Exclusion limits from data of directional Dark Matter detectors

Abstract

Directional detection is a promising search strategy to discover galactic Dark Matter. Taking advantage on the rotation of the Solar system around the Galactic center through the Dark Matter halo, it allows to show a direction dependence of WIMP events. Even though the goal of directional search is to identify a WIMP positive detection, exclusion limits are still needed for very low exposure with a rather large background contamination, such as the one obtained with prototype experiments. Data of directional detectors are composed of energy and 3D track of recoiling nuclei. However, to set robust exclusion limits, we focus on the angular part of the event distribution, arguing that the energy part of the WIMP distribution is featureless and may even be mimic by the background one. Then, as the angular distributions of both background and WIMP events are known, a Bayesian approach to set exclusion limits is possible. In this paper, a statistical method based on an extended likelihood is proposed, compared to existing ones and is shown to be optimal. Eventually, a comprehensive study of the effect of detector configuration on exclusion limits is presented. It includes the effect of having or not sense recognition, a finite angular resolution, taking into account energy threshold as well as some astrophysical uncertainties.

12 pages, 11 figures, final version, to appear in Phys. Rev. D (2010)

References in corpus (13)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Likelihoods and Parameters from the WMAP data
• The Astrophysical Uncertainties Of Dark Matter Direct Detection Experiments
• Improved Spin-Dependent WIMP Limits from a Bubble Chamber
• Optimizing WIMP directional detectors
• Determining the WIMP mass using direct detection experiments
• Determining the WIMP mass from a single direct detection experiment, a more detailed study
• Direction-sensitive dark matter search results in a surface laboratory
• Determining the WIMP mