Direct Detection of Dark Matter

Bernard Sadoulet Dept. of Physics /LBNL UC Berkeley

UC Institute for Nuclear and Particle Astrophysics and Cosmology (INPAC) Direct Detection of Dark Matter Four broad classes of models Situation May 2017 Low mass, DAMA High WIMP Mass Noble liquids PICO Low WIMP Mass Low temperature detectors Super CDMS Gas Further in the future at very low mass

PATRAS May 17, 2017 1 B.Sadoulet The Emerging Mystery of Dark Matter From Zwicky (1933), Vera Rubin (1970), Faber-Gallagher (1979) =>Convincing evidence for dark matter http://physics.ucsc.edu/~joel/Ay/214/Jan12-Primack-DM-History.pdf Clusters 26 %

69.1 % The Ultimate Copernican Revolution ≠ Not made of ordinary matter! (Big Bang Nucleothesis, CMB) Somewhat eclipsed by the discovery of Dark Energy 1998 Standard Cosmological model Lambda CDM! Not light neutrinos! “Cold”=non relativistic at time of galaxy formation. Extremely successful. No unambiguous sign of special properties Dwarf galaxies: core, too big to fail? Likely “gastrophysics" PATRAS May 17, 2017 2 B.Sadoulet 4 Complementary Approaches LHC Cosmological Observations

Planck Dark Matter Keck telescopes Galactic Halo (simulation)

WIMP production on Earth

VERITAS, also HESS, Magic + IceCube (v) CDMS

WIMP annihilation in the cosmos

GLAS Fermi/GLAST T

WIMP scattering on Earth:e.g. Super CDMS,LUX etc.

PATRAS May 17, 2017 33 B.Sadoulet Four Classes of Particle Dark Matter

Could detect these by scattering of Particles in thermal equilibrium + decoupling when non-

galactic dark matter on a suitable target in laboratory relativistic Freeze out when annihilation rate ≈ expansion rate 3⋅10-27 cm3 / s α 2 ⇒ Ω h2 = Ω ≈ 25% ⇒ σ ≈ DM v DM A M 2 σ A EW Cosmology points to W&Z scale Inversely standard particle model requires new physics at this scale => significant amount of dark matter Weakly Interacting Massive Particles Problem: not (yet?) seen yet at the LHC A dark sector which could be as complex as matter sector

Self interacting dark matter, dark photon etc. could be light mass, involve light mediators maybe even dark matter—anti dark matter asymmetry If similar to baryon anti-baryon asymmetry 2 ρDM ≈ 5 × ρbaryon ⇒ M DM ≈ 5 GeV/c Sterile neutrino as warm Dark Matter May not help. 3.5keV line in question Athermal production: Result of spontaneous symmetry breaking Main example Peccei Quinn axions to dynamically restore CP in QCD PATRAS May 17, 2017 4 B.Sadoulet Situation in May 2017

At High Mass

Nothing so far ��

] -�� -� �� ] Broadly consistent with the � �� [ absence of Super Sym. �� [ � observation at LHC �� -�� -� �� Focus point solution in �� CMSSM ≈10-45 is mostly �� -�� -� �� -�� excluded �� -�� -�� -� �� ν �� -�� ν �� Low Mass ��-�� -�� A number of closed contours, and strong -�� -�� ν �� limits �� - �� - �� What is going on? ��-�� [��/��]

PATRAS May 17, 2017 5 B.Sadoulet A 10 Gev/c2 WIMP ??? 2014: wave of optimism CoGeNT probably incorrect cannot be nuclear physics Accumulation of claims in that region DAMA CoGeNT CRESST �� ] -�� -� ��

CDMS Si (no claim) ]

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Just the region expected �� [ � for asymmetric dark �� -�� -� ��

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2017: Unlikely -�� -� �� Exclusion by well -�� calibrated experiments -�� -� �� ν �� XENON 100 �� - �� ν �� LUX �� Panda X II ��-�� -�� SuperCDMS Soudan CDEX ��-�� -��

The latter two ��- �� experiments are Ge ��- �� -�� cannot be explained by �� nuclear physics �� [��/��] Outliers close to threshold! PATRAS May 17, 2017 6 B.Sadoulet NaI: How to prove/disprove DAMA

Clearly modulation although not blind Is it Dark Matter or instrumental? How do we make progress? Lower threshold: LIBRA has changed Phototubes to high QE Results 2017 (Cerulli) Experiment by other groups: DM-Ice,ANAIS,KIMS, Princeton

COSINE (Kyungwon Kim’s talk)

PATRAS May 17, 2017 7 B.Sadoulet Spin Dependent

New limit LUX on neutron last week

PATRAS May 17, 2017 8 B.Sadoulet Nuclear couplings Note that SD proton/neutron is an approximation Many more couplings than axial vector coupling Velocity dependent effects (including Fermi) Haxton, Zurek

arXiv:1405.6690

PATRAS May 17, 2017 9 B.Sadoulet Where Do We Want To Go?

