, LBL, LLNL, UCD)PRL 70 2521
M.S. Atiya et al.
(BNL E787 Collab.)
PRL 71 305 (errat.)
M.S. Atiya et al.
(BNL E787 Collab.)PR D48 1
M.S. Atiya et al.
(BNL E787 Collab.)
EPL 22 239
G. Bassompierre et al.
(LAPP, TORI, LYON)
PRL 70 2853
M. Beck et al.
(MPIK, KIAE, SASSO)
PR D47 3707
R.E. Cameron et al.
(ROCH, BNL, FNAL+)
PL B316 51
S. Chang, K. Choi
PRL 71 3247
T.C.P. Chui, W.T. Ni(NTHU)
PRL 71 4120
M. Minowa et al.
(TOKY)
PR D48 2941
K.W. Ng(AST)
PRL 70 701
R.C. Ritter et al.
PR D48 5412
J. Tanaka, H. Ejiri(OSAK)PRL 68 278
C. Alliegro et al.
(BNL, FNAL, PSI+)PRL 69 733
M.S. Atiya et al.
(BNL, LANL, PRIN+)
PL B295 154
L.S. Barabash et al.
(JINR, CERN, SERP+)PRL 69 2341
T. Bernatowicz et al.
(WUSL, TATA)

https://pdg.lbl.gov

Page 76

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

BLUEMLEIN
92
HALLIN92
HENDERSON 92C
HICKS
92
LAZARUS92
MEIJERDREES 92
PAN
92
RUOSO
92
SKALSEY
92
VENEMA
92
WANG
92
WANG
92C
WU
92
AKOPYAN91
ASAI
91
BERSHADY
91
BLUEMLEIN91
BOBRAKOV
91

