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 $g_{A\gamma}$ is accidentally small enough as originally emphasized by KAPLAN 85; see Fig. 1.

40 BORISOV 97 bound is on the axion-electron coupling $g_{ae} < 1 \times 10^{-13}$ from the photo-production of axions off of magnetic fields in the outer layers of neutron stars.

41 KACHELRIESS 97 bound is on the axion-electron coupling $g_{ae} < 1 \times 10^{-10}$ from the production of axions in strongly magnetized neutron stars. The authors also quote a stronger limit, $g_{ae} < 9 \times 10^{-13}$ which is strongly dependent on the strength of the magnetic field in white dwarfs.

42 KEIL 97 uses new measurements of the axial-vector coupling strength of nucleons, as well as a reanalysis of many-body effects and pion-emission processes in the core of the neutron star, to update limits on the invisible-axion mass.

43 RAFFELT 95 reexamined the constraints on axion emission from red giants due to the axion-electron coupling. They improve on DEARBORN 86 by taking into proper account degeneracy effects in the bremstrahlung 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 ALTHERT 94 bound is on the axion-electron coupling $g_{ae} < 1.5 \times 10^{-13}$, from energy loss via axion emission.

45 CHANG 93 updates ENGEL 90 bound with the Kaplan-Manohar ambiguity in $z=m_{\mu}/m_{d}$ (see the Note on the Quark Masses in the Quark Particle Listings). It leaves the window $f_{A}=3 \times 10^{5}-3 \times 10^{6}$ 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 $\gamma$ 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 saxon (scalar component 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 bremstrahlung processes.

49 RESSELL 91 uses absence of any intracluster line emission to set limit.

50 ENGEL 90 rule out $10^{-10} \lesssim g_{AN} \lesssim 10^{-3}$, which for a hadronic axion with EMC motivated axion-nucleon couplings corresponds to $2.5 \times 10^{-3}$ eV $\lesssim m_{A0} \lesssim 2.5 \times 10^4$ eV. The constraint is loose in the middle of the range, i.e. for $g_{AN} \sim 10^{-6}$.

51 RAFFELT 90d is a re-analysis of DEARBORN 86.

52 The region $m_{A0} \lesssim 2$ eV is also allowed.

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 naïve quark model couplings of axion to nucleons. Limit based on couplings motivated by EMC measurements is 2-4 times weaker. The limit from axion-electron coupling is weak: see HATSUDA 88b.

55 RAFFELT 88b derives a limit for the energy generation rate by exotic processes in helium-burning stars $\epsilon < 100$ erg $g^{-1}$ s$^{-1}$, which gives a firmer basis for the axion limits based on red giant cooling.

56 RAFFELT 87 also gives a limit $g_{A\gamma} < 1 \times 10^{-10}$ GeV$^{-1}$.

57 DEARBORN 86 also gives a limit $g_{A\gamma} < 1.4 \times 10^{-11}$ GeV$^{-1}$.

58 RAFFELT 86 gives a limit $g_{A\gamma} < 1.1 \times 10^{-10}$ GeV$^{-1}$ from red giants and $< 2.4 \times 10^{-9}$ GeV$^{-1}$ from the sun.

59 KAPLAN 85 says $m_{A0} < 23$ eV is allowed for a special choice of model parameters.

60 FUKUGITA 82 gives a limit $g_{A\gamma} < 2.3 \times 10^{-10}$ GeV$^{-1}$.

Search for Relic Invisible Axions

Limits are for the dimensionless quantity $[G_{A\gamma\gamma}/m_{A0}]^2\rho_{A}$ where $G_{A\gamma\gamma}$ denotes the axion two-photon coupling, $L_{int} = -\frac{G_{A\gamma\gamma}}{4}\phi_{A}F_{\mu\nu}\bar{F}^{\mu\nu} = G_{A\gamma\gamma}\phi_{A}E\cdot B$, and $\rho_{A}$ is the axion energy density near the earth, unless otherwise stated. Notice that for QCD axions $G_{A\gamma\gamma}/m_{A0}$ does not depend on $m_{A0}$. For the reference values $m_{A0} = 1$ µeV, $G_{A\gamma\gamma} = 3.9 \times 10^{-16}$ GeV$^{-1}$ (that would apply to KSVZ axions at that mass), and $\rho_{A} = 300$ MeV/cm$^3$ one finds $[G_{A\gamma\gamma}/m_{A0}]^2\rho_{A} = 3.5 \times 10^{-43}$.

<table><thead><tr><th>VALUE</th><th>CL%</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>&lt;1.3 &times; 10<sup>-3</sup></td><td>95</td><td>1 ADACHI</td><td>23d CMB</td><td>$m_{A0} = 0.096-2.2 &times; 10^{-20}$ eV</td></tr><tr><td>&lt;7.5 &times; 10<sup>-43</sup></td><td>90</td><td>2 DI-VORA</td><td>23 QUAX</td><td>$m_{A0} = 42.8178-42.8190$ &mu;eV</td></tr><tr><td>&lt;2.3 &times; 10<sup>-42</sup></td><td>90</td><td>3 JEWELL</td><td>23 HYST</td><td>$m_{A0} = 18.44-18.71$ &mu;eV</td></tr><tr><td>&lt;2.0 &times; 10<sup>-42</sup></td><td>90</td><td>4 JEWELL</td><td>23 HYST</td><td>$m_{A0} = 16.96-17.12, 17.14-17.28$ &mu;eV</td></tr><tr><td>&lt;2.5 &times; 10<sup>-42</sup></td><td>90</td><td>5 KIM</td><td>23 CASK</td><td>$m_{A0} = 9.39-9.51$ &mu;eV</td></tr><tr><td>&lt;3.0 &times; 10<sup>-4</sup></td><td>95</td><td>6 OSHIMA</td><td>23 DANC</td><td>$m_{A0} = 4.1 &times; 10^{-16}-2.0 &times; 10^{-12}$ eV</td></tr><tr><td>&lt;2.56 &times; 10<sup>-24</sup></td><td>95</td><td>7 THOMSON</td><td>23 UPLD</td><td>$m_{A0} = 1.12-1.20$ &mu;eV</td></tr><tr><td>&lt;6.09 &times; 10<sup>-43</sup></td><td>90</td><td>8 YANG</td><td>23 CAPP</td><td>$m_{A0} = 19.883-19.926$ &mu;eV</td></tr><tr><td>&lt;6.6 &times; 10<sup>-44</sup></td><td>90</td><td>9 YI</td><td>23 CASK</td><td>$m_{A0} = 4.51-4.59$ &mu;eV</td></tr><tr><td>&lt;2.6 &times; 10<sup>-44</sup></td><td>90</td><td>10 YI</td><td>23 ACR</td><td>$m_{A0} = 4.51-4.59$ &mu;eV</td></tr><tr><td>&lt;4.7 &times; 10<sup>-5</sup></td><td>95</td><td>11 ADE</td><td>22 CMB</td><td>$m_{A0} = 0.16-4.8 &times; 10^{-20}$ eV</td></tr><tr><td>&lt;1.0 &times; 10<sup>-41</sup></td><td>90</td><td>12 ALESINI</td><td>22 QUAX</td><td>$m_{A0} = 42.8210-42.8223$ &mu;eV</td></tr><tr><td>&lt;7 &times; 10<sup>-33</sup></td><td>95</td><td>13 BATTYE</td><td>22 ASTR</td><td>$m_{A0} = 4.2-6.0$ &mu;eV</td></tr><tr><td>&lt;5.8 &times; 10<sup>-41</sup></td><td>95</td><td>14 CHANG</td><td>22 TASE</td><td>$m_{A0} = 19.4687-19.8436$ &mu;eV</td></tr><tr><td>&lt;3.2 &times; 10<sup>-6</sup></td><td>95</td><td>15 FERGUSON</td><td>22 CMB</td><td>$m_{A0} = 0.047-4.7 &times; 10^{-20}$ eV</td></tr><tr><td>&lt;8.4 &times; 10<sup>-43</sup></td><td>90</td><td>16 LEE</td><td>22 CASK</td><td>$m_{A0} = 19.764-19.890$ &mu;eV</td></tr><tr><td>&lt;4.9 &times; 10<sup>-39</sup></td><td>95</td><td>17 QUISKAMP</td><td>22 ORGN</td><td>$m_{A0} = 63.2-67.1$ &mu;eV</td></tr><tr><td>&lt;3.6 &times; 10<sup>-43</sup></td><td>90</td><td>18 YOON</td><td>22 CASK</td><td>$m_{A0} = 19.764-19.890$ &mu;eV</td></tr></tbody></table>

<table><tr><td>&lt;1.03 &times; 10<sup>-35</sup></td><td>95</td></tr><tr><td>&lt;2.8 &times; 10<sup>-4</sup></td><td>95</td></tr><tr><td>&lt;1.1 &times; 10<sup>-41</sup></td><td>90</td></tr><tr><td>&lt;1 &times; 10<sup>-44</sup></td><td>90</td></tr><tr><td>&lt;1.6 &times; 10<sup>-29</sup></td><td>95</td></tr><tr><td>&lt;1.4 &times; 10<sup>-23</sup></td><td>95</td></tr><tr><td>&lt;7 &times; 10<sup>-43</sup></td><td>90</td></tr><tr><td>&lt;4.6 &times; 10<sup>-40</sup></td><td>95</td></tr><tr><td>&lt;3.5 &times; 10<sup>-28</sup></td><td>95</td></tr><tr><td>&lt;3 &times; 10<sup>-3</sup></td><td>95</td></tr><tr><td>&lt;1 &times; 10<sup>-2</sup></td><td>95</td></tr></table>

<table><tr><td>19 ZHOU</td><td>22 ASTR</td><td>$m_{A0} = 3.18-4.35$ &mu;eV</td></tr><tr><td>20 ADE</td><td>21 CMB</td><td>$m_{A0} = 0.16-4.8 &times; 10^{-20}$ eV</td></tr><tr><td>21 ALESINI</td><td>21 QUAX</td><td>$m_{A0} = 43$ &mu;eV</td></tr><tr><td>22 BARTRAM</td><td>21A ADMX</td><td>$m_{A0} = 3.3-4.2$ &mu;eV</td></tr><tr><td>23 DEVLIN</td><td>21 TRAP</td><td>$m_{A0} = 2.7906-2.7914$ neV</td></tr><tr><td>24 GRAMOLIN</td><td>21 Sشت</td><td>$m_{A0} = 0.012-12$ &mu;eV</td></tr><tr><td>25 KWON</td><td>21 CASK</td><td>$m_{A0} = 10.7126-10.7186$ &mu;eV</td></tr><tr><td>26 MELCON</td><td>21 RADE</td><td>$m_{A0} = 34.6738-34.6771$ &mu;eV</td></tr><tr><td>27 SALEM</td><td>21 ABRA</td><td>$m_{A0} = 0.41-8.27$ neV</td></tr><tr><td>28 THOMSON</td><td>21</td><td>$m_{A0} = 7.44-19.38$ &mu;eV</td></tr><tr><td>28 THOMSON</td><td>21</td><td>$m_{A0} = 74.4-74.5$ &mu;eV</td></tr><tr><td>29 YUAN</td><td>21 ASTR</td><td>$m_{A0} = 10^{-20}-10^{-17}$ eV</td></tr><tr><td>30 BRAINE</td><td>20 ADMX</td><td>$m_{A0} = 2.81-3.31$ &mu;eV</td></tr><tr><td>31 CRISOSTO</td><td>20 SLIC</td><td>$m_{A0} = 180.07-180.15$ neV</td></tr><tr><td>32 DARLING</td><td>20A ASTR</td><td>$m_{A0} = 4.2-165.6$ &mu;eV</td></tr><tr><td>33 FOSTER</td><td>20 ASTR</td><td>$m_{A0} = 5-7, 10-11$ &mu;eV</td></tr><tr><td>34 JEONG</td><td>20 CASK</td><td>$m_{A0} = 13.0-13.9$ &mu;eV</td></tr><tr><td>35 KENNEDY</td><td>20</td><td>$m_{S0} = 10^{-19}-10^{-17}$ eV</td></tr><tr><td>36 LEE</td><td>20A CASK</td><td>$m_{A0} = 6.62-6.82$ &mu;eV</td></tr><tr><td>37 ALESINI</td><td>19 QUAX</td><td>$m_{A0} = 37.5$ &mu;eV</td></tr><tr><td>38 FUJITA</td><td>19 ASTR</td><td>$m_{A0} < 10^{-21}$ eV</td></tr><tr><td>39 OUELLET</td><td>19A ABRA</td><td>$m_{A0} = 0.31-8.3$ neV</td></tr><tr><td>40 BOUTAN</td><td>18 ADMX</td><td>$m_{A0} = 17.38-17.57$ &mu;eV</td></tr><tr><td>40 BOUTAN</td><td>18 ADMX</td><td>$m_{A0} = 21.03-23.98$ &mu;eV</td></tr><tr><td>40 BOUTAN</td><td>18 ADMX</td><td>$m_{A0} = 29.67-29.79$ &mu;eV</td></tr><tr><td>41 DU</td><td>18 ADMX</td><td>$m_{A0} = 2.66-2.81$ &mu;eV</td></tr><tr><td>42 ZHONG</td><td>18 HYST</td><td>$m_{A0} = 23.15-24$ &mu;eV</td></tr><tr><td>43 BRANCA</td><td>17 AURG</td><td>$m_{S0} = 3.5-3.9$ peV</td></tr><tr><td>44 BRUBAKER</td><td>17 HYST</td><td>$m_{A0} = 23.55-24.0$ &mu;eV</td></tr><tr><td>45 CHOI</td><td>17 CASK</td><td>$m_{A0} = 24.7-29.1$ &mu;eV</td></tr><tr><td>46 MCALLISTER</td><td>17 ORGN</td><td>at $m_{A0} = 110$ &mu;eV</td></tr><tr><td>47 HOSKINS</td><td>16 ADMX</td><td>$m_{A0} = 3.36-3.52$ or $3.55-3.69$ &mu;eV</td></tr><tr><td>48 BECK</td><td>13</td><td>$m_{A0} = 0.11$ meV</td></tr><tr><td>49 HOSKINS</td><td>11 ADMX</td><td>$m_{A0} = 3.3-3.69 &times; 10^{-6}$ eV</td></tr><tr><td>50 ASZTALOS</td><td>10 ADMX</td><td>$m_{A0} = 3.34-3.53 &times; 10^{-6}$ eV</td></tr><tr><td>51 DUFFY</td><td>06 ADMX</td><td>$m_{A0} = 1.98-2.17 &times; 10^{-6}$ eV</td></tr><tr><td>52 ASZTALOS</td><td>04 ADMX</td><td>$m_{A0} = 1.9-3.3 &times; 10^{-6}$ eV</td></tr><tr><td>53 KIM</td><td>98 THEO</td><td></td></tr><tr><td>54 HAGMANN</td><td>90 CNTR</td><td>$m_{A0} = (5.4-5.9)10^{-6}$ eV</td></tr><tr><td>55 WUENSCH</td><td>89 CNTR</td><td>$m_{A0} = (4.5-10.2)10^{-6}$ eV</td></tr><tr><td>55 WUENSCH</td><td>89 CNTR</td><td>$m_{A0} = (11.3-16.3)10^{-6}$ eV</td></tr></table>

1 ADACHI 23d is analogous to ADE 21. They used POLARBEAR data, and take account of a stochastic local axion field amplitude with the time-averaged local axion density $\rho_{A} = 0.3$ GeV/cm$^3$. Limits are set at $G_{A\gamma\gamma} < 2.4 \times 10^{-11}$ GeV$^{-1}$ ($m_{A0}/10^{-21}$ eV), 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 for mass-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.

5 KIM 23 is an update of KWON 21 on the CAPP-PACE experiment. See their Fig. 4 for mass-dependent limits.

6 OSHIMA 23 report first limits from the DANCE experiment. This experiment is based on 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. The axion signal is resonantly enhanced when the axion mass matches the difference between a cavity which is pumped with power and another resonant mode close in frequency that is 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 and 4.8181 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 with a Bayesian method.

9 YI 23 is analogous to LEE 20A, using the CAPP-12TB haloscope. See their Fig. 4 for mass-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 or a velocity dispersion $\delta v = 20$ 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 $1 \times 10^{-23}-6 \times 10^{-19}$ eV.

12 ALESINI 22 is an update of ALESINI 21, using the TM030 mode of the cylindrical dielectric cavity. See their Fig. 8 for mass-dependent limits.
# Gauge & Higgs Boson Particle Listings
## Axions ($A^0$) and Other Very Light Bosons

## Invisible $A^0$ (Axion) Limits from Photon Coupling

Limits are for the modulus of the axion-two-photon coupling $G_{A\gamma\gamma}$ defined by $L = -G_{A\gamma\gamma}\phi_S A^0 B^0$. For scalars $S^0$ the limit is on the coupling constant in $L = G_{S\gamma\gamma}\phi_S(E^2 - B^2)$. The relation between $G_{A\gamma\gamma}$ and $m_{A^0}$ is not used unless stated otherwise, i.e., many of these bounds apply to low-mass axion-like particles (ALPs), not to QCD axions.

<table><thead><tr><th>VALUE (GeV<sup>-1</sup>)</th><th>CL%</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>&lt;3 &times; 10<sup>-11</sup></td><td>95</td><td>1 PANT</td><td>24</td><td>ASTR m<sub>A0</sub> = 0.3-1 neV</td></tr><tr><td>&lt;5.5 &times; 10<sup>-11</sup></td><td>95</td><td>2 BATTYE</td><td>23</td><td>DM m<sub>A0</sub> = 3.9-4.7 &mu;eV</td></tr><tr><td>&lt;2 &times; 10<sup>-13</sup></td><td>95</td><td>3 BEAUFORT</td><td>23</td><td>ASTR m<sub>A0</sub> = 3-38 keV</td></tr><tr><td>&lt;2 &times; 10<sup>-12</sup></td><td>99</td><td>4 BERNAL</td><td>23</td><td>COSM m<sub>A0</sub> = 8-25 eV</td></tr><tr><td>&lt;4 &times; 10<sup>-14</sup></td><td>99</td><td>5 CAPOZZI</td><td>23</td><td>COSM m<sub>A0</sub> = 30-800 eV</td></tr><tr><td>&lt;1.3 &times; 10<sup>-7</sup></td><td>95</td><td>6 CAPOZZI</td><td>23A</td><td>DUMP m<sub>A0</sub> = 10<sup>3</sup>-2 &times; 10<sup>8</sup> eV</td></tr><tr><td>&lt;5 &times; 10<sup>-12</sup></td><td>95</td><td>7 DAVIES</td><td>23</td><td>ASTR m<sub>A0</sub> = 5-200 neV</td></tr><tr><td>&lt;1.7 &times; 10<sup>-10</sup></td><td>95</td><td>8 DIAMOND</td><td>23</td><td>ASTR m<sub>A0</sub> = 2-56 MeV</td></tr><tr><td>&lt;6 &times; 10<sup>-29</sup></td><td>95</td><td>9 FILZINGER</td><td>23</td><td>Dilaton-like dark matter</td></tr><tr><td>&lt;4.5 &times; 10<sup>-12</sup></td><td>95</td><td>10 HOOF</td><td>23</td><td>ASTR m<sub>A0</sub> = 4 &times; 10<sup>-10</sup> eV</td></tr><tr><td>&lt;3 &times; 10<sup>-12</sup></td><td>95</td><td>11 HOOF</td><td>23</td><td>ASTR m<sub>A0</sub> = 60 MeV</td></tr><tr><td>&lt;2.7 &times; 10<sup>-11</sup></td><td>99.7</td><td>12 JACOBSEN</td><td>23</td><td>ASTR m<sub>A0</sub> &lt; 3 &times; 10<sup>-7</sup> eV</td></tr><tr><td>&lt;2 &times; 10<sup>-11</sup></td><td>99</td><td>13 LI</td><td>23H</td><td>ASTR m<sub>A0</sub> = 1-100 neV</td></tr><tr><td>&lt;3.0 &times; 10<sup>-12</sup></td><td>95</td><td>14 NOORDHUIS</td><td>23</td><td>ASTR m<sub>A0</sub> = 10<sup>-9</sup>-10<sup>-5</sup> eV</td></tr><tr><td>&lt;5 &times; 10<sup>-11</sup></td><td>95</td><td>15 PANT</td><td>23</td><td>ASTR m<sub>A0</sub> = 0.1-1000 neV</td></tr><tr><td>&lt;5 &times; 10<sup>-26</sup></td><td>95</td><td>16 SHERRILL</td><td>23</td><td>DM Dilaton-like dark matter</td></tr><tr><td>&lt;8 &times; 10<sup>-9</sup></td><td>95</td><td>17 SULAI</td><td>23</td><td>DM m<sub>A0</sub> = 0.25-2 &times; 10<sup>-14</sup> eV</td></tr><tr><td>&lt;7.9 &times; 10<sup>-12</sup></td><td>95</td><td>18 YAO</td><td>23</td><td>ASTR m<sub>A0</sub> &lt; 10<sup>-13</sup> eV</td></tr><tr><td>&lt;3.8 &times; 10<sup>-22</sup></td><td>95</td><td>19 ZHANG</td><td>23A</td><td>Dilaton-like dark matter</td></tr><tr><td>&lt;5 &times; 10<sup>-10</sup></td><td>90</td><td>20 APRILE</td><td>22B</td><td>XENT Solar axions</td></tr><tr><td>&lt;1.45 &times; 10<sup>-9</sup></td><td>95</td><td>21 ARNQUIST</td><td>22</td><td>MAJD m<sub>A0</sub> &lt; 100 eV</td></tr><tr><td>&lt;7 &times; 10<sup>-11</sup></td><td>95</td><td>22 ARZA</td><td>22</td><td>DM m<sub>A0</sub> = 0.2-7 &times; 10<sup>-17</sup> eV</td></tr><tr><td>3-6 &times; 10<sup>-11</sup></td><td>95</td><td>23 BERNAL</td><td>22</td><td>COSM m<sub>A0</sub> = 8-20 eV</td></tr><tr><td>&lt;3.76 &times; 10<sup>-11</sup></td><td>95</td><td>24 CALORE</td><td>22</td><td>ASTR m<sub>A0</sub> &lt; 10<sup>-11</sup> eV</td></tr><tr><td>&lt;2 &times; 10<sup>-10</sup></td><td>95</td><td>25 CAPUTO</td><td>22</td><td>ASTR m<sub>A0</sub> = 1-500 MeV</td></tr><tr><td>&lt;3 &times; 10<sup>-14</sup></td><td>95</td><td>26 CASTILLO</td><td>22</td><td>ASTR m<sub>A0</sub> = 3 &times; 10<sup>-23</sup> eV</td></tr><tr><td>&lt;6 &times; 10<sup>-12</sup></td><td>90</td><td>27 DEROCCO</td><td>22</td><td>ASTR m<sub>A0</sub> = 5-30 keV</td></tr><tr><td>&lt;5.4 &times; 10<sup>-12</sup></td><td>95</td><td>28 DESSERT</td><td>22A</td><td>ASTR m<sub>A0</sub> &lt; 3 &times; 10<sup>-7</sup> eV</td></tr><tr><td>&lt;2.1 &times; 10<sup>-11</sup></td><td>95</td><td>29 ECKNER</td><td>22</td><td>ASTR m<sub>A0</sub> &lt; 2 &times; 10<sup>-7</sup> eV</td></tr><tr><td>&lt;1 &times; 10<sup>-11</sup></td><td>95</td><td>30 FOSTER</td><td>22</td><td>ASTR m<sub>A0</sub> = 16.5-32.5 &mu;eV</td></tr><tr><td>&lt;1.14 &times; 10<sup>-5</sup></td><td>95</td><td>31 KIRITA</td><td>22</td><td>SAPH m<sub>A0</sub> = 0.5-500 meV</td></tr><tr><td>&lt;2 &times; 10<sup>-16</sup></td><td>95</td><td>32 LANGHOFF</td><td>22</td><td>COSM m<sub>A0</sub> = 0.1-3 &times; 10<sup>4</sup> keV</td></tr><tr><td>&lt;6 &times; 10<sup>-12</sup></td><td>95</td><td>33 LI</td><td>22</td><td>ASTR m<sub>A0</sub> = 0.2-20 neV</td></tr><tr><td>&lt;1.3 &times; 10<sup>-11</sup></td><td>95</td><td>34 LI</td><td>22C</td><td>ASTR m<sub>A0</sub> = 8-200 neV</td></tr><tr><td>&lt;1 &times; 10<sup>-5</sup></td><td>95</td><td>35 LUCENTE</td><td>22</td><td>ASTR m<sub>A0</sub> &lt; 0.4 MeV</td></tr><tr><td>&lt;9.2 &times; 10<sup>-11</sup></td><td>95</td><td>36 BASU</td><td>22</td><td>ASTR m<sub>A0</sub> = 3.6 &times; 10<sup>-21</sup> eV</td></tr><tr><td>&lt;1.8 &times; 10<sup>-10</sup></td><td>95</td><td>37 BI</td><td>21</td><td>ASTR m<sub>A0</sub> = 2-6 &times; 10<sup>-7</sup> eV</td></tr><tr><td>&lt;1.6 &times; 10<sup>-10</sup></td><td>95</td><td>38 DOLAN</td><td>21A</td><td>ASTR m<sub>A0</sub> = 1-570 keV</td></tr><tr><td>&lt;5 &times; 10<sup>-11</sup></td><td>95</td><td>39 GUO</td><td>21</td><td>ASTR m<sub>A0</sub> = 8-23 neV</td></tr><tr><td>&lt;1.2 &times; 10<sup>-4</sup></td><td>95</td><td>40 HOMMA</td><td>21</td><td>SAPH m<sub>A0</sub> = 0.4-600 meV</td></tr><tr><td>&lt;1.2 &times; 10<sup>-11</sup></td><td>95</td><td>41 LI</td><td>21B</td><td>ASTR m<sub>A0</sub> = 0.5-500 neV</td></tr><tr><td>&lt;1 &times; 10<sup>-13</sup></td><td>95</td><td>42 LLOYD</td><td>21</td><td>Magnetars</td></tr><tr><td></td><td></td><td>43 REGIS</td><td>21</td><td>ASTR m<sub>A0</sub> = 2.7-5.3 eV</td></tr></tbody></table>