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= US G2 program ] -�� -� �� ] � ��

+ equivalent (Xenon, DEAP,XMASS) �� [ ��

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��-�� -�� - �� - �� -�� 2 directions�� [��/� ] 1. Improve sensitivity at large mass

2. Improve sensitivity at small mass

PATRAS May 17, 2017 10 B.Sadoulet High WIMP Mass

PATRAS May 17, 2017 11 B.Sadoulet Large WIMP Mass 1 Need large target mass: noble liquids most adapted

�� XENON �� ] -�� -� �� ] � ��

�� [ �� Xenon 1T (approved [ � �� -�� -� 2012, cf. E. Aprile’s �� Talk) �� -�� -� �� -�� -�� -> Xenon nT ≈2019 �� -�� -� �� -�� ν �� -�� -�� LUX->LZ (≈2020, cf. �� Lindote’s talk) �� -�� -�� ν

�� - �� - �� -�� XMASS � � �� XMASS 1.5 Operation in 2017 ? �� [��/��] ≈ XENON1T at high mass + XMASS 2 Operation ≈2019? close to LZ at high mass

PATRAS May 17, 2017 12 B.Sadoulet Large WIMP Mass 2 ARGON (New) Argon Collaboration • DarkSide-20k approved by Researchers from o DarkSide INFN and LNGS in April 2017 o DEAP DS-20K multi-100-T o ArDM • 68 institutes o MiniCLEAN

planning to collaborate on future program: • 350 researchers

o Completion of current science and R&D programs by each collaboration • 12 nations: (DS-50, DEAP-3600, MiniCLEAN, ArDM)

o Joint collaboration on DS-20K at LNGS, including Low Radioactivity Brasil, Canada, China, Argon (operation starting 2021) and SiPM photodetectors France, Greece, Italy,

o Joint collaboration on future multi-hundred-tonne LAr detector, site TBD Poland, Romania, Spain, (mid-2020’s) Switzerland, UK, USA 10-41

Mark Boulay WARP (2007) 10-42 PICO (2015)

-43 10 DarkSide-50 (2015)

-44 CDMS 10 (2015) DarkSide-50 (3 yr proj.) XENON100 (2012) ] 2 -45 LUX (2016) 10 PandaX-II (2016)

[cm -46

σ 10

DarkSide-20k (100 t yr proj.) -47 10 1 ν-induced NR DarkSide-20k (200 t yr proj.) Argo (1000 t yr proj.) 10-48

10-49 Coherent neutrino-nucleus scattering floor

10-50 10 102 103 104 M [GeV/c2] PATRAS May 17, 2017 χ 13 B.Sadoulet Large Mass WIMPs 3 DARWIN cf Talk of M. Schumann Reaching the neutrino floor TDR ≈ 2021 Operation in 2027?

Spin dependent: noble liquids+ PICO

Future

PATRAS May 17, 2017 14 B.Sadoulet Low WIMP Mass

PATRAS May 17, 2017 15 B.Sadoulet CDMS:Use of Phonons and Cooper Pairs

<1meV quanta h+ e- => sensitivity but requires ≈30mK detailed information about the event

Recognition of nuclear recoils Nuclear Recoils • 8% e-/h+ • 92% phonons Electron Recoils • 25% e-/h+ Charge/Phonon • 75% phonons

Fiducialization ionization or phonons Recoil Energy (keVr) We can efficiently get rid of surfaces

Luke Phonons Amplification of ionization ΔV CDMS-HV: give up nuclear recoil ID Recoil Phonons

Etotal = Einitial phonons + NqΔV

PATRAS May 17, 2017 16 B.Sadoulet SuperCDMS SNOLAB Selected as part of the US Generation 2 experiments Mission: Cover the low WIMP mass region: 0.5-10 GeV/c2 Low temperature technology sensitivity is unique in this region Science does not require very large target mass. Complementary to noble liquids Project currently being baselined for CD2/3 in Dec 2017 first data in 2020 1st HV tower to be tested at CUTE underground facility in 2019 and possibly producing first science