IJMP A7 3835
J. Bluemlein et al.
(BERL, BUDA, JINR+)PR D45 3955
A.L. Hallin et al.
(PRIN)PRL 69 1733
S.D. Henderson et al.
(YALE, BNL)PL B276 423
K.H. Hicks, D.E. Alburger(OHIO, BNL)PRL 69 2333
D.M. Lazarus et al.
(BNL, ROCH, FNAL)PRL 68 3845
R. Meijer Drees et al.
(SINDRUM I Collab.)
MPL A7 1287
S.S. Pan, W.T. Ni, S.C. Chen(NTHU)ZPHY C56 505
G. Ruoso et al.
(ROCH, BNL, FNAL, TRST)PRL 68 456
M. Skalsey, J.J. Kolata(MICH, NDAM)
PRL 68 135
B.J. Venema et al.
MPL A7 1497
J. Wang(ILL)
PL B291 97
J. Wang(ILL)
PRL 69 1729
X.Y. Wu et al.
(BNL, YALE, CUNY)
PL B272 443
M.V. Akopyan et al.
(INRM)PRL 66 2440
S. Asai et al.
(ICEPP)PRL 66 1398
M.A. Bershady, M.T. Ressell, M.S. Turner(CHIC+)ZPHY C51 341
J. Bluemlein et al.
(BERL, BUDA, JINR+)JETPL 53 294
V.F. Bobrakov et al.
(PNPI)
Translated from ZETFP 53 283.
BROSS
91
PRL 67 2942
A.D. Bross et al.
(FNAL, ILL)KIM
91C PRL 67 3465
J.E. Kim(SEOUL)RAFFELT91
PRPL 198 1
G.G. Raffelt(MPIM)RAFFELT91B PRL 67 2605
G. Raffelt, D. Seckel(MPIM, BART)RESSELL91
PR D44 3001
M.T. Ressell(CHIC, FNAL)TRZASKA91
PL B269 54
W.H. Trzaska et al.
(TAMU)TSERTOS91
PL B266 259
H. Tsertos et al.
(ILLG, GSI)WALKER91
APJ 376 51
T.P. Walker et al.
(HSCA, OSU, CHIC+)WIDMANN91
ZPHY A340 209
E. Widmann et al.
(STUT, GSI, STUTM)
WINELAND91
PRL 67 1735
D.J. Wineland et al.
(NBSB)ALBRECHT
90E PL B246 278
H. Albrecht et al.
(ARGUS Collab.)
ANTREASYAN 90C PL B251 204
D. Antreasyan et al.
(Crystal Ball Collab.)
ASANUMA90
PL B237 588
T. Asanuma et al.
(TOKY)ATIYA90
PRL 64 21
M.S. Atiya et al.
(BNL E787 Collab.)
ATIYA
90B PRL 65 1188
M.S. Atiya et al.
(BNL E787 Collab.)
BAUER
90
NIM B50 300
W. Bauer et al.
(STUT, VILL, GSI)
BURROWS
90
PR D42 3297
A. Burrows, M.T. Ressell, M.S. Turner(ARIZ+)
DEBOER90
JP G16 L1
F.W.N. de Boer, J. Lehmann, J. Steyaert(LOUV)ENGEL
90
PRL 65 960
J. Engel, D. Seckel, A.C. Hayes(BART, LANL)GNINENKO
90
PL B237 287
S.N. Gninenko et al.
(INRM)GUO
90
PR D41 2924
R. Guo et al.
(NIU, LANL, FNAL, CASE+)
HAGMANN90
PR D42 1297
C. Hagmann et al.
(FLOR)JUDGE90
PRL 65 972
S.M. Judge et al.
(ILLG, GSI)
RAFFELT90D PR D41 1324
G.G. Raffelt(MPIM)RITTER90
PR D42 977
R.C. Ritter et al.
(UVA)
SEMERTZIDIS 90
PRL 64 2988
Y.K. Semertzidis et al.
(ROCH, BNL, FNAL+)
TSUCHIAKI
90
PL B236 81
M. Tsuchiaki et al.
(ICEPP)
TURNER90
PRPL 197 67
M.S. Turner(FNAL)BARABASH89
PL B223 273
A.S. Barabash et al.
(ITEP, INRM)
BINI
89
PL B221 99
M. Bini et al.
(FIRZ, CERN, AARH)
BURROWS
89
PR D39 1020
A. Burrows, M.S. Turner, R.P. Brinkmann(ARIZ+)Also
PRL 60 1797
M.S. Turner(FNAL, EFI)
DEBOER89B PRL 62 2639
F.W.N. de Boer, R. van Dantzig(ANIK)ERICSON89
PL B219 507
T.E.O. Ericson, J.F. Mathiot(CERN, IPN)FAISSNER89
ZPHY C44 557
H. Faissner et al.
(AACH3, BERL, PSI)
FOX
89
PR C39 288
J.D. Fox et al.
(FSU)
MAYLE
89
PL B219 515
R. Mayle et al.
(LLL, CERN, MINN, FNAL+)
Also
PL B203 188
R. Mayle et al.
(LLL, CERN, MINN, FNAL+)
MINOWA89
PRL 62 1091
H. Minowa et al.
(ICEPP)
ORITO
89
PRL 63 597
S. Orito et al.
(ICEPP)PERKINS89
PRL 62 2638
D.H. Perkins(OXF)
TSERTOS89
PR D40 1397
H. Tsertos et al.
(GSI, ILLG)
VANBIBBER
89
PR D39 2089
K. van Bibber et al.
(LLL, TAMU, LBL)WUENSCH89
PR D40 3153
W.U. Wuensch et al.
(ROCH, BNL, FNAL)
Also
PRL 59 839
S. de Panfilis et al.
(ROCH, BNL, FNAL)AVIGNONE88
PR D37 618
F.T. Avignone et al.
(PRIN, SCUC, ORNL+)
BALKE
88
PR D37 587
B. Balke et al.
(LBL, UCB, COLO, NWES+)BJORKEN88
PR D38 3375
J.D. Bjorken et al.
(FNAL, SLAC, VPI)BLINOV88
SJNP 47 563
A.E. Blinov et al.
(NOVO)
Translated from YAF 47 889.

