- iDM@IDM - Interpreting DAMA with Inelastic Dark Matter: - iDM@IDM - Interpreting DAMA with Inelastic Dark Matter: Predictions for Ge,I,Xe,W CHANG, KRIBS, TUCKER-SMITH, NW HEP-PH/0807.2250 Neal Weiner Center for Cosmology and Particle Physics New York University

INTERPRETING DAMA DAMA has 8.2 s result Seems incompatible with standard WIMPs scattering via SI interactions If it is dark matter, what is it? why has it not been seen in other experiments? what are the implications for other experiments? (i.e., how do you test it?) Neal Weiner, NYU; IDM 2008

INELASTIC DARK MATTER (TUCKER-SMITH, NW 2001) Inelastic dark matter provides a simple explanation for DAMA while yielding null results at other experiments Achieves this through three principle effects Suppressing signals at lighter targets vs heavier (i.e. Ge vs I) Enhancing the modulated signal vs unmodulated (as high as 100% but typically 20-30%) Eliminating low energy events, with signal peaking at higher energies (~ 35 keV for I/Xe, ~ 70 keV for Ge, ~25 keV for W) Neal Weiner, NYU; IDM 2008

WHAT IS INELASTIC DARK MATTER? The inelastic dark matter scenario is defined by two basic features (Tucker-Smith + NW, 2001) Two dark matter states, c and c*, with a splitting Elastic scattering: (c N -> c N) is highly suppressed or zero, inelastic scattering: (c N -> c* N) is allowed Must have enough energy to scatter Different kinematics -> different signals Neal Weiner, NYU; IDM 2008

ARISES NATURALLY FROM WEAK INTERACTIONS A Dirac fermion y is composed of two degenerate Majorana fermions c1 and c2 The Z-boson couples off diagonally between these states, i.e. Neal Weiner, NYU; IDM 2008 c1 c2 = c* N Z N

These two states are degenerate because of a U(1) symmetry (e. g These two states are degenerate because of a U(1) symmetry (e.g., hypercharge). If that is broken, these states become split by an amount d Some examples: fourth generation “neutrino”/Higgsino (Tucker-Smith,NW 2005), “sneutrino” (Han, Hempfling ‘97; Hall, Moroi,Murayama ’98, Arkani-Hamed et al ‘01) The inelasticity is very natural the coincidence d ~ mc v2 needs to be explained by a more fundamental theory Neal Weiner, NYU; IDM 2008

A SMALL SPLITTING WITH BIG CONSEQUENCES Must have enough kinetic energy to scatter This is more stringent for lighter target nuclei Neal Weiner, NYU; IDM 2008 visible to DAMA f(v) visible to DAMA and CDMS

MODULATION IS ENHANCED Because this model is sensitive to the high velocity component of the halo, modulation is significantly enhanced Need more stringent limits than in the elastic case Neal Weiner, NYU; IDM 2008 Mc=100 GeV

SPECTRUM IS DRAMATICALLY MODIFIED Standard WIMPs have spectrum which peaks at low ER Neal Weiner, NYU; IDM 2008 Angle, et al, PRL 2008 One event at low energy gives strong limits

SPECTRAL DIFFERENCES IMPORTANT XENON10 data adjusted for efficiencies (taking unpublished acceptance x efficiency = 0.3, error bars estimated) Neal Weiner, NYU; IDM 2008 Mc=100 GeV, d = 120 keV, normalized inelastic XENON10 signal Mc=100 GeV, d = 120 keV, normalized to DAMA 2-6 keV

EVEN HEAVIER TARGETS CRESST has a tungsten (CaWO4) target (see talk by F. Petricca) W (A~184) vs I (A~127) should be able to test this scenario Neal Weiner, NYU; IDM 2008 Six events seen in tungsten band – would have naturally expected ~10 assuming Maxwell-Boltmann halo, normalizing to DAMA Background? Next set of CRESST results should clarify

“BENCHMARK” POINTS ZEPLIN II (Xe) Upcoming ZEPLIN III results can further constrain (see talk by T. Sumner) “BENCHMARK” POINTS Neal Weiner, NYU; IDM 2008 KIMS: CsI – should have order of magnitude or more increase in exposure soon

Will be updating all to pmax shortly Limits are not Poisson; pmax for CRESST, max gaps for others (Yellin ‘02); Will be updating all to pmax shortly XENON10 KIMS CDMS ZEPLIN II Neal Weiner, NYU; IDM 2008 CRESST – tension principally that 90% Poisson limit from 6 events is 10.5, which is ~ iDM expected

A PLEA: Not all models look like standard neutralinos! High energy events can be important, too. Please, please include information on high energy even if it isn’t relevant to your analysis (events, efficiencies) Pretty please Neal Weiner, NYU; IDM 2008

CONCLUDING Inelastic dark matter provides a model in which the DAMA results are consistent with other existing results “Inelastic” phenomenology easy to realize in particle physics – d ~ mcv2 input by hand Not a moving target, predictions are same as in 2001 Heavier targets favored Significant spectral distortion Irrespective of DAMA, provides alternative scenario to test with different properties from standard WIMPs Upcoming results from Ge (peak @ ~70 keV), Xe (35 keV), I (35 keV) and W (25 keV) should definitively test this explanation for the DAMA signal Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

Neal Weiner, NYU; IDM 2008

VESC=600 KM/S Neal Weiner, NYU; IDM 2008