Bernard Sadoulet Dept. of Physics /LBNL UC Berkeley UC Institute for Nuclear and Particle Astrophysics and Cosmology (INPAC) UC Dark Matter Initiative The G2 Direct Detection Program in a Broader Scientific Context The Nature of Dark Matter: Current understanding: observations/theoretical ideas The Generation 2 Direct Detection Dark Matter Program ADMX, LZ, CDMS: Plans and Challenges Complementarity with other US and international efforts Timeliness Preparing for the Generation 3 Be ready for a breakthrough Not for presentation: Appendix: submission by collaborations (51 slides!). A useful snapshot of Direct Detection in the world Many thanks to my colleagues, but opinions/errors are mine! HEPAP 140930 1 B.Sadoulet The Nature of Dark Matter Current understanding: observations/paradigms HEPAP 140930 2 B.Sadoulet Standard Model of Cosmology A surprising but consistent picture Λ Ω Ωmatter Not ordinary matter (Baryons) Nucleosynthesis Ωm >> Ωb = 0.049 ± 0.001 from WMAP/Planck χ h2 h2 + internally to WMAP/Planck Ωm ≠ Ωb ≈20 σ's Mostly cold: Not light neutrinos≠ small scale structure HEPAP 140930 3 B.Sadoulet Particle Physics:Favorite Possibilities Axions <= Strong CP problem 10-6 -3 eV Peccei Quinn solution: dynamic restoration of CP Weak scale WIMPs <= hierarchy problem 1011-12 eV ! Freeze out when annihilation rate ≈ expansion rate ! 3⋅10-27 cm3 / s α 2 ! ⇒ Ω h2 = ⇒ σ ≈ ≡ Weak scale x σ v A M 2 ! A EW coincidence between Cosmology and Particle Physics Dark Matter Hidden Sector: not necessarily weak scale e.g., Asymmetric Dark Matter (Zurek) <-> Baryon-Antibaryon asymmetry ρdark matter 2 ≈ 6 ⇒ M dark matter ≈ 6 GeV/c ! ρbaryon Dark Photon (Arkani Hamed-Finkbeiner-Weiner), atomic DM, Self Interacting Intriguing but less predictive 106-13 eV Sterile neutrino in keV range ≈103 eV with very small mixing angle (≠1 eV) HEPAP 140930 4 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. CDMS, Xenon 100,etc. HEPAP 140930 55 B.Sadoulet Recent inputs from Cosmology Remarkable success of Lambda CDM Cosmic Microwave Background Large scale structure ! Potential Problems at small scale Observe Core instead of NFW cusp Do not observe enough large satellites “which should too big to fail” ! Debate on whether this is a sign of Poor understanding/simulation of gas and feedback mechanisms or new dark matter physics Warm Dark Matter: few keV sterile neutrino with tiny mixing angles Some excitement about an 3.5 keV X ray line (but ≤3σ) => 7keV sterile neutrino seen in Andromeda, Perseus Cluster, co-added clusters Balbul et al. arcXiv: 1402.2031 Boyarski et al. arXiv:1402.4119 but not in co-added dwarfs. Should be clear with Astro-H! Would probably have the same problem as CDMD with cusp ! Self Interactive Dark Matter: which would smooth the center distribution Would clearly be a sign for a “Dark Sector” HEPAP 140930 6 B.Sadoulet Particle Detection Axions No detection so far but at the Cosmological limit HEPAP 140930 7 B.Sadoulet Direct Detection Current- Situation (September 2014)- C D D A M - M S - I l C i t e (2012) ( - 2 - 0 CoGeNT ] 1 (2012) ] 3 ) - S CDMS Si - u [ (2013) p [ e r - AsymmetricC SIMPLE (2012) - D DAMA M COUPP (2012) S CRESST CRESST (2014) - L - Dark T ZEPLIN-III (2012) (2 01 - 4) CDMS II Ge (2009) - OH EDELWEISS (2011) C ER Xenon100 (2012) EN - 7Be T - N LUX (2013) EU Neutrinos TR TTERIN IN O SCA G - 8B - Neutrinos - C - - O - HE Higgs - R - E G NT RIN ATTE SC N O RIN - NEUT - E ENT U COHER TR - I N RING - O SCATTE Atmospheric and DSNB Neutrinos - - [/] HEPAP 140930 8 B.Sadoulet Low Mass Region Optimistic Accumulation of claims in that region The exclusion by some experiments is based on unreliable calibration CDEX-1 Just the region expected for asymmetric dark matter ! Pessimistic Not compelling evidence ! Close to threshold: Outliers ? ! Excluded by XENON100 LUX SuperCDMS Soudan Hope for grand unification of claims was clearly premature! HEPAP 140930 9 B.Sadoulet Modulation DAMA clear summer-winter modulation ! ! Wide suspicion that this is instrumental but no convincing explanation so far! CoGeNT weak evidence CoGeNT 5 year data to be released soon Not necessarily a proof of Not seen in CDMS II above 5 keVnr WIMPs Difficult control of systematics But we need to check! ! KIMS NaI 200kg run starts at the end of 2015 ANAIS DM-ICE NaI See appendix SABRE NaI low radioactivity neutron veto C4 (Ge) HEPAP 140930 10 B.Sadoulet Spin dependent limits (e.g. p) Finally entering SUSY region LHC Monojets (χγ µγ 5 χ)(qγ µγ 5q) HEPAP 140930 11 B.Sadoulet Indirect Detection No significant evidence Fermi-LAT