<footnote n="13">¹³BATTYE 22 is analogous to DARLING 20A, and use plasma ray tracing technique to analyze the propagation of radio photons converted from axion dark matter in the magnetosphere of PSR J1745-2900. The quoted limit assumes $\rho_A = 6.5 \times 10^4$ GeV/cm³ in the vicinity of the magnetar. See their Fig. 1 for mass-dependent limits.</footnote>

<footnote n="14">¹⁴CHANG 22 used a microwave cavity detector to search for dark matter axions. See Fig. 3 for the mass-dependent limits.</footnote>

<footnote n="15">¹⁵FERGUSON 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 $0.047-9.5 \times 10^{-20}$ eV.</footnote>

<footnote n="16">¹⁶LEE 22 is analogous to LEE 20A. They used an 18T high-temperature superconducting magnet haloscope. See their Fig. 5 for mass-dependent limits.</footnote>

<footnote n="17">¹⁷QUISKAMP 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.</footnote>

<footnote n="18">¹⁸YOON 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.</footnote>

<footnote n="19">¹⁹ZHOU 22 is analogous to DARLING 20A, and they use the data from the MeerKAT radio telescope's observation of the neutron star J0806.4-1423, which is 250 pc from Earth. See their Fig. 3 for mass-dependent limits.</footnote>

<footnote n="20">²⁰ADE 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 $m_{A^0} = 4.8 \times 10^{-20}-5.7 \times 10^{-19}$ eV. See their Eq. (80) and Fig. 6 for mass-dependent limits.</footnote>

<footnote n="21">²¹ALESINI 21 is an update of ALESINI 19. See their Figs. 5 and 6 for the mass-dependent limits.</footnote>

<footnote n="22">²²BARTRAM 21A is analogous to DU 18. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="23">²³DEVLIN 21 use the superconducting resonant detection circuit of a cryogenic Penning trap with a single antiproton. See their Fig. 3 for mass-dependent limits.</footnote>

<footnote n="24">²⁴GRAMOLIN 21 use two detection channels, each consisting of two stacked toroids to look for the axion-induced oscillating magnetic field. The quoted limit applies at $m_{A^0} = 0.02$ neV. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="25">²⁵KWON 21 is analogous to LEE 20A. They also obtain weaker limits in the range of $m_{A^0} = 10.16-11.37$ µeV. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="26">²⁶MELCON 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 their Fig. 9 for mass-dependent limits.</footnote>

<footnote n="27">²⁷SALEMI 21 is an update of OUELLET 19A. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="28">²⁸THOMSON 21 use a resonant cavity supporting two spatially overlapping microwave modes, which is sensitive to the axion mass corresponding to the sum or difference of the two resonant frequencies. The original limit was retracted due to a sign error. See their Fig. 2 in the erratum for the corrected limits.</footnote>

<footnote n="29">²⁹YUAN 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 of $G_{A\gamma\gamma} = 8 \times 10^{-13}-3 \times 10^{-11}$ GeV⁻¹.</footnote>

<footnote n="30">³⁰BRAINE 20 is analogous to DU 18. See Fig. 4 for their mass-dependent limits.</footnote>

<footnote n="31">³¹CRISOSTO 20 used a resonant LC circuit to look for lighter axion dark matter. They obtained a similar, slightly weaker limit for $m_{A^0} = 174.98-175.19$ and $177.34-177.38$ neV. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="32">³²DARLING 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 angular resolution, by adding sub-optimal data. They use $\rho_A = 6.5 \times 10^4$ GeV/cm³ in the vicinity of the magnetar. See their Fig. 2 for mass-dependent limits.</footnote>

<footnote n="33">³³FOSTER 20 look for radio-frequency radiation converted from axion dark matter in the magnetic field around neutron stars. They use the observed data of isolated local neutron stars and in the Galactic center. The quoted limit applies to $m_{A^0} \approx 7$ µeV. See their Fig. 2 for mass-dependent limits.</footnote>

<footnote n="34">³⁴JEONG 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.</footnote>

<footnote n="35">³⁵KENNEDY 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, $\rho_S = 0.3$ GeV/cm³, they obtain a limit $G_{S\gamma\gamma} < 5.8 \times 10^{-24}$ GeV⁻¹ at $m_{S0} = 2 \times 10^{-19}$ eV. See their Fig. 2 for mass-dependent limits as well as limits on the modulus coupling to electrons.</footnote>

<footnote n="36">³⁶LEE 20A used a microwave cavity detector at the IBS/CAPP to search for dark matter axions. See Fig. 3 for the mass-dependent limits.</footnote>

<footnote n="37">³⁷ALESINI 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 $m_{A^0} = 37.5$ µeV.</footnote>

<footnote n="38">³⁸FUJITA 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.</footnote>

<footnote n="39">³⁹OUELLET 19A look for the axion-induced oscillating magnetic field generated by a toroidal magnetic field. The quoted limit applies at $m_{A^0} = 8$ neV. See their Fig. 3 for the mass-dependent limits.</footnote>

<footnote n="40">⁴⁰BOUTAN 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.</footnote>

<footnote n="41">⁴¹DU 18 is analogous to DUFFY 06. They upgraded a dilution refrigerator to reduce the system noise. The quoted limit is around $m_{A^0} = 2.69$ µeV for the boosted Maxwellian axion line shape. See Fig. 4 for their mass-dependent limits.</footnote>

<footnote n="42">⁴²ZHONG 18 is analogous to BRUBAKER 17. The quoted limit applies at $m_{A^0} = 23.76$ µeV. See their Fig. 4 for their mass-dependent limits.</footnote>

<footnote n="43">⁴³BRANCA 17 look for modulations of the fine-structure constant and the electron mass due to moduli dark matter by using the cryogenic resonant-mass AURIGA detector. The limit on the assumed dilatonic coupling implies $G_{S\gamma\gamma} < 1.5 \times 10^{-24}$ GeV⁻¹ for the scalar to two-photon coupling. See Fig. 5 for the mass-dependent limits.</footnote>

<footnote n="44">⁴⁴BRUBAKER 17 used a microwave cavity detector at the Yale Wright Laboratory to search for dark matter axions. See Fig. 3 for the mass-dependent limits.</footnote>

<footnote n="45">⁴⁵CHOI 17 used a microwave cavity detector with toroidal geometry. See Fig. 4 for their mass-dependent limits.</footnote>

<footnote n="46">⁴⁶MCALLISTER 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.</footnote>

<footnote n="47">⁴⁷HOSKINS 16 is analogous to DUFFY 06. See Fig. 12 for mass-dependent limits in terms of the local dark matter density.</footnote>

<footnote n="48">⁴⁸BECK 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 $m_{A^0} = 0.11$ meV.</footnote>

<footnote n="49">⁴⁹HOSKINS 11 is analogous to DUFFY 06. See Fig. 4 for the mass-dependent limit in terms of the local density.</footnote>

<footnote n="50">⁵⁰ASZTALOS 10 used the upgraded detector of ASZTALOS 04 to search for halo axions. See their Fig. 5 for the $m_{A^0}$ dependence of the limit.</footnote>

<footnote n="51">⁵¹DUFFY 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. 10 of their paper on the axion mass dependence of the limit.</footnote>

<footnote n="52">⁵²ASZTALOS 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 mass dependence of the limit.</footnote>

<footnote n="53">⁵³KIM 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 $G_{A\gamma\gamma}$ and hence the bound from relic axion search.</footnote>

<footnote n="54">⁵⁴HAGMANN 90 experiment is based on the proposal of SIKIVIE 83.</footnote>

<footnote n="55">⁵⁵WUENSCH 89 looks for condensed axions near the earth that could be converted to photons in the presence of an intense electromagnetic field via the Primakoff effect, following the proposal of SIKIVIE 83. The theoretical prediction with $[G_{A\gamma\gamma}/m_{A^0}]^2 = 2 \times 10^{-14}$ MeV⁻⁴ (the three generation DFSZ model) and $\rho_A = 300$ MeV/cm³ that makes up galactic halos gives $(G_{A\gamma\gamma}/m_{A^0})^2 \rho_A = 4 \times 10^{-44}$. Note that our definition of $G_{A\gamma\gamma}$ is $(1/4\pi)$ smaller than that of WUENSCH 89.</footnote>
See key on page 1171

# Gauge & Higgs Boson Particle Listings
## Axions ($A^0$) and Other Very Light Bosons

<table><tbody><tr><td>&lt;1.8 &times; 10<sup>-11</sup></td><td>95</td><td>44 XIAO</td><td>21</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 3.5 &times; 10<sup>-11</sup>eV</td></tr><tr><td>&lt;7 &times; 10<sup>-4</sup></td><td>95</td><td>45 ABUDINEN</td><td>20</td><td>BEL2</td><td>m<sub>A0</sub> = 0.2-1 GeV</td></tr><tr><td>&lt;2 &times; 10<sup>-4</sup></td><td>90</td><td>46 BANERJEE</td><td>20A</td><td>NA64</td><td>m<sub>A0</sub> &lt; 55 MeV</td></tr><tr><td>&lt;1.0 &times; 10<sup>-11</sup></td><td>95</td><td>47 BUEHLER</td><td>20</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 3 neV</td></tr><tr><td>&lt;5 &times; 10<sup>-10</sup></td><td></td><td>48 CALORE</td><td>20</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 10<sup>-11</sup> eV</td></tr><tr><td></td><td></td><td>49 CARENZA</td><td>20</td><td>ASTR</td><td>Globular clusters</td></tr><tr><td>2-4 &times; 10<sup>-10</sup></td><td>95</td><td>50 DENT</td><td>20A</td><td>ASTR</td><td>Solar axions</td></tr><tr><td>&lt;3.6 &times; 10<sup>-12</sup></td><td>95</td><td>51 DEPTA</td><td>20</td><td>COSM</td><td>Axion-like particles</td></tr><tr><td></td><td></td><td>52 DESSERT</td><td>20A</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 5 &times; 10<sup>-11</sup> eV</td></tr><tr><td></td><td></td><td>53 ESTEBAN</td><td>20</td><td>ANIT</td><td>Axion-like particles</td></tr><tr><td>4-6 &times; 10<sup>-10</sup></td><td>90</td><td>54 GAO</td><td>20</td><td>ASTR</td><td>Solar axions</td></tr><tr><td>&lt;2.8 &times; 10<sup>-11</sup></td><td>95</td><td>55 KOROCHKIN</td><td>20</td><td>ASTR</td><td>m<sub>A0</sub> = 25 eV</td></tr><tr><td>none 6.0 &times; 10<sup>-9</sup>-1.3 &times; 10<sup>-5</sup></td><td></td><td>56 LUCENTE</td><td>20A</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 270 MeV</td></tr><tr><td>&lt;2.6 &times; 10<sup>-11</sup></td><td>95</td><td>57 MEYER</td><td>20</td><td>FLAT</td><td>m<sub>A0</sub> &lt; 3 &times; 10<sup>-10</sup> eV</td></tr><tr><td>&lt;8.4 &times; 10<sup>-8</sup></td><td>99</td><td>58 YAMAMOTO</td><td>20</td><td>COSM</td><td>m<sub>A0</sub> &lt; 4 &times; 10<sup>-6</sup> eV</td></tr><tr><td>&lt;1 &times; 10<sup>-3</sup></td><td>95</td><td>59 ALONI</td><td>19</td><td>PRMX</td><td>m<sub>A0</sub> = 0.16 GeV</td></tr><tr><td>&lt;1.4 &times; 10<sup>-14</sup></td><td>95</td><td>60 CAPUTO</td><td>19</td><td>ASTR</td><td>m<sub>A0</sub> = 5 &times; 10<sup>-24</sup> eV</td></tr><tr><td>&lt;9.6 &times; 10<sup>-14</sup></td><td>95</td><td>61 FEDDERKE</td><td>19</td><td>CMB</td><td>m<sub>A0</sub> = 10<sup>-22</sup> eV</td></tr><tr><td>&lt;7 &times; 10<sup>-13</sup></td><td>95</td><td>62 IVANOV</td><td>19</td><td>ASTR</td><td>m<sub>A0</sub> = 5 &times; 10<sup>-23</sup> eV</td></tr><tr><td>&lt;4 &times; 10<sup>-11</sup></td><td>95</td><td>63 LIANG</td><td>19</td><td>ASTR</td><td>m<sub>A0</sub> = 1.2 &times; 10<sup>-7</sup> eV</td></tr><tr><td>&lt;3 &times; 10<sup>-12</sup></td><td></td><td>64 FORTIN</td><td>18</td><td>ASTR</td><td>Axion-like particles</td></tr><tr><td>&lt;5.0 &times; 10<sup>-3</sup></td><td>90</td><td>65 JAECKEL</td><td>18</td><td>ASTR</td><td>m<sub>A0</sub> = 30-100 MeV</td></tr><tr><td>&lt;1 &times; 10<sup>-11</sup></td><td>99.9</td><td>66 YAMAJI</td><td>18</td><td>LSW</td><td>m<sub>A0</sub> = 46-1020 eV</td></tr><tr><td>&lt;6.6 &times; 10<sup>-11</sup></td><td>95</td><td>67 ZHANG</td><td>18</td><td>ASTR</td><td>m<sub>A0</sub> = 0.6-4 neV</td></tr><tr><td></td><td></td><td>68 ADE</td><td>17</td><td>CMB</td><td>Axion-like particles</td></tr><tr><td>&lt;2.51 &times; 10<sup>-4</sup></td><td>95</td><td>69 ANASTASSO...</td><td>17</td><td>CAST</td><td>m<sub>A0</sub> &lt; 0.02 eV</td></tr><tr><td>&gt;1.5 &times; 10<sup>-11</sup></td><td>95</td><td>70 DOLAN</td><td>17</td><td>RVUE</td><td>Axion-like particles</td></tr><tr><td>&lt;2.6 &times; 10<sup>-12</sup></td><td>95</td><td>71 INADA</td><td>17</td><td>LSW</td><td>m<sub>A0</sub> &lt; 0.1 MeV</td></tr><tr><td>&lt;6 &times; 10<sup>-13</sup></td><td>95</td><td>72 KOHRI</td><td>17</td><td>ASTR</td><td>m<sub>A0</sub> = 0.7-50 neV</td></tr><tr><td>&lt;5 &times; 10<sup>-12</sup></td><td>95</td><td>73 MARSH</td><td>17</td><td>ASTR</td><td>m<sub>A0</sub> &le; 10<sup>-13</sup> eV</td></tr><tr><td>&lt;1.2 &times; 10<sup>-7</sup></td><td>95</td><td>74 TIWARI</td><td>17</td><td>COSM</td><td>m<sub>A0</sub> &le; 10<sup>-15</sup> eV</td></tr><tr><td>&lt;7.2 &times; 10<sup>-8</sup></td><td>95</td><td>75 AJELLO</td><td>16</td><td>ASTR</td><td>m<sub>A0</sub> = 0.5-5 neV</td></tr><tr><td>&lt;8 &times; 10<sup>-4</sup></td><td>95</td><td>76 DELLA-VALLE</td><td>16</td><td>LASR</td><td>m<sub>A0</sub> = 1.3 meV</td></tr><tr><td>&lt;6 &times; 10<sup>-21</sup></td><td></td><td>77 DELLA-VALLE</td><td>16</td><td>LASR</td><td>m<sub>A0</sub> &lt; 0.5 meV</td></tr><tr><td>&lt;1.47 &times; 10<sup>-10</sup></td><td>95</td><td>78 JAECKEL</td><td>16</td><td>ALPS</td><td>m<sub>A0</sub> = 0.1-100 GeV</td></tr><tr><td>&lt;3.5 &times; 10<sup>-8</sup></td><td>95</td><td>79 LEEFER</td><td>16</td><td></td><td>m<sub>S0</sub> &lt; 10<sup>-18</sup> eV</td></tr><tr><td>&lt;5.42 &times; 10<sup>-4</sup></td><td>95</td><td>80 ANASTASSO...</td><td>15</td><td>CAST</td><td>Chameleons</td></tr><tr><td>&lt;4.1 &times; 10<sup>-10</sup></td><td>99.7</td><td>81 ARIK</td><td>15</td><td>CAST</td><td>m<sub>A0</sub> = 0.39-0.42 eV</td></tr><tr><td>&lt;3.3 &times; 10<sup>-10</sup></td><td>95</td><td>82 BALLOU</td><td>15</td><td>LSW</td><td>m<sub>A0</sub> &lt; 2 &times; 10<sup>-4</sup> eV</td></tr><tr><td>&lt;6.6 &times; 10<sup>-11</sup></td><td>95</td><td>83 BRAX</td><td>15</td><td>ASTR</td><td>m<sub>S0</sub> &lt; 4 &times; 10<sup>-12</sup> eV</td></tr><tr><td>&lt;1.4 &times; 10<sup>-7</sup></td><td>95</td><td>84 HASEBE</td><td>15</td><td>LASR</td><td>m<sub>A0</sub> = 0.15 eV</td></tr><tr><td>&lt;8 &times; 10<sup>-8</sup></td><td>95</td><td>85 MILLEA</td><td>15</td><td>COSM</td><td>Axion-like particles</td></tr><tr><td>&lt;1.47 &times; 10<sup>-10</sup></td><td>95</td><td>86 VANTILBURG</td><td>15</td><td></td><td>Dilaton-like dark matter</td></tr><tr><td>&lt;3.5 &times; 10<sup>-8</sup></td><td>95</td><td>87 VINYOLES</td><td>15</td><td>ASTR</td><td>m<sub>A0</sub> = 0.6-185 eV</td></tr><tr><td>&lt;2.1 &times; 10<sup>-11</sup></td><td>95</td><td>88 ARIK</td><td>14</td><td>CAST</td><td>m<sub>A0</sub> = 0.64-1.17 eV</td></tr><tr><td>&lt;2.15 &times; 10<sup>-9</sup></td><td>95</td><td>89 AYALA</td><td>14</td><td>ASTR</td><td>Globular clusters</td></tr><tr><td>&lt;4.5 &times; 10<sup>-8</sup></td><td>95</td><td>90 DELLA-VALLE</td><td>14</td><td>LASR</td><td>m<sub>A0</sub> = 1 meV</td></tr><tr><td>&lt;8 &times; 10<sup>-11</sup></td><td>95</td><td>91 EJLLI</td><td>14</td><td>COSM</td><td>m<sub>A0</sub> = 2.66-48.8 &mu;eV</td></tr><tr><td>&lt;1 &times; 10<sup>-11</sup></td><td>95</td><td>92 PUGNAT</td><td>14</td><td>LSW</td><td>m<sub>A0</sub> &lt; 0.3 meV</td></tr><tr><td>&lt;2.1 &times; 10<sup>-11</sup></td><td>95</td><td>93 REESMAN</td><td>14</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 1 &times; 10<sup>-10</sup> eV</td></tr><tr><td>&lt;6.5 &times; 10<sup>-8</sup></td><td>95</td><td>94 ABRAMOWSKI...</td><td>13A</td><td>IACT</td><td>m<sub>A0</sub> = 15-60 neV</td></tr><tr><td>&lt;2.4 &times; 10<sup>-9</sup></td><td>95</td><td>95 ARMENGAUD</td><td>13</td><td>EDEL</td><td>m<sub>A0</sub> &lt; 200 eV</td></tr><tr><td>&lt;1.2-2.8 &times; 10<sup>-10</sup></td><td>95</td><td>96 BETZ</td><td>13</td><td>LSW</td><td>m<sub>A0</sub> = 7.2 &times; 10<sup>-6</sup> eV</td></tr><tr><td>&lt;7 &times; 10<sup>-10</sup></td><td></td><td>97 FRIEDLAND</td><td>13</td><td>ASTR</td><td>Red giants</td></tr><tr><td>&lt;1.3 &times; 10<sup>-6</sup></td><td>95</td><td>98 MEYER</td><td>13</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 1 &times; 10<sup>-7</sup> eV</td></tr><tr><td>&lt;3.5 &times; 10<sup>-7</sup></td><td>99.7</td><td>99 WOUTERS</td><td>13</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 7 &times; 10<sup>-12</sup> eV</td></tr><tr><td>&lt;1.2 &times; 10<sup>-6</sup></td><td>95</td><td>100 CADAMURO</td><td>12</td><td>COSM</td><td>Axion-like particles</td></tr><tr><td>&lt;1.2-2.8 &times; 10<sup>-10</sup></td><td>95</td><td>101 PAYEZ</td><td>12</td><td>ASTR</td><td>m<sub>A0</sub> &lt; 4.2 &times; 10<sup>-14</sup> eV</td></tr><tr><td>&lt;5 &times; 10<sup>-7</sup></td><td>95</td><td>102 ARIK</td><td>11</td><td>CAST</td><td>m<sub>A0</sub> = 0.39-0.64 eV</td></tr><tr><td>&lt;8.8 &times; 10<sup>-11</sup></td><td>95</td><td>103 EHRET</td><td>10</td><td>ALPS</td><td>m<sub>A0</sub> &lt; 0.7 meV</td></tr><tr><td>&lt;1.25 &times; 10<sup>-6</sup></td><td>95</td><td>104 AHMED</td><td>09A</td><td>CDMS</td><td>m<sub>A0</sub> &lt; 100 eV</td></tr><tr><td>&lt;2.5 &times; 10<sup>-10</sup></td><td>95</td><td>105 ARIK</td><td>09</td><td>CAST</td><td>m<sub>A0</sub> = 0.02-0.39 eV</td></tr><tr><td>&lt;3.5 &times; 10<sup>-10</sup></td><td>95</td><td>106 CHOU</td><td>09</td><td></td><td>Chameleons</td></tr><tr><td>&lt;1.2-2.8 &times; 10<sup>-10</sup></td><td>95</td><td>107 GONDOLO</td><td>09</td><td>ASTR</td><td>m<sub>A0</sub> &lt; few keV</td></tr><tr><td>&lt;1.3 &times; 10<sup>-6</sup></td><td>95</td><td>108 AFANASEV</td><td>08</td><td></td><td>m<sub>S0</sub> &lt; 1 meV</td></tr><tr><td>&lt;3.5 &times; 10<sup>-7</sup></td><td>99.7</td><td>109 CHOU</td><td>08</td><td></td><td>m<sub>A0</sub> &lt; 0.5 meV</td></tr><tr><td>&lt;1.1 &times; 10<sup>-6</sup></td><td>99.7</td><td>110 FOUCHE</td><td>08</td><td></td><td>m<sub>A0</sub> &lt; 1 meV</td></tr><tr><td>&lt;5.6-13.4 &times; 10<sup>-10</sup></td><td>95</td><td>111 INOUE</td><td>08</td><td></td><td>m<sub>A0</sub> = 0.84-1.00 eV</td></tr><tr><td>&lt;5 &times; 10<sup>-7</sup></td><td></td><td>112 ZAVATTINI</td><td>08</td><td></td><td>m<sub>A0</sub> &lt; 1 meV</td></tr><tr><td>&lt;8.8 &times; 10<sup>-11</sup></td><td>95</td><td>113 ANDRIAMON...</td><td>07</td><td>CAST</td><td>m<sub>A0</sub> &lt; 0.02 eV</td></tr><tr><td>&lt;1.25 &times; 10<sup>-6</sup></td><td>95</td><td>114 ROBILLARD</td><td>07</td><td></td><td>m<sub>A0</sub> &lt; 1 meV</td></tr><tr><td>&lt;2-5 &times; 10<sup>-6</sup></td><td></td><td>115 ZAVATTINI</td><td>06</td><td></td><td>m<sub>A0</sub> = 1-1.5 meV</td></tr><tr><td>&lt;1.1 &times; 10<sup>-9</sup></td><td>95</td><td>116 INOUE</td><td>02</td><td></td><td>m<sub>A0</sub> = 0.05-0.27 eV</td></tr><tr><td>&lt;2.78 &times; 10<sup>-9</sup></td><td>95</td><td>117 MORALES</td><td>02B</td><td></td><td>m<sub>A0</sub> &lt; 1 keV</td></tr><tr><td>&lt;1.7 &times; 10<sup>-9</sup></td><td>90</td><td>118 BERNABEI</td><td>01B</td><td></td><td>m<sub>A0</sub> &lt;100 eV</td></tr></tbody></table>

