WIMP探索
世界のロードマップ
ダークマター懇談会2019＠早稲⽥⼤学
東京⼤学 宇宙線研究所・数物連携宇宙研究機構
森⼭ 茂栄
2019年7⽉5⽇

1

本研究会のお題• 標準理論を超えた物理の代表格の⼀つ”DM”をもとにより深い
物理の基礎原理を解明したい。
• 本業ニュートリノの物理は別で議論• ⼀⽅素粒⼦としてのDMはなかなか兆候を掴ませてくれない。
• PBHもまだ候補• 世界中での興味が散逸するなか、フォーカスする物理、ここだ
けはやっておくべき物理等、将来戦略（１０−２０年）を考えましょう。
• green frame: stolen “slides” (see next page)2

世界のDM communityの最近の議論• European Particle Physics Strategy Update (EPPSU) 2018-2020, May 12-17,
2019 (Info from Shoji Asai)• https://europeanstrategyupdate.web.cern.ch• Input to the committee• https://indico.cern.ch/event/765096/contributions/• Symposium• https://indico.cern.ch/event/808335/timetable/#20190513.detailed• European Astroparticle Physics Strategy 2017-2026• https://www.appec.org/roadmap• US Cosmic Vision 2017 (info. from Kaixuan Ni): direct detection (accelerators)• https://arxiv.org/abs/1707.04591• Follow-up workshop after Cosmic Vision 2017 (invitation only), Oct. 15-18, 2018 (Basic
Research Needs Workshop on Dark Matter Small Projects New Initiatives)• https://orau.gov/hepbrn2018/default.htm• Summary in APS• http://meetings.aps.org/Meeting/APR19/Session/T04.7• DOE announced funding opportunity• https://govtribe.com/opportunity/federal-grant-opportunity/dark-matter-new-initiatives-defoa0002112• For larger detectors: no further update yet• http://mitchell.tamu.edu/next-generation-dark-matter-and-neutrino-detection/3

欧州での議論
Direct detection: Jocelyn Monroe

4Model Space
Wide range of parameters!
Direct detection searches generally optimised for WIMP sensitivity...

Baer et al., arXiv:1407.0017
Jocelyn Monroe

May 13, 2019 / p. 11

5Model Space
Wide range of parameters!
Direct detection searches generally optimised for WIMP sensitivity...

Xenon 1T (2017)

n-nT
Xeno

Schumann, arXiv:1903.03026

Baer et al., arXiv:1407.0017
Jocelyn Monroe

May 13, 2019 / p. 11

6Model Space
Wide range of parameters!
Direct detection searches generally optimised for WIMP sensitivity...
starting to look for axion-like particles too!

axion model spacedark matter = axions= part axions
Baer et al., arXiv:1407.0017
Jocelyn Monroe

May 13, 2019 / p. 7

7

WIMP community input to the ESPPU• DarkSide-20k, DS-LM, Argo: direct detection• DARWIN: direct detection
FASER at LHC• NA64: e dump, sub-GeV dark photon• SHiP at SPS beam dump: search for hidden particles• AWAKE: dark photons using 50 GeV e beam (future 3 TeV)
• IAXO: axion• Vacuum Magnetic Birefringence: axion• MAGIS-1K: atom interferometer for DM and GW•…

8

Generation-3: DARWIN the Ultimate W

JCAP 11, 017 (20Baseline scena~30 t fiducial m~40 t LXe TPC~50 t total LXe~1000 photose

Liquid Xenon detectors• 2019- XENONnT, 20 tyr• ESPPU Document #97: DARWIN
collaboration• 40 ton of LXe target, > 5 GeV, a few x
10-49 cm2@50 GeV SI• Spin dependent, inelastic scattering,
solar axions, pp solar nu, neutrinolessdouble beta decay, double electron
capture, SN neutrinos• TDR 2022-23, XENONnT運転中(~2025)に建設、nT終了後commissioning• 場所は決めていないがcollaborationは
LNGSへのinterestを表明。

Multi-purpose de! sensitivity of a f! reach the sensi! solar and super! 0v2b260 cm!

The need ofKaixuan
an ultimate
WIMP detector
to reach
Ni (UCSD) – DARWIN
other proposed
G3 LXe experime
200 t x y exposurespin-independent WIMP-nucleon interactions

K. Ni

Exposure
0.1 t x y
2txy
20 t x y
200 t x y

Neutrino-Nucleus
Coherent Scattering
PRD 89, 023524 (2014)9need O(10~100 ton) liquid xenon detector
Kaixuan Ni (UCSD) – DARWIN

5

backgrounds such as radon. This unique property of argon extends the sensitivity with respect to technwith more limited ER discrimination. The throughput of the Urania argon extraction system would
400 t of UAr to be extracted and purified in the Aria facility over a period of about 6 yr. SNOLAB w
strong potential site for this detector motivated by the dark matter search, but also possibly enabl
observation of ultra-rare solar neutrino sources (CNO, hep) [20]. A Letter of Intent has been sent to SN
and funding is being sought for this to be a long term underground storage location for the extract
to prevent activating. Energy [keV ]DS-20k

nr

20

40

60

80

100

120

140

160

180

200

2
Thus, the GADMC program will completely cover
to sever500the WIMP hypothesis from 1 GeV/c
0.9
2dreds of TeV/c masses in the search for spin-independent coupling.
1%

0.8

400
50%
The GADMC collaboration
submits this input to theEuropean Strategy because there is a strong sc
0.7
correspondence
andimportanttechnology
synergywiththe capabilities at CERN. The ProtoDUNE c
99%
0.6
300
designis being adopted as the basis for the DarkSide-20k and the DarkSide-LowMass detectors, as
0.5
being
consideredfor Argo, which is still being designed. It is hoped that the cooperation that has de
0.4
200
with
CERN
to
date
may be continued and extended for these future programs as the CERN sc
0.3
interest
and technical capabilities are very well matched to the objectives of the GADMC program f
0.2
100
matter detection. This would be naturally aligned with the strong support for dark matter researchf90

Liquid Ar detectors01• Global Argon Dark Matter
Collaborationが結成 ~2017(DEAP, ArDM, MiniCLEAN,
10
DarkSide)
FIG. 3. Left: DarkSide-50 532.4 live-days high-mass WIMP search [5]. Observed events in the f10
surviving all cuts in the energy region of interest. The solid blue outline indicates the dark matter se• ESPPU Document #62
10 99 % f acceptance
1 %, 50 %, andcontours
for nuclear
recoils, as derived
from The
fits toour shows
AmBe
FIG. 4. 3Dschematicsof the DarkSide-20k
experiment.
drawingthe
DARWINare shown asthedashedlines.
Right:
the
DarkSide-50
Nspectraatlow
recoilenergyfromthsurrounded by the VETO detector made of Gd-loaded PMMA shell sandwiched bet
10• Underground Ar
last 500 days of exposure comparedG4DSof thebackgroundfrom kn
inner one, withnameda IAB
andsimulation
the outer one,
named
OAB in thecomponentstext), all containedi
10 [6]. Also shown
The OABis opticallythe recoils
AAr in induced
contact withcryostatwall
by a mcontaminants
are thespectraseparated
expectedbyfor
by thedarkmatterparticlbe defined.
and 10 GeV/c
for a 10 are yet
cm tocrosssection. The y-axis scales at right hand side are approxim
10• ProtoDune-like cryostat 5,normalized
at N = 10 e lower.
bias voltage. SiPMs can also be efficiently integrated into tiles that cover10
radiopurity
up to an order of magnitude than PMTs.
• DarkSide-20k (2022- 50 ton,10
“neutrino floor”,
initially conceived as indicative of the maximum sensitivity attainable by an
Utilization
ProtoDUNE
cryostat:
Thetarget,
decisionexperimental
to abandon antechnorgan
presence
is ofcriticallydependent
on the10of CE⌫NS background,
LNGS), 1.6NR by atm nu inthe
to host DS-20k within a ProtoDUNE-like cryostat was originally motivated b
analysis, neutrino flux uncertainty
and theoretical cross section uncertainty. We therefore inclu
environmental impact on underground LNGS operations but carries signific
10100 ton year exposure
accounting of the CE⌫NS
and elastic
scatteringo↵ electronin cryostat
the sensitivity
Indeed,operating
the TPC directlyin thebackgrounds
ProtoDUNE-likeallows10potential curves shown here,
in Fig.
and Fig.
2. modules outside the TPC, thus keeping most ra
cryostatand 1
placing
SiPMs• DS-LM (light mass)
10
away afrom
the20active
volume. Also,
evenexperiment
We conservatively
estimatetotal% uncertainty
on thethescalability
neutrino tobackgroundDS larger
200 fort yrhigh-mai
searches with
10 Argo: this accounts for a 15 % uncertainty on the atmospheric
Argo 3neutrino
kt yr flux
• Argo (400 ton) @SNOLAB?locations suchas SNOLAB or LNGS, based on the latest data-driven models of cosmic primari
10
0.1

0
0

50

100

150

−37

200

Dark Matter-Nucleon σSI [cm2]

−38
−39
−40

250
S1 [PE]ES
CD STMS II
Li I
te 20
90
20 17
17
Da
r

−42 2

40

−44

−45
−46

−47

−48
−49

350

400

450

0

CR

−41

−43e

300

241

e

ATLAS 2018 (Vector Z', 95% CL)

kS

id2
e5

0

SuperCDMS GeDarkSi

20

-3
DEAP

18

HV pro

de-LM

j.

proj.

600

2017

2017
LUX
2017.
2018
-II
oj
-50
NDAX600 pr
e
A
d
P
i
S
3
8
k
1
r
P
20 DEA
Da
roj.
N1T
LZ p
XENO
.
proj
oj.
NnT
O
N
r pr
E
X
0t× y
0
2
oj. DARWINr pr
0 t× y
0
2
-20k
.
Side
proj
Dark
t× yr
0
0
30
Argo
Neutrino floor on xenon−50

2models of solar cycle, seasonal,
geographic
and geomagnetic
dependence
of10
the10
neutrino10flux
[3
10−3
10−2
10−1
1
2
M χ interaction[TeV/c ] cross-section, driven by the nucl
theoretical uncertainty on the Standard Model
V. DARKSIDE-20K
uncertainties;
and for the constraint on non-Standard Model contributions stemming from
FIG. 1. 90 % C.L. exclusion limits, showing leading results from direct (continuous lines, Ref. [5, 6, 8–1
plannedby the COHERENT
collaboration
LArtargetbywiththeirsensitivities
current 1oaccelerator-based
dark matter searches(region withabove atheyellowline, [33],[12]) driven
comparedDS-20kbe located
the
of
the
Gran Sasso
National
on neutrino
flux[22];andandfora 6 will%direct
uncertainty
on Hall-C
theLAr
response
asthismeasuredby“neutrin
SCEN
germanium-,xenon-,
argon-based
searches in(dashedlines,
Ref.
[13–17]andwork). LaboratoryThe
twodetectors:
the95%
innerdetectorand thethe ATLAS
veto detector,
bothishosted
infora aProt
curve
follows
thedefinition
of
Ref.
[18].
The
C.L.
limit
from
Experiment
shown
ben
ARIS [36]. The planned improvements of COHERENT, including a sharper characterization

TheWIMPs
inner detector
is a ordinary
Liquid Argon
Projection
Chamber(LAr
TPC)
model in which Dirac-fermion
interact withmatterTime
via a vector
mediator[19]withcouplingsAccelerators:

99• Energy frontierに加え、新たな加速器を⽤いた探索 MeV-GeV DM, DS
12

12

9

f
f

) Searches
DDは軽いDMに対する

9

New accelerator
based
searchesfor MeV - GeV dark matter
SM: LLP @ Beam Dumps
New Particle Decays to New
SM: Particle
LLP @Decays
BeamtoDumps

敷居値があるが

12

f

Procedure
to probe for Dark Photon, Scalar,
Vector and Neutrino
portals
Dark Portals [Vector,(Pseudo)Scalar,
Neutrino]
at Beam
Dumps (e. g. NA62++, SHiP)e
Procedure to probe for Dark Photon, Scalar, Vector and Neutrino
portals
New Particle Decays to SM:
LLP @ Beam Dumps
eLUNA
Downstream Spectrometer+Particle ID

C. Doglioni’s presentation, arxiv: 1809.05937

Borexino

LLP decay
Downstream Spectrometer+Particle
ID

O⇤

p
LUNA Procedure to probe for Dark Photon,
19Scalar, Vector and Neutrino portals

Beam dump

16

p
19

O

LUNA

F

16
19

F

e

Borexino

LLP
decaySpectrometer+Particlee.gIDA
Downstream

f

⇤

p

O

Beam dump
Borexino

DD

F

e.g

e.g

A0

A0

✏Y 0 µ⌫
F B
2 µ⌫

L=

(1)

12

C

⇡

A
e, p, N . . .

2
/ gSM
A

e+

0

e
e
a)

A0

2
/ gSM

Z

e

/ gSM

e

Rate / g

/ gSM
A

b)

A0
p, n
Z

0

scatter is the
The energy depositedDM
in detector
H Z signal
4eRate / gSM

DD

3

Production of dark particle decaying to DM pair.

p, nDM scatters inside the detector24s(p · k1

ip · k2 )2 ,(4)3DM Scattering in Detector

Rate ~ ε4A0¯DM Scatteringin Detectorp
To directly compare to previous
studies[], wewill
focus
averaged over photon spins, isC
L = so Fwe
Bwill focus(1)
do a few
more scans
to be
sure.
–gk) The main denegligible
for ourThis
sensitivity
estimates,
2 µ⌫
h
i
2 2
tectionbackgrounds
comeneutrino
paper is organized
as follows.
4✏2 ↵D↵2h In Sec. II, we de- 2 h|A
2 from neutral-current
2 2
on vector
portalmodels
of be
the
dark
sector
[14–16].
Here, onenergy✏2 ↵of|2 i =i 2(s + 2m2 ) m2⇡s
8s(p · k1 )(p · k2 ) ,(5)where theA0 caneitheronor ono↵-shell.
Similarly,
DMofproduction
2through
D ↵A0 and dark matter2production
scattering
nuclei, but because
the maximum
the mechanism
h|A⇡ scribe4m ) m2⇡s
4s(p⇡· k!1 p¯· k2 )2 ⇡f,(4)⇡ [(s m2A )2 + m2A 2A ]!
¯| i =
02 )2 + m2
2 ] (s2 [(s+⇡fma massive
photoninAa scintillator
from
a new
neutrinos
producedfromat rest is 52.8 MeV,AA
DM candark
be detectedor U(1)mineraloildecays
detecin the DAE ⇡ALUS target.
InA Sec.
D ⇡kinetically
0 III, we describe the
FIG. 1: Schematic diagram of DM production in protonDark
matter,which
caneitherbeascalarorafermion,
⇡
12
12
0
0
0(⇤)
0
backgrounds can be substantially mitigated
2 FIG. 10: a) Scalar DM pair production from electron-beammechanismofdarkmatterscatteringin a detector
such
p +by a C !
+charge⇡fermion,, ⇡ +1!
A, A¯This(3)where ↵D ⌘ Carbon
gD/4⇡, pcollisions,is the photon
whichmomentum,
copiously
produceneutral pions
tor withthroughrecoilethese+ DM! e + DMgaugeornuclearA
mixes
theelectron
standard
model
hyperchargeboson
andpif + is aC
Dirac
this
expression
is !
has
under
the
U(1)
has
four
simplecut on the nuclear
recoil energy.
D . IV,00 is radiatedas NO⌫A,
and the associatedsignals.
in Sec.
we modelsurcollisions.
An
Amomenta,
and decays
is the A0 width,
k1 exotic
and k2decays
are on-shelltheyield
DMA
whose
through andkinetic
mixing.o↵ diagonally
Z + DM 1! Z + DM through a t-channel A0 . (Gorfree parameters:
the A0 mass
mAin, Sec.
the dark
couvia recoil
the operator
h and
0 pairs. b) Inelastic0 up scattering of the lighter ' into
2 2suchV we gauge
This paper is organized as follows. In Sec. II, we des = (k1 +k2 )2 . iIf to
the'A
go on-shell, the↵D ↵2 a search,
0 vey the2 backgrounds4✏toh, can2
Anarrow width
2
2
0

0

0

0

0

0

0

e

0

0

0

0

00

0

/g

2
/ gWSM

0

0

0

e

A

The energyedeposited in edetector is the signal

0

0

p

4⌫e
/ gSM

A’ decays promptly to DM

Rate
DM scatters inside detector

2
/ gSM

2
/ gWSMh|A⇡ !

¯| i =and ifis a Dirac fermion, this expression b)is⇡f⇡2 [(sm2A0 )2 + m2A0

2 ]
A0

(s

4m ) m⇡0

e

n

e

e

4

b)

e

The energy deposited in detector is the signal
4Rate / gSM

a small portion neutrinos
coming produced
from bremsstrahlung
tar-MeV,from ⇡ + decays at inresttheis 52.8
these backgrounds
cansubstantially
getforanddecays! p + .DM.
We behavecheckedmitigated(Matt,by a(2) validboth scalarsimple
and fermioniccut on
the nuclear
recoil energy.
check
this? dark
–yk)
that
modes
other
⇡ 0 decayareWe
simulatedmatterproduction
by thanobtaininga⌫e

DM scattersinside detector
b)

0

⇡0

e

A’ decays promptly to DM

the A
or
o↵-shelldependingonh|A⇡canieither= sensitivity(s+ ✏2m) m✏⇡As
8s(pdark· k1 )(p · k2 ) ,(5)dan, change this sentencescribe
onceknowofwhich
onematter whereg 2 [(s, onthemkinetic
parameter
and
the
! be
¯ |pling
present
ourthemmixing
parametersandY ,for
2 to
2
2
thewe
mechanism
A0 and dark
production
thebeheavier
A0 exchange.
approximationcanused to stateobtainvia
a simple
expressionFor order-one (or larger)
⇡f⇡D
)2 +
A0m
A A ]
the mass
DM.mattermass masses.
mADM . Afterelectroweak
dark matterWe conclude
in Sec.symmetry
VI. De- breaking
in the –yk)
DAE ALUS
target.
Sec. III, we describe
the of thevarious
gives us the best sensitivity.
(WiththeIn recoil
for the branchingratio,¯
masssplittings,
the metastablestate promptly
de-excites0 inII.
DARK
MATTERPRODUCTION
IN THE02 variousof dark matter scattering in a detector
such DMtheproduction
scattering
calculations
anddiagonalizing
theandkinetic
terms,
inherits a univerwheretails
⌘
gD
/4⇡,
p is
the photon
momentum,If theis↵Da ofscalar,theanalytic
expressionforAA theside the'h ! '
e+ e . The signal of interest is
cuts we have to impose
toavoid
neutrinos,I
be✏Y 0mechanism✓ detector◆via
DAE
TARGET
3 ALUS
12 k1 inµ⌫ and the associated signals. in Sec. IV, we suras NO⌫A,
2
p ismatrix
found
Appendicesandmomenta,
B. currents
thecanA0 bewidth,
andk0totheADMand with
0
2 are
m2A
sal
coupling
electromagnetic
strength ✏e,0C
involvesarecoilingtargetwithtwo charged
L
=
F
B
(1)
2
0
three-bodyelement⇡!
¯
throughanA,lieve the answer is electron
recoils,but
I needtoand in Sec. V we s = (k1 +k2 )2 . If the A0 can go on-shell, the narrow widthBr(⇡ !
¯) = 2✏ 1
Br(⇡ e,!p, N), .energy(6)
vey thebackgrounds
to sucha search,.background. ER and
0
2
2 µ⌫
where
✏
⌘
✏
cos
✓
.
In
particular,
the
A
can
replaceamtrackstoyieldainstinctive,
zero
signature.
Y
W
SM
present
our sensitivity
to theparametersmA for overaveragedphoton can
spins,
is to obtain a simple expression
approximation
be useddo a few more scans to besure.
–gk) Themainde- ✏ andAs mentioned ⇡in Sec. I, A0 vectors are produced by rephoton in any kinematically-allowed process, with an acvarious dark matter masses. We conclude in Sec. VI. De0
for the branching ratio,
placingaphoton
with
an
A
in
any
kinematicallyallowed
valid
for
both
scalarandfermionicDM.
tection backgrounds come fromneutral-current
neutrino
companying
factor✏, suchthat any tree-level process
tails of the various production and scattering calculationsi
1 The A
0 can acquire
2mass
2eitherofthroughahStückelberg field or a
✏2the
↵✓D
↵
◆3
We2simulated
dark matter
obtainingaprocess.
At theproduction
kinetic
energies of the
2 sector
2 is propor2800 MeVbyproton2
scattering
nuclei,canbuteitherbecausemaximum
can be thein Appendicesenergy
and B.of
coupling
visiblesector0production
to(sthe dark
1: |2SchematicDM
Higgs.diagram
mof
h|AFIG.
iBr(⇡=2 dark4m)in mproton4s(p· k1ALUS
p · kbeam,
,(4)
0
2
A 2
Dark
matter,onwhich
befounda scalaror a Afermion,
2 ) simulation⇡0 !
⇡ 0 listsof ⇡ 0 events
from
a GEANT4(Matt,
ref2 the!Scalar¯) =this2✏DMBr(⇡! region), of(6)parameter2 [(s2 1)2 pairDAE
⌘ mesons
are kinematicallyinaccesThroughout
we
focus
on
2m
FIG.¯ collisions,10:a)production
fromelectron-beam
⇡f
m
+
to
✏2Apaper,
DM
can
via
0. copiously
0be0]neutrinos produced from ⇡ + decays at rest is 52.8 MeV,m⇡tionalA
Aproduced
Carbonwhich
produceneutralpions⇡
erence? –yk)modeling
the DAEcome
ALUS
target geomespace where the A0 primarily
decays into dark matter rather
has thesecharge+1 under thebeU(1)model hasbyfour
sible,
so photons
primarily
from ⇡ 0 decays, with
D . This mitigated
00 is radiatedcollisions.
Anon-shellA
anddecayso↵diagonallybackgrounds cansubstantiallyathanvisible-sector
particles,
namely
g
>
✏e.
try,
and
generating
Monte
Carlo
eventsbydecayingtheD
whose exotic
decaysyield
Athroughmixing.
for
bothscalarandthisfermionic
DM. kinetic
freesimple
parameters:
thenuclear
A0 massmAAenergy.
, the
dark
gauge
andfieldifto
is avalidDiracfermion,expression
is of the lighter ' into a small portion coming from bremsstrahlung in the tar1 The
00 canacquiremass either
throughcoua Stückelberg
or a '
cut on therecoilpairs.
b) dark
Inelasticupsimulatedmatterah, We
get anddecays ! p + . We have checked (Matt,⇡ 0production! scattering
A0(⇤)by!obtaining
DM DM,(2)edark Higgs.
00pling gD , the kinetic mixing parameter✏Y , andthe dark
list of ⇡ events
a GEANT4
simulation (Matt,
ref2
this paper,
we focus on the region of parametercheck this? –yk)h order-one
i that modes other than ⇡ 0 decay are
the heavier
statefromvia
For(or larger)
2 exchange.
2This paper is organized as Throughout
follows.
InA0 Sec.
II,decays
we de4✏2A↵theerence?
–yk) modeling
DAE ALUS target geome- 22
spacewhere theprimarily
into dark matter rather
22D↵b) will focus
negligible
sensitivity estimates, so wemattermass mDM . Afterofelectroweak
symmetrybreakingh|A⇡0 !
|splittings,
i and= generating(s+the2m ) de-excitesms in-8s(p· k1 )(pfor· k2our) ,(5)
0mass¯DARK
metastable
promptly
than visible-sector
particles,
namely gD > ✏e.
try,
Monte
by
2 state2 decaying
scribe the mechanism
A0 anddark matterproduction
2 [(sthe2PRODUCTION
2⇡
II.
IN
THE
⇡fMATTER
m2AA0 0)Carlo+ events
m
]
0
0
0
where
the
can
eitherbeonoro↵-shell.
Similarly,onDM
production
through⇡A+ A
andindiagonalizing
the target.
kinetic In
terms,
a universide the detector
viabe'detected
e aescintillator. The signalof interest
the DAE ALUS
Sec. A
III,inherits
we describe
the
h ! '
DAE
ALUS
TARGETDM
caninor mineraloil detec- is
sal coupling
toofelectromagnetic
currentsinwith
strength
2 recoilingmechanismdark matter scatteringa detectorsuch✏e, whereinvolves
withenergyE!
charged p +12 C ! p +12 C + ⇡0 , ⇡0 ! A0(⇤) , A0 ! ¯ (3)tor pthroughrecoile + DM+ADM
or nuclear
R eand0 two↵D ⌘ gaD/4⇡,
is target
theelectron
photonmomentum,
0 IV, we surZk+
DM ! Z zero+DM
DM backgroundthrough a t-channel
A0 . (Goras NO⌫A,
signals.the
in A
Sec.
where
✏ ⌘ ✏Y andcos ✓theIn particular,
can replace a is thetracks
to yielda instinctive,
signature.
W .associatedA0 width,
k1recoilandmomenta,and2 are the0
where the A0 can be either on- or o↵-shell depending on
dan,changethisvectors
sentence
once
weknow bywhich
one
mentioned
in
I,
A
are
produced
re2
0 Sec.
vey thebackgrounds
to such a search,and in with
Sec. V
photonin anykinematically-allowed
process,
anweac- s = (kAs
+k
)
.
If
the
A
can
go
on-shell,thenarrowwidth
1
2
the mass of the DM.
0
gives
usan
theAbest–yk) (Withthe recoil
placing a photonwithin sensitivity.
any
kinematicallyallowedpresent oursensitivity
to thethat
parameters✏ and mprocess
A0 forapproximation
can beusedobtaina simplecompanying
factorof ✏, such
any tree-level
If the DM is a scalar, the analytic expression for the
cuts
we to
have
to impose
to expression
avoid neutrinos, I bevarious dark matter masses. We conclude in Sec. VI. DeAt the
800 theMeV
protonkineticrecoils,
energies
the to three-body matrix element ⇡0 !
the branchingratio,¯ through an A0 ,lieveansweris electron
butof
I needcoupling
the visible
sector to thedarksectoris propor- forprocess.
ptails of thevariousproduction
andscattering
calculations
averaged over photon spins, isdo a✓few
more ◆
scans
be sure. –gk) inaccesThe main de2
DAE ALUS beam,⌘ mesons
are tokinematicallytional. DMincan
be produced
3
2
canto
be✏foundAppendices
A andvia
B.
0
tectionbackgrounds
comeneutral-current
neutrino
mA0h0 so photons
2come
0from ⇡
2 2 2
sible,
primarily
fromdecays,with✏↵↵Br(⇡ !
¯) =scattering2✏ 1 on nuclei,
Br(⇡
! the
), maximum
(6)
2
2
2
D
but because
energy of
0
m2
0

A0

e, p, N . . .

0

0

0

DM DM,A0Z

e
Downstream
Detector
3

4
e
/ gSM
/g
+
Borexino e
Downstream
Detector
TheBeamdeposited in detector is the
H signal
dump
2energy
2 DM scatter⇡ 0 ! A0(⇤) !

e
e+

New
Particle
Decays
DM: Scatter@ Beam Dumps
energydeposited
into
detectoris theH signal
ε defines dark photon- photon mixing
Ae0 @ Beam
New Particle Decays toThe
DM:
Scatter
Dumps
e
Rate
Beam
/ g dump

1 The A0 can acquire mass either through a Stückelberg field or a

3
3

e

A0

FIG. 1: Schematic diagram of DM production in protonFIG. 10: a) Scalar DM pair production from electron-beam

Carbon collisions, which copiously
produce neutral pions
has charge +1 under the U(1)D . This model has four0collisions.
Anon-shell
A00 throughis radiatedand decays
whose
exotic A
decaysyield A
kinetic
mixing.o↵ diagonally0
free parameters: the A0 mass mA0 , A
thedark gauge couto 'h, pairs. b) Inelastic upof the lighter ' into0
A0 scattering
pling gD , the kinetic mixing parameter 0✏Y , and the¯dark
the heavier state via A0 exchange. For order-one (or larger)✏Y 0 µ⌫12
p matter mass
C
L=
F B
(1)
mDM . After electroweak A
symmetry breaking ¯
massDARK
splittings,
state promptly
de-excites ine, p,MATTER
N .the. . metastable
2 µ⌫
II.
PRODUCTION
IN THEand diagonalizing the kinetic terms, A0 inherits a universide the detector
viaALUS'h ! '
e+ e . The signal of interest is
DAE
TARGET✏Y 0 µ⌫psal12
coupling
to electromagnetic currents with strength ✏e,involves a recoiling target
C
L=
Fµ⌫ B
(1)
e e,withp,
Nenergy. . . ER and two charged+
FIG. where
1: Schematic
production
proton0matter, which can either be a scalar or a fermion,✏a)⌘Scalar✏Y diagram
cosDM✓W pair. ofInDM
particular,
theinA
can replace a2 Darktracks to yield a instinctive,
zero background signature.
FIG.
10:production
fromelectron-beam
0
Carbon collisions, which copiously
produce neutral pions
As mentioned in Sec. I, A LUNA
vectors are produced by rehas charge +1 under the U(1)D . This model has four
photonin anykinematically-allowed
process, with an accollisions.
Anon-shell
A00 throughis radiatedand decays
whose
exotic decays
yield A
kinetic
mixing.o↵ diagonally2scattering
2
placing a photon with an A0 in any kinematically allowed
free parameters: the A0 mass mA0 , the dark gauge couof up✏, suchthat ofany
to companying'h, pairs. b) factor
Inelastic
thetree-levellighter ' processinto
process. At the 800 MeV proton kinetic energies SMof thepling gD , the kinetic mixing parameter ✏Y , andthe darkSMFIG.
1: Schematic
diagramDM
productionin (orprotonthecouplingheavierstate
via ofA0 exchange.
For darkorder-onethe visible
sectorto thesectorislarger)proporDark matter, which can either
bemassa scalaror electroweaka fermion,mattermDM . After
symmetry breaking
LUNA
2 thepairDAE ALUS beam, ⌘ mesons16are⇤ kinematically inacces- b)
FIG. collisions,
10: a)
Scalarproduction
fromelectron-beammasssplittings,
metastablestate promptly
de-excites
intional
to ✏DM. DM
canPRODUCTION
be produced
via
Carbonwhich
copiously
produceneutral
pions
II.
DARK
MATTER
IN
THE
O
0
0
p
has charge +1 under the U(1)fourand diagonalizing
the kinetichas
terms,A inherits a universible, so photons comeprimarily from ⇡ decays, with
D . This modelside thedetector'hradiated!'e+ e .andThe decays
signal of o↵interest
is
00 is
DAE
ALUS
TARGET
collisions.
Anon-shellAvia
diagonallywhose
exotic decaysAthrough
sal coupling
to electromagnetic
strength✏e,F bremsstrahlung in the tarinvolves yielda recoilingtarget withkinetic
energy Emixing.
a small portion coming 19
fromR and two charged
free parameters: the A0 mass
mA0 , thedark gaugecurrents
cou- with0
to'pairs.
b)
Inelasticup
scatteringofthelighter'
into
0(⇤)
where ✏ ⌘ ✏Y cos ✓W . In particular, the A can replace h,atracks to yield a instinctive,
get anddecays⇡0 0 !
!backgroundDM
DM,signature.
(2)
0 zero4 ! p + . We have checked (Matt,pling gD , the kinetic mixingphoton
parameter✏Y , and the dark
mentioned
I, AA
vectorsareproducedby re-(or larger)
Borexino
in any kinematically-allowed
process, withthean acheavierAsstate
via inASec.
exchange.
Fororder-onecheck this?
–yk) that modes other than ⇡ 0 decay areplacing a16
photonwith an A0 in any kinematically allowedO⇤ metastableSMcompanying factorof ✏, suchthat any tree-level massprocesspsplittings,
matter mass mDM . After electroweak
symmetrybreaking
sensitivity estimates, so we will focus
the
state
promptly
de-excites
in-negligible for our
process.
At
the 800
protonkinetic
energies
the
MATTERPRODUCTION
INofTHE
theAvisible
sector ato univerthe dark sector is II.
propor-DARK
0 MeV
0+be on- or o↵-shell.2 Similarly,
19 wheretheAcaneitheron DM production throughand diagonalizing the kineticcouplingterms,
inherits2
side
thedetector
via
'
!
'
e
e
.
The
signalofinterest
is
DAE
ALUS
beam,
⌘
mesonsarekinematicallyinaccesFhtional to ✏ . DM can be produced via
DAE
TARGETDM
can beALUS
detected
in a scintillator
or mineraloil detecso photons
come primarily
from ⇡ 0 decays,withsal coupling to electromagnetic currents with strength ✏e,involves sible,
a recoilingtargetwithenergyandtwocharged p +12 C ! p +12 C + ⇡0 , ⇡0 ! A0(⇤) , A0 ! ¯ (3)torportion
throughelectronrecoile + DM E!Rein+
DMtaror nuclear
a smallcomingfrombremsstrahlungthe0
where ✏ ⌘ ✏Y cos ✓W . In particular, the0 A canreplace a
trackstogetyield
a instinctive,
backgroundsignature.
recoilZ + DM !
+zero
DMthrougha t-channel
A0 . (Gorand
!0Z
p+
. We
have checked(Matt,⇡ ! A0(⇤) ! DM DM,(2)
As mentioned
in decaysSec.
I, thisA
vectors
by rewhere the A0 can be either on- or o↵-shell depending on
photon in any kinematically-allowed process, with an acchange
sentence are
onceproduced
we0 know which
one
checkdan,this?
–yk) that0 modes other than ⇡ decay are
the mass of the DM.
placing a photon
withansensitivity
A
insensitivity.
any
kinematicallyallowed
gives
usour
the
best
–yk)
the recoil
negligibleforestimates,
so we(Withwill focus
companying factor of ✏, such that any
tree-level processTo
directlycompareto previous
studiesI [],the DM is a scalar, the analytic expression for thewhere the A0 can either be on- or o↵-shell.2process.
Similarly, Atonthe
cuts
weMeV
have
to imposeto avoid
neutrinos,
be-we willIffocus
DM
production
through800
protonkinetic
energiesofthecoupling the visible sector todark
sectoris proporon vector
portalmodelsrecoils,of the dark
Here, matrix element ⇡ 0 !
three-body¯ through an A0 ,DMthe
can bedetected
in a scintillator
or mineral oil deteclieve theansweris electron
but Isector
need [14–16].
to
12
12
0 are
0(⇤) 0 0
ALUS pbeam,
mesonskinematicallyinacces+doCa !
+C +scans⇡, ⇡ 0photon!
, Afrom! ¯aThe(3)mainaveraged over photon spins, is
tor throughor nucleara⌘pmassive
dark
A
new
U(1)
tional to ✏2 . DM can be produced
viaelectron recoil e + DM ! e + DMDAE
D kinetically
few
more
to
beA sure.
–gk)
de0
⇡0
so photons
comeprimarily
from ⇡model
decays,with gauge boson
recoil Z + DM ! Z + DM through a t-channelsible,
A0 . (Gormixes
with the standard
hypercharge
tection0 backgrounds come from neutral-current neutrinoh2 2where the A can be either on- 1or o↵-shell depending on✏ 2 ↵D↵2dan, change this sentence once we know awhich
oneportion2
2
scattering
onfromnuclei,but because the maximum
energyofsmall
comingbremsstrahlunginthetarviatheoperator
0
h|A
|
i
=
(s 4m2 ) m2⇡0 s⇡ !
¯
the mass of the DM.
2 )2 + m2
2
gives us the best sensitivity. –yk) (With the recoil+⇡f⇡2 [(s mA
0neutrinos
producedfrom⇡have
decaysat rest is(Matt,
52.8 MeV,00(⇤)
A0 A0 ]
A0
getanddecays!
p+.
WecheckedIf the DM is a scalar, the analytic expression for the⇡ ! A!cutsDM
DM,to impose to avoid(2)neutrinos, I bewe havethese backgrounds
canby a
0 be substantially
0 mitigatedthree-bodymatrix modes
element⇡other!
¯ throughan A0 , arelieve the answer is electron recoils, but check
I need to
this?
–yk)
and if is a Dirac fermion, this 12
expression is✏Y ⇡0 decay
simple thatcut on the nuclear
recoilthanenergy.
µ⌫Rate ~ ε4

e+

e

e
a)

v / g4

Production of long-lived dark particle
decaying to SM particles

v / (mg4 < m )

¯

+

0
0⇡
Dark matter, which can either
be a scalar or a fermion,04(m < m )

0

p

f

v/g
⇡0

(m < mA )2

To directly compare to previous
studies[], wewill focus
To directlycompareto previous
studies [], we will focus
on vector
modelsof the dark
sector [14–16]. Here,on vector portal models of thedarkportal
sector
[14–16].
Here,a massive dark photon A0 from a new U(1)D kineticallya massive dark photon A0 froma new U(1)D model
kineticallymixes with the standard
hypercharge gauge boson
mixes with the standard model
hypercharge
gauge boson
via theoperator1
via the operator1

2

LLP decay⇤

To directly compare to previous studies [], we will focus
on vector portal models of the dark sector [14–16]. Here,a massive dark photon A0 from a new U(1)D kineticallymixes with the standard model hypercharge gauge boson
via the operator1
2

Invisible decays of the Higgs.

E. Graverini’s talk

Beam dump

16

colliders

9

e

n b)

s

2

4s(p · k1

i2
p · ke
,(4)
2)

A0

4 Z

DM, DS
Summary
14
Asai & Carena
Many other
11
Ideas
there

Indirect Detection: Christoph Weniger
1. Self annihilation• Fermi LAT: 銀河中⼼, dwarf spheroidal galaxies• HESS: 銀河中⼼ ~a few TeV• HAWK: 100TeV以上を改善できる可能性。
• CTA: HESSを10倍改善予定(natural scaleを探索）• 反陽⼦: 天体物理学的可能性の排除は難しい, 15 GVのエクセス？
• GAPS: エネルギーの低い反重⽔素• IceCube, Super-K, Hyper-K, KM3NeT: ニュートリノ（太陽、地球、銀河？）

2. Decay• Sterile neutrinos: 7 keV nu à 3.5 keV n+3.5 keV g Hitomiは⾒えなかった

3. Conversion• Axion探索
12

Anti-proton ~15 GV excess?
Cuoco+ 2019●
First identified in Cuoco+ 2017, with ~4 sigma
significance●
After new systematic checks, still at few sigma
level●
Marginalizing over pbar production crosssection reduces significance●Correlated instrumental systematics areimportant, of same order as excess, butcorrelation structure is now publicallyavailable

Cholis+ 2019●
Check time-/charge-dependend diffusion●
Confirm excess with even higher significance(though no marginalization over all parameters)

64-88 GeVのDMのせい？

Reinart & Winkler 2017

13 May 2019

C. Weniger - Indirect DM detection overview

1213

10 22bb̄, Einasto

Self-annihilation cross-section h vi [cm3 s 1 ]CTAbb̄, Contracted NFW⌧ + ⌧ , Einasto

10 23

W + W , Einastoµ+ µ , Einasto

10 24

10 25

10 26

10 27

102

• “natural scale”に⼿が届く103
DM particle mass m [GeV]

104

Figure 7. Comparison of h vi limits from CTA observations of the GC, assuming di↵erent annihilation channels and DM halo profiles. Einasto lines assume the main halo profile described 14
in Sec. 3.
The contracted NFW profile with an inner slope of = 1.3 can also be found in that section. Alllines assume 1% systematics, 100 hr of observations and include GDE.
8

ofesult,
thephysicsnding
titanicofk-holeof all,ur infantneds (i.e.
s anddate

The field of astroparticle physics has quickly
established itself as an extremely successful endeavour.
Since 2001 four Nobel Prizes (2002, 2006, 2011 and2015) have been awarded to astroparticle physics andthe recent – revolutionary – first direct detections ofgravitational waves is literally opening an entirely new
and exhilarating window onto our Universe. We lookforward to an equally exciting and productive future.

European Astroparticle Physics Strategy
2017-2026 (APPEC)Many of the next generation of astroparticle physics
research infrastructures require substantial capital
investment and, for Europe to remain competitivein this rapidly evolving global field of research bothon the ground and in space, a clear, collective,
resource-aware strategy is essential. As a relatively
new field, European astroparticle physics does notbenefit from a natural and strong inter-governmental

15

reconcile, however, with the upper limits reported
by many other experiments. To ascertain whether
the DAMA/LIBRA modulation is indeed due toDark Matter particles, independent confirmationis needed from other experiments and especiallyfrom those now planned at LNGS and in thesouthern hemisphere.

European Astroparticle Physics Strategy
2017-2026 (APPEC)
Projected annual costs

Projected annual capital investment (for instrument prototyping and construction, excluding
manpower) and projected annual running costs (for consumables and employee expenses, i.e. traveland manpower; included in the shaded area) anticipated from the European astroparticle physics
funding agencies and required to realise APPEC’s ‘European Strategy for Astroparticle Physics’. Costs
related to actual scientific exploitation (data calibration, analysis, interpretation, publication etc.)
are not considered in this projection. Also excluded are other, often substantial subsidies notably
from regional and EU structural funds and from the European astronomy and particle physics
research communities, and contributions from APPEC’s non-European partners. The uncertainties inthis projection increase rapidly with time.

120

ν-mixing
gravitational waves

Expenses (M€)

80

γ-ray telescopes

60

40

ν-telescopes
ν-properties

cosmic rays

dark matter

20

underground laboratories
0
2017

2018

2019

2020

2021

CMB

next APPEC roadmap update

100

2022

dark energy

2023

2024

2025

Towards the ultimate direct searchPresent technologies can be pushed until they
hit the background produced by coherent
scattering of solar and atmospheric neutrinos –albeit an interesting signal in itself. In Europe, toprobe WIMP masses up to 10 GeV, the EURECA
consortium aims to push cryogenic detectors as
used by CRESST and EDELWEISS to the ton-scale.
Similarly, the DARWIN (50 tons of xenon) and Argo
(200 tons of argon) consortia plan to construct theultimate noble-liquid detectors to explore WIMP
masses in the 10 GeV to 1 TeV range.
Going beyond the coherent neutrino-scatteringwall will require direction-sensitive detectors. Aslong as convincing Dark Matter signals are found,such detectors will almost certainly be crucial
to assessing the detailed nature as well as theastrophysical origin of Dark Matter. Anticipating
16 begun.
this, detector R&D in this sphere has already

2026

Year

Dark Energy
Unravelling the exact nature of Dark Energy posesUSでの議論• US Cosmic Vision 2017にて、それまで進めてきたG2実験計画（LZ, SuperCDMS, ADMX)の⼤型計画以外のactivityを再開発。
• DMには巨⼤なパラメータ空間があり、⼤型実験だけに集中するのはリスクが⾼い。

• G2実験には優先度があるが、Low-cost, high-impactのプログ
ラムに投資。
• “New Ideas in DM” workshop• $10Mかもっと安く実⾏できるcomplementary scienceを議論• 100以上のトークがあつまった• これをまとめてCV2017が作られた(2017 ７⽉）
17US CV 2017のfollow up workshop (2018 Oct.)のサマリ(2019 Apr)

Rocky Kolb
182019 April APS Meeting

Create and detect dark-matter particles and associated forces
below the proton mass, leveraging DOE accelerators.

Green areas are high-priority parameter space identified at
BRN, singled out by thermal models for the origin of dark
matter – many are uniquely explored at accelerators

19

Detect individual galactic dark-matter particles below the
proton mass through interactions with advanced, ultrasensitive detectors

Thrust 1: Probe dark-matter interactions with nuclei, as motivated bytheoretical ideas for the nature of light dark matter, including its
possible thermal and non-thermal origins.
Thrust 2: Probe dark-matter interactions with electrons, as motivatedby theoretical ideas for the nature of light dark matter, including its
possible thermal and non-thermal origins.

20

Observe wave dark matter using innovative technologies
Improvements in our understanding of cosmology show these very
light particles to be excellent dark-matter candidates. Techniques
required to search for very light particles differ from those forprevious dark-matter searches and rely heavily on advances inquantum sensing.

Thrust 1: Utilize new detector technologies to explore large parts of dark-matter parameter space covering a broad
range of mass from 100 Hz to 10 GHz (roughly 10-12 eV - 10-4 eV), and targeting sensitivity to the QCD axion where
possible.
Thrust 2: Develop or transfer new detector technologies to enable experiments to cover the remaining parameter
space for well-motivated dark-matter models spanning the entire 20 orders of magnitude in mass and also targeting
21
complete coverage of QCD axion models.

Three PRDs Cover Entire Range Below Proton Mass
• Thermally produced dark matter must have mass larger than a keV from astrophysicalconsiderations• Accelerator searches (PRD 1) are sensitive to much lower mass dark-sector particles even if
not dark matter• Direct detection (PRD 2) can also probe lower-mass galactic particles that can be subdominant component to dark matter• Thermal particle dark-matter (freeze-out) particles must have mass less than about 200 TeV• Dark matter must have mass larger than 10-22 eV so that its deBroglie wavelength is smaller
than the size of the dark matter dominated objects

22

G3に向けたUSでの研究会
Friday, February 1

Mitchell Institute: Hawking Auditorium

Speaker

Title

9:00-9:15am

Lang/Strigari

Welcome/Plan for meeting

9:15-9:45 AM

Kaixuan Ni (UCSD)

Hermetically-sealed XeTPC for the ultimate dark matter search

9:45-10:15AM

Ethan Brown (RPI)

Rn-free gas and liquid xenon pumps

10:15-10:45AM

Liang Yang (Illinois)

Photodetectors for a G3 dark matter experiment

10:45-11:00 AM

Coﬀee break

11:00-11:30 AM

Bjoern Penning (Brandeis)High NR searches

11:30AM-12:00 PM

Richard Saldanha (PNNL)VUV-reflective PTFE coatings for Xe detectors

12:00-1:30PM

Lunch

1:30-1:55PM

Rupak Mahapatra (TAMU)SuperCDMS

1:55-2:20PM

Andrew Renshaw (Houston)

Argon/DarkSide

2:20-2:45PM

Igor Ostrovskiy (Alabama)

Experience with Deep Learning in EXO

2:45-3:15PM

Coﬀee break

3:15-3:40PM

Chris Tunnell (Rice)

NEST v2 and future

3:40-3:55PM

Louis Strigari (TAMU)

Atmospheric and solar neutrino benchmarks for G3

3:55-4:30PM

Jayden Newstead (Arizona State)

Migdal eﬀect for neutrinos and dark matter

4:30-5:00PM

Any participant not listed

One slide overviews

5:00-6:00PM

Group discussion led by R. Lang

Discussion/Plan for Saturday

6pm: Dinner/reception

23

⽇本• master plan 2017, road map 2017
• Direct detection: XMASS-1.5• Indirect detection: Hyper-K, IceCube,…
• Accelerators: HL-LHC• XMASS-Iは1 tonサイズの役割を成功裏に果たした。
• 太陽ニュートリノのバックグラウンドを⼗分に低減できる液体
キセノン２相式検出器を世界のメンバーとともに建設・発⾒ orindicationを狙っている(G2, conventional SUSY)。
• その後のより⾼感度な装置でイニシアティブを取って研究を進めたい。⼤型装置は結果が出せる１つの重要な⽅法だと考える。
(G3, EW WIMPs, and beyond)24

現在のステップG2

令和元年新規 新学術領域研究代表 井上邦雄「地下から解き明かす宇宙の歴史と物質の進化」
計画研究 森⼭茂栄ほか「⾼感度⼤型装置で推進する暗⿊物質直接探索」
等による科研費によるサポート• ⼭下⽒が説明するとおり。⽇本グループが活躍中。
Test in LXe @ Kamioka

Anode
Grid a(φ38.7) set up had a problem ofelectric field line because about
20 -30 % of filed line end up with
filed shaping ring.

20cm•We found the previous ICF70• We enlarged the diameter of

PMT and use ICF114 (φ 59.5mm) x 200 mm length. Within φ38
at photocathode reaches anode.

Grid cCathodeDrift Length: 204 mm
Volume: 1.1 L

25

CYGNUSDRIFT, NEWAGE を中⼼とした将来の⽅向感度実験
Steering committee: N. Spooner, K. Miuchi, E. Baracchini, S. Vahsen, G. Lane
現状：1m3 検出器をそれぞれ開発 & 10m3コンセプトデザイン検討
⽇本：CYGNUS-KM1として1m3 検出器製作中次CYGNUS-KM8 8m3 でXeのニュートリノフロアを超えた探索(右図☆)
その後：w/⽔シールド ⼤型ガス検出器
CYGNUS-KM1 chamber@神⼾

26

27

興味を共有するpure wino/higgsino“WIMP Standard Candles”• Higgs 125 GeVやLHCでの結果
等と⽭盾せず、DMの密度をう
まく説明する可能性のあるモデ
ルが予⾔。
• ⽇本⼈のcontributionが⼤きい。
• 核⼦との断⾯積も⾼い精度で予⾔されている。
• ⾼いシナジーが有りうる• G2で兆候、G3で発⾒？
• LHCやFCCでのdisappearance
track探索。
• CTAで最初の兆候が期待？

Pure wino28

今後の戦略は？
• カミオカ地下の⼤きな資産を⽤いてさらなる発⾒へ結びつける
具体的⽅法は？
• フォーカスする物理は？
• 明⽇議論する可能性のある質問を照会し、頭出し。
• いくつかはグラナダのシンポジウムからパクリ

29

DM発⾒のための最適な道のりは？

30

DD/ID/Accで信号が⾒えたらDMと信じるか？
確認のため何をするか？

31

DD/ID/Accのよりよい関係は32

ニュートリノフロアを超えてゆく必要性と意義はなにか33

⼤型DM検出器のさらなる多⽬的化は

34

⽅向検出器が信号を⾒るには35軽い暗⿊物質（候補探索）での加速器の優位性はどうか

36

Breakthroughがあるとしたらなにか

37

地下⼤空洞があったらどう使いたいか38