https://pdg.lbl.gov

Page 77

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

BOLTON88
Also
Also
CHANDA
88
CHOI
88
CONNELL
88
DATAR
88
DEBOER
88
Also
Also
Also
DEBOER88C
DOEHNER
88
EL-NADI
88
ENGEL
88
FAISSNER88
HATSUDA
88B
LORENZ88
MAYLE
88
PICCIOTTO
88
RAFFELT88
RAFFELT
88B
SAVAGE88
TSERTOS88
TSERTOS88B
VANKLINKEN 88
VANKLINKEN 88B
VONWIMMER...88
VOROBYOV88
DRUZHININ
87
FRIEMAN87
GOLDMAN87
KORENCHE... 87
MAIER
87
MILLS
87
RAFFELT87
RIORDAN87
TURNER
87
VANBIBBER87
VONWIMMER...87
BADIER
86
BROWN
86
BRYMAN86B
DAVIER86
DEARBORN
86
EICHLER86
HALLIN86
JODIDIO
86
Also
KETOV
86
KOCH
KONAKAMAIANIPECCEIRAFFELTRAFFELTSAVAGEAMALDIANANEV

86
86
86
86
86
86B
86B
85
85

BALTRUSAIT... 85
BERGSMA85
KAPLAN85
IWAMOTO
84
YAMAZAKI
84
ABBOTT
83
CARBONI83
CAVAIGNAC
83
DICUS
83
DINE
83

PR D38 2077
R.D. Bolton et al.
(LANL, STAN, CHIC+)PRL 56 2461
R.D. Bolton et al.
(LANL, STAN, CHIC+)PRL 57 3241
D. Grosnick et al.
(CHIC, LANL, STAN+)
PR D37 2714
R. Chanda, J.F. Nieves, P.B. Pal(UMD, UPR+)PR D37 3225
K. Choi et al.
(JHU)
PRL 60 2242
S.H. Connell et al.
(WITW)PR C37 250
V.M. Datar et al.
(IPN)
PRL 61 1274
F.W.N. de Boer, R. van Dantzig(ANIK)PRL 62 2644 (errat.)
F.W.N. de Boer, R. van Dantzig(ANIK)PRL 62 2638
D.H. Perkins(OXF)
PRL 62 2639
F.W.N. de Boer, R. van Dantzig(ANIK)JP G14 L131
F.W.N. de Boer et al.
(LOUV)
PR D38 2722
J. Dohner et al.
(HEIDP, ANL, ILLG)
PRL 61 1271
M. el Nadi, O.E. Badawy(CAIR)PR C37 731
J. Engel, P. Vogel, M.R. Zirnbauer
ZPHY C37 231
H. Faissner et al.
(AACH3, BERL, SIN)
PL B203 469
T. Hatsuda, M. Yoshimura(KEK)
PL B214 10
E. Lorenz et al.
(MPIM, PSI)PL B203 188
R. Mayle et al.
(LLL, CERN, MINN, FNAL+)
PR D37 1131
C.E. Picciotto et al.
(TRIU, CNRC)
PRL 60 1793
G. Raffelt, D. Seckel(UCB, LLL, UCSC)
PR D37 549
G.G. Raffelt, D.S.P. Dearborn(UCB, LLL)
PR D37 1134
M.J. Savage, B.W. Filippone, L.W. Mitchell(CIT)
PL B207 273
A. Tsertos et al.
(GSI, ILLG)
ZPHY A331 103
A. Tsertos et al.
(GSI, ILLG)
PL B205 223
J. van Klinken et al.