CDMS project goals 1) Design, build an experimental infrastructure able to reach the neutrino floor Cryogenic system Shield Ultra low radioactivity tower design able to accommodate next generation HV (improved CDMSLite) and phonon+ionization (iZIP) detectors. + flexibility to adapt to new ideas/discoveries in the next decade. 2) Construct first generation payload able to make impressive progress at low mass in the first two years: 2HV,2 iZIP iZIPs used in this first payload to reliably estimate HV background and allow background subtraction

CDMS Short 6/21/2016 17 B.Sadoulet (≈2020)

PATRAS May 17, 2017 18 B.Sadoulet SuperCDMS Science Goals

First pay load -> �� ] -�� -� �� ]

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Optimal Interval �� no background subtraction -�� -� but will attempt (better by 5) �� -�� no nuclear recoil -�� -� discrimination for HV �� ν �� 3 - H dominant for Ge �� ν �� 32 �� Si dominant for Si �� -�� -�� Upgrade paths Phys. Rev. D 95, 082002 (2017) SuperCDMS+Eureca ��-�� -��

Serious discussion of ��- �� - ��

merging at SNOLAB => �� -�� larger target mass x2-3 �� e.g., for 4 to 10 GeV/c2+8B �� [��/��] Recovering nuclear recoil discrimination at low mass, e.g., through ≤10eV rms Note phonon resolution in HV New sensitivity curves with background subtraction detectors -> Neutrino Floor prepared for the summer

CDMS Short 6/21/2016 19 B.Sadoulet EDELWEISS Thermal Phonon +Ionization

Potentially in SuperCDMS cryogenic infrastructure in SNOLAB (Canada) 2020+

PATRAS May 17, 2017 20 B.Sadoulet CRESST light + phonon CRESST II 250g CaW04 300 eV threshold, σ= 80eV Impressive limit ��-�� -�

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See Kluck’s talk

PATRAS May 17, 2017 21 B.Sadoulet Low WIMP mass

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PATRAS May 17, 2017 22 B.Sadoulet Other Ideas Gas Mostly low mass Non directional TREX-DM see talk by Theopisti Dafni Large gas spheres (Gerbier,Giomataris arXiv:1512.04346)

Directional: Clever schemes DRIFT, DMTPC, NEWAGE (Physics Procedia 61 (2015) 737 – 741) For the time being relatively high threshold

e.g. DRIFT J.B.R. Battat et al. / Astroparticle Physics 91 (2017) 65–74

PATRAS May 17, 2017 23 B.Sadoulet The “Immediate” Future

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PATRAS May 17, 2017 24 B.Sadoulet Further Out Ideas: Ultra Low Mass At low mass plenty of mass, plenty of signal with Luke-Neganov amplification in SuperCDM- HV +Edelweiss but need to reduce background 32Si,3 H, 210Pb on surfaces restore background rejection (when ionization peters out) 2 ideas to restore background rejection Long term SuperCDMS R&D: increase phonon resolution down to <10eV rms (should go as Tc3 but needs careful control of parasitic power => restoration of nuclear recoils discrimination for HV mode of operation: e.g., 1 e-h pair for electron recoil =3 eV, total phonon energy at 100V= 3+100 eV for nuclear recoil= 30 eV, total phonon energy at 100V= 30+100 eV => ionization+ phonon with phonon measurement only by using the locality of Luke Phonon emission. 4He (McKinsey renewing HERON idea) Go drastically lower in mass ≈ keV (warm dark matter) Kathryn Zurek/Matt Pyle: breaking Cooper Pair in superconductors difficulty of dealing with single quanta (cf. QBits)

PATRAS May 17, 2017 25 B.Sadoulet Where Are We Going? Importance of the 13 TeV LHC run - Discovery of supersymmetry: still possible - No new physics: Even larger importance of direct detection -> Dark Sector (low mass) + High Mass

Impressive technical progress Importance of current program - Pushing both down and left Do not be afraid to be creative e.g.,DNA (Druikier) which through sequencing tricks could provide nm position resolution - Search broadly, not only under the theoretical lamp post - However, try to reach critical mass: unambiguous results Fascinating time 4 prong approach=> complementary coverage constrain theory speculations

PATRAS May 17, 2017 26 B.Sadoulet