Prospects for Inelastic Dark Matter Daniele Alves Stanford / SLAC - PowerPoint PPT Presentation

Prospects for Inelastic Dark Matter Daniele Alves Stanford / SLAC In collaboration with M. Lisanti and J. Wacker PHENO ’10

DAMA’s 8.9 σ annual modulation in single hit rate Bernabei et.al. Eur.Phys.J. C56(2008) DM interpretation due to Sun and Earth’s motion

Elastic heavy WIMP interpretation excluded by other searches Aprile et.al. arXiv: 1005.0380 DAMA

Inelastic Dark Matter (iDM) Tucker-Smith & Weiner Phys.Rev. D64 (2001) 043502 m+ δ m m 127 I 127 I E R δ m ~ 100 keV

1 ( δ m + m E µ ) v min = N R √ 2m E N R Heavy elements are favored 0.35 DM Local Velocity Distribution 0.30 0.25 0.20 127 I 0.15 72 Ge 0.10 0.05 0.00 0 100 200 300 400 500 600 v � km � s �

1 ( δ m + m E µ ) v min = N R √ 2m E N R 0.35 Summer DM Local Velocity Distribution 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 100 200 300 400 500 600 v � km � s �

1 ( δ m + m E µ ) v min = N R √ 2m E N R 0.35 Winter DM Local Velocity Distribution 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 100 200 300 400 500 600 v � km � s �

1 ( δ m + m E µ ) v min = N R √ 2m E N R High modulation fraction 0.35 inelastic DM Local Velocity Distribution 0.30 0.25 0.20 Rate elastic 0.15 0.10 0.05 0.0 0.5 1.0 1.5 2.0 2.5 3.0 time � years � 0.00 0 100 200 300 400 500 600 v � km � s �

CRESST experiment might have seen less events than typically predicted by iDM in the 10 - 40 keV region preliminary W. Seidel - WONDER 2010 Workshop

XENON100 only 11 live days of exposure for calibration run strongest current limits on DM XENON100 collaboration arXiv: 1005.0380

XENON100 only 11 live days of exposure for calibration run strongest current limits on DM XENON100 collaboration Decisively arXiv: 1005.0380 CONFIRM or REFUTE iDM hypothesis

What affects predictions for Dark Matter Direct Detection ? Astrophysical uncertainties Local DM velocity distribution Particle physics uncertainties DM interactions & scattering kinematics Detector uncertainties Target nucleus form factor & quenching factor

Astrophysical uncertainties scattering rate in iDM is highly sensitive to velocity distribution � v esc f ( � v + � v earth ) dR d � v dt ∝ v v min standard assumption: Maxwell-Boltzmann distribution v 2 − v 2 esc − v 2 v 2 0 ) Θ ( | � f ( � v ) ∝ ( e v | ) 0 − e v esc − � standard procedure: benchmark velocity parameters and v 0 v esc narrows the parameter space and limits the predictions broader and more sensible procedure: marginalize over unknown velocity parameters

Astrophysical uncertainties numerical simulations of galactic DM structure: significant departure from Maxwell-Boltzmann distribution substructures and streams? Law & Majewski observations of Saggitarius stellar tidal steam Ap.J. 714 (2010) 229-254 triaxial Milky Way halo? symmetry axes of halo and disk unrelated?

Astrophysical uncertainties Investigate 3 scenarios: − v 2 Standard Maxwell-Boltzmann v 2 0 Θ ( | � f ( � v ) ∝ e v | ) v esc − � marginalize over and v 0 v esc Local stream v ) = δ 3 ( � f ( � v stream ) v − � marginalize over magnitude and direction of � v stream − v 2 v ) ∝ e − α L 2 Axisymmetric halo v 2 0 Θ ( | � f ( � v | ) y e v esc − � marginalize over , and v 0 v esc α

Astrophysical uncertainties 1.0 Typical range when Modulation Fraction DM Stream benchmarking 0.8 Mod Fraction 0.6 Axisymmetric 0.4 Maxwellian 0.2 0.0 50 0 20 30 40 10 0.0 0.1 0.2 0.3 0.4 0.5 # CRESST events / 100kg-d (10-40 keV)

Uncertainties in iDM particle properties Cross-Section dependence on momentum transfer (e.g. sneutrino) σ ∝ σ 0 Dark Matter Form Factor (sign of compositeness) σ ∝ σ 0 q 2 (e.g. CiDM) σ ∝ σ 0 q 4

Uncertainties in iDM particle properties DAMA σ 0 σ 0 q 2 Modulation Amplitude � cpd � kg � keVee � ) e 0.03 e V � e k � / g k σ 0 q 4 0.02 / d p c � ( e � t a � R 0.01 � d e � t a � l � u � d 0.00 � o � M 0 20 40 60 80 Recoil Energy � keV �

Uncertainties in iDM particle properties CRESST 0.10 σ 0 σ 0 q 2 Modulation Amplitude � cpd � kg � keVee � 0.03 0.08 Rate � cpd � kg � keV � � � 0.06 σ 0 q 4 0.02 � 0.04 � � 0.01 � 0.02 � � � � 0.00 0.00 � � 0 20 40 60 80 0 20 40 60 80 Recoil Energy � keV � Recoil Energy � keV �

Uncertainties in iDM particle properties 1.0 Typical range when σ 0 q 4 benchmarking Modulation Fraction 0.8 σ 0 q 2 Mod Fraction 0.6 0.4 σ 0 0.2 0.0 0 10 20 30 40 50 0.0 0.1 0.2 0.3 0.4 0.5 # CRESST events / 100kg-d (10-40 keV) � Events � kg � day

Detector uncertainties Quenching Factor for 127 I q = E scintillation E nuclear recoil Several independent measurements found 0 . 05 ≤ q I ≤ 0 . 09 Recoil Energy (keV) Reference Q I q I Bernabei et.al. PLB389 (1996) 22-330 0.09 ± 0.01 Pecourt et.al. ApJ11 (1999) 40-100 0.08 ± 0.02 Tovey et.al. PLB433 (1998) 10-71 0.086 ± 0.007 Fushimi et.al. PRC47 (1993) 40-300 0.05 ± 0.02

Detector uncertainties DAMA q=0.085 ) Modulation Amplitude � cpd � kg � keVee � e 0.03 e V � e k � / g k 0.02 / d p c � ( � e � t a 0.01 � R d � e � t � a l � u 0.00 � � d o M 0 20 40 60 80 100 120 Recoil Energy � keV �

Detector uncertainties DAMA q=0.070 ) Modulation Amplitude � cpd � kg � keVee � Modulation Amplitude � cpd � kg � keVee � e 0.03 0.03 e V � � e k � � / g k 0.02 0.02 / d p c � � ( � � e � � t a 0.01 0.01 � � R d � � e � � t � � a l � � u 0.00 0.00 � � � � d o M 0 0 20 20 40 40 60 60 80 80 100 100 120 120 Recoil Energy � keV � Recoil Energy � keV �

Detector uncertainties DAMA q=0.060 ) Modulation Amplitude � cpd � kg � keVee � Modulation Amplitude � cpd � kg � keVee � Modulation Amplitude � cpd � kg � keVee � e 0.03 0.03 0.03 e V � � � e k � � � / g k 0.02 0.02 0.02 / d p c � � � ( � � � e � � � t a 0.01 0.01 0.01 � � � R d � � � e � � � t � � � a l � � � u 0.00 0.00 0.00 � � � � � � d o M 0 0 0 20 20 20 40 40 40 60 60 60 80 80 80 100 100 100 120 120 120 Recoil Energy � keV � Recoil Energy � keV � Recoil Energy � keV �

Detector uncertainties CRESST q=0.085 0.10 q=0.070 0.08 Rate � cpd � kg � keV � q=0.060 0.06 0.04 0.02 0.00 0 50 100 150 Recoil Energy � keV �

Detector uncertainties # CRESST events / 100kg-d 25 0.25 q=0.060 40-100 keV window 20 0.20 N events � kgday � 40 � 100 keV � 15 0.15 q=0.070 Typical range when benchmarking 10 0.10 q=0.085 5 0.05 0 0.00 40 10 20 30 0 0.0 0.1 0.2 0.3 0.4 10-40 keV window N events � kgday � 10 � 40 keV �

Summary and Conclusions Uncertainties on the DM velocity distribution, DM form factor and 127 I quenching factor have a dramatic impact on predictions for direct detection In light of that, it is unlikely that the next CRESST data release will rule out iDM in a completely model independent way. XENON100 data from this summer will decisively exclude of confirm iDM. In case it confirms iDM, it might tell us a lot about properties of the dark matter particle and our Milky Way halo.

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