(GRON, GSI)PRL 60 2442
J. van Klinken(GRON)PRL 60 2443
U. von Wimmersperg(BNL)
PL B208 146
P.V. Vorobiev, Y.I. Gitarts(NOVO)ZPHY C37 1
V.P. Druzhinin et al.
(NOVO)
PR D36 2201
J.A. Frieman, S. Dimopoulos, M.S. Turner(SLAC+)
PR D36 1543
T. Goldman et al.
(LANL, CHIC, STAN+)SJNP 46 192
S.M. Korenchenko et al.
(JINR)
Translated from YAF 46 313.
ZPHY A326 527
K. Maier et al.
(STUT, GSI)PR D36 707
A.P. Mills, J. Levy
(BELL)
PR D36 2211
G.G. Raffelt, D.S.P. Dearborn(LLL, UCB)PRL 59 755
E.M. Riordan et al.
(ROCH, CIT+)PRL 59 2489
M.S. Turner(FNAL, EFI)PRL 59 759
K. van Bibber et al.
(LLL, CIT, MIT+)PRL 59 266
U. von Wimmersperg et al.
(WITW)ZPHY C31 21
J. Badier et al.
(NA3 Collab.)
PRL 57 2101
C.N. Brown et al.
(FNAL, WASH, KYOT+)PRL 57 2787
D.A. Bryman, E.T.H. Clifford(TRIU)PL B180 295
M. Davier, J. Jeanjean, H. Nguyen Ngoc
(LALO)PRL 56 26
D.S.P. Dearborn, D.N. Schramm, G. Steigman(LLL+)PL B175 101
R.A. Eichler et al.
(SINDRUM Collab.)
PRL 57 2105
A.L. Hallin et al.
(PRIN)
PR D34 1967
A. Jodidio et al.
(LBL, NWES, TRIU)
PR D37 237 (errat.)
A. Jodidio et al.
(LBL, NWES, TRIU)JETPL 44 146
S.N. Ketov et al.
(KIAE)
Translated from ZETFP 44 114.
NC 96A 182
H.R. Koch, O.W.B. Schult(JULI)PRL 57 659
A. Konaka et al.
(KYOT, KEK)
PL B175 359
L. Maiani, R. Petronzio, E. Zavattini(CERN)PL B172 435
R.D. Peccei, T.T. Wu, T. Yanagida(DESY)
PR D33 897
G.G. Raffelt(MPIM)PL 166B 402
G.G. Raffelt(MPIM)PRL 57 178
M.J. Savage et al.
(CIT)
PL 153B 444
U. Amaldi et al.
(CERN)SJNP 41 585
V.D. Ananev et al.
(JINR)
Translated from YAF 41 912.
PRL 55 1842
R.M. Baltrusaitis et al.
(Mark III Collab.)
PL 157B 458
F. Bergsma et al.
(CHARM Collab.)
NP B260 215
D.B. Kaplan(HARV)PRL 53 1198
N. Iwamoto(UCSB, WUSL)PRL 52 1089
T. Yamazaki et al.
(INUS, KEK)
PL 120B 133
L.F. Abbott, P. Sikivie(BRAN, FLOR)
PL 123B 349
G. Carboni, W. Dahme(CERN, MUNI)
PL 121B 193
J.F. Cavaignac et al.
(ISNG, LAPP)PR D28 1778
D.A. Dicus, V.L. Teplitz(TEXA, UMD)
PL 120B 137
M. Dine, W. Fischler(IAS, PENN)

