Is a WIMP explanation of the DAMA modulation effect still viable? - PowerPoint PPT Presentation

Is a WIMP explanation of the DAMA modulation effect still viable? Gaurav Tomar Based on Phys.Rev. D99 (2019) no.2, 023017 and JCAP 1906 (2019) no.06, 048 In collaboration with S. Scopel, S. Kang, and J. H. Yoon Sogang University, Seoul

Search of Dark Matter Dark matter can be searched by many ways: Status of Dark Matter Detection: 1707.06277 1 / 39

WIMP direct detection Elastic recoil of non relativistic halo WIMPs off the nuclei of an underground detector. � Recoil energy of the nucleus lies in the keV range. � Expected signal is very low. � large exposure and extremely low background is required. 2 / 39

The DAMA signal � First result published 20 years ago. � In strong tension with experiments using different target material for standard spin-independent, spin-dependent interactions and Maxwellian velocity distribution. � Modulation detectors sharing the similar NaI target (ANAIS(?), COSINE-100) are not yet sensitive enough. � Limits extended to specific generalizations: inelastic scattering, non-relativistic models, halo-independent approaches etc. 3 / 39

Theoretical predictions for the WIMP direct detection depend on two main ingredients: 1. A scaling law for the cross-section to compare experiments with different targets Spin-independent interaction: σ χ N ∝ [ c p Z + ( A − Z ) c n ] 2 Spin-dependent WIMP–nucleon interaction: � 2 � c p S A p + c n S A σ χ N ∝ n 2. A model for the velocity distribution of WIMPs Generally, a Maxwellian distribution 4 / 39

Nuclear response functions at vanishing momentum transfer S.Kang, S.Scopel, GT, J.H. Yoon, “Present and projected sensitivities of Dark Matter direct detection experiments to effective WIMP-nucleus couplings” Astropart.Phys. 109 (2019) 50-68 Nuclear response function W ′ s is normalized such as 16 π 16 π (2 j T + 1) × W p TM ( y = 0) = Z 2 TM ( y = 0) = ( A T − Z T ) 2 (2 j T + 1) × W n T , 5 / 39

Reduction of sensitivity ◦ Isospin-violating models (1102.4331, 1205.2695) , � c n Z c p ≃ Z − A ≃ − 0 . 7 ◦ WIMP-Xenon interaction is suppressed which reduces the sensitivity of Xenon detector. ◦ A Spin–Dependent WIMP–nucleon interaction, � L int ∋ c p � S χ · � S p + c n � S χ · � S n , ◦ Only two isotopes with 47% of target number contribute reducing the sensitivity of Xenon detector. We will use DAMA as a benchmark to explore these scenarios and what about other non-standard interactions? 6 / 39

Non-relativistic EFT

� Hamiltonian density of WIMP-nucleus interaction, 15 ( c 0 j + c 1 � H ( r ) = j τ 3 ) O j ( r ) j =1 c p j = ( c 0 j + c 1 j = ( c 0 j − c 1 j ) / 2 (proton) and c n j ) / 2 (neutron) � All operators is guaranteed to be Hermitian if built out of the following four 3-vectors, i � q v ⊥ , � S χ , � m N , � S N v ⊥ = � v ⊥ · � with � v + � q / 2 µ N ⇒ � q = 0 . A.L.Fitzpatrick, W.Haxton, E.Katz, N.Lubbers and Y.Xu, JCAP1302, 004 (2013),1203.3542. 8 / 39

Possible operators N.Anand, A.L.Fitzpatrick and W.C.Haxton, Phys.Rev.C89, 065501 (2014),1308.6288. S N · ( � q O 2 = ( v ⊥ ) 2 ; O 3 = i � v ⊥ ) = 1 χ 1 N ; m N × � O 1 S χ · ( � q S χ · � q S N · � q S χ · � � O 5 = i � O 6 = ( � m N )( � v ⊥ ); O 4 = S N ; m N × � m N ) S N × � q � v ⊥ ; O 8 = � v ⊥ ; O 9 = i � S χ · ( � = S N · � S χ · � m N ) O 7 S N · � q S χ · � q i � O 11 = i � O 12 = � S χ · ( � v ⊥ ) O 10 = m N ; m N ; S N × � S N · � S χ · � q q i ( � v ⊥ )( � O 14 = i ( � m N )( � v ⊥ ) = S χ · � m N ); S N · � O 13 S χ · � q v ⊥ ) · � q − ( � m N )(( � S N × � O 15 = m N ) . 9 / 39

Factorization of WIMP physics and nuclear physics � The expected rate, dR χ T ρ WIMP � d σ T � d 3 v T f ( � ( t ) = v T , t ) v T , N T dE R m WIMP dE R v min T with, d σ T = 2 m T � 1 1 � 2 j T + 1 |M T | 2 , 4 π v 2 dE R 2 j χ + 1 T � Besides usual spin-dependent and spin-independent interactions, new contributions arise with explicit dependence on � q and WIMP incoming velocity. 10 / 39

pSIDM: proton-Philic Spin Dependent Inelas- tic Dark Matter

pSIDM WIMP model for DAMA which complies with other experiments. How? � Xe, Ge are neutron odd targets. Spin-dependent WIMP-proton cross-section by choosing, c n / c p = − 0 . 028 � F is proton odd target. v ∗ Na , I esc < v ∗ F < v lab min min � v ∗ min = 2 δ/µ χ N 12 / 39

Inelastic Dark Matter In Inelastic scenario δ � = 0 m χ ′ − m χ = δ The minimal velocity to deposit a recoil 1 � � m N E R � � √ 2 m N E R v min = + δ � � µ χ N � � 13 / 39

pSIDM S.Kang, S.Scopel, GT, J.H. Yoon, “Proton-philic spin-dependent inelastic dark matter as a viable explanation of DAMA/LIBRA-phase2” Phys.Rev. D99 (2019) no.2, 023017 m χ =12.1 (GeV) 0.030 XENON1T 10 −30 χ 2 =13.1937 CDMSLite DAMA0 δ =18.3 (keV) 0.025 COUPP σ 0 =7.95e-35 (cm 2 ) 10 −32 PICO60( C 3 F 8 ) S m (cpd/kg/keVee) 0.020 σ 0 (cm 2 ) PICASSO total PANDAX -II sodium SuperCDMS 0.015 10 −34 iodine CDEX DAMA KIMS 0.010 CRESST-II 10 −36 PICO60( CF 3 I ) COSINE-100 0.005 DAMA 10 −38 0.000 9 10 11 12 13 14 15 16 1 2 3 4 5 6 7 8 m χ (GeV) E ′ (keVee) Maxwellian velocity distribution 14 / 39

̃ pSIDM S.Kang, S.Scopel, GT, J.H. Yoon, “Proton-philic spin-dependent inelastic dark matter as a viable explanation of DAMA/LIBRA-phase2” Phys.Rev. D99 (2019) no.2, 023017 η 0 ( v min )+ ˜ η 1 ( v min ) cos[ ω ( t − t 0 )] η ( v min , t ) = ˜ ˜ 10 −14 XENON1T CDMSLite 10 −16 DAMA0 η (days −1 ) PANDAX -II SuperCDMS � ∞ 0 dv min ˜ CDEX η i R [ E ′ 10 −18 KIMS 1 , E ′ 2 ] ˜ CRESST-II η i [ v min , 1 , v min , 2 ] = � ∞ COSINE-100 DAMA 0 dv min R [ E ′ 10 −20 1 , E ′ 2 ] R i 10 −22 [ E ′ 1 , E ′ 640 660 680 700 720 740 760 780 2 ] v min (km/s) = � ∞ 0 dv min R [ E ′ 1 , E ′ 2 ] Halo independent case. 15 / 39

pSIDM 32 m χ = 11.4 GeV, δ = 23.7 KeV 30   ′ , ξ = 1.0  ′ , ξ = 0.8 28  ′ , ξ = 0.6  ′ , ξ = 0.4 26  ′ , ξ = 0.2 δ (KeV)  ′ , ξ = 0.1 24 22 20 18 6 8 10 12 14 16 18 m χ (GeV) ξ : modulation fraction; D : compatibility factor ∗ pSIDM is still viable for 18 keV < δ < 29 keV, 8 GeV < m χ < 17 GeV. 16 / 39

pSIDM and COSINE-100 COSINE-100 Collaboration, G. Adhikariet al., Nature 564 (2018) 83-86 � Exclude DAMA at low mass using similar target, NaI � Spin-independent interaction � Maxwellian velocity distribution 17 / 39

pSIDM and COSINE-100 � Important point: DAMA measures modulation S DAMA while m COSINE-100 constraints time average S COSINE . 0 S DAMA / S COSINE is model dependent m 0 � S DAMA ≃ 0 . 02 events/kg/day/keVee, S COSINE ≤ 0 . 13 m 0 events/kg/day/keVee S DAMA = S DAMA × S COSINE m m 0 ≥ 0 . 12 S DAMA S COSINE S DAMA 0 0 0 � In Spin-independent case: S DAMA m < 0 . 12, for pSIDM scenario: S DAMA 0 S DAMA m > 0 . 12 S DAMA 0 S.Kang, S.Scopel, GT, J.H. Yoon, “Proton-philic spin-dependent inelastic dark matter as a viable explanation of DAMA/LIBRA-phase2” Phys.Rev. D99 (2019) no.2, 023017 18 / 39

COSINE-100 and DAMA- phase2

Assumptions and Inputs � One coupling is dominant at a time. � Sensitivity is expressed in terms of 90% C.L. bounds on effective cross-section, σ N , lim = max( σ p , σ n ) j ) 2 µ 2 j ) 2 µ 2 χ N χ N σ p = ( c p σ n = ( c n , π π 20 / 39

COSINE-100 and DAMA-phase2 in WIMP effective models COSINE-100 Collaboration, S.Kang, S.Scopel, GT, J.H. Yoon, “COSINE-100 and DAMA/LIBRA-phase2 in WIMP effective models” JCAP 1906 (2019) no.06, 048 21 / 39

COSINE-100 Collaboration, S.Kang, S.Scopel, GT, J.H. Yoon, “COSINE-100 and DAMA/LIBRA-phase2 in WIMP effective models” JCAP 1906 (2019) no.06, 048 22 / 39

� NR EFT couplings besides standard SI and SD interactions have larger modulation fraction � Average rate less sensitive to modulation. no exclusion for most of them. 23 / 39

106 kg of NaI, 97.7 kg yr 112.5 kg of NaI, 157.55 kg yr Phys.Rev.Lett. 123 (2019) no.3, 031301 “consistent with both a null hypothesis and DAMA/LIBRA’s Phys.Rev.Lett. 123 (2019) no.3, 2-6 keV best fit value“ 031302 Need more statistics. ANAIS ”best fits in [2-6] Kev and [1-6] shares the same threshold of keV energy intervals incompatible DAMA-phase-2 (1 keV), at 2.5 σ and 1.9 σ “ COSINE-100 threshold is 2 keV 24 / 39

WIMPyDD: code for dark matter direct detection � Based on Python. � 14 existing experiments included: XENON1T, PandaX-II, KIMS, CDMSLite, SuperCDMS, COUPP, PICASSO, PICO-60 ( CF 3 I and C 3 F 8 targets), CRESST-II, DAMA (modulation data), DAMA0 (average count rate), CDEX, and DarkSide-50 � Allows to implement experiments by providing energy resolution, exposure, efficiency, quenching etc in different forms. � Flexible to easily implement any new experiment and/or update new information. Efficient to calculate and handle a large number of response functions. � Tabulates the response functions as a function of the recoil energy. 25 / 39