Christopher M. Savage University of Michigan – Ann Arbor Can WIMP Spin Dependent Couplings explain DAMA? Limits from DAMA and Other Experiments Christopher M. Savage University of Michigan – Ann Arbor Katie Freese (University of Michigan) Paolo Gondolo (University of Utah) astro-ph/0408346 11/29/2018 IDM 2004 - Spin Dependent Limits

IDM 2004 - Spin Dependent Limits Overview DAMA/NaI positive signal and CDMS II null result are not compatible for spin-independent couplings (assuming the standard halo model) WIMPs may alternatively have spin-dependent couplings; examine if this case has parameter space consistent with the DAMA signal and the null results of other experiments P. Ullio, M. Kamionkowski, and P. Vogel, JHEP 0107, 044 (2001). F. Giuliani, arXiv:hep-ph/0404010. 11/29/2018 IDM 2004 - Spin Dependent Limits

IDM 2004 - Spin Dependent Limits Direct Detection Detector WIMP Scatter Elastic scattering of WIMP off detector nuclei Rate: Recoils: Efficiencies, quenching, multiple elements CDMS, CRESST, Edelweiss, SIMPLE, ZEPLIN, etc. 11/29/2018 IDM 2004 - Spin Dependent Limits

IDM 2004 - Spin Dependent Limits Annual Modulation 30 km/s 232 km/s WIMP Halo Wind Earth’s motion With disk (June) Against disk (December) Modulation Amplitude: DAMA Nma = 0.0200 ± 0.0032 /kg/day/keVee (2-6 keVee) Elegant V, etc. (R. Bernabei et al., 2003) 11/29/2018 IDM 2004 - Spin Dependent Limits

IDM 2004 - Spin Dependent Limits Indirect Detection n WIMP Gravitational capture  Annihilation Neutrino-induced muons Sun: WIMP-proton cross-section BAKSAN, Super-K, etc. 11/29/2018 IDM 2004 - Spin Dependent Limits

Spin-Dependent Cross-Section Nuclear structure functions Odd proton: Spp >> Snn Odd neutron: Snn >> Spp Finite momentum transfer q = 0  SD  (ap + an)2  (<Sp> ap + <Sn> an)2 q  0: larger masses 11/29/2018 IDM 2004 - Spin Dependent Limits

Spin-Dependent Limits Null Result: Positive Signal: A, B, C Depend on detector parameters, WIMP mass Relative magnitude dependent upon Spp, Spn, Snn Conics Parallel lines Ellipse Multiple Elements EOGM OGM q  0 11/29/2018 IDM 2004 - Spin Dependent Limits

Spin-Dependent Limits Proton only coupling (an = 0) Neutron only coupling (ap = 0) General couplings 11/29/2018 IDM 2004 - Spin Dependent Limits

WIMP-Proton Cross-Section Limits (for an = 0) 11/29/2018 IDM 2004 - Spin Dependent Limits

WIMP-Neutron Cross-Section Limits (for ap = 0) 11/29/2018 IDM 2004 - Spin Dependent Limits

IDM 2004 - Spin Dependent Limits Allowed Couplings 11/29/2018 IDM 2004 - Spin Dependent Limits

Allowed Couplings (Low Mass) 11/29/2018 IDM 2004 - Spin Dependent Limits

IDM 2004 - Spin Dependent Limits Results WIMP masses of 5-13 GeV: Parameter spaces still remain which are compatible with DAMA signal and all null results Allows for comparable proton and neutron couplings (e.g. ap = an = 2.0 at 10 GeV) All solutions have No MSSM candidates 11/29/2018 IDM 2004 - Spin Dependent Limits

IDM 2004 - Spin Dependent Limits Conclusions DAMA can still be explained by a WIMP with spin-dependent couplings, although at masses lower too low for MSSM. Extending analysis of Super-K (BAKSAN) results to lower masses could confirm or rule out the remaining spin-dependent parameter space for DAMA (for standard halo). Odd-Z experiments (CRESST I, SIMPLE) will also be able to examine this remaining space. 11/29/2018 IDM 2004 - Spin Dependent Limits