What is the probability that direct detection experiments have observed Dark Matter?

Abstract

In Dark Matter direct detection we are facing the situation of some experiments reporting positive signals which are in conflict with limits from other experiments. Such conclusions are subject to large uncertainties introduced by the poorly known local Dark Matter distribution. We present a method to calculate an upper bound on the joint probability of obtaining the outcome of two potentially conflicting experiments under the assumption that the Dark Matter hypothesis is correct, but completely independent of assumptions about the Dark Matter distribution. In this way we can quantify the compatibility of two experiments in an astrophysics independent way. We illustrate our method by testing the compatibility of the hints reported by DAMA and CDMS-Si with the limits from the LUX and SuperCDMS experiments. The method does not require Monte Carlo simulations but is mostly based on using Poisson statistics. In order to deal with signals of few events we introduce the so-called "signal length" to take into account energy information. The signal length method provides a simple way to calculate the probability to obtain a given experimental outcome under a specified Dark Matter and background hypothesis.

23 pages, 7 figures, v2: version accepted for publication in JCAP, added section 6

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• Dark Matter Results from 225 Live Days of XENON100 Data
• New results from DAMA/LIBRA
• Results from a Search for Light-Mass Dark Matter with a P-type Point Contact Germanium Detector
• Search for Low-Mass WIMPs with SuperCDMS
• Results from a Low-Energy Analysis of the CDMS II Germanium Data
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• Interpreting Dark Matter Direct Detection Independently of the Local Velocity and Density Distribution
• Taking Halo-Independent Dark Matter Methods Out of the Bin
• Quantifying (dis)agreement between direct detection experiments in a halo-independent way
• Halo Independent Direct Detection of Momentum-Dependent Dark Matter
• Statistical Issues in Astrophysical Searches for Particle Dark Matter
• Quantifying the evidence for Dark Matter in CoGeNT data

Cited by in corpus (6)

• On the Direct Detection of Dark Matter Annihilation
• Studying generalised dark matter interactions with extended halo-independent methods
• Limits on the flux of nuclearites and other heavy compact objects from the "Pi of the Sky" project
• Assessing Compatibility of Direct Detection Data: Halo-Independent Global Likelihood Analyses
• A halo-independent lower bound on the dark matter capture rate in the Sun from a direct detection signal
• Halo-Independent analysis of direct dark matter detection data for any WIMP interaction