https://pdg.lbl.gov

Page 78

Created: 7/25/2024 17:21

Citation: S. Navas et al. (Particle Data Group), Phys. Rev. D 110, 030001 (2024)

ELLIS
FAISSNERFAISSNERFRANKHOFFMANPRESKILLSIKIVIE
Also
ALEKSEEV

83B
83
83B
83B
83
83
83

NP B223 252
J. Ellis, K.A. Olive(CERN)
PR D28 1198
H. Faissner et al.
(AACH)
PR D28 1787
H. Faissner et al.
(AACH3)
PR D28 1790
J.S. Frank et al.
(LANL, YALE, LBL+)
PR D28 660
C.M. Hoffman et al.
(LANL, ARZS)PL 120B 127
J. Preskill, M.B. Wise, F. Wilczek(HARV, UCSBT)PRL 51 1415
P. Sikivie(FLOR)PRL 52 695 (errat.)
P. Sikivie(FLOR)
82
JETP 55 591
E.A. Alekseeva et al.
(KIAE)
Translated from ZETF 82 1007.
ALEKSEEV
82B JETPL 36 116
G.D. Alekseev et al.
(MOSU, JINR)
Translated from ZETFP 36 94.
ASANO
82
PL 113B 195
Y. Asano et al.
(KEK, TOKY, INUS, OSAK)
BARROSO82
PL 116B 247
A. Barroso, G.C. Branco(LISB)DATAR
82
PL 114B 63
V.M. Datar et al.
(BHAB)EDWARDS82
PRL 48 903
C. Edwards et al.
(Crystal Ball Collab.)
FETSCHER82
JP G8 L147
W. Fetscher(ETH)
FUKUGITA82
PRL 48 1522
M. Fukugita, S. Watamura, M. Yoshimura(KEK)
FUKUGITA
82B PR D26 1840
M. Fukugita, S. Watamura, M. Yoshimura(KEK)
LEHMANN82
PL 115B 270
P. Lehmann et al.
(SACL)RAFFELT82
PL 119B 323
G. Raffelt, L. Stodolsky(MPIM)ZEHNDER82
PL 110B 419
A. Zehnder, K. Gabathuler, J.L. Vuilleumier(ETH+)ASANO
81B PL 107B 159
Y. Asano et al.
(KEK, TOKY, INUS, OSAK)
BARROSO81
PL 106B 91
A. Barroso, N.C. Mukhopadhyay(SIN)
FAISSNER81
ZPHY C10 95
H. Faissner et al.
(AACH3)
FAISSNER
81B PL 103B 234
H. Faissner et al.
(AACH3)
KIM
81
PL 105B 55
B.R. Kim, C. Stamm(AACH3)
VUILLEUMIER 81
PL 101B 341
J.L. Vuilleumier et al.
(CIT, MUNI)ZEHNDER81
PL 104B 494
A. Zehnder(ETH)
FAISSNER80
PL 96B 201
H. Faissner et al.
(AACH3)JACQUES80
PR D21 1206
P.F. Jacques et al.
(RUTG, STEV, COLU)
SOUKAS80
PRL 44 564
A. Soukas et al.
(BNL, HARV, ORNL, PENN)BECHIS79
PRL 42 1511
D.J. Bechis et al.
(UMD, COLU, AFRR)
CALAPRICE79
PR D20 2708
F.P. Calaprice et al.
(PRIN)
COTEUS79
PRL 42 1438
P. Coteus et al.
(COLU, ILL, BNL)DISHAW79
PL 85B 142
J.P. Dishaw et al.
(SLAC, CIT)ZHITNITSKII 79
SJNP 29 517
A.R. Zhitnitsky, Y.I. Skovpen(NOVO)
Translated from YAF 29 1001.
ALIBRAN78
PL 74B 134
P. Alibran et al.
(Gargamelle Collab.)
ASRATYAN
78B PL 79B 497
A.E. Asratyan et al.
(ITEP, SERP)BELLOTTI78
PL 76B 223
E. Bellotti, E. Fiorini, L. Zanotti(MILA)BOSETTI
78B PL 74B 143
P.C. Bosetti et al.
(BEBC Collab.)
DICUS
78C PR D18 1829
D.A. Dicus et al.
(TEXA, VPI, STAN)
DONNELLY
78
PR D18 1607
T.W. Donnelly et al.
(STAN)Also
PRL 37 315
F. Reines, H.S. Gurr, H.W. Sobel
(UCI)
Also
PRL 33 179
H.S. Gurr, F. Reines, H.W. Sobel
(UCI)
HANSL
78D PL 74B 139
T. Hansl et al.
(CDHS Collab.)
MICELMAC... 78
LNC 21 441
G.V. Mitselmakher, B. Pontecorvo(JINR)MIKAELIAN78
PR D18 3605
K.O. Mikaelian(FNAL, NWES)
SATO
78
PTP 60 1942
K. Sato(KYOT)
VYSOTSKII
78
JETPL 27 502
M.I. Vysotsky et al.
(ASCI)
Translated from ZETFP 27 533.
YANG78
PRL 41 523
T.C. Yang(MASA)PECCEI77
PR D16 1791
R.D. Peccei, H.R. Quinn(STAN, SLAC)
Also
PRL 38 1440
R.D. Peccei, H.R. Quinn(STAN, SLAC)REINES76
PRL 37 315
F. Reines, H.S. Gurr, H.W. Sobel
(UCI)
GURR
74
PRL 33 179
H.S. Gurr, F. Reines, H.W. Sobel
(UCI)
ANAND
53
PRSL A22 183
B.M. Anand

OTHER RELATED PAPERSSREDNICKIBARDEEN

85
78

NP B260 689
PL 74B 229

https://pdg.lbl.gov

M. Srednicki
W.A. Bardeen, S.-H.H. Tye

Page 79(UCSB)(FNAL)Created: 7/25/2024 17:21