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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. 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

11. 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

12. “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

13. 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

14. 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

15. 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 ~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

16. Neal Weiner, NYU; IDM 2008

17. Neal Weiner, NYU; IDM 2008

18. Neal Weiner, NYU; IDM 2008

19. Neal Weiner, NYU; IDM 2008

20. Neal Weiner, NYU; IDM 2008

21. Neal Weiner, NYU; IDM 2008

22. Neal Weiner, NYU; IDM 2008

23. Neal Weiner, NYU; IDM 2008

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25. Neal Weiner, NYU; IDM 2008

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