<table><tbody><tr><td>&lt;1.5 &times; 10<sup>-4</sup></td><td>90</td><td>119 ASTIER</td><td>00B</td><td>NOMD</td><td>m<sub>A0</sub> &lt;40 eV</td></tr><tr><td>&lt;2.7 &times; 10<sup>-9</sup></td><td>95</td><td>120 MASSO</td><td>00</td><td>THEO</td><td>induced &gamma; coupling</td></tr><tr><td>&lt;6.0 &times; 10<sup>-10</sup></td><td>95</td><td>121 AVIGNONE</td><td>98</td><td>SLAX</td><td>m<sub>A0</sub> &lt; 1 keV</td></tr><tr><td>&lt;3.6 &times; 10<sup>-7</sup></td><td>95</td><td>122 MORIYAMA</td><td>98</td><td></td><td>m<sub>A0</sub> &lt; 0.03 eV</td></tr><tr><td>&lt;6.7 &times; 10<sup>-7</sup></td><td>95</td><td>123 CAMERON</td><td>93</td><td></td><td>m<sub>A0</sub> &lt; 10<sup>-3</sup> eV, optical rotation</td></tr><tr><td>&lt;3.6 &times; 10<sup>-9</sup></td><td>99.7</td><td>124 CAMERON</td><td>93</td><td></td><td>m<sub>A0</sub> &lt; 10<sup>-3</sup> eV, photon regeneration</td></tr><tr><td>&lt;7.7 &times; 10<sup>-9</sup></td><td>99.7</td><td>125 LAZARUS</td><td>92</td><td></td><td>m<sub>A0</sub> &lt; 0.03 eV</td></tr><tr><td>&lt;7.7 &times; 10<sup>-7</sup></td><td>99</td><td>125 LAZARUS</td><td>92</td><td></td><td>m<sub>A0</sub> = 0.03-0.11 eV</td></tr><tr><td>&lt;2.5 &times; 10<sup>-6</sup></td><td>99</td><td>126 RUOSO</td><td>92</td><td></td><td>m<sub>A0</sub> &lt; 10<sup>-3</sup> eV</td></tr><tr><td></td><td></td><td>127 SEMERTZIDIS</td><td>90</td><td></td><td>m<sub>A0</sub> &lt; 7 &times; 10<sup>-4</sup> eV</td></tr></tbody></table>

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.

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 data on the pulsar PSR J2144-3933. The quoted limit applies to an assumed magnetic field of $2 \times 10^{12}$ G and a dark matter density of 0.45 GeV/cm$^3$.

3. BEAUFORT 23 extends DEROCO 22 who searched for the X-ray decay of axions that build 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 astrophysical component, and attribute the residual to axion two-photon decay. The quoted limit is for $m_{A0} \simeq 25$ eV. See their Fig. 3 for the mass-dependent limits.

5. CAPOZZI 23 use Planck CMB and Lyman-alpha observations to set limits on early energy injection by decaying dark matter axions that would affect CMB anisotropies and the reionisation history of the Universe. The quoted limit applies to $m_{A0} = 100$ eV and 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 the axion-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 that would 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 $m_{A0} = 56$ MeV. See their Fig. 2 for mass-dependent limits.

9. FILZINGER 23 searched for oscillations in the fine structure constant induced by dilaton-like dark matter by measuring the frequency ratio between the E3 and E2 transitions of $^{171}$Yb$^+$: They assume the local dark matter density $\rho_S = 0.4$ GeV/cm$^3$. The quoted limit is set at $m_{S0} \simeq 4 \times 10^{-23}$ eV. See their Fig. 4 for the limits over $m_{S0} = 1 \times 10^{-24} - 1 \times 10^{-17}$ eV.

10. HOOF 23 consider axions emitted from SN1987A converting to gamma rays in Galactic magnetic fields, using temporal information of the Solar Maximum Mission data. They set a limit $G_{A\gamma} \lesssim 5 \times 10^{-12}$ for masses $m_{A0} \lesssim 2 \times 10^{-10}$ eV. See left panel in 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 mass-dependent limits.

12. JACOBSEN 23 search for the imprints of axion-photon mixing on the TeV spectra of several 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 population of axions, which would then convert into an observable outgoing radio flux in the presence of the neutron star's B-field. They search for this signal in 27 pulsars and set mass-dependent limits shown in their Fig. 2.

15. PANT 23 study the effect of axion-photon oscillations on the gamma-ray spectrum from the extragalactic neutrino source, TXS 0506+056. The quoted limit is at $m_{A0} \simeq 2.7 \times 10^{-7}$ 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 optical-to-optical clock comparison between $^{171}$Yb$^+$ and $^{87}$Sr. Quoted limit applies at the smallest 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 in context. 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 blazars induced by the axion-photon mixing. The quoted limit assumes the transverse magnetic field at the jet's emission site, with $B_T = 1$ G, and this limit inversely scales with $B_T$. See their Fig. 3 for the limits' dependence on $B_T$ and electron density.
# Gauge & Higgs Boson Particle Listings
## Axions ($A^0$) and Other Very Light Bosons

19 ZHANG 23A searched for oscillations in the fine structure constant induced by dilatonic 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 $\rho_S \simeq 0.4$ GeV/cm$^3$. The quoted limit is set at $m_{S0} \simeq 1 \times 10^{-17}$ eV. See their Fig. 3 for the limits over $m_{S0} = 1 \times 10^{-17}-8.3 \times 10^{-13}$ 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 $g_{Aee}$. See Fig. 6 for correlation between $G_{A\gamma\gamma}$ and $g_{Aee}$.

21 ARQUIST 22 is analogous to AVIGNONE 98, and supersedes ANASTASSOPOULOS 17 for $m_{A^0} \gtrsim 1.2$ eV.

22 ARZA 22 search for low-mass axions as dark matter using the Earth as a transducer for axion-photon conversion. The concept works because the region between the Earth and the ionsphere forms an insulating cavity that parametrically enhances the axion signal by 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 over 20 years compiled by the SuperMAG collaboration. Quoted limit applies for masses $3-4 \times 10^{-17}$ eV, see Fig. 1 for mass-dependent limits.

23 BERNAL 22 explored the possibility that the excess in the cosmic optical background measured by New Horizons Long Range Reconnaissance 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 in the region 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 the limits by the radiative energy deposition $< 10^{50}$ erg and progenitor radius $= 5 \times 10^{13}$ cm. The quoted limit is at $m_{A^0} = 150$ MeV. See their Fig. 2 for mass-dependent limits.

26 CASTILLO 22 update CAPUTO 19 using the polarization measurements of the Crab Pulsar by the QUIJOTE MFI instrument and 20 Galactic pulsars from the PPTA project. See their Table 1 for the assumed local axion energy density $\rho_A$ for each pulsar and their Fig. 7 for the mass-dependent limits in the range of $3 \times 10^{-23}$ eV $\le m_{A^0} \le 10^{-19}$ eV.

27 DEROCCO 22 uses the NuSTAR data to search for monochromatic X-ray lines produced by the decay of solar axions trapped on bound orbits. The quoted limit applies to $m_{A^0} \simeq 9$ keV. They also derive limits in the plane of $g_{Aee}$ and $G_{A\gamma\gamma}$. 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 AS$_\gamma$ 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 recovered 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 center region. 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 $m_{A^0} \simeq 17-25$ µeV. See their Fig. 1 for mass-dependent limits.

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 $m_{A^0} = 0.18$ eV. 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 $m_{A^0} = 2$ MeV for the reheating temperature 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 $m_{A^0} \simeq 8 \times 10^{-10}$ 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 $m_{A^0} \simeq 1 \times 10^{-8}$ 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 CALORE 20 by evaluating 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 images of 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 the emitting region, $\rho_A = 20$ GeV/cm$^3$. Limits between $9.2 \times 10^{-11}-7.7 \times 10^{-8}$ GeV$^{-1}$ are obtained for $m_{A^0} = 3.6 \times 10^{-21}-4.6 \times 10^{-16}$ eV. See their Fig. 2 for mass-dependent 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 gamma-rays from the Crab Nebula by the Tibet AS$_\gamma$ and HAWC experiments, together with MAGIC 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.

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 $m_{A^0} \simeq 0.178$ eV. See their Fig. 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 $m_{A^0} \simeq 1 \times 10^{-9}$ 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 $g_{ANN} G_{A\gamma\gamma} \lesssim 4.6 \times 10^{-19}$ GeV$^{-1}$ for $m_{A^0} \lesssim 10^{-5}$ eV by using the quiescent soft gamma-ray flux upper limits in five magnetars. We use $g_{ANN} = G_{AN} 2m_N$ to translate their limits. See their Table II and Fig. 3 for the limits.

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 make up all of dark matter and use the integrated dark matter density along the line of sight determined by observations.

44 XIAO 21 use X-ray data from Betelgeuse to look for signals from axions produced in the stellar 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 $e^+e^- \to \gamma A^0$ ($A^0 \to \gamma\gamma$) and set upper limits of around $10^{-3}$ over the mass range. The quoted limit is at $m_{A^0} = 0.3$ GeV. See their 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 $G_{A\gamma\gamma} = 2 \times 10^{-4}-5 \times 10^{-2}$ GeV$^{-1}$ for $m_{A^0} < 55$ MeV. See their Fig. 5 for mass-dependent limits.

47 BUEHLER 20 look for the $\gamma$-ray transparency due to axion-photon oscillations using high-energy 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 $\gamma$-ray background measured by the Fermi-LAT to constrain the $\gamma$-ray flux converted in the Galactic magnetic field from axions produced from past core-collapse supernovae. They also derive a limit from a heavier axion with $m_{A^0} \gtrsim 5$ keV decaying into two photons of $G_{A\gamma\gamma} \lesssim 5 \times 10^{-11}$ GeV$^{-1}$ for $m_{A^0} = 5$ keV. See their Figs. 5 and 7 for the limits as well as limits in the presence of axion-nucleon couplings.

49 CARENZA 20 extend the globular cluster bound of AYALA 14 to heavier masses ($m_{A^0} \le$ a few 10 keV) by taking account of the coalescence process $\gamma + \gamma \to A^0$ 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 $G_{A\gamma\gamma}$ and $g_{Aee}$ 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, $N_{\text{eff}}$, 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 star clusters 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 the reflected radio pulses that are resonantly produced in the ionsphere via axion-photon conversion for $m_{A^0} \lesssim 1 \times 10^{-7}$ eV, if an axion clump passes the Earth about once 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 $G_{A\gamma\gamma}$ and $g_{Aee}$ corresponding to the excess reported in APRILE 20.

55 KOROCHKIN 20 assume the axion makes up all dark matter, and look for a dip in the observed 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 $G_{A\gamma\gamma} \sim 3 \times 10^{-11}-2 \times 10^{-10}$ GeV$^{-1}$ over a range of $m_{A^0} = 2-18$ eV. See their Fig. 1 for mass-dependent limits between $0.25 < m_{A^0} < 25$ eV.

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 coalescence as well as gravitational trapping that become relevant at $m_{A^0} > 100$ MeV. See their Fig. 12 for the mass-dependent limit.

57 MEYER 20 look for prompt $\gamma$-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 from the 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 $\tau = 4.32 \times 10^{17}$ 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 on a 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 $\rho_A = 0.3$ GeV/cm$^3$. See their Fig. 2 for mass-dependent limits for $5 \times 10^{-24}$ eV $\le m_{A^0} \le 2 \times 10^{-19}$ eV.

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 their Fig. 3 for mass-dependent limits for $m_{A^0} = 10^{-22}-10^{-19}$ eV.

62 IVANOV 19 look for the axion-induced periodic changes in the polarization angle of parsec-scale jets in active galactic nuclei observed by the MOJAVE program, where they use the axion energy density $\rho_A = 20$ GeV/cm$^3$. See their Fig. 6 for mass-dependent limits for $5 \times 10^{-23}$ eV $\le m_{A^0} \le 1.2 \times 10^{-21}$ eV.

63 LIANG 19 look for spectral irregularities in the spectrum of 10 bright H.E.S.S. sources in 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 a magnetor 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 $m_{A^0} = 0.01-100$ MeV.

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 $G_{Aγγ} < 4.2 \times 10^{-3} \text{ GeV}^{-1}$ for $m_{A^0} < 10$ 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 the intercluster 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 $G_{Aγγ} H_I < 7.2 \times 10^{-2}$ at 95% CL for $m_{A^0} < 10^{-28}$ eV, where $H_I$ is the Hubble parameter during inflation.

69 ANASTASSOPOULOS 17 looked for solar axions by the CAST axion helioscope in the vacuum phase, and supersedes ANDRIAMONJE 07.

70 DOLAN 17 update existing limits on $G_{Aγγ}$ for axion-like particles. The limits from the proton beam dump experiments in their Fig. 2 contained an error, and the corrected version 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 mass-dependent 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 by their scenario.

73 MARSH 17 is similar to WOUTERS 13, using Chandra observations of M87. See their Fig. 6 for mass-dependent limits.

74 TIWARI 17 use observed limits of the cosmic distance-duality relation to constrain the photon-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 their Fig. 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 $Z \to 2\gamma$ and $Z \to 3\gamma$ to constrain the ALP production via $e^+ e^- \to Z \to A^0 \gamma$ ($A^0 \to \gamma\gamma$), assuming the ALP coupling with two hypercharge bosons. See their Fig. 4 for mass-dependent limits.

79 LEEFER 16 derived limits by using radio-frequency spectroscopy of dysprosium and atomic 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 $m_{A^0}$ around 0.2 and 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 by searching 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 $G_{Sγγ} < 2.62 \times 10^{-4} \text{ GeV}^{-1}$ at $m_{S0} = 0.15$ eV. See their Figs. 11 and 12 for mass-dependent limits.

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 dysprosium transition frequency data, induced by coherent oscillations of the fine-structure constant due to dilaton-like dark matter, and set the limits, $G_{Sγγ} < 6 \times 10^{-27} \text{ GeV}^{-1}$ at $m_{S0} = 6 \times 10^{-23}$ eV. See their Fig. 4 for mass-dependent limits between $1 \times 10^{-24} < m_{S0} < 1 \times 10^{-15}$ eV.

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 their Fig. 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 optical depth based on a certain extragalactic background light model. See their Fig. 5 for mass-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 field around 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 evolution of red giants with 7-12 solar masses.

98 MEYER 13 attributed to axion-photon oscillations the observed excess of very high-energy $\gamma$-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 observed by Chandra. See their Fig. 4 for mass-dependent limits.

100 CADAMURO 12 derived cosmological limits on $G_{Aγγ}$ for axion-like particles. See their Fig. 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.

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 $3\sigma$ the range $2.6 \times 10^{-7} \text{ GeV}^{-1} < G_{Aγγ} < 4.2 \times 10^{-6} \text{ GeV}^{-1}$ for vacuum $m_{A^0}$ roughly below 6 meV for density scaling index exceeding 0.8.

107 GONDOLO 09 use the all-flavor measured solar neutrino flux to constrain solar interior temperature and thus energy losses.

108 LIPSS photon regeneration experiment, assuming scalar particle $\xi^0$. See Fig. 4 for mass-dependent 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 and pulsed 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 and birefringence 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 the Primakoff effect in Germanium detector.

118 BERNABEI 01 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 the interaction 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 $g_p^2/4\pi \sim 1.7 \times 10^{-9}$ for the coupling $g_p^2\gamma_5 P\phi_A$.

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 is obtained by taking the noise amplitude as the upper limit. Limits extend to $m_{A^0} = 4 \times 10^{-3}$ where $G_{Aγγ} < 1 \times 10^{-4} \text{ GeV}^{-1}$.

## Limit on Invisible $A^0$ (Axion) Electron Coupling

The limit is for $g_{Aee} e^+ e^- (i\gamma_5)e^+$, or equivalently, the dipole-dipole potential

$$ \frac{g_{Aee}^2}{16m^2} ((\sigma_1, \sigma_2) - 3(\sigma_1, n) (\sigma_2, n))/r^3 \text{ where } n=\mathbf{r}/r \text{ and the sign of the potential was corrected based on DAIDO 17.} $$

<table><thead><tr><th>VALUE</th><th>CL%</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>&lt;2.35 &times; 10<sup>-12</sup></td><td>90</td><td>1 AALBERS</td><td>23A LZ</td><td>Solar axions</td></tr><tr><td>&lt;1.3 &times; 10<sup>-14</sup></td><td>90</td><td>2 AALBERS</td><td>23A LZ</td><td>$m_{A^0} = 1-17$ keV</td></tr><tr><td>&lt;1.61 &times; 10<sup>-11</sup></td><td>90</td><td>3 ADHIKARI</td><td>23 C100</td><td>Solar axions</td></tr><tr><td>&lt;6 &times; 10<sup>-13</sup></td><td>90</td><td>4 ADHIKARI</td><td>23A C100</td><td>$m_{A^0} = 10-1000$ keV</td></tr><tr><td>&lt;8 &times; 10<sup>-14</sup></td><td>90</td><td>5 AGNES</td><td>23A DS50</td><td>$m_{A^0} = 0.03-20$ keV</td></tr><tr><td>&lt;3 &times; 10<sup>-9</sup></td><td>95</td><td>6 APRILE</td><td>23B XE1T</td><td>Neutron star merger</td></tr><tr><td>&lt;6 &times; 10<sup>-15</sup></td><td></td><td>7 CAPOZZI</td><td>23A DUMP</td><td>$m_{A^0} = 10^4-2 \times 10^7$ eV</td></tr><tr><td>&lt;4 &times; 10<sup>-12</sup></td><td>90</td><td>8 WADEKAR</td><td>23 ASTR</td><td>$m_{A^0} = 100$ keV</td></tr><tr><td>&lt;9 &times; 10<sup>-15</sup></td><td>90</td><td>9 APRILE</td><td>22 XE1T</td><td>$m_{A^0} = 0.01-0.4$ keV</td></tr><tr><td>&lt;2 &times; 10<sup>-12</sup></td><td>90</td><td>10 APRILE</td><td>22B XENT</td><td>$m_{A^0} = 1-39, 44-140$ keV</td></tr><tr><td>&lt;2.6 &times; 10<sup>-6</sup></td><td>95</td><td>11 APRILE</td><td>22B XENT</td><td>Solar axions</td></tr><tr><td>&lt;2.5 &times; 10<sup>-18</sup></td><td></td><td>12 DESSERT</td><td>22 ASTR</td><td>Magnetic white dwarf</td></tr><tr><td></td><td></td><td>13 IKEDA</td><td>22 COSM</td><td>$m_{A^0} = 33.117-33.130$ μeV</td></tr><tr><td></td><td></td><td>14 LANGHOFF</td><td>22 COSM</td><td>$m_{A^0} = 20-3 \times 10^4$ keV</td></tr></tbody></table>
The quoted limit applies to $m_{A^0} = 10^{-23}-10^{-18}$ eV and assumes a local axion dark matter density, $\rho_A = 0.45$ GeV/cm$^3$. See their Fig. 5 for mass-dependent limits.

34 ABE 18f is an update of ABE 14f. The quoted limit applies to $m_{A^0} = 60$ keV. See their 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 mass-dependent limits.

37 CRESCINI 18 look for collective excitations of the electron spins caused by dark matter axions. The quoted limit assumes the local dark matter density, $\rho_A = 0.45$ GeV/cm$^3$.

38 FICEK 18 use the measurements of the hyperfine structure of antiprotonic helium to constrain a dipole-dipole potential between electron and antiproton. See their Fig. 3 for limits 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 $< m_{A^0} < 97$ keV.

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 $< m_{A^0} < 40$ keV.

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 for limits up to $m_{A^0} = 10$ keV.

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 $< m_{A^0} < 20$ keV.

47 LIU 17A look for solar axions produced from Compton, bremsstrahlung, atomic-recombination and decixitation channels, and set a limit for $m_{A^0} < 1$ keV.

48 LUO 17 use a recent measurement of the dipole-dipole interaction between two iron atoms at the nanometer scale and set a limit for $m_{A^0} < 1$ keV. See their Fig. 3 for 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 L192-2 based on an asteroseismic model.

51 YOON 16 look for solar axions with the axio-electric effect in Csl(TI) crystals and set a limit for $m_{A^0} < 1$ keV.

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 $m_{A^0} = 500$ µeV.