arXiv:1310.0828 from dwarf galaxies although limit at small masses higher than expected in all channels arXiv:1310.0828 10-30 GeV/c2 towards Galactic Center? arXiv: 1402.6703 Standard question: Is it dark matter or standard astrophysics: millisecond pulsar also 135 GeV/c2 line: would need strange couplings: no continuum, large �� cross section statistical significance decreasing? HEPAP 140930 12 B.Sadoulet Recent Input from Particle Physics Higgs at 126 GeV/c No sign for supersymmetry CMSSM too simple ->pMSSM,NSSM Crisis of naturalness? Map into Direct Detection No evidence from mono-jets,mono- Plane -2 10 -35 -35 10 -35 10 10 mφ >> m 10-3 CRESST-I X m φ >> mm ’s -40 -40 φ >> m 10 XENON 10 10 -40 X � -4 10 X 10 GeC -5 ] A ] ] 2 -45 2 10 2 10 10-45 -45 Note: Limits only apply with high mass mediator e 10 B g [cm [cm [cm e e -6 p σ σ 10 σ Large width -50 -50 10 10 10-50 Large width Dark Sector models have typically low mass 10-7 Large width Decay beforeDecay BBNbefore BBN -8 10 -55 -55 -55 10 Decay before BBN 10 10 mediators 10-9 0.001 1 0.010 0.100 1.000 10 0.001 0.0010.010 0.010 0.100 0.100 1.000 1.000 m [GeV]m [GeV] m [GeV]m [GeV] Complementarity with “Dark Photon” searches φ X X X Lin, Yu, KZ 1111.0293 Figure 5:Figure(Left) 4:Constraints(Left) Nucleon on mediator scattering mass throughmφ and avector coupling mediator. to electrons Thege greenfor m shaφ <mdedX region.Theshadedregion indicates the allowed is excludedparameter from electron space of anomalous direct detection magnetic cross moment, sections. beam The d ligumphter experiments, green region and imposes supernova the bound cooling of thermal [65]. The coupling red dashedbetween line shows the two theProjected sectorsge value (“large used maximum towidth”) derive while the sensitivity corresponding the larger shaof redded direct dashed region detection lineonly (“C”) requiresin experiment the mediator right plot. decay(Right) before BBN. Basic complementarity ConstraintsAlso on shown electron is the scattering lower bound from for Fig. the 4. heavy The mediator boundaries (m A,φ ≫ B,m andX )case. C are(Right) discussedElectron in more scattering detail in through the text. a vector mediator, for mφ <mX (green) and mφ ≫ mX (red); the intersection of the two regions is shaded brown. Weshow the projected sensitivityCut-out of a Ge experiment, gives combined taken from [64constraints]. Beam dump, of supernova,beam dump and halo + supernova shape constraints + g-2 apply here and carve out the region of large σe at low mX .Formoredetails,seethetext.Inthelightergreenregion, LHC probes well: labeledthe as “Decay condition before of thermal BBN” equilibrium in Fig. (4). between the visible andhiddensectorsisimposed. For reference, we also give the lower bound on the cross section in the case where m m .Here φ ≫ X DM annihilation occurs directly to SM final states through φµ, with annihilation cross section σv = 2 2 4 ⟨ ⟩ 4αX gnmX /mφ. Since the same combination of parameters enters in both the annihilation cross section and in this mass range if φµ decays dominantly to electrons, for which the efficiency factor is f 1. For φµ masses below mH/2 or high mass mediator the nucleon scattering cross section, we can directly apply the relic density constraint to obtain ∼ coupling primarily to quarks, f 0.2 and CMB bounds don’t apply above mX 2 GeV. Then the minimum ≈ 2 2 25 3 ∼ 5 annihilation cross section is σv παX /mX 10− cm2 /s, giving a2 bound of αX ! 5.2 10− (mX /GeV). ⟨ ⟩≈ 37 2 ≈1GeV µn × Requiring thermal equilibriumσn ! 5 between10− thecm hidden and visible sectors,. we take the bound on gq in(36) Eq. (26), × mX 0.5GeV with √geff 9. Combining the limits above results! in" a lower bound on the nucleon scattering cross section: intermediate mass in decay of gluinos (≈6x ≈ # $ This is the “mφ mX ” line in Fig. (4). However, this scenario is ruled out by the direct detection limits 4 6 2 ≫ 48 2 mX GeV µn on the cross section. σn ! 10− cm . (34) LSP), but needs to produce it! × GeV mφ 0.5GeV ! " # $ ! " Since m <m , this quantity is saturated for any m if we set m to its maximum value of m m . φ X B. Electron ScatteringX φ φ ∼ X This bound is indicated by the “Large width” line in Fig. (4). Coincidentally, the lower limit here is similar to the best achievable sensitivity for WIMP-nucleon scattering if the dominant irreducible background is Direct Detection do not mind light mediators We consider scattering off electrons for DM in the mass range 1 MeV <m < 1 GeV. The DM-electron coherent scattering of atmospheric neutrinos off of nuclei [71–73].