Chasing a consistent picture for dark matter direct searches

Abstract

In this paper we assess the present status of dark matter direct searches by means of Bayesian statistics. We consider three particle physics models for spin-independent dark matter interaction with nuclei: elastic, inelastic and isospin violating scattering. We shortly present the state of the art for the three models, marginalising over experimental systematics and astrophysical uncertainties. Whatever the scenario is, XENON100 appears to challenge the detection region of DAMA, CoGeNT and CRESST. The first aim of this study is to rigorously quantify the significance of the inconsistency between XENON100 data and the combined set of detection (DAMA, CoGeNT and CRESST together), performing two statistical tests based on the Bayesian evidence. We show that XENON100 and the combined set are inconsistent at least at 2 sigma level in all scenarios but inelastic scattering, for which the disagreement drops to 1 sigma level. Secondly we consider only the combined set and hunt the best particle physics model that accounts for the events, using Bayesian model comparison. The outcome between elastic and isospin violating scattering is inconclusive, with the odds 2:1, while inelastic scattering is disfavoured with the odds of 1:32 because of CoGeNT data. Our results are robust under reasonable prior assumptions. We conclude that the simple elastic scattering remains the best model to explain the detection regions, since the data do not support extra free parameters. Present direct searches therefore are not able to constrain the particle physics interaction of the dark matter. The outcome of consistency tests implies that either a better understanding of astrophysical and experimental uncertainties is needed, either the dark matter theoretical model is at odds with the data.

18 pages, 8 figures and 7 tables; minor revisions following referee report. Accepted for publication in Phys.Rev.D

References in corpus (22)

• Dark Matter Results from 225 Live Days of XENON100 Data
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Trigonometric Parallaxes of Massive Star Forming Regions: VI. Galactic Structure, Fundamental Parameters and Non-Circular Motions
• New results from DAMA/LIBRA
• The RAVE Survey: Constraining the Local Galactic Escape Speed
• Results from a Low-Energy Analysis of the CDMS II Germanium Data
• The Milky Way's circular velocity curve between 4 and 14 kpc from APOGEE data
• On the local dark matter density
• Constraints on Low-Mass WIMP Interactions on 19F from PICASSO
• New Limits on Interactions between Weakly Interacting Massive Particles and Nucleons Obtained with CsI(Tl) Crystal Detectors
• Measuring the effective complexity of cosmological models
• Commissioning Run of the CRESST-II Dark Matter Search
• Composite dark matter from a model with composite Higgs boson
• The velocity dispersion and mass profile of the Milky Way
• Low-threshold analysis of CDMS shallow-site data
• Complementarity of Dark Matter Direct Detection Targets
• Dark Forces and Light Dark Matter
• Bayesian Selection of sign(mu) within mSUGRA in Global Fits Including WMAP5 Results
• Bayesian Calibrated Significance Levels Applied to the Spectral Tilt and Hemispherical Asymmetry
• First Results of the Phase II SIMPLE Dark Matter Search
• Fundamental statistical limitations of future dark matter direct detection experiments
• Improved determination of the WIMP mass from direct detection data

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• Compatibility of Planck and BICEP2 in the Light of Inflation
• Quantifying the evidence for Dark Matter in CoGeNT data
• Complementarity of direct and indirect Dark Matter detection experiments
• Dwarf spheroidal galaxies and Bose-Einstein condensate dark matter
• On the spin-dependent sensitivity of XENON100
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• Bayesian Reconstruction of the Velocity Distribution of Weakly Interacting Massive Particles from Direct Dark Matter Detection Data
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