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 $m_{A^0} = 40-120$ 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 their Fig. 3 for mass-dependent limits.

57 MILLER-BERTOLAMI 14 studied the impact of axion emission on white dwarf cooling in 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 $< m_{A^0} < 100$ keV.

60 ARMENGAUD 13 is similar to DERBIN 12, and take account of axio-recombination and axio-deexcitation effects. See their Fig. 12 for mass-dependent limits.

61 BARTH 13 search for solar axions produced by axion-electron coupling, and obtained the limit, $g_{Aee} \cdot G_{A\gamma\gamma} < 8.1 \times 10^{-23}$ GeV$^{-1}$ at 95%CL.

62 DERBIN 13 looked for 5.5 MeV solar axions produced in $pd \to {}^3$He $A^0$ in a BGO detector through the axioelectric effect. See their Fig. 4 for mass-dependent limits.

63 HECKEL 13 studied the influence of 2 or 4 stationary sources each containing $6.0 \times 10^{24}$ polarized electrons, on a rotating torsion pendulum containing $9.8 \times 10^{24}$ 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 to emission of axions with $g_{Aee} \approx 4.8 \times 10^{-13}$.

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 the axio-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 spin-dependent 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 either of 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.

<table><tr><td>&lt; 0.016</td><td>95</td></tr><tr><td>&lt;320</td><td>90</td></tr></table>

<table><tr><td>4</td><td>BUSCHMANN</td><td>22</td><td>ASTR</td><td>Neutron star cooling</td></tr><tr><td>5</td><td>GAVRILYUK</td><td>22</td><td>CNTR</td><td>Solar axion</td></tr><tr><td>6</td><td>SCHULTHESS</td><td>22</td><td></td><td>Neutron EDM</td></tr><tr><td>7</td><td>AYBAS</td><td>21</td><td>CASP</td><td>Nucleon EDM</td></tr><tr><td>8</td><td>BHUSAL</td><td>21</td><td></td><td>Solar axion</td></tr><tr><td>9</td><td>JIANG</td><td>21</td><td>NMR</td><td>Axion dark matter</td></tr><tr><td>10</td><td>ROUSSY</td><td>21</td><td></td><td>Molecular EDM</td></tr><tr><td>11</td><td>ZHANG</td><td>21B</td><td>ASTR</td><td>Neutron star inspiral</td></tr><tr><td>12</td><td>ABDELHAME.</td><td>20</td><td>CNTR</td><td>Solar axion</td></tr><tr><td>13</td><td>ABDELHAME.</td><td>20</td><td>CNTR</td><td>Solar axion</td></tr><tr><td>14</td><td>APRILE</td><td>20</td><td>XEIT</td><td>Solar axion</td></tr><tr><td>15</td><td>KLIMCHITSK.</td><td>20</td><td></td><td>Casimir effect</td></tr><tr><td>16</td><td>WANG</td><td>20A</td><td>CDEX</td><td>Solar axion</td></tr><tr><td>17</td><td>LEINSON</td><td>19</td><td>ASTR</td><td>Neutron star cooling</td></tr><tr><td>18</td><td>LLOYD</td><td>19</td><td>ASTR</td><td>γ-rays from NS</td></tr><tr><td>19</td><td>SMORRA</td><td>19</td><td></td><td>π g-factor</td></tr><tr><td>20</td><td>WU</td><td>19</td><td>NMR</td><td>Axion dark matter</td></tr><tr><td>21</td><td>AKHMATOV</td><td>18</td><td>CNTR</td><td>Solar axion</td></tr><tr><td>22</td><td>ARMENGAUD</td><td>18</td><td>EDE3</td><td>Solar axion</td></tr><tr><td>23</td><td>BEZNOGOV</td><td>18</td><td>ASTR</td><td>Neutron star cooling</td></tr><tr><td>24</td><td>GAVRILYUK</td><td>18</td><td>CNTR</td><td>Solar axion</td></tr><tr><td>25</td><td>HAMAGUCHI</td><td>18</td><td>ASTR</td><td>Neutron star cooling</td></tr><tr><td>26</td><td>ABEL</td><td>17</td><td></td><td>Neutron EDM</td></tr><tr><td>27</td><td>ABGRALL</td><td>17</td><td>HPGE</td><td>Solar axion</td></tr><tr><td>28</td><td>FU</td><td>17A</td><td>PNDX</td><td>Solar axion</td></tr><tr><td>29</td><td>KLIMCHITSK...</td><td>17A</td><td></td><td>Casimir effect</td></tr><tr><td>30</td><td>LIU</td><td>17A</td><td>CDEX</td><td>Solar axion</td></tr><tr><td>31</td><td>BERENJI</td><td>16</td><td>ASTR</td><td>γ-rays from NS</td></tr><tr><td>32</td><td>GAVRILYUK</td><td>15</td><td>CNTR</td><td>Solar axion</td></tr><tr><td>33</td><td>KLIMCHITSK...</td><td>15</td><td></td><td>Casimir-less</td></tr><tr><td>34</td><td>BEZERRA</td><td>14</td><td></td><td>Casimir effect</td></tr><tr><td>35</td><td>BEZERRA</td><td>14A</td><td></td><td>Casimir effect</td></tr><tr><td>36</td><td>BEZERRA</td><td>14B</td><td></td><td>Casimir effect</td></tr><tr><td>37</td><td>BEZERRA</td><td>14C</td><td></td><td>Casimir effect</td></tr><tr><td>38</td><td>BLUM</td><td>14</td><td>COSM</td><td>⁴He abundance</td></tr><tr><td>39</td><td>LEINSON</td><td>14</td><td>ASTR</td><td>Neutron star cooling</td></tr><tr><td>&lt;250</td><td></td><td>95</td><td>40</td><td>ALESSANDRIA13</td><td>CNTR</td></tr><tr><td>&lt;155</td><td></td><td>90</td><td>41</td><td>ARMENGAUD</td><td>Solar axion</td></tr><tr><td>&lt; 8.6</td><td>× 10<sup>3</sup></td><td>90</td><td>42</td><td>BELLI</td><td>Solar axion</td></tr><tr><td>&lt; 1.4</td><td>× 10<sup>4</sup></td><td>90</td><td>43</td><td>BELLINI</td><td>BORX Solar axion</td></tr><tr><td>&lt;145</td><td></td><td>95</td><td>44</td><td>DERBIN</td><td>CNTR Solar axion</td></tr><tr><td></td><td></td><td></td><td>45</td><td>BELLI</td><td>CNTR Solar axion</td></tr><tr><td></td><td></td><td></td><td>46</td><td>ADELBERGER</td><td>Test of Newton's law</td></tr></table>

1 LELLA 24 update constraints on the axion-proton coupling from supernova 1987A based on the SN cooling argument (including a treatment of the trapping regime) as well as the non-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 a window 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 $m_{A^0} = 0.496-0.502$ neV. Assuming axions account for all dark matter with $\rho_A \approx 0.55$ GeV/cm$^3$, they derived constraints on axion couplings to the deuteron EDM operator, gluons, and the deuteron spin. 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 $g_{Ann} < 2.4 \times 10^{-10}$ GeV$^{-1}$ at 95% CL for $m_{A^0} = 0.4-4$ eV. They assumed axions form all dark matter with a density of 0.3 GeV/cm$^3$. See their Fig. 5 for the limits.

4 BUSCHMANN 22 studied the axion emission from five neutron stars with ages ~ $10^5-10^6$ years, comparing the simulation with axions to age and luminosity measurements. The mass bound assumes the KSVZ axion model with $C_p = -0.47$ and $C_n = -0.02$. 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 $m_{A^0} = 10^{-19}-4 \times 10^{-12}$ eV.

7 AYBAS 21 limits the axion couplings to the nucleon EDM and the nucleons as $g_{ANN} < 9.5 \times 10^{-4}$ GeV$^{-2}$ and $g_{ANN}/2m_N < 0.28$ GeV$^{-1}$ (95% CL) for $m_{A^0} = 162-166$ neV, based on a measurement of $^{207}$Pb solid-state NMR in a polarized ferroelectric crystal. Here $m_N$ is the nucleon mass and $g_{ANN}$ is the dimensionless axion-nucleon coupling. They assume that axions make up all the dark matter with $\rho_A \approx 0.46$ GeV/cm$^3$. See their Fig. 3 for the limits.

8 BHUSAL 21 looked for 5.5 MeV solar axions produced by $pd \to {}^3$He $A^0$ through the axion-induced dissociation of deuterons by using SNO data, and set a limit on the isovector axion-nucleon coupling, $|g_{a,N}| < 2 \times 10^{-5}$ GeV$^{-1}$, which is equivalent to $|g_{Ann} - g_{App}| < 4 \times 10^{-5}$ 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 the axion couplings to nucleons as $g_{ANN}/2m_N < 3.2 \times 10^{-9}$ GeV$^{-1}$ (95% CL) at $m_{A^0} = 52.94$ feV, and comparable limits in the mass range of 8.3-744 feV. Here $m_N$ is the nucleon mass and $g_{ANN}$ is the dimensionless axion-nucleon coupling. They assume that axions make up all the dark matter with $\rho_A \approx 0.4$ GeV/cm$^3$. See their Fig. 4 for the limits.

10 ROUSSY 21 look for a time-oscillating EDM of molecular ions $Hf^+$ induced by axion dark matter couplings to gluons. See their Fig. 3 for limits in the range of $m_{A^0} = 10^{-22}-10^{-15}$ eV.

## Invisible $A^0$ (Axion) Limits from Nucleon Coupling

Limits are for the axion mass in eV.

<table><thead><tr><th>VALUE (eV)</th><th>CL (%)</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td>• • •</td><td>We do not use the following data for averages, fits, limits, etc. • • •</td><td></td><td></td><td></td></tr><tr><td>&lt; 0.01</td><td>95</td><td>1 LELLA</td><td>24</td><td>ASTR SN1987A</td></tr><tr><td></td><td></td><td>2 KARANTH</td><td>23</td><td>Deuterium EDM</td></tr><tr><td></td><td></td><td>3 LEE</td><td>23</td><td>Axion dark matter</td></tr></tbody></table>
# Gauge & Higgs Boson Particle Listings
## Axions ($A^0$) and Other Very Light Bosons

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 by cancellation with additional contributions. They exclude $1.6 \times 10^{16} < f_A < 10^{18}$ GeV at $3 \sigma$ for $m_{A^0} \lesssim 10^{-13}$ eV. See their Fig. 1 for mass-dependent limits.

12 ABDELHAMEED 20 look for the resonant excitation of $^{169}\text{Tm}$ (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 $g_{A\gamma\gamma} \cdot g_{App} < 1.44 \times 10^{-14}$ GeV$^{-1}$ (90 % CL).

13 ABDELHAMEED 20 look for the resonant excitation of $^{169}\text{Tm}$ (8.41 keV) by solar axions produced via the axion-electron coupling. They set a limit on the product of axion couplings to electrons and nucleons as $g_{Aee} \cdot g_{App} < 2.81 \times 10^{-16}$ (90 % CL).

14 APRILE 20 look for solar axions from the ABC interactions, the Primakoff conversion, and the 14.4 keV M1 transition of $^{57}\text{Fe}$. 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-coated microsphere and a SiC plate to constrain the force due to two-axion exchange for $17.8 < m_{A^0} < 100$ eV. See their Fig. 2 for mass-dependent limits.

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 based on the Tolman's analytic solution to the Einstein equations of spherical fluids in hydrostatic equilibrium. The dimensionless axion-neutron coupling is constrained as $g_{Ann} < 1.0 \times 10^{-10}$.

18 LLOYD 19 is analogous to BERENJL 16. They highlight that the limit obtained with this 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 $\bar{p}$ spin-flip resonance data. Assuming $\rho_A = 0.4$ GeV/cm$^3$, they constrain the dimensionless axion-nucleon coupling as $g_{APP} < 2-9$ at 95% CL for $m_{A^0} = 2 \times 10^{-23}-4 \times 10^{-17}$ eV. See the right panel of their Fig. 3.

20 WU 19 look for axion-induced time-oscillating features of the NMR spectrum of acetonitrile-2-$^{13}$C. Assuming $C_p = C_n$ and $\rho_A = 0.4$ GeV/cm$^3$, they constrain the dimensionless axion-nucleon coupling as $g_{ANN} < 6 \times 10^{-5}$ for $m_{A^0} = 10^{-21}-1.3 \times 10^{-17}$ eV. Note that the limits for $m_{A^0} < 10^{-21}$ eV in their Fig. 3(a) should be weaker than those for heavier masses. See ADELBERGER 19 and WU 19C on this issue.

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 to electrons and nucleons.

23 BEZNOGOV 18 constrain the axion-neutron coupling by assuming that thermal evolution of the hot neutron star HESS 11731-347 is dominated by the lowest possible neutrino emission. The quoted limit assumes the KSVZ axion with the effective Peccei-Quinn charge of the neutron $C_n = -0.02$. The dimensionless axion-neutron coupling is constrained as $g_{Ann} < 2.8 \times 10^{-10}$.

24 GAVRILYUK 18 look for the resonant excitation of $^{83}\text{Kr}$ (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 based on the minimal cooling scenario which explains the observed rapid cooling rate. The quoted limit corresponds to $f_A > 5 \times 10^8$ GeV obtained for the KSVZ axion with $C_p = -0.47$ and $C_n = -0.02$.

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 $m_{A^0} = 10^{-24}-10^{-17}$ eV.

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 $^{57}\text{Fe}$ solar axion. The limit assumes the DFSZ axion model. See their Fig. 3 for mass-dependent limits on the axion-electron coupling. Notice that in 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 $< m_{A^0} < 0.9$ eV. See their Figs. 1 and 2 for mass 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 BERENJL 16 used the Fermi LAT observations of neutron stars to look for photons from axion decay. They assume the effective Peccei-Quinn charge of the neutron $C_n = 0.1$ and a neutron-star core temperature of 20 MeV.

32 GAVRILYUK 15 look for solar axions emitted by the M1 transition of $^{83}\text{Kr}$ (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 and rotating source masses of Au and Si to constrain the force due to two-axion exchange for $1.7 \times 10^{-3} < m_{A^0} < 0.9$ eV. See their Figs. 1 and 2 for mass dependent limits.

34 BEZERRA 14 use the measurement of the thermal Casimir-Polder force between a Bose-Einstein condensate of $^{87}\text{Rb}$ atoms and a $^{80}\text{SiO}_2$ plate to constrain the force mediated by exchange of two pseudoscalars for 0.1 meV $< m_{A^0} < 0.3$ eV. See their Fig. 2 for the mass-dependent limit on pseudoscalar coupling to nucleons.

35 BEZERRA 14A is analogous to BEZERRA 14. They use the measurement of the Casimir pressure between two Au-coated plates to constrain pseudoscalar coupling to nucleons for $1 \times 10^{-3}$ eV $< m_{A^0} < 15$ eV. See their Figs. 1 and 2 for the mass-dependent limit.

36 BEZERRA 14B is analogous to BEZERRA 14. BEZERRA 14B uses the measurement of the normal and lateral Casimir forces between sinusoidally corrugated surfaces of a sphere and a plate to constrain pseudoscalar coupling to nucleons for 1 eV $< m_{A^0} < 20$ eV. See their Figs. 1-3 for mass-dependent limits.

37 BEZERRA 14C is analogous to BEZERRA 14. They use the measurement of the gradient of the Casimir force between Au- and Ni-coated surfaces of a sphere and a plate to constrain pseudoscalar coupling to nucleons for $3 \times 10^{-5}$ eV $< m_{A^0} < 1$ eV. See their Figs. 1, 3, and 4 for the mass-dependent limits.

38 BLUM 14 studied effects of an oscillating strong CP phase induced by axion dark matter on the primordial $^{4}\text{He}$ abundance. See their Fig. 1 for mass-dependent limits.

39 LEINSON 14 attributes the excessive cooling rate of the neutron star in Cassiopeia A to axion emission from the superfluid core, and found $C_n^2 m_{A^0}^2 \simeq 5.7 \times 10^{-6}$ eV$^2$, where $C_n$ 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 $^{57}\text{Fe}$ 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 $^{7}\text{Li}^*$ (478 keV) after the electron capture of $^{7}\text{Be}$, using the resonant excitation $^{7}\text{Li}$ 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 $\rho d \to {}^3\text{He} A^0$. The limit assumes the hadronic axion model. See their Figs. 6 and 7 for mass-dependent limits on product of axion couplings to photons, electrons, and nucleons.

44 DERBIN 11 looked for solar axions emitted by the M1 transition of thermally excited $^{57}\text{Fe}$ nuclei in the Sun, using their possible resonant capture on $^{57}\text{Fe}$ in the laboratory. The mass bound assumes $m_u/m_d = 0.56$ and the flavor-singlet axial vector matrix element $S = 3F - D \simeq 0.5$.

45 BELLINI 08 consider solar axions emitted in the M1 transition of $^{7}\text{Li}^*$ (478 keV) and look for a peak at 478 keV in the energy spectra of the Counting Test Facility (CTF), a Borexino prototype. For $m_{A^0} < 450$ keV they find mass-dependent limits on products of 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 $m_{A^0}$ below about 1 meV.

## Axion Limits from T-violating Medium-Range Forces

The limit is for the coupling $g = g_p g_s$ in a T-violating potential between nucleons, nucleon and electron, or electrons of the form $V = \frac{g\hbar^2}{8\pi m_p}(\sigma \cdot \hat{p}) (\frac{1}{r^2} + \frac{1}{\lambda r}) e^{-r/\lambda}$, where $g_s$ and $g_p$ 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 $\lambda = \hbar/(m_A C)$ is the range of the force.

<table><thead><tr><th>VALUE</th><th>DOCUMENT ID</th><th>TECN</th><th>COMMENT</th></tr></thead><tbody><tr><td></td><td>1 AYRES</td><td>23</td><td>ultracold neutrons</td></tr><tr><td></td><td>2 PODDAR</td><td>23</td><td>solar system</td></tr><tr><td></td><td>3 ZHANG</td><td>23</td><td>NMR polarized <sup>129</sup>Xe and <sup>131</sup>Xe</td></tr><tr><td></td><td>4 CRESCINI</td><td>22</td><td>paramagnetic GSO crystal</td></tr><tr><td></td><td>5 FENG</td><td>22</td><td>NMR polarized <sup>129</sup>Xe and <sup>131</sup>Xe</td></tr><tr><td></td><td>6 AFACH</td><td>21</td><td>GNME Optical magnetometers</td></tr><tr><td></td><td>7 DZUBA</td><td>18</td><td>THEO atomic EDM</td></tr><tr><td></td><td>8 STADNIK</td><td>18</td><td>THEO atomic and molecular EDMs</td></tr><tr><td></td><td>9 CRESCINI</td><td>17</td><td>SQID paramagnetic GSO crystal</td></tr><tr><td></td><td>10 AFACH</td><td>15</td><td>ultracold neutrons</td></tr><tr><td></td><td>11 STADNIK</td><td>15</td><td>THEO nucleon spin contributions for nuclei</td></tr><tr><td></td><td>12 TERRANO</td><td>15</td><td>torsion pendulum</td></tr><tr><td></td><td>13 BULATOWICZ</td><td>13</td><td>NMR polarized <sup>129</sup>Xe and <sup>131</sup>Xe</td></tr><tr><td></td><td>14 CHU</td><td>13</td><td>polarized <sup>3</sup>He</td></tr><tr><td></td><td>15 TULLNEY</td><td>13</td><td>SQID polarized <sup>3</sup>He and <sup>129</sup>Xe</td></tr><tr><td></td><td>16 RAFFELT</td><td>12</td><td>stellar energy loss</td></tr><tr><td></td><td>17 HOEDL</td><td>11</td><td>torsion pendulum</td></tr><tr><td></td><td>18 PETUKHOV</td><td>10</td><td>polarized <sup>3</sup>He</td></tr><tr><td></td><td>19 SEREBROV</td><td>10</td><td>ultracold neutrons</td></tr><tr><td></td><td>20 IGNATOVICH</td><td>09</td><td>RVUE ultracold neutrons</td></tr><tr><td></td><td>21 SEREBROV</td><td>09</td><td>RVUE ultracold neutrons</td></tr><tr><td></td><td>22 BAESSLER</td><td>07</td><td>ultracold neutrons</td></tr><tr><td></td><td>23 HECKEL</td><td>06</td><td>torsion pendulum</td></tr><tr><td></td><td>24 NI</td><td>99</td><td>paramagnetic Tb F<sub>3</sub></td></tr><tr><td></td><td>25 POSPELOV</td><td>98</td><td>THEO neutron EDM</td></tr><tr><td></td><td>26 YOUDIN</td><td>96</td><td></td></tr><tr><td></td><td>27 RITTER</td><td>93</td><td>torsion pendulum</td></tr><tr><td></td><td>28 VENEMA</td><td>92</td><td>nuclear spin-precession frequencies</td></tr><tr><td></td><td>29 WINELAND</td><td>91</td><td>NMR</td></tr></tbody></table>

1 AYRES 23 at PSI use their neutron EDM setup to look for a mm to micron-range spin-dependent force between ultracold spin-polarized neutrons stored in vacuum and the unpolarisated nucleons in the surrounding apparatus. They constrain a nucleon-neutron monopole-dipole interaction parameterised by the coupling $g_s^N g_p^N$. They set a limit of $g_s^N g_p^N < 10^{-20}$ (95% CL) for a 1 meV mass axion, see Fig. 6.

2 PODDAR 23 search for long-range monopole-dipole forces between the polarized population of electrons inside the Earth and the unpolarisated nucleons in the Sun, which would affect the precession of orbital perihelion. However, the most competitive limit is obtained by combining the monopole-monopole force constraints on $g_s^N$ from planetary precession with the strongest stellar bound on the pseudoscalar electron coupling ($g_p^e$), shown in Fig. 5.

3 ZHANG 23 look for changes of the ratio of precession frequencies between $^{129}\text{Xe}$ and $^{131}\text{Xe}$ as the bias field is flipped in Earth's gravitational field after Earth roation effect is subtracted. They find $g_p^N g_s^N < 1 \times 10^{-26}-3.7 \times 10^{-36}$ for $\lambda = 0.3-1 \times 10^{10}$ m. See their Fig. 4 for limits as a function of $\lambda$.
⁴ CRESCINI 22 is an update of CRESCINI 17, and find $g_p^e g_s^N \le 5.7 \times 10^{-32}$ and $g_p^e g_s^e \le 1.6 \times 10^{-31}$ for $\lambda \gtrsim 10$ cm at 95% CL. See their Fig. 4 for limits as a function of $\lambda$.

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 $g_p^n g_s^N < 2 \times 10^{-20}-3 \times 10^{-24}$ for $\lambda = 0.11-0.55$ mm. See their Fig. 4 for limits as a function of $\lambda$.

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 $4 \times 10^5$ GeV for $m_{A0}$ in 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 the pseudoscalar coupling to nucleon and the scalar coupling to electron, which improved on the laboratory bounds for $m_{A0} > 0.01$ eV. See their Fig. 1 for mass-dependent limits.

⁸ STADNIK 18 used atomic and molecular EDM experiments to derive limits on the product of the pseudoscalar couplings to electron and the scalar coupling to nucleon and electron. See their Fig. 2 for mass-dependent limits, which improved on the laboratory bounds for $m_{A0} > 0.01$ eV.

⁹ CRESCINI 17 use the QUAX-$g_p g_s$ experiment to look for variation of a paramagnetic GSO crystal magnetization when rotating lead disks are positioned near the crystal, and find $g_p^n g_s^N < 4.3 \times 10^{-30}$ for $\lambda = 0.1-0.2$ m at 95% CL. See their Fig. 6 for limits as a function of $\lambda$.

¹⁰ AFACH 15 look for a change of spin precession frequency of ultracold neutrons when a magnetic field with opposite directions is applied, and find $g < 2.2 \times 10^{-27}$ $(m/\lambda)^2$ at 95% CL for $1 \mu\text{m} < \lambda < 5$ mm. See their Fig. 3 for their limits.

¹¹ STADNIK 15 studied proton and neutron spin contributions for nuclei and derive the limits $g < 10^{-28}-10^{-23}$ for $\lambda > 3 \times 10^{-4}$ m using the data of TULLNEY 13. See their Figs. 1 and 2 for $\lambda$-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, $g < 9 \times 10^{-29}-5 \times 10^{-26}$ for $m_{A0} < 1.5-400$ µeV. See their Fig. 5 for mass-dependent limits.

¹³ BULATOWICZ 13 looked for NMR frequency shifts in polarized $^{129}$Xe and $^{131}$Xe when a zirconia rod is positioned near the NMR cell, and find $g < 1 \times 10^{-19}-1 \times 10^{-24}$ for $\lambda = 0.01-1$ 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 presence of an unpolarized mass, in analogy to YOUDIN 96. See Fig. 3 for limits on $g$ in the approximate $m_{A0}$ range $0.02-2$ meV.

¹⁵ TULLNEY 13 look for a shift of the precession frequency difference between the collocated $^3$He and $^{129}$Xe in the presence an unpolarized mass, and derive limits $g < 3 \times 10^{-29}-2 \times 10^{-22}$ for $\lambda > 3 \times 10^{-4}$ cm. See their Fig. 3 for $\lambda$-dependent limits.

¹⁶ RAFFELT 12 show that the pseudoscalar couplings to electron and nucleon and the scalar 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 of an external magnet. In their Fig. 3 they show restrictive limits on $g$ in the approximate $m_{A0}$ range $0.03-10$ meV.

¹⁸ PETUKHOV 10 use spin relaxation of polarized $^3$He and find $g < 3 \times 10^{-23}$ $(\text{cm}/\lambda)^2$ at 95% CL for the force range $\lambda = 10^{-4}-1$ cm.

¹⁹ SEREBROV 10 use spin precession of ultracold neutrons close to bulk matter and find $g < 2 \times 10^{-21}$ $(\text{cm}/\lambda)^2$ at 95% CL for the force range $\lambda = 10^{-4}-1$ cm.

²⁰ IGNATOVICH 09 use data on depolarization of ultracold neutrons in material traps. They show $\lambda$-dependent limits in their Fig. 1.

²¹ SEREBROV 09 uses data on depolarization of ultracold neutrons stored in material traps and finds $g < 2.96 \times 10^{-21}$ $(\text{cm}/\lambda)^2$ for the force range $\lambda = 10^{-3}-1$ cm and $g < 3.9 \times 10^{-22}$ $(\text{cm}/\lambda)^2$ for $\lambda = 10^{-4}-10^{-3}$ 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 $1 \mu\text{m}-10$ 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 $9 \times 10^{22}$ 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$_3$ salt. See their Fig. 1 for the result.

²⁵ POSPELOV 98 studied the possible contribution of $T$-violating Medium-Range Force to the neutron electric dipole moment, which is possible when axion interactions violate CP. The size of the force among nucleons must be smaller than gravity by a factor of $2 \times 10^{-10}$ $(1 \text{ cm}/\lambda_A)$, where $\lambda_A=\hbar/m_A$.

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 for their 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 $\chi$ which is defined by the Lagrangian

$$L = -\frac{1}{2} F_{\mu\nu} F^{\mu\nu} - \frac{1}{4} F'_{\mu\nu} F'^{\mu\nu} - \frac{3}{2} F_{\mu\nu} F'^{\mu\nu} + \frac{m^2}{2} A'_{\mu} A'^{\mu}$$

where $A_{\mu}$ and $A'_{\mu}$ are the photon and hidden-photon fields with field strengths $F_{\mu\nu}$ and $F'_{\mu\nu}$, respectively, and $m_{\gamma'}$ is the hidden-photon mass.

VALUE DOCUMENT ID TECHN COMMENT

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

<table><tr><td>&lt; 4</td><td>× 10<sup>-6</sup></td><td>90</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 1.3</td><td>× 10<sup>-8</sup></td><td>90</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-16</sup></td><td>90</td></tr><tr><td>&lt; 1.6</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 1.61</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 6</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 2.1</td><td>× 10<sup>-3</sup></td><td>95</td></tr><tr><td>&lt; 1.1</td><td>× 10<sup>-16</sup></td><td>90</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-12</sup></td><td>95</td></tr><tr><td>&lt; 5</td><td>× 10<sup>-6</sup></td><td>90</td></tr><tr><td>&lt; 5.0</td><td>× 10<sup>-14</sup></td><td>68</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-7</sup></td><td>90</td></tr><tr><td>&lt; 2.2</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-11</sup></td><td>95</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-15</sup></td><td></td></tr><tr><td>&lt; 7.9</td><td>× 10<sup>-13</sup></td><td>95</td></tr><tr><td>&lt; 1.6</td><td>× 10<sup>-9</sup></td><td>95</td></tr><tr><td>(4.6 +0.5/-0.4) × 10<sup>-15</sup></td><td></td><td>68</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-13</sup></td><td>90</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-12</sup></td><td>90</td></tr><tr><td>&lt; 8.7</td><td>× 10<sup>-11</sup></td><td>95</td></tr><tr><td>&lt; 7.97</td><td>× 10<sup>-9</sup></td><td>95</td></tr><tr><td>&lt; 6.86</td><td>× 10<sup>-11</sup></td><td>90</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-2</sup></td><td>95</td></tr><tr><td>&lt; 8</td><td>× 10<sup>-6</sup></td><td>90</td></tr><tr><td>&lt; 2.3</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 1.6</td><td>× 10<sup>-4</sup></td><td>95</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-5</sup></td><td>90</td></tr><tr><td>&lt; 1.68</td><td>× 10<sup>-15</sup></td><td>90</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-16</sup></td><td>90</td></tr><tr><td>&lt; 1.8</td><td>× 10<sup>-13</sup></td><td></td></tr><tr><td>&lt; 3</td><td>× 10<sup>-12</sup></td><td>95</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-2</sup></td><td>95</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-8</sup></td><td>90</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 4.1</td><td>× 10<sup>-12</sup></td><td>90</td></tr><tr><td>&lt; 3.3</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 1.2</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 6.72</td><td>× 10<sup>-13</sup></td><td>95</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-16</sup></td><td>90</td></tr><tr><td>&lt; 9</td><td>× 10<sup>-16</sup></td><td>90</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-5</sup></td><td>90</td></tr><tr><td>&lt; 7</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 8.2</td><td>× 10<sup>-5</sup></td><td>90</td></tr><tr><td>&lt; 7</td><td>× 10<sup>-15</sup></td><td>90</td></tr></table>

<table><tr><td>1 ABREU</td><td>24</td><td>FASR</td><td>m<sub>γ'</sub> ≈ 50 MeV</td></tr><tr><td>2 AAD</td><td>23BO</td><td>ATLS</td><td>m<sub>γ'</sub> = 5-40 GeV</td></tr><tr><td>3 AAD</td><td>23I</td><td>ATLS</td><td>m<sub>γ'</sub> = 0.017-15 GeV</td></tr><tr><td>4 AAD</td><td>23T</td><td>ATLS</td><td>m<sub>γ'</sub> ≈ 40 GeV</td></tr><tr><td>5 AALBERS</td><td>23A</td><td>LZ</td><td>m<sub>γ'</sub> = 1-17 keV</td></tr><tr><td>6 ABLIKIM</td><td>23AF</td><td>BES3</td><td>m<sub>γ'</sub> = 1.5-2.9 GeV</td></tr><tr><td>7 ABUDINEN</td><td>23B</td><td>BEL2</td><td>m<sub>γ'</sub> = 4-9.7 GeV</td></tr><tr><td>8 ADHIKARI</td><td>23</td><td>C100</td><td>m<sub>γ'</sub> = 215 eV</td></tr><tr><td>9 ADHIKARI</td><td>23A</td><td>C100</td><td>m<sub>γ'</sub> = 10-1000 keV</td></tr><tr><td>10 ADRIAN</td><td>23</td><td>HPS</td><td>m<sub>γ'</sub> = 19-81 MeV</td></tr><tr><td>11 AGNES</td><td>23A</td><td>DS50</td><td>m<sub>γ'</sub> = 0.03-20 keV</td></tr><tr><td>12 AN</td><td>23A</td><td>ATLS</td><td>m<sub>γ'</sub> = 4.1-6.2 μeV</td></tr><tr><td>13 ANDREEV</td><td>23</td><td>NA64</td><td>m<sub>γ'</sub> = 10<sup>-3</sup>-1.5 GeV</td></tr><tr><td>14 BAJJALI</td><td>23</td><td>BRAS</td><td>m<sub>γ'</sub> = 49.63-74.44 μeV</td></tr><tr><td>15 CORTINA-GIL</td><td>23C</td><td>NA62</td><td>m<sub>γ'</sub> = 10-700 MeV</td></tr><tr><td>16 HAYRAPETY</td><td>23G</td><td>CMS</td><td>m<sub>γ'</sub> = 1.1-7.9 GeV</td></tr><tr><td>17 KOTAKA</td><td>23</td><td>DORR</td><td>m<sub>γ'</sub> = 74-110 μeV</td></tr><tr><td>18 LI</td><td>23I</td><td>ASTR</td><td>m<sub>γ'</sub> = 10<sup>-3</sup>-10<sup>5</sup> eV</td></tr><tr><td>19 RAMANATH</td><td>23</td><td>QULP</td><td>m<sub>γ'</sub> = 19.7-30.5 μeV</td></tr><tr><td>20 ROMANENKO</td><td>23</td><td>LSW</td><td>m<sub>γ'</sub> = 0.21-5.7 μeV</td></tr><tr><td>21 XIA</td><td>23</td><td>ASTR</td><td>m<sub>γ'</sub> ≈ 10<sup>-23</sup>eV</td></tr><tr><td>22 AAD</td><td>22J</td><td>ATLS</td><td>m<sub>γ'</sub> = 1-60 GeV</td></tr><tr><td>23 AAD</td><td>22S</td><td>ATLS</td><td>m<sub>γ'</sub> ≈ 10 GeV</td></tr><tr><td>24 APRILE</td><td>22</td><td>XE1T</td><td>m<sub>γ'</sub> = 0.9 keV</td></tr><tr><td>25 APRILE</td><td>22</td><td>XE1T</td><td>m<sub>γ'</sub> = 0.01-0.4 keV</td></tr><tr><td>26 APRILE</td><td>22B</td><td>XENT</td><td>m<sub>γ'</sub> = 1-39.44-140 keV</td></tr><tr><td>27 BATTAGLIERI</td><td>22</td><td>BDMP</td><td>m<sub>γ'</sub> = 3-100 MeV</td></tr><tr><td>28 BOLTON</td><td>22</td><td>ASTR</td><td>m<sub>γ'</sub> = (8.4 ± 0.6) × 10<sup>-14</sup> eV</td></tr><tr><td>29 CERVANTES</td><td>22</td><td>ORPH</td><td>m<sub>γ'</sub> = 65.5-69.3 μeV</td></tr><tr><td>30 CHILES</td><td>22</td><td>m<sub>γ'</sub> = 0.7-0.8 eV</td></tr><tr><td>31 HOCHBERG</td><td>22</td><td>NSNP</td><td>m<sub>γ'</sub> = 0.73-30 eV</td></tr><tr><td>32 LEES</td><td>22</td><td>BABR</td><td>m<sub>γ'</sub> = 1 × 10<sup>-3</sup>-3.16 GeV</td></tr><tr><td>33 LU</td><td>22</td><td>ASTR</td><td>m<sub>γ'</sub> ≈ 3 × 10<sup>-5</sup> eV</td></tr><tr><td>34 MANENTI</td><td>22</td><td>MDHI</td><td>m<sub>γ'</sub> = 1.61 eV</td></tr><tr><td>35 THOMAS</td><td>22</td><td>m<sub>γ'</sub> = 1-80 GeV</td></tr><tr><td>36 TUMASYAN</td><td>22AH</td><td>CMS</td><td>m<sub>γ'</sub> = 4-62.5 GeV</td></tr><tr><td>37 TUMASYAN</td><td>22N</td><td>CMS</td><td>m<sub>γ'</sub> = 0.6-49 GeV</td></tr><tr><td>38 WU</td><td>22A</td><td>PPTA</td><td>m<sub>γ'</sub> ≈ 10<sup>-23</sup>eV</td></tr><tr><td>39 ANDREEV</td><td>21</td><td>NA64</td><td>m<sub>γ'</sub> = 1 × 10<sup>-3</sup>-1 GeV</td></tr><tr><td>40 ANDREEV</td><td>21A</td><td>NA64</td><td>m<sub>γ'</sub> = 0.1-0.35 GeV</td></tr><tr><td>41 BI</td><td>21</td><td>ASTR</td><td>m<sub>γ'</sub> = 0.03-0.06 eV</td></tr><tr><td>42 CAZZANIGA</td><td>21</td><td>NA64</td><td>m<sub>γ'</sub> = 10-390 MeV</td></tr><tr><td>43 DIXIT</td><td>21</td><td>CNTR</td><td>m<sub>γ'</sub> = 24.86 μeV</td></tr><tr><td>44 GHOSH</td><td>21</td><td>RVUE</td><td>m<sub>γ'</sub> = 2-30 μeV</td></tr><tr><td>45 GODFREY</td><td>21</td><td>m<sub>γ'</sub> = 0.2637-0.2648 μeV</td></tr><tr><td>46 KOPYLOV</td><td>21A</td><td>CNTR</td><td>m<sub>γ'</sub> = 9-40 eV</td></tr><tr><td>47 KRIBS</td><td>21</td><td>m<sub>γ'</sub> ≈ 10 GeV</td></tr><tr><td>48 SCHMIDT</td><td>21</td><td>THEO</td><td>m<sub>γ'</sub> < 0.6 GeV</td></tr><tr><td>49 TSAI</td><td>21</td><td>BDMP</td><td>m<sub>γ'</sub> = 0.78 GeV</td></tr><tr><td>50 AAIJ</td><td>20C</td><td>LHCB</td><td>m<sub>γ'</sub> = 214 MeV</td></tr><tr><td>51 AAIJ</td><td>20C</td><td>LHCB</td><td>m<sub>γ'</sub> = 218-315 MeV</td></tr><tr><td>52 ABLIKIM</td><td>20AB</td><td>BES3</td><td>m<sub>γ'</sub> = 0.2-2.1 GeV</td></tr><tr><td>53 AGOSTINI</td><td>20</td><td>HPGE</td><td>m<sub>γ'</sub> = 60 keV - 1 MeV</td></tr><tr><td>54 AMARAL</td><td>20</td><td>SCDM</td><td>m<sub>γ'</sub> = 1.2-50 eV</td></tr><tr><td>55 AN</td><td>20</td><td>XE1T</td><td>m<sub>γ'</sub> = 200 eV</td></tr><tr><td>56 ANDRIANAV</td><td>20</td><td>FUNK</td><td>m<sub>γ'</sub> = 1.95-8.55 eV</td></tr><tr><td>57 APRILE</td><td>20</td><td>XE1T</td><td>m<sub>γ'</sub> = 1-200 keV</td></tr><tr><td>58 ARALIS</td><td>20</td><td>SCDM</td><td>m<sub>γ'</sub> = 0.04-500 keV</td></tr><tr><td>59 ARGUELLES</td><td>20</td><td>THEO</td><td>m<sub>γ'</sub> = 0.01 GeV</td></tr><tr><td>60 ARNAUD</td><td>20</td><td>EDEL</td><td>m<sub>γ'</sub> = 1-40 eV</td></tr><tr><td>61 BANERJEE</td><td>20</td><td>NA64</td><td>m<sub>γ'</sub> = 1.5-24 MeV</td></tr><tr><td>62 BARAK</td><td>20</td><td>SENS</td><td>m<sub>γ'</sub> = 1.2-12.8 eV</td></tr><tr><td>63 KRASNIKOV</td><td>20</td><td>RVUE</td><td>m<sub>γ'</sub> = 16.7 MeV</td></tr></table>
# Gauge & Higgs Boson Particle Listings
## Axions (A⁰) and Other Very Light Bosons

<table><tr><td>&lt; 1.4</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 1.3</td><td>× 10<sup>-15</sup></td><td>90</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 4.3</td><td>× 10<sup>-10</sup></td><td>95</td></tr><tr><td>&lt; 9</td><td>× 10<sup>-16</sup></td><td>90</td></tr><tr><td>&lt; 6</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 3.4</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 8</td><td>× 10<sup>-15</sup></td><td>90</td></tr><tr><td>&lt; 9</td><td>× 10<sup>-17</sup></td><td>90</td></tr><tr><td>&lt; 7.5</td><td>× 10<sup>-6</sup></td><td>90</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-11</sup></td><td></td></tr><tr><td>&lt; 5</td><td>× 10<sup>-12</sup></td><td>95</td></tr><tr><td>&lt; 4.4</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-5</sup></td><td>95</td></tr><tr><td>&lt; 6</td><td>× 10<sup>-9</sup></td><td>95</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-11</sup></td><td>95</td></tr><tr><td>&lt; 1.5</td><td>× 10<sup>-9</sup></td><td></td></tr><tr><td>&lt; 3</td><td>× 10<sup>-14</sup></td><td>95</td></tr><tr><td>&lt; 4.5</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 2.5</td><td>× 10<sup>-3</sup></td><td>95</td></tr><tr><td>&lt; 4.4</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 4</td><td>× 10<sup>-15</sup></td><td>90</td></tr><tr><td>&lt; 1.8</td><td>× 10<sup>-5</sup></td><td>90</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-8</sup></td><td>90</td></tr><tr><td>&lt; 3.1</td><td>× 10<sup>-14</sup></td><td>90</td></tr><tr><td>&lt; 6</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 7</td><td>× 10<sup>-15</sup></td><td>90</td></tr><tr><td>&lt; 1.2</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-11</sup></td><td>90</td></tr><tr><td>&lt; 4.5</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 4</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 4.4</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 1.7</td><td>× 10<sup>-6</sup></td><td>95</td></tr><tr><td>&lt; 4</td><td>× 10<sup>-2</sup></td><td>95</td></tr><tr><td>&lt; 1.4</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 1.7</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 4.2</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-13</sup></td><td>99.7</td></tr><tr><td>&lt; 6</td><td>× 10<sup>-12</sup></td><td></td></tr><tr><td>&lt; 2.3</td><td>× 10<sup>-13</sup></td><td>99.7</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-13</sup></td><td></td></tr><tr><td>&lt; 1.8</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 9.0</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 1.3</td><td>× 10<sup>-7</sup></td><td>95</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-18</sup></td><td></td></tr><tr><td>&lt; 3.5</td><td>× 10<sup>-4</sup></td><td>90</td></tr><tr><td>&lt; 9</td><td>× 10<sup>-4</sup></td><td>95</td></tr><tr><td>&lt; 3</td><td>× 10<sup>-15</sup></td><td></td></tr><tr><td>&lt; 7</td><td>× 10<sup>-14</sup></td><td></td></tr><tr><td>&lt; 8</td><td>× 10<sup>-4</sup></td><td></td></tr><tr><td>&lt; 2</td><td>× 10<sup>-3</sup></td><td>90</td></tr><tr><td>&lt; 2.2</td><td>× 10<sup>-13</sup></td><td></td></tr><tr><td>&lt; 8.06</td><td>× 10<sup>-5</sup></td><td>95</td></tr><tr><td>&lt; 2</td><td>× 10<sup>-10</sup></td><td>95</td></tr><tr><td>&lt; 1.7</td><td>× 10<sup>-7</sup></td><td></td></tr></table>

<table><tr><td>64 SHE</td><td>20</td><td>CDEX</td><td>m<sub>γ'</sub> = 10-300 eV</td></tr><tr><td>65 SHE</td><td>20</td><td>CDEX</td><td>m<sub>γ'</sub> = 0.1-4 keV</td></tr><tr><td>66 SIRUNYAN</td><td>20AQ</td><td>CMS</td><td>m<sub>γ'</sub> = 11.5-75 GeV,<br>110-200 GeV</td></tr><tr><td>67 TOMITA</td><td>20</td><td></td><td>m<sub>γ'</sub> =<br>115.79-115.85 μeV</td></tr><tr><td>68 WANG</td><td>20A</td><td>CDEX</td><td>m<sub>γ'</sub> = 0.185-10 keV</td></tr><tr><td>69 AABOUD</td><td>19G</td><td>ATLS</td><td>m<sub>γ'</sub> = 20-60 GeV</td></tr><tr><td>70 ABLIKIM</td><td>19A</td><td>BES3</td><td>m<sub>γ'</sub> = 0.01-2.4 GeV</td></tr><tr><td>71 ABLIKIM</td><td>19H</td><td>BES3</td><td>m<sub>γ'</sub> = 0.1-2.1 GeV</td></tr><tr><td>72 AGUILAR-AR...</td><td>19A</td><td>DAMC</td><td>m<sub>γ'</sub> = 1.2-30 eV</td></tr><tr><td>73 APRILE</td><td>19D</td><td>XE1T</td><td>m<sub>γ'</sub> = 0.186-5 keV</td></tr><tr><td>74 BANERJEE</td><td>19</td><td>NA64</td><td>m<sub>γ'</sub> = 1-200 MeV</td></tr><tr><td>75 BHOONAH</td><td>19</td><td>ASTR</td><td>m<sub>γ'</sub> = 10<sup>-22</sup>-10<sup>-10</sup></td></tr><tr><td>76 BRUN</td><td>19</td><td>SHUK</td><td>m<sub>γ'</sub> = 20.8-28.3 μeV</td></tr><tr><td>77 CORTINA-GIL</td><td>19</td><td>NA62</td><td>m<sub>γ'</sub> = 60-110 MeV</td></tr><tr><td>78 DANILOV</td><td>19</td><td>TEXO</td><td>m<sub>γ'</sub> = 20 eV - 1 GeV</td></tr><tr><td>79 HOCHBERG</td><td>19</td><td></td><td>m<sub>γ'</sub> = 0.8-4 eV</td></tr><tr><td>80 KOPYLOV</td><td>19</td><td>CNTR</td><td>m<sub>γ'</sub> = 9-40 eV</td></tr><tr><td>81 KOVETZ</td><td>19</td><td>COSM</td><td>m<sub>γ'</sub> = 10<sup>-23</sup>-10<sup>-13</sup></td></tr><tr><td>82 NGUYEN</td><td>19</td><td>WDMX</td><td>m<sub>γ'</sub> = 6 neV - 2.07<br>μeV</td></tr><tr><td>83 ABE</td><td>18F</td><td>XMAS</td><td>m<sub>γ'</sub> = 40-120 keV</td></tr><tr><td>84 ADRIAN</td><td>18</td><td>HPS</td><td>m<sub>γ'</sub> = 19-81 MeV</td></tr><tr><td>85 ANASTASI</td><td>18B</td><td>KLOE</td><td>m<sub>γ'</sub> = 519-987 MeV</td></tr><tr><td>86 ARMENGAUD</td><td>18</td><td>EDE3</td><td>m<sub>γ'</sub> = 0.8-500 keV</td></tr><tr><td>87 BANERJEE</td><td>18</td><td>NA64</td><td>m<sub>γ'</sub> = 1-23 MeV</td></tr><tr><td>88 BANERJEE</td><td>18A</td><td>NA64</td><td>m<sub>γ'</sub> = 1-100 MeV</td></tr><tr><td>89 KNIRCK</td><td>18</td><td></td><td>m<sub>γ'</sub> = 0.67-0.92 meV</td></tr><tr><td>90 ABGRALL</td><td>17</td><td>HPGE</td><td>m<sub>γ'</sub> = 11.8 keV</td></tr><tr><td>91 ABLIKIM</td><td>17AA</td><td>BES3</td><td>m<sub>γ'</sub> = 1.5-3.4 GeV</td></tr><tr><td>92 ANGLOHER</td><td>17</td><td>CRES</td><td>m<sub>γ'</sub> = 0.3-0.7 keV</td></tr><tr><td>93 BANERJEE</td><td>17</td><td>NA64</td><td>m<sub>γ'</sub> = 0.002-0.4 GeV</td></tr><tr><td>94 CHANG</td><td>17</td><td>ASTR</td><td>m<sub>γ'</sub> = 15 MeV</td></tr><tr><td>95 DUBININA</td><td>17</td><td>EMUL</td><td>m<sub>γ'</sub> = 1.1-24 MeV</td></tr><tr><td>96 LEES</td><td>17E</td><td>BABR</td><td>m<sub>γ'</sub> = 4.7 GeV</td></tr><tr><td>97 AAD</td><td>16AG</td><td>ATLS</td><td>m<sub>γ'</sub> = 0.1-2 GeV</td></tr><tr><td>98 ANASTASI</td><td>16</td><td>KLOE</td><td>m<sub>γ'</sub> = 527-987 MeV</td></tr><tr><td>99 KHACHATRY...</td><td>16</td><td>CMS</td><td>m<sub>γ'</sub> = 2 GeV</td></tr><tr><td>100 AAD</td><td>15CD</td><td>ATLS</td><td>m<sub>γ'</sub> = 15-55 GeV</td></tr><tr><td>101 ADARE</td><td>15</td><td></td><td>m<sub>γ'</sub> = 30-90 MeV</td></tr><tr><td>102 AN</td><td>15A</td><td></td><td>m<sub>γ'</sub> = 12 eV - 40 keV</td></tr><tr><td>103 ANASTASI</td><td>15</td><td>KLOE</td><td>m<sub>γ'</sub> = 2mμ - 1 GeV</td></tr><tr><td>104 ANASTASI</td><td>15A</td><td>KLOE</td><td>m<sub>γ'</sub> = 5-320 MeV</td></tr><tr><td>105 BATLEY</td><td>15A</td><td>NA48</td><td>m<sub>γ'</sub> = 36 MeV</td></tr><tr><td>106 JAEGLE</td><td>15</td><td>BELL</td><td>m<sub>γ'</sub> = 0.1-3.5 GeV</td></tr><tr><td>107 KAZANAS</td><td>15</td><td>ASTR</td><td>m<sub>γ'</sub> = 2m e - 100 MeV</td></tr><tr><td>108 SUZUKI</td><td>15</td><td></td><td>m<sub>γ'</sub> = 1.9-4.3 eV</td></tr><tr><td>109 VINYoles</td><td>15</td><td>ASTR</td><td>m<sub>γ'</sub> = 8 eV</td></tr><tr><td>110 ABE</td><td>14F</td><td>XMAS</td><td>m<sub>γ'</sub> = 40-120 keV</td></tr><tr><td>111 AGAKISHIEV</td><td>14</td><td>HDES</td><td>m<sub>γ'</sub> = 63 MeV</td></tr><tr><td>112 BABUSCI</td><td>14</td><td>KLOE</td><td>m<sub>γ'</sub> = 969 MeV</td></tr><tr><td>113 BATELL</td><td>14</td><td>BDMP</td><td>m<sub>γ'</sub> = 10<sup>-3</sup>-1 GeV</td></tr><tr><td>114 BLUEMLEIN</td><td>14</td><td>BDMP</td><td>m<sub>γ'</sub> = 0.6 GeV</td></tr><tr><td>115 FRADETTE</td><td>14</td><td>COSM</td><td>m<sub>γ'</sub> = 50-300 MeV</td></tr><tr><td>116 LEES</td><td>14J</td><td>BABR</td><td>m<sub>γ'</sub> = 0.2 GeV</td></tr><tr><td>117 MERKEL</td><td>14</td><td>A1</td><td>m<sub>γ'</sub> = 40-300 MeV</td></tr><tr><td>118 AN</td><td>13B</td><td>ASTR</td><td>m<sub>γ'</sub> = 2 keV</td></tr><tr><td>119 AN</td><td>13C</td><td>XE10</td><td>m<sub>γ'</sub> = 100 eV</td></tr><tr><td>120 DIAMOND</td><td>13</td><td>BDMP</td><td>m<sub>γ'</sub> = 30-250 MeV</td></tr><tr><td>121 GNINENKO</td><td>13</td><td>BDMP</td><td>m<sub>γ'</sub> = 25-120 MeV</td></tr><tr><td>122 HORVAT</td><td>13</td><td>HPGE</td><td>m<sub>γ'</sub> = 230 eV</td></tr><tr><td>123 INADA</td><td>13</td><td>LSW</td><td>m<sub>γ'</sub> = 0.04 eV-26 keV</td></tr><tr><td>124 MIZUMOTO</td><td>13</td><td></td><td>m<sub>γ'</sub> = 1 eV</td></tr><tr><td>125 PARKER</td><td>13</td><td>LSW</td><td>m<sub>γ'</sub> = 53 μeV</td></tr></table>

<table><tr><td>&lt; 5.32</td><td>× 10<sup>-15</sup></td><td>126 PARKER</td><td>13</td><td>m<sub>γ'</sub> = 53 μeV</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-15</sup></td><td>127 REDONDO</td><td>13</td><td>m<sub>γ'</sub> = 2 keV</td></tr><tr><td>&lt; 8</td><td>× 10<sup>-8</sup></td><td>128 GNINENKO</td><td>12A</td><td>m<sub>γ'</sub> = 1-135 MeV</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-7</sup></td><td>129 GNINENKO</td><td>12B</td><td>m<sub>γ'</sub> = 1-500 MeV</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-3</sup></td><td>130 ABRAHAMY...</td><td>11</td><td>m<sub>γ'</sub> = 175-250 MeV</td></tr><tr><td>&lt; 9</td><td>× 10<sup>-8</sup></td><td>131 BLUEMLEIN</td><td>11</td><td>m<sub>γ'</sub> = 70 MeV</td></tr><tr><td>&lt; 1</td><td>× 10<sup>-7</sup></td><td>132 BJORKEN</td><td>09</td><td>m<sub>γ'</sub> = 2-400 MeV</td></tr><tr><td>&lt; 5</td><td>× 10<sup>-9</sup></td><td>133 BJORKEN</td><td>09</td><td>m<sub>γ'</sub> = 2-50 MeV</td></tr></table>

1. ABREU 24 look for hidden photons produced from the pp collision in the decay channel $γ' → e^+e^-$, and exclude at 90% CL the region of $χ = 4 \times 10^{-6} - 2 \times 10^{-4}$ and $m_{γ'} = 10-80$ MeV, with the newly excluded region near the higher values of $χ$. See their Fig. 7 for mass-dependent limits.

2. AAD 23B 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 into $e^+e^-$ or $μ^+μ^-$.

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 $1 \times 10^{-4} - 1 \times 10^{-8}$ for the given mass range. The quoted limit is for $m_{A0} \approx 13$ 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 ZH production mode, and set the upper 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 $m_{γ'} = 1.4$ keV. The local density $ρ_{γ'} = 0.3$ GeV/cm³ is assumed. See their Fig. 7 for mass-dependent limits.

6. ABLIKIM 23AF look for invisible decays of hidden photons produced in the reaction $e^+e^- → γ'γ'$.

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, $\chi^2 \cdot \alpha_D$, in the range of $1.7 \times 10^{-8} - 2 \times 10^{-6}$ 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 $m_{γ'} \approx 12$ keV. Limits between $6 \times 10^{-14} - 3 \times 10^{-11}$ 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 $m_{γ'} \approx 74$ MeV. See their Fig. 28 for the mass-dependent limits.

11. AGNES 23A look for an absorption of hidden photon dark matter. The quoted limit is for $m_{γ'} = 0.03$ keV. The local density $ρ_{γ'} = 0.3$ GeV/cm³ is assumed. See their Fig. 2 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 $ρ_{γ'} = 0.3$ GeV/cm³ is 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 $m_{γ'} = 1$ MeV. See their Fig. 3 for mass-dependent limits.

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 $ρ_{γ'} = 0.3$ GeV/cm³. See their Figure 12 for mass-dependent limits in the range of $m_{γ'} = 50-75$ μeV under the assumption of randomly aligned hidden 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 $ω(2S)$ resonances. Mass dependent limits given in their Fig. 6.

17. KOTAKA 23 is an update of TOMITA 20, and set limits $χ < 0.3 \times 10^{-10}$ for the quoted mass range. The local density $ρ_{γ'} = 0.39$ GeV/cm³ is assumed. See their Fig. 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 longitudinal modes. 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 dish antenna cooled to 20 mK. The local density $ρ_{γ'} = 0.45$ GeV/cm³ is assumed. Limits between $7.9 \times 10^{-13}$ and $3.81 \times 10^{-12}$ are obtained. See their Fig. 5 for mass-dependent limits.

20. ROMANENKO 23 employed two superconducting radio frequency cavities with a high quality factor, optimized for detecting the longitudinal polarization of the hidden photon. The quoted limit is set at $m_{γ'} \approx 5$ μeV. See their Fig. 4 for the mass-dependent limits.

21. XIA 23 is analogous to WU 22A and use the Fermi-LAT puls timing array. They set a bound on the local density as $ρ_{γ'} \lesssim 7$ GeV/cm³ for $m_{γ'} \lesssim 10^{-23}$ eV at 95% CL, with weaker constraints up to $10^{-22}$ eV. See their Fig. 1 for the mass-dependent limits.
22 AAD 22j look for exotic decays of the SM-like Higgs boson, $H \to \gamma'/\gamma'/4\ell$ and $H \to Z\gamma' \to 4\ell$, and set limits on the kinetic mixing and the Higgs portal coupling. See their Figs. 19 and 20 for the mass-dependent limits.

23 AAD 22s look for decays of a Higgs boson into $\gamma$ and $\gamma'$ 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 $\chi < 3 \times 10^{-13}$ (eV/$m_{\gamma'}$) for $m_{\gamma'} < 3$ eV (90% C.L.). For $m_{\gamma'} > 3$ eV, see their Fig. 16 for mass-dependent limits.

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 $m_{\gamma'} = 0.09$ keV. See their Fig. 15 for mass-dependent limits.

26 APRILE 22e is an update of APRILE 20, and set limits $\chi < 5 \times 10^{-17}-2 \times 10^{-13}$. The quoted limit applies to $m_{\gamma'} = 1$ keV. They exclude the $\chi\sqrt{\chi\text{ENONIT}}$ excess found in 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 $7 \times 10^{-5}-1 \times 10^{-2}$ are obtained for the dark matter mass $m_{\gamma'}/3$ and the hidden gauge coupling $\alpha_D = 0.1$. See their Fig. 11.

28 BOLTON 22 use the Ly-$\alpha$ forest at $z \simeq 0.1$ as a calorimeter for heating in the inter-galactic 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-$\alpha$ absorption linewidths.

29 CERVANTES 22 use a dielectrically loaded Fabry-Perot open cavity to look for hidden photon dark matter. The local density $\rho_{\gamma'} = 0.45$ GeV/cm$^3$ is assumed. See their Fig. 5 for mass-dependent limits.

30 CHILES 22 look for hidden photon dark matter by using a layered dielectric target and a superconducting nanowire single-photon detector. The local density $\rho_{\gamma'} = 0.4$ GeV/cm$^3$ is assumed. See their Fig. 4 for mass-dependent limits.

31 HOCHBERG 22 update HOCHBERG 19. The quoted limit applies to $m_{A^0} \simeq 11$ eV. 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 $e^+e^-$, $\mu^+\mu^-$, or $\pi^+\pi^-$: For the bound-state mass in the range of 0.05-9.5 GeV, limits at the level of $5 \times 10^{-5}-1 \times 10^{-3}$ 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 $6.86 \times 10^{-11}$ and $5 \times 10^{-8}$ are obtained for $m_{\gamma'} \simeq 1.1-3.1$ eV. See their Fig. 11 for mass-dependent limits.

35 THOMAS 22 improved KRIBS 19 by taking account of the changes in the parton distribution functions due to the inclusion of hidden photons. The quoted limit is at $m_{\gamma'} \simeq 4$ GeV. Limits in the range of $3 \times 10^{-2}-9 \times 10^{-2}$ are obtained for $m_{\gamma'} = 1-80$ GeV. See their Fig. 1 for the limits.

36 TUMASYAN 22AH look for exotic decays of the SM-like Higgs boson, $H \to Z\gamma' \to 4\ell$, 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, $H \to \gamma'/\gamma'(\gamma' \to \mu^+\mu^-)$, and set limits on the branching fraction product. See their Fig. 7 for mass- and 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 $\rho_{\gamma'} \lesssim 5$ GeV/cm$^3$ for $m_{\gamma'} \lesssim 10^{-23}$ eV at 95% CL.

39 ANDREEV 21 is analogous to BANERJEE 18A. The quoted limit applies to $m_{\gamma'} = 1$ 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 $m_{\gamma'} = 0.23$ GeV, assuming the fermion dark matter of mass $m_{\gamma'}/3$ and the hidden gauge coupling $\alpha_D = 0.1$. 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 ASy and HAWC experiments, together with MAGIC and HEGRA gamma-ray data. See their Fig. 4 for mass-dependent limits.

42 CAZZANIGA 21 look for semi-visible decays of hidden photons, $\gamma' \to \chi_1\chi_2(\chi_2 \to \chi_1 e^+e^-)$, where $\chi_1$ and $\chi_2$ are hidden fermions. They exclude $3 \times 10^{-5} \lesssim \chi \lesssim 2 \times 10^{-2}$ assuming the hidden gauge coupling $\alpha_D = 0.1$, and the fermion masses $m_{\chi_1} = m_{\gamma'}/3$, $(m_{\chi_2} - m_{\chi_1})/m_{\chi_1} = 0.4$. See their Fig. 4 for mass-dependent limits.

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 $\rho_{\gamma'} = 0.4$ GeV/cm$^3$ 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 $m_{\gamma'} \simeq 3$ μeV. See their Fig. 1 for mass-dependent limits.

45 GODFREY 21 look for hidden photon dark matter by using a wideband antenna, and set 5σ limits on $\chi$. The local density $\rho_{\gamma'} = 0.38$ GeV/cm$^3$ is assumed. See their updated Fig. 12 in arXiv:2101.02805v4 for mass-dependent limits in the range of $m_{\gamma'} = 0.207-1.24$ μeV.

46 KOPYLOV 21A is an update of KOPYLOV 19, but use Ne gas instead of Ar. The quoted limit applies to $m_{\gamma'} = 12$ eV. See their Fig. 4 for mass-dependent limits.

47 KRIBS 21 used the HERA data on neutral current deep inelastic ep 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 data on the search for $\gamma' \to e^+e^-$. See their Fig. 5 for the mass-dependent limits for various 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 of additional production channels from proton bremsstrahlung and $\eta$ meson decays, respectively. Limits between $3 \times 10^{-8}$ and $1 \times 10^{-4}$ are obtained for $0.01 < m_{\gamma'} < 0.8$ GeV (see their Fig. 1).

50 AAIJ 20C look for hidden photons produced from the pp collision in the decay channel $\gamma' \to \mu^+\mu^-$. For prompt decaying hidden photons, limits at the level of $10^{-4}-10^{-3}$ are obtained for $m_{\gamma'} = 0.214-30$ GeV. See their Fig. 2 for mass-dependent limits.

51 AAIJ 20C look for hidden photons produced from the pp collision in the decay channel $\gamma' \to \mu^+\mu^-$. For hidden photons with lifetimes of order ps, limits at the level of $10^{-5}$ are obtained for $m_{\gamma'} = 218-315$ MeV. See their Fig. 4 for mass-dependent limits.

52 ABLIKIM 20AB search for $J/\psi \to \eta'\gamma'(\gamma' \to \gamma\pi^0)$, 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 $m_{\gamma'} = 150$ keV. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. Their limits in their Fig. 3 were 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 $m_{\gamma'} \simeq 17$ eV. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. See their Fig. 3 for mass-dependent limits.

55 AN 20 updates the direct detection limit of AN 13c on solar flux of hidden photons; $\chi < 1.6 \times 10^{-12}$ (eV/$m_{\gamma'}$) for $m_{\gamma'} < 6$ eV (90% C.L.). For $m_{\gamma'} > 6$ eV, see their Fig. 1 for mass-dependent limits.

56 ANDRIANAVALOMAHEFA 20 is analogous to SUZUKI 15, but uses a mirror that is about one order of magnitude larger than in similar studies in the past. Limits at the level of $10^{-12}$ are obtained for $m_{\gamma'} = 2.5-7$ eV. See their Fig.23 and Table III for mass-dependent limits.

57 APRILE 20 is analogous to ABE 14F, and set limits $\chi \lesssim 10^{-16}-10^{-12}$. The quoted limit applies to $m_{\gamma'} = 1$ keV. They also found an excess over known backgrounds, which favors the mass $m_{\gamma'} = 2.3 \pm 0.2$ keV with a $3 \sigma$ significance. See their Fig. 10 for mass-dependent limits.

58 ARALIS 20 is analogous to ABE 14F. The quoted limit applies to $m_{\gamma'} = 0.1$ keV. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. The limits at masses above 3 keV in their Fig. 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 lifetime of $\tau_c = 0.1$ 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 $m_{\gamma'} \simeq 9$ eV. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. See their Fig. 3 for mass-dependent limits.

61 BANERJEE 20 is an update of BANERJEE 18. They exclude $8.2 \times 10^{-5} \lesssim \chi \lesssim 1 \times 10^{-2}$ for $m_{\gamma'} = 1.5-24$ MeV. In particular, they exclude $\chi = 1.2 \times 10^{-4}-6.8 \times 10^{-4}$ 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 $m_{\gamma'} = 12.8$ eV. See their Fig. 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 or axial-vector interactions.

64 SHE 20 look for solar hidden photons. The quoted limit applies to $m_{\gamma'} = 180$ eV. See their Fig. 4 for mass-dependent limits.

65 SHE 20 look for hidden photon dark matter and set limits $\chi < 1.3 \times 10^{-15}-2.8 \times 10^{-14}$ for the quoted mass range. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. See their Fig. 6 for mass-dependent limits.

66 SIRUNYAN 20AQ look for a narrow resonance decaying into a pair of muons. For $m_{\gamma'} < 45$ GeV, they use dedicated high-rate dimuon triggers to reduce the muon transverse momentum thresholds. The quoted limit applies to $m_{\gamma'} = 50$ GeV, and limits of order $10^{-3}$ 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 $\chi < 1.8-4.3 \times 10^{-10}$ for the quoted mass range. The local density $\rho_{\gamma'} = 0.39$ GeV/cm$^3$ is assumed. See their Fig. 7 for mass-dependent limits.

68 WANG 20A is analogous to ABE 14F. The quoted limit applies to $m_{\gamma'} = 185$ eV. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. See their Fig. 11 for mass-dependent limits.

69 AABOUD 19G look for $h \to \gamma'/\gamma'(\gamma' \to \mu^+\mu^-)$ and exclude a kinetic mixing around $10^{-9}-10^{-8}$ for B($h \to \gamma'/\gamma'$) = 0.01 and 0.1. See their Fig. 9 for mass-dependent limits.

70 ABLIKIM 19A look for $J/\psi \to \gamma'/\eta(\gamma' \to e^+e^-)$. Limits between $6 \times 10^{-3}$ and $5 \times 10^{-2}$ are obtained (see their Fig. 8).

71 ABLIKIM 19H look for $J/\psi \to \gamma'/\eta'(\gamma' \to e^+e^-)$. Limits between $3.4 \times 10^{-3}$ and $2.6 \times 10^{-2}$ are obtained. See their Fig. 5 for mass-dependent limits.

72 AGUILAR-AREVALO 19A look for the absorption signal of hidden photon dark matter by using a CCD. The quoted limit applies to $m_{\gamma'} = 17$ eV. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. See their Fig. 4 for mass-dependent limits.

73 APRILE 19d is analogous to ABE 14F. The quoted limit applies to $m_{\gamma'} = 0.7$ keV. See their Fig. 5(f) for mass-dependent limits.

74 BANERJEE 19 is an update of BANERJEE 18A. The quoted limit is at $m_{\gamma'} = 1$ MeV. See their Fig. 3 for mass-dependent limits.
<footnote n="75">75 BHOONAH 19 examine heating of Galactic Center gas clouds by hidden photon dark matter. The quoted limit applies to $m_{\gamma'} \simeq 10^{-12}$ eV. See their Fig. 2 for mass-dependent limits.</footnote>

<footnote n="76">76 BRUN 19 is analogous to SUZUKI 15. The limit is derived under an assumption that hidden photons constitute the local dark matter density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$.</footnote>

<footnote n="77">77 CORTINA-GIL 19 look for an invisible hidden photon in the reaction $K^+ \to \pi^+\pi^0$ ($\pi^0 \to \gamma\gamma'$). The quoted limit applies to $m_{\gamma'} = 62.5-65$ MeV. See their Figs. 6 and 7 for mass-dependent limits.</footnote>

<footnote n="78">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 weaker for $m_{\gamma'}$ less than the effective photon mass in proportion to $1/m_{\gamma'}^2$. See their Fig. 1 for mass-dependent limits.</footnote>

<footnote n="79">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 $m_{\gamma'} \simeq 1$ eV. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="80">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 $m_{\gamma'} = 12$ eV. See their Fig. 7 for mass-dependent limits.</footnote>

<footnote n="81">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 $T_{21} > -100$ mK. The quoted limit applies to $m_{\gamma'} \simeq 2 \times 10^{-14}$ eV. See their Fig. 3 for mass-dependent limits.</footnote>

<footnote n="82">82 NGUYEN 19 look for hidden photon dark matter with a resonant cavity, and set limits $\sim 10^{-12}$ for $m_{\gamma'} = 0.2-2.07\mu eV$. The quoted limit applies to $m_{\gamma'} = 1.3\mu eV$. The local density $\rho_{\gamma'} = 0.3$ GeV/cm$^3$ is assumed. See their Fig. 19 for mass-dependent limits.</footnote>

<footnote n="83">83 ABE 18f is an update of ABE 14f. The quoted limit applies to $m_{\gamma'} \simeq 40$ keV. See their Fig. 5 for mass-dependent limits.</footnote>

<footnote n="84">84 ADRIAN 18 look for a hidden photon resonance in the reaction $e^-Z \to e^-Z\gamma'$ ($\gamma' \to e^+e^-$). The quoted limit applies to $m_{\gamma'} = 40$ MeV. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="85">85 ANASTASI 18B look for a hidden photon resonance in the reaction $e^+e^- \to \gamma'\gamma'$ ($\gamma' \to \mu^+\mu^-$). The quoted limit is obtained by combining the result of ANASTASI 16 and it applies to $m_{\gamma'} \simeq 519-987$ MeV. See their Fig. 9 for mass-dependent limits.</footnote>

<footnote n="86">86 ARMENGAUD 18 is analogous to ABE 14f. The quoted limits applies to $m_{\gamma'} = 1.6$ keV. See their right panel of Fig. 5 for mass-dependent limits.</footnote>

<footnote n="87">87 BANERJEE 18 look for hidden photons produced in the reaction $e^-Z \to e^-Z\gamma'$ ($\gamma' \to e^+e^-$), and exclude $9.2 \times 10^{-5} \lesssim \chi \lesssim 1 \times 10^{-2}$ for $m_{\gamma'} = 1-23$ MeV. They also set a 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.</footnote>

<footnote n="88">88 BANERJEE 18A look for invisible decays of hidden photons produced in the reaction $e^-Z \to e^-Z\gamma'$. The quoted limit is at $m_{\gamma'} = 1$ MeV. See their Fig. 15 for mass-dependent limits.</footnote>

<footnote n="89">89 KNIRCK 18 is analogous to SUZUKI 15. See their Fig. 5 for mass-dependent limits.</footnote>

<footnote n="90">90 AGBRALL 17 is analogous to ABE 14F using the MAJORANA DEMONSTRATOR. See their Fig. 3 for limits between 6 keV $< m_{\gamma'} < 97$ keV.</footnote>

<footnote n="91">91 ABLIKIM 17A look for $e^+e^- \to \gamma'\gamma'$ ($\gamma' \to e^+e^-$ or $\mu^+\mu^-$). Limits between $10^{-3}$ and $10^{-4}$ are obtained (see their Fig. 3).</footnote>

<footnote n="92">92 ANGLOHER 17 is analogous to ABE 14F. The quoted limit is at $m_{\gamma'} = 0.7$ keV. See their Fig. 8 for mass-dependent limits.</footnote>

<footnote n="93">93 BANERJEE 17 look for invisible decays of hidden photons produced in the reaction $e^-Z \to e^-Z\gamma'$. The quoted limit applies to $m_{\gamma'} = 2$ MeV. See their Fig. 3 for mass-dependent limits.</footnote>

<footnote n="94">94 CHANG 17 examine the hidden photon emission from SN1987A, including the effects of finite temperature and density on $\chi$ and obtain limits $\chi(m_{\gamma'}/\text{MeV}) \lesssim 3 \times 10^{-9}$ for $m_{\gamma'} < 15$ MeV and $\chi \lesssim 10^{-9}$ for $m_{\gamma'} = 15-120$ MeV.</footnote>

<footnote n="95">95 DUBININA 17 look for $\mu^+ \to e^+\nu_\mu\nu e^-$ ($\gamma' \to e^+e^-$) in a nuclear photoemulsion. The quoted limit applies to $m_{\gamma'} = 1.1$ MeV. Limits between $4.5 \times 10^{-3}$ and $10^{-2}$ are obtained (see their Fig. 3).</footnote>

<footnote n="96">96 LEES 17E look for invisible decays of hidden photons produced in the reaction $e^+e^- \to \gamma\gamma'$. See their Fig. 5 for limits in the mass range $m_{\gamma'} \le 8$ GeV.</footnote>

<footnote n="97">97 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.</footnote>

<footnote n="98">98 ANASTASI 16 look for the decay $\gamma' \to \pi^+\pi^-$ in the reaction $e^+e^- \to \gamma\gamma'$. Limits between $4.3 \times 10^{-3}$ and $4.4 \times 10^{-4}$ are obtained for $527 < m_{\gamma'} < 987$ MeV (see their Fig. 9).</footnote>

<footnote n="99">99 KHACHATRYAN 16 look for $\gamma' \to \mu^+\mu^-$ in a dark SUSY scenario where the SM-like Higgs boson decays into a pair of the visible lightest neutralinos with mass 10 GeV, both of which decay into $\gamma'$ and a hidden neutralino with mass 1 GeV. See the right panel in their Fig. 2.</footnote>

<footnote n="100">100 AAD 15CD look for $H \to Z\gamma' \to 4\ell$ with the ATLAS detector at LHC and find $\chi < 4-17 \times 10^{-2}$ for $m_{\gamma'} = 15-55$ GeV. See their Fig. 6.</footnote>

<footnote n="101">101 ADARE 15 look for a hidden photon in $\pi^0$, $\eta^0 \to \gamma e^+e^-$ at the PHENIX experiment. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="102">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 $\chi < 1.3 \times 10^{-15}$ at $m_{\gamma'} = 18$ eV. See their Fig. 1 for mass-dependent limits.</footnote>

<footnote n="103">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 muons and the hidden Higgs boson lighter than $m_{\gamma'}$ escape detection. See their Figs. 6 and 7 for mass-dependent limits on a product of the hidden fine structure constant and the kinetic mixing.</footnote>

<footnote n="104">104 ANASTASI 15A look for the decay $\gamma' \to e^+e^-$ in the reaction $e^+e^- \to e^+e^-\gamma$. Limits between $1.7 \times 10^{-3}$ and $1 \times 10^{-2}$ are obtained for $m_{\gamma'} = 5-320$ MeV (see their Fig. 7).</footnote>

<footnote n="105">105 BATLEY 15A look for $\pi^0 \to \gamma\gamma'$ ($\gamma' \to e^+e^-$) at the NA48/2 experiment. Limits between $4.2 \times 10^{-4}$ and $8.8 \times 10^{-3}$ are obtained for $m_{\gamma'} = 9-120$ MeV (see their Fig. 4).</footnote>

<footnote n="106">106 JAEGLE 15 look for the decay $\gamma' \to e^+e^-, \mu^+\mu^-, \text{ or } \pi^+\pi^-$ in the dark Higgstrahlung channel, $e^+e^- \to \gamma'\gamma' (H' \to \gamma'/\gamma')$ 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 the hidden fine structure constant and the kinetic mixing. See their Figs. 3 and 4.</footnote>

<footnote n="107">107 KAZANAS 15 set limits by studying the decay of hidden photons $\gamma' \to e^+e^-$ inside and near the progenitor star of SN1987A. See their Fig. 6 for mass-dependent limits.</footnote>

<footnote n="108">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 $\chi < 6 \times 10^{-12}$ for $m_{\gamma'} = 1.9-4.3$ eV. See their Fig. 7 for mass-dependent limits.</footnote>

<footnote n="109">109 VINYoles 15 performed a global fit analysis based on helioseismology and solar neutrino observations, and set the limits $\chi m_{\gamma'} < 1.8 \times 10^{-12}$ eV for $m_{\gamma'} = 3 \times 10^{-5}-8$ eV. See their Fig. 11.</footnote>

<footnote n="110">110 ABE 14F look for the photoelectric-like interaction in the XMASS detector assuming the hidden photon constitutes all the local dark matter. Limits between $2 \times 10^{-13}$ and $1 \times 10^{-12}$ are obtained, where the relation $\chi^2 = \alpha'^2/\alpha$ is used to translate the original bound on the ratio of the hidden and EM fine-structure constants. See their Fig. 3 for mass-dependent limits.</footnote>

<footnote n="111">111 AGAKISHIEV 14 look for hidden photons $\gamma' \to e^+e^-$ at the HADES experiment, and set limits on $\chi$ for $m_{\gamma'} = 0.02-0.6$ GeV. See their Fig. 5 for mass-dependent limits.</footnote>

<footnote n="112">112 BABUSCI 14 look for the decay $\gamma' \to \mu^+\mu^-$ in the reaction $e^+e^- \to \mu^+\mu^-\gamma$. Limits between $4 \times 10^{-3}$ and $9.0 \times 10^{-4}$ are obtained for 520 MeV $< m_{\gamma'} < 980$ MeV (see their Fig. 7).</footnote>

<footnote n="113">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 the decay of the hidden photon. Limits at the level of $10^{-4}-10^{-1}$ are obtained for $m_{\gamma'} = 10^{-3}-1$ GeV, depending on the dark matter mass and the hidden gauge coupling (see their Fig. 2).</footnote>

<footnote n="114">114 BLUEMLEIN 14 analyzed the beam dump data taken at the U-70 accelerator to look for $\gamma'$-bremsstrahlung and the subsequent decay into muon pairs and hadrons. See their Fig. 4 for mass-dependent excluded region.</footnote>

<footnote n="115">115 FRADETTE 14 studied effects of decay of relic mixing photons from BBN and CMB to set constraints on very small values of the kinetic mixing. See their Figs. 4 and 7 for mass-dependent excluded regions.</footnote>

<footnote n="116">116 LEES 14J look for hidden photons in the reaction $e^+e^- \to \gamma\gamma' (\gamma' \to e^+e^-, \mu^+\mu^-)$. Limits at the level of $10^{-4}-10^{-3}$ are obtained for 0.02 GeV $< m_{\gamma'} < 10.2$ GeV. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="117">117 MERKEL 14 look for $\gamma' \to e^+e^-$ at the A1 experiment at the Mainz Microtron (MAMI). See their Fig. 3 for mass-dependent limits.</footnote>

<footnote n="118">118 AN 13b examined the stellar production of hidden photons, correcting an important error of the production rate of the longitudinal mode which now dominates. See their Fig. 2 for mass-dependent limits based on solar energy loss.</footnote>

<footnote n="119">119 AN 13c use the solar flux of hidden photons to set a limit on the atomic ionization rate in the XENON10 experiment. They find $\chi m_{\gamma'} < 3 \times 10^{-12}$ eV for $m_{\gamma'} < 1$ eV. See their Fig. 2 for mass-dependent limits.</footnote>

<footnote n="120">120 DIAMOND 13 analyzed the beam dump data taken at the SLAC millil charge experiment to constrain a hidden photon invisibly decaying into lighter long-lived particles, which undergo elastic scattering off nuclei in the detector. Limits between $8 \times 10^{-4}-2 \times 10^{-2}$ are obtained. The quoted limit is applied when the dark gauge coupling is set equal to the electromagnetic coupling. See their Fig.4 for mass-dependent limits.</footnote>

<footnote n="121">121 GINENENKO 13 used the data taken at the SINDRUM experiment to constrain the decay, $\pi^0 \to \gamma\gamma' (\gamma' \to e^+e^-)$ to derive limits. See their Fig. 2 for their mass-dependent excluded region.</footnote>

<footnote n="122">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.</footnote>

<footnote n="123">123 INADA 13 search for hidden photons using an intense X-ray beamline at SPring-8. See their Fig. 4 for mass-dependent limits.</footnote>

<footnote n="124">124 MIZUMOTO 13 look for solar hidden photons. See their Fig.5 for mass-dependent limits.</footnote>

<footnote n="125">125 PARKER 13 look for hidden photons using a cryogenic resonant microwave cavity. See their Fig.5 for mass-dependent limits.</footnote>

<footnote n="126">126 PARKER 13 derived a limit for the hidden photon CDM with a randomly oriented hidden photon field.</footnote>

<footnote n="127">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 the currently best limits from other arguments.</footnote>

<footnote n="128">128 GINENENKO 12A obtained bounds on $B(\pi^0 \to \gamma\gamma') \cdot B(\gamma' \to e^+e^-)$ from the NOMAD and PS191 neutrino experiments, and derived limits between $8 \times 10^{-8}-2 \times 10^{-4}$. See their Fig.4 for mass-dependent excluded regions.</footnote>

<footnote n="129">129 GINENENKO 12B used the data taken at the CHARM experiment to constrain the decay, $\eta(\eta') \to \gamma\gamma' (\gamma' \to e^+e^-)$, and derived limits between $1 \times 10^{-7}-1 \times 10^{-4}$. See their Fig.4 for mass-dependent excluded region.</footnote>

<footnote n="130">130 ABRAHAMYAN 11 look for $\gamma' \to e^+e^-$ in the electron-nucleon fixed-target experiment at the Jefferson Laboratory (APEX). See their Fig. 5 for mass-dependent limits.</footnote>

<footnote n="131">131 BLUEMELIN 11 analyzed the beam dump data taken at the U-70 accelerator to look for $\pi^0 \to \gamma\gamma' (\gamma' \to e^+e^-)$. See their Fig. 5 for mass-dependent limits.</footnote>

<footnote n="132">132 BJORKEN 09 analyzed the beam dump data taken at E137, E141, and E774 to constrain a hidden photon produced by bremsstrahlung, subsequently decaying into $e^+e^-$, and</footnote>
derived 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 $\gamma'$ emission from the core of SN1987A not to exceed $10^{53}$ erg/s, and the energy limits between $5 \times 10^{-9}$ and $2 \times 10^{-6}$. See their Fig. 1 for mass-dependent excluded region.

REFERENCES FOR Searches for Axions (A⁰) and Other Very Light Bosons

<table><thead><tr><th></th><th></th><th></th><th></th></tr></thead><tbody><tr><td>ABREU</td><td>24</td><td>PL B848 13878</td><td>H. Abreu et al. (FASER Collab.)</td></tr><tr><td>ELLA</td><td>24</td><td>PL B23001</td><td>A. Nella et al. (BARI, STOH, INFN+, IITF)</td></tr><tr><td>PANT</td><td>24</td><td>PR D109 023011</td><td>B.P. Pant</td></tr><tr><td>AAD</td><td>23B0</td><td>PR L13 251801</td><td>G. Aad et al. (ATLAS Collab.)</td></tr><tr><td>AAD</td><td>23</td><td>PR L13 221802</td><td>G. Aad et al. (ATLAS Collab.)</td></tr><tr><td>AAD</td><td>23T</td><td>JHEP 2306 153</td><td>G. Aad et al. (ATLAS Collab.)</td></tr><tr><td>AALBERS</td><td>23A</td><td>PR D108 072006</td><td>J. Albers et al. (LZ Collab.)</td></tr><tr><td>ABLIKIM</td><td>23A</td><td>PR B839 137785</td><td>(BESIII Collab.)</td></tr><tr><td>ABLIKIM</td><td>23E</td><td>PL B838 137698</td><td>M. Ablikim et al. (BESIII Collab.)</td></tr><tr><td>ABUDINEN</td><td>23B</td><td>PR L130 071804</td><td>F. Abudinen et al. (BELLE II Collab.)</td></tr><tr><td>ACCIARRI</td><td>23B</td><td>PR L130 221802</td><td>R. Acciarri et al. (ArgoNeut Collab.)</td></tr><tr><td>ADACHI</td><td>23A</td><td>PR L130 180183</td><td>I. Adachi et al. (BELLE II Collab.)</td></tr><tr><td>ADACHI</td><td>23A</td><td>PR L130 043017</td><td>(POLARBEAR Collab.)</td></tr><tr><td>ADACHI</td><td>23K</td><td>PR D108 111104</td><td>(BELLE II Collab.)</td></tr><tr><td>ADHIKARI</td><td>23A</td><td>PR D107 122004</td><td>G. Adhikari et al. (COSINE-100 Collab.)</td></tr><tr><td>ADHIKARI</td><td>23A</td><td>PR D108 041301</td><td>G. Adhikari et al. (COSINE-100 Collab.)</td></tr><tr><td>ADRIAN</td><td>23</td><td>PR D108 012015</td><td>P.H. Adrian et al. (HPS Collab.)</td></tr><tr><td>AGNES</td><td>23A</td><td>PR L130 101002</td><td>P. Agnes et al. (DarkSide-50 Collab.)</td></tr><tr><td>ANDREEV</td><td>23B</td><td>PR L131 161801</td><td>Yu.M. Andreev et al. (NA64 Collab.)</td></tr><tr><td>APRILE</td><td>23B</td><td>PR D108 072015</td><td>E. Aprile et al. (XENON Collab.)</td></tr><tr><td>AYRES</td><td>23</td><td>NJP 25 103012</td><td>N.J. Ayres et al. (CUPID-0 Collab.)</td></tr><tr><td>AZZOLINI</td><td>23</td><td>PR D107 032006</td><td>O. Azzolini et al. (CUPID-0 Collab.)</td></tr><tr><td>BAJALI</td><td>23</td><td>PL B308 077</td><td>F. Bajali et al. (BRASS Collab.)</td></tr><tr><td>BATTEY</td><td>23</td><td>PR D108 063001</td><td>R. Battye et al. (BRASS Collab.)</td></tr><tr><td>BEAUFORT</td><td>23</td><td>PR D108 061302</td><td>C. Beaufort et al. (JHU, TELA, REHO+)</td></tr><tr><td>BERNAL</td><td>23</td><td>PR L107 103406</td><td>J.L. Bernal et al. (JHU, TELA, REHO+)</td></tr><tr><td>BERTUZZO</td><td>23</td><td>PR L130 171801</td><td>E. Bertuzzo et al. (SPaul)</td></tr><tr><td>BOZZI</td><td>23</td><td>PR D103 02060</td><td>F. Capozzi et al. (SPaul)</td></tr><tr><td>CAPOZZI</td><td>23A</td><td>PR D108 075019</td><td>F. Capozzi et al. (SPaul)</td></tr><tr><td>CHENG</td><td>23A</td><td>PR D107 063021</td><td>L.-d. Cheng, H. Zhang, S.-s. Bao (SHDNQ)</td></tr><tr><td>CORTINA-GIL</td><td>23B</td><td>PL B846 138193</td><td>E. Cortina-Gil et al. (NA62 Collab.)</td></tr><tr><td>CORTINA-GIL</td><td>23C</td><td>JHEP 2309 035</td><td>E. Cortina-Gil et al. (NA62 Collab.)</td></tr><tr><td>DAVIES</td><td>23</td><td>PR D107 063027</td><td>J. Davies, M. Meyer, G. Cotter (OXF, HAMB)</td></tr><tr><td>DALLA-MON...</td><td>23</td><td>PR D108 0211303</td><td>R. Della Monica, I. de Martino (JHU, TELA, REHO+)</td></tr><tr><td>DERBIN</td><td>23</td><td>JETPL 118 06</td><td>A.V. Derbin et al. (PNI)</td></tr><tr><td>DIAMOND</td><td>23</td><td>PR D108 049902</td><td>M. Diamond et al. (SPaul)</td></tr><tr><td>DIVORA</td><td>23</td><td>PR D108 062602</td><td>R. Di Vora et al. (QUAX Collab.)</td></tr><tr><td>FILZINGER</td><td>23</td><td>PR L130 253001</td><td>M. Filzinger et al. (SPaul)</td></tr><tr><td>FIORELLO</td><td>23</td><td>JHEP 2301 021001</td><td>D. FioRELLO, G.G. Raffelt, E. Vitagliano (NBI+)</td></tr><tr><td>FIORILO</td><td>23</td><td>JHEP 2311 0270</td><td>A. Hayrapetyan et al. (CMS Collab.)</td></tr><tr><td>HOOF</td><td>23</td><td>JCAP 2303 054</td><td>S. Hoof, L. Schulz (KIT, GOET)</td></tr><tr><td>JACOBSEN</td><td>23</td><td>JCAP 2309 009</td><td>S. Jacobsen, T. Linden, K. Freese (STOH, TEXA+)</td></tr><tr><td>JEWELL</td><td>23</td><td>PR D107 072007</td><td>M.J. Jewell et al. (HAYSTAC Collab.)</td></tr><tr><td>KARANTH</td><td>23</td><td>PR L130 031004</td><td>S. Karanth et al. (JEDI Collab.)</td></tr><tr><td>KIM</td><td>23</td><td>PR L130 091602</td><td>J. Kim et al. (KAIST, RIKEN, TOKY)</td></tr><tr><td>KOTAKA</td><td>23</td><td>PR L130 071805</td><td>S. Kotaka et al. (DOSUE-RR Collab.)</td></tr><tr><td>LEE</td><td>23</td><td>PR L13 011050</td><td>J. Lee et al. (ASTAR, PRIN)</td></tr><tr><td>LI</td><td>23H</td><td>JCAP 2307 063</td><td>H.-J. Li, W. Chao (BNORM)</td></tr><tr><td>LI</td><td>23H</td><td>JCAP 2309 009</td><td>S.-P. Li, X.-J. Xu (BHEP)</td></tr><tr><td>NOORDHUIS</td><td>23</td><td>PR L131 111004</td><td>D. Noordhuis et al. (AMST, PRIN, STAR+)</td></tr><tr><td>NOTARI</td><td>23</td><td>PR L131 011004</td><td>A. Notari, F. Rompineve, G. Villadoro (ICCUB+)</td></tr><tr><td>OSHIHA</td><td>23</td><td>PR D108 072005</td><td>Y. Oshima et al. (DANCE Collab.) (IITF)</td></tr><tr><td>PANT</td><td>23</td><td>PR D108 023016</td><td>B.P. Pant et al. (IITF)</td></tr><tr><td>PODDAR</td><td>23</td><td>PR D108 103024</td><td>T.K. Poddar, D. Pachhar (IITF)</td></tr><tr><td>RAMANATH...</td><td>23</td><td>PR L130 231001</td><td>K. Ramanan et al. (CIT, JPL)</td></tr><tr><td>ROGERS</td><td>23</td><td>JCAP 2306 023</td><td>K.K. Rogers et al. (JPL)</td></tr><tr><td>ROMANENKO</td><td>23</td><td>JCAP 2306 1281</td><td>A. Romanenko et al. (FNAL)</td></tr><tr><td>SANDNER</td><td>23</td><td>NEP J83 409</td><td>S. Sandner, M. Escudero, S.J. Witte (VALE, CERN+)</td></tr><tr><td>SHERRILL</td><td>23</td><td>JPJ 25 093012</td><td>N. Sherrill et al. (SUSS, NPLT)</td></tr><tr><td>SHERRILL</td><td>23</td><td>PR L130 043031</td><td>C. Sherrill et al. (JEDI Collab.)</td></tr><tr><td>SULAI</td><td>23</td><td>PR D108 096206</td><td>S. Sulai et al. (SNiPE Hunt Collab.)</td></tr><tr><td>THOMSON</td><td>23</td><td>PR D108 112003</td><td>C. A. Thomson et al. (UPLOAD Collab.)</td></tr><tr><td>WADEKAER</td><td>23</td><td>PR D107 083011</td><td>D. Wadekar, Z. Wang (IAS, NYU)</td></tr><tr><td>XIA</td><td>23</td><td>PR L107 121302</td><td>D.-Q. Xia et al. (CAPP18T Collab.)</td></tr><tr><td>XIA</td><td>23</td><td>PR L131 081901</td><td>B. Yang et al. (CAPP18T Collab.)</td></tr><tr><td>YANG</td><td>23</td><td>PR L130 043031</td><td>R.-M. Yao et al. (CAPP18T Collab.)</td></tr><tr><td>YI</td><td>23</td><td>PR L130 071002</td><td>A.K. Yi et al. (CAPP18T Collab.)</td></tr><tr><td>YI</td><td>23A</td><td>PR L108 2012304</td><td>A.K. Yi et al. (CAPP18T Collab.)</td></tr><tr><td>ZHANG</td><td>23</td><td>PR L130 201401</td><td>S.-B. Zhang et al. (CST)</td></tr><tr><td>ZHANG</td><td>23A</td><td>PR L130 250102</td><td>X. Zhang et al. (MAINZ, REHO, UCB+, ATCAS, UCB)</td></tr><tr><td>ZHANG</td><td>23A</td><td>PR L130 20243</td><td>G. Zhang et al. (ATLAS Collab.)</td></tr><tr><td>AAD</td><td>22S</td><td>JP E8 125</td><td>A. Aad et al. (ATLAS Collab.)</td></tr><tr><td>ADE</td><td>22C</td><td>PR D105 022006</td><td>P.A.R. Ade et al. (BICEP/Keck Collab.)</td></tr><tr><td>ADHIKARI</td><td>22</td><td>PR D105 052007</td><td>S. Adhikari et al. (GLUEX Collab.)</td></tr><tr><td>AGOSTINI</td><td>22A</td><td>JCAP 2212 012</td><td>M. Agostini et al. (GERDA Collab.)</td></tr><tr><td>AGOSTINI</td><td>22A</td><td>PR L130 072001</td><td>S. Karanth et al. (JEDI Collab.)</td></tr><tr><td>ALESINI</td><td>22A</td><td>PR D108 052007</td><td>D. Alesini et al. (QUAX Collab.)</td></tr><tr><td>APRILE</td><td>22</td><td>PR D106 022001</td><td>E. Aprile et al. (XENON1 Collab.)</td></tr><tr><td>APRILE</td><td>22B</td><td>PR L129 168105</td><td>E. Aprile et al. (XENON1 Collab.)</td></tr><tr><td>ARNQUIST</td><td>22</td><td>PR L129 081803</td><td>I.J. Arnquist et al. (MAJORANA Collab.)</td></tr><tr><td>ARZA</td><td>22</td><td>PR L106 095007</td><td>A. Arza et al. (ITEP, JHU, STAN, CSEB)</td></tr><tr><td>BATTAGLIERI</td><td>22</td><td>PR D105 072001</td><td>A. BATTAGLIERI (BDX-MINI Collab.)</td></tr><tr><td>BATTEY</td><td>22</td><td>PR D105 1203150</td><td>R.A. Battye et al. (JHU, G. Sato-Polito, M. Kamionkowski)</td></tr><tr><td>BERNAL</td><td>22</td><td>PR L129 233101</td><td>J.L. Bernal, G. Sato-Polito, M. Kamionkowski (JHU)</td></tr><tr><td>BOLTON</td><td>22</td><td>PR L129 211102</td><td>J.S. Bolton et al. (PRIN, MICH, UCB+)</td></tr><tr><td>BUSCHMANN</td><td>22</td><td>PR L128 091102</td><td>M. Busmann et al. (PRIN, MICH, UCB+)</td></tr><tr><td>CAHRE</td><td>22</td><td>PL D108 0563028</td><td>F. Calore et al. (LAPTH, STOH, BARI, WROC+)</td></tr><tr><td>CAPUTO</td><td>22</td><td>PR L128 221103</td><td>A. Caputo et al. (LAPTH, STOH, BARI, WROC+)</td></tr><tr><td>CASTILLO</td><td>22</td><td>JCAP 2206 040</td><td>A. Castillo et al. (ADMX Collab.)</td></tr><tr><td>CERVANTES</td><td>22</td><td>PR L129 201301</td><td>R. Cervantes et al. (ADMX Collab.)</td></tr><tr><td>CHANG</td><td>22</td><td>PR L129 111801</td><td>H. Chang et al. (TASEH Collab.)</td></tr><tr><td>CHILES</td><td>22A</td><td>PR L128 231802</td><td>J. Chiles et al. (TASEH Collab.)</td></tr><tr><td>CHILES</td><td>22A</td><td>PR L128 231802</td><td>CA. Coloma et al. (TASEH Collab.) (IFT, CNYIT, ICC, ICREA+)</td></tr><tr><td>CRESCINI</td><td>22</td><td>PR D105 022007</td><td>N. Crescini et al. (SPT-3G Collab.)</td></tr><tr><td>DEROCO</td><td>22</td><td>PR L129 101101</td><td>W. DeRocco et al. (SPT-3G Collab.)</td></tr><tr><td>DESSERT</td><td>22</td><td>PR L129 071102</td><td>C. Dessert, A.J. Long, B.R. Safdi (MICH, UCB+)</td></tr><tr><td>DESSERT</td><td>22A</td><td>PR D105 103034</td><td>C. Dessert, D. Dunsky, B.R. Safdi (UCB, LBL+)</td></tr><tr><td>DECKNER</td><td>22</td><td>PR D106 083020</td><td>C. Eckner, F. Calore (LAPTH)</td></tr><tr><td>FENG</td><td>22</td><td>PR L128 231803</td><td>Y.-K. Feng et al. (LAPTH)</td></tr><tr><td>FERGUSON</td><td>22</td><td>PR D106 042011</td><td>K.R. Ferguson et al. (JWP, Foster et al.)</td></tr><tr><td>FOSTER</td><td>22</td><td>PR L129 251102</td><td>J.W. Foster et al. (JWP, Foster et al.)</td></tr><tr><td>GAVRILYUK</td><td>22</td><td>JETPL 116 11</td><td>Yu.M. Gavrilyuk et al. (JWP, Foster et al.)</td></tr><tr><td>HOCHBERG</td><td>22</td><td>PR D106 112005</td><td>Y. Hochberg et al. (SNSPD Collab.)</td></tr><tr><td>IKEDA</td><td>22</td><td>PR D105 102004</td><td>T. Ikeda et al. (SNSPD Collab.)</td></tr><tr><td>JIA</td><td>22</td><td>PR L128 081804</td><td>S. Jia et al. (BELLE Collab.)</td></tr><tr><td>KIRITA</td><td>22</td><td>JHEP 2011 176</td><td>Y. Kirita et al. (SAPPHIRES Collab.)</td></tr><tr><td>LAGUE</td><td>22</td><td>JCAP 2201 049</td><td>A. Lague et al. (BELLE Collab.)</td></tr><tr><td>LANGHOFF</td><td>22</td><td>PR L128 241101</td><td>K. Langhoff, N.J. Outmezguine, N.L. Rodd (UCB+)</td></tr><tr><td>LEE</td><td>22</td><td>PR L128 241805</td><td>J. Lee et al. (CAPP18T Collab.)</td></tr><tr><td>LEES</td><td>22</td><td>PR L128 021802</td><td>J.P. Lees et al. (BABAR Collab.)</td></tr></tbody></table>

<table><thead><tr><th></th><th></th><th></th><th></th></tr></thead><tbody><tr><td>LEES</td><td>22B</td><td>PL 128 131802</td><td>J.P. Lees et al. (BABAR Collab.)</td></tr><tr><td>LI</td><td>22</td><td>PL B829 137047</td><td>H.-J. Li (BNIORM)</td></tr><tr><td>LI</td><td>22C</td><td>CP C46 085107</td><td>H.-J. Li, X.-J. Bi, P.-F. Yin</td></tr><tr><td>LU</td><td>22</td><td>PR D105 123017</td><td>G. Lucente et al. (BRIAN Collab.)</td></tr><tr><td>LUENTE</td><td>22</td><td>PR D105 052010</td><td>L. Manenti et al. (MudH Collab.)</td></tr><tr><td>MANENTI</td><td>22</td><td>SADV 8. 27</td><td>A. Manenti et al. (BRIAN Collab.)</td></tr><tr><td>QUIKAMP</td><td>22</td><td>PR L129 191801</td><td>I. Quiskamp et al. (BERN, ILLG)</td></tr><tr><td>SCHULTHESS</td><td>22</td><td>PR D105 031901</td><td>A.W. Thomas, X.G. Wang, A.G. Williams (ADL)</td></tr><tr><td>THOMAS</td><td>22</td><td>PR D105 031901</td><td>A. Tumasyan et al. (CMS Collab.)</td></tr><tr><td>TUMASYAN</td><td>22A</td><td>EPJ C82 290</td><td>A. Tumasyan et al. (CMS Collab.)</td></tr><tr><td>TUMASYAN</td><td>22N</td><td>JHEP 2204 062</td><td>A. Tumasyan et al. (CMS Collab.)</td></tr><tr><td>TUMASYAN</td><td>22R</td><td>JHEP 2204 087</td><td>A. Tumasyan et al. (CMS Collab.)</td></tr><tr><td>WANG</td><td>22C</td><td>PR L129 051801</td><td>Y. Wang et al. (PPTA Collab.)</td></tr><tr><td>WU</td><td>22A</td><td>PR D106 081101</td><td>Y.M. Wu et al. (PPTA Collab.)</td></tr><tr><td>XIAO</td><td>22</td><td>PR D106 221309</td><td>M. Xiao et al. (PPTA Collab.)</td></tr><tr><td>YOON</td><td>22</td><td>PR D106 092007</td><td>H. Yoon et al. (PPTA Collab.)</td></tr><tr><td>YUAN</td><td>22A</td><td>PR D106 023020</td><td>C. Yuan, Y. Jiang, Q.-G. Huang (BRIAN Collab.)</td></tr><tr><td>ZHU</td><td>22</td><td>PR D106 083006</td><td>Y.-F. Zhou et al. (MeerKAT-Axion Collab.)</td></tr><tr><td>AAD</td><td>21F</td><td>JHEP 2111 050 (errat.)</td><td>G. Aad et al. (ATLAS Collab.)</td></tr><tr><td>AAD</td><td>21K</td><td>JHEP 2102 226</td><td>G. Aad et al. (ATLAS Collab.)</td></tr><tr><td>AAD</td><td>21N</td><td>JHEP 2103 243</td><td>G. Aad et al. (ATLAS Collab.)</td></tr><tr><td>Also</td><td></td><td>JHEP 2111 050 (errat.)</td><td>G. Aad et al. (ATLAS Collab.)</td></tr><tr><td>ABRATENKO</td><td>21</td><td>PR L127 151803</td><td>P. Abratenko et al. (MicBooNE Collab.)</td></tr><tr><td>ADE</td><td>21</td><td>PR D103 042002</td><td>P.A.R. Abad et al. (BICEP Collab.)</td></tr><tr><td>AFACH</td><td>21</td><td>NAPT 17 1396</td><td>A. Afach et al. (GNOME Collab.)</td></tr><tr><td>AGUILAR-AR...</td><td>21A</td><td>PR D103 052006</td><td>A. Aguilar-Arevalo et al. (PIENU Collab.)</td></tr><tr><td>ALESINI</td><td>21</td><td>PR D103 102004</td><td>D. Alesini et al. (QUAX Collab.)</td></tr><tr><td>AL-KHARUSI</td><td>21</td><td>PR D104 112002</td><td>S. Al Kharusi et al. (EXO-200 Collab.)</td></tr><tr><td>ANDREEV</td><td>21</td><td>PR L126 211802</td><td>Yu.M. Andreev et al. (NA64 Collab.)</td></tr><tr><td>ANDREEV</td><td>21A</td><td>PR D104 091701</td><td>Yu.M. Andreev et al. (NA64 Collab.)</td></tr><tr><td>ANDREEV</td><td>21B</td><td>PR D104 111102</td><td>Yu.M. Andreev et al. (NA64 Collab.)</td></tr><tr><td>ARALIS</td><td>21</td><td>PR D103 039901 (errat.)</td><td>T. Aralis et al. (SuperCDMS Collab.)</td></tr><tr><td>AYBAS</td><td>21</td><td>PR L126 141802</td><td>D. Aybas et al. (CASPEr Collab.)</td></tr><tr><td>BACKES</td><td>21</td><td>NAP T50 238</td><td>K. Banck et al. (CASPEr Collab.)</td></tr><tr><td>BANIK</td><td>21</td><td>JCAP 2110 238</td><td>N. Banik et al. (HAYSTAC Collab.)</td></tr><tr><td>BARTRAM</td><td>21A</td><td>PR L127 261803</td><td>C. Bartram et al. (ADMX Collab.)</td></tr><tr><td>BASU</td><td>21</td><td>PR L126 191102</td><td>A. Basu et al. (BIEL, NAGO)</td></tr><tr><td>BAUMHOLZ...</td><td>21</td><td>JCAP 2105 004</td><td>S. Baumholzer, V. Brdar, E. Morgante (MAINF+, FNAL+)</td></tr><tr><td>BI</td><td>21</td><td>PR L126 091601</td><td>A. Bhusal, N. Houston, T. Li (BELL)</td></tr><tr><td>CALORE</td><td>21</td><td>PR D104 043016</td><td>X.-J. Bi et al. (BHEP, TSIN)</td></tr><tr><td>CARRA</td><td>21</td><td>PR D104 092005</td><td>F. Calore et al. (BHEP, TSIN)</td></tr><tr><td>CARRA</td><td>21</td><td>PR D104 092005</td><td>S. Carr et al. (BHEP, TSIN)</td></tr><tr><td>CAZZANIGA</td><td>21</td><td>EPJ C81 959</td><td>C. Cazzaniga et al. (NA64 Collab.)</td></tr><tr><td>CORTINA-GIL</td><td>21</td><td>JCAP 2108 136259</td><td>E. Cortina Gil et al. (NA62 Collab.)</td></tr><tr><td>CORTINA-GIL</td><td>21C</td><td>JHEP 2103 058</td><td>E. Cortina Gil et al. (NA62 Collab.)</td></tr><tr><td>CORTINA-GIL</td><td>21C</td><td>JHEP 2102 201</td><td>E. Croon et al. (TRIU, WASH, MIT, FNAL)</td></tr><tr><td>CROON</td><td>21</td><td>PR L121 107</td><td>J.A. Devinl et al. (BASE Collab.)</td></tr><tr><td>DEVLIN</td><td>21</td><td>PR L126 041301</td><td>A.V. Dicot et al. (CHIC, RUTG, UCB+)</td></tr><tr><td>DIXIT</td><td>21</td><td>PR L126 141302</td><td>M.J. Dolan et al. (MELB, BRCO, DSY)</td></tr><tr><td>DIAN</td><td>21</td><td>PR D102 190 190 (errat.)</td><td>M.J. Dolan, F.J. Hiskens, R.R. Volkas (MELB)</td></tr><tr><td>DOLAN</td><td>21A</td><td>JCAP 2109 010</td><td>K. Fujikura et al. (MELB)</td></tr><tr><td>FUJIKURA</td><td>21</td><td>PR D104 123012</td><td>S. Ghosh et al. (MELB)</td></tr><tr><td>GOSH</td><td>21</td><td>PR D104 092016</td><td>B. Godfrey et al. (UCD, CSUS, STAN)</td></tr><tr><td>GODFREY</td><td>21</td><td>PR D104 012013</td><td>A.V. Godfrey et al. (SHAST Collab.)</td></tr><tr><td>GRAMOLIN</td><td>21</td><td>NAP T17 79</td><td>A.V. Godfrey et al. (SHAST Collab.)</td></tr><tr><td>GUO</td><td>21</td><td>CP C45 025105</td><td>A. Guo et al. (BHEP)</td></tr><tr><td>HOMMA</td><td>21</td><td>JHEP 2112 108</td><td>K. Homa et al. (SAPPHIRES Collab.)</td></tr><tr><td>JIANG</td><td>21</td><td>NAP T7 140 142</td><td>M. Jiang et al. (SAPPHIRES Collab.)</td></tr><tr><td>KOPYLOV</td><td>21A</td><td>PPN 52 31</td><td>A.V. Kopylov, I.V. Orekhov, V.V. Petukhov (INRM)</td></tr><tr><td>KRIBS</td><td>21</td><td>PR L126 011801</td><td>G.D. Kripš, D. McKeen, N. Raj (OREG, TRIU)</td></tr><tr><td>KWON</td><td>21</td><td>PR L126 191802</td><td>O. Kwon et al. (CAPP-ACTION Collab.)</td></tr><tr><td>LI</td><td>21</td><td>PR D103 083003</td><td>H.-J. Li et al. (BHEP)</td></tr><tr><td>LLOYD</td><td>21</td><td>PR D103 023010</td><td>S.J. Lloyd et al. (DURK, OKLA)</td></tr><tr><td>LUCENTE</td><td>21</td><td>PR D103 103007</td><td>G. Lucente, P. Carena (BARI)</td></tr><tr><td>MARTINCAM...</td><td>21</td><td>PR D103 L121301</td><td>J.M. Camalich et al. (CAST-RADES Collab.)</td></tr><tr><td>MELCON</td><td>21</td><td>PR L125 01102</td><td>A.A. Melkon et al. (MIT, ANIK, UTE, LEUV)</td></tr><tr><td>NG</td><td>21</td><td>PR L126 151102</td><td>S.-H. Park et al. (BELLE Collab.)</td></tr><tr><td>PARK</td><td>21</td><td>PR L126 194 191</td><td>M. Regis et al. (MUSE Collab.)</td></tr><tr><td>REGIS</td><td>21</td><td>PR B116 136075</td><td>K.K. Rogers, H.V. Peiris (STOH, LOUC)</td></tr><tr><td>ROGERS</td><td>21</td><td>PR L126 071302</td><td>T.S. Roussy et al. (COLO, MAINZ)</td></tr><tr><td>SALEM</td><td>21</td><td>PR L126 081801</td><td>C.P. Sakemi et al. (ABRACADABRA Collab.)</td></tr><tr><td>SCHMIDT</td><td>21</td><td>PR D104 015008</td><td>I. Schmidt et al. (FRAN, GSI, +)</td></tr><tr><td>THOMSON</td><td>21</td><td>PR D102 081803</td><td>C.A. Thomson et al. (WAUS)</td></tr><tr><td>Also</td><td></td><td>PR L127 091901 (errat.)</td><td>C.A. Thomson et al. (WAUS)</td></tr><tr><td>TSUKADA</td><td>21</td><td>PR L126 181801</td><td>Y.-D. Tsai, P. deNiverville, M.X. Liu (FNAL+)</td></tr><tr><td>TSUKADA</td><td>21</td><td>PR D103 083005</td><td>L. Tsukada et al. (ROMA, TOKY, WATER)</td></tr><tr><td>XIAO</td><td>21</td><td>PR L126 031101</td><td>M. Xiao et al. (CST)</td></tr><tr><td>YUAN</td><td>21</td><td>JCAP 2103 018</td><td>J. Zhang et al. (CST)</td></tr><tr><td>ZHANG</td><td>21B</td><td>PR L127 161101</td><td>R. Aalj et al. (LHCb Collab.)</td></tr><tr><td>20A</td><td>PR L127 2010 156</td><td>R. Aalj et al. (LHCb Collab.)</td></tr><tr><td>20C</td><td>PR L128 041001</td><td>A. Aalh, A. Aalh, N. Nagata (TOKY)</td></tr><tr><td>ABDELHAME...</td><td>20B</td><td>EPJ C80 376</td><td>T. Abe, K. Hamaguchi, N. Nagata (TOKY)</td></tr><tr><td>ABLIKIM</td><td>20AB</td><td>PR D102 052005</td><td>M. Ablikim et al. (BESIII Collab.)</td></tr><tr><td>ABUDINEN</td><td>20</td><td>PR L125 161806</td><td>F. Abudinen et al. (BELLE II Collab.)</td></tr><tr><td>AGOSTINI</td><td>20</td><td>PR L125 011801</td><td>M. Agostini et al. (GERDA Collab.)</td></tr><tr><td>AGOSTINI-AR...</td><td>20</td><td>PR D101 052014</td><td>A. Agostini et al. (SUPERCDMS Collab.)</td></tr><tr><td>AMARAL</td><td>20</td><td>PR D102 091101</td><td>D.W. Amaral et al. (SUPERCDMS Collab.)</td></tr><tr><td>AN</td><td>20</td><td>PR D102 115022</td><td>H. An et al. (VIEN, MINN, VICT, TSN)</td></tr><tr><td>ANDRIANAV...</td><td>20</td><td>PR D102 042001</td><td>A. Andrianavalomahefa et al. (FUNK Collab.)</td></tr><tr><td>APRILE</td><td>20</td><td>PR D102 072004</td><td>E. Aprile et al. (XENON Collab.)</td></tr><tr><td>Also</td><td></td><td>PR D101 052005 (errat.)</td><td>T. Aralis et al. (SUPERCDMS Collab.)</td></tr><tr><td>ARGUELLES</td><td>20</td><td>JHEP 2002 190</td><td>A. Aralis et al. (SUPERCDMS Collab.)</td></tr><tr><td>ARNAUD</td><td>20</td><td>PR L125 141301</td><td>C. Arguelles et al. (MIT, VALE)</td></tr><tr><td>BALDINI</td><td>20</td><td>EPJ C80 858</td><td>Q. Araud et al. (EDELWEISS Collab.)</td></tr><tr><td>BANERJEE</td><td>20</td><td>PR L129 071101</td><td>A.M. Baldini et al. (MEG Collab.)</td></tr><tr><td>BANERJEE</td><td>20A</td><td>PR L125 081801</td><td>D. Banerjee et al. (MEG Collab.)</td></tr><tr><td>BANERJEE</td><td>20A</td><td>PR L125 081801</td><td>D. Banerjee et al. (MEG Collab.)</td></tr><tr><td>BARAK</td><td>20</td><td>PR L125 171802</td><td>L. Barak et al. (SENSEI Collab.)</td></tr><tr><td>BARINE</td><td>20</td><td>PR L124 101303</td><td>T. Barak et al. (SENSEI Collab.)</td></tr><tr><td>BUEHLER</td><td>20</td><td>JCAP 2009 027</td><td>R. Buehler et al. (DESY, MADU)</td></tr><tr><td>CALEORE</td><td>20</td><td>PR L102 123005</td><td>F. Calore et al. (LAPP, BARI, HEID, +)</td></tr><tr><td>CAPOZZI</td><td>20</td><td>PR L102 083007</td><td>P. Carenza et al. (MPIM)</td></tr><tr><td>CARENZA</td><td>20</td><td>PL B809 135709</td><td>N. Cresini et al. (MPIM)</td></tr><tr><td>CRESCINI</td><td>20</td><td>PR L124 127181</td><td>N. Crisosto et al. (ADMX SLIC Collab.)</td></tr><tr><td>CRISOSTO</td><td>20</td><td>PR L124 241101</td><td>J. Darling</td></tr><tr><td>DARLING</td><td>20A</td><td>PR L125 121103</td><td>J. Darling</td></tr><tr><td>DARLING</td><td>20A</td><td>PL D102 1200 128</td><td>J. Darling</td></tr><tr><td>DENT</td><td>20A</td><td>JCAP 205 131805</td><td>J.B. Dent et al. (MICH, ILL, TOKY+)</td></tr><tr><td>DEPTA</td><td>20A</td><td>JCAP 205 0009</td><td>P.F. Depta, M. Hufnagel, K. Schmidt-Hobger (DESY)</td></tr><tr><td>DESSERT</td><td>20A</td><td>PR L125 261102</td><td>C. Dessert, J.W. Foster, B.R. Safdi (MICH)</td></tr><tr><td>ESTEBAN</td><td>20A</td><td>EPJ C80 259</td><td>I. Esteban et al. (MICH, ILL, TOKY+)</td></tr><tr><td>FOSTER</td><td>20</td><td>PR L125 171102</td><td>J.W. Foster et al. (MICH, ILL, TOKY+)</td></tr><tr><td>GOU</td><td>20</td><td>PR L125 171806</td><td>C. M. Gouveia et al. (FINAL, EFI, CHIC, ANL+)</td></tr><tr><td>GAVELA</td><td>20</td><td>PR L125 051802</td><td>M.B. Gavela et al. (MICH, ILL, TOKY+)</td></tr><tr><td>GOSH</td><td>20A</td><td>JCAP 2010 060</td><td>D. Ghosh, D. Sachdeva (MICH, ILL, TOKY+)</td></tr><tr><td>IRSCIC</td><td>20</td><td>PR D101 123581</td><td>V. Irsic, H. Xiao, M. McQuinn</td></tr><tr><td>JEONG</td><td>20</td><td>PR L125 212302</td><td>J. Jeong et al. (MICH, ILL, TOKY+)</td></tr><tr><td>KEEDLYDE</td><td>20</td><td>PR L125 050602</td><td>G.J. Klimchitskaya, P. Kuusk, V.M. Mostepanenko</td></tr><tr><td>KLIMCHITSK...</td><td>20</td><td>JCAP 2003 064</td><td>A. Korochkin, A. Neronov, D. Semikoz</td></tr><tr><td>KOROKCHKIN</td><td>20</td><td>JCAP 2003 064</td><td>A. Korochkin, A. Neronov, D. Semikoz</td></tr></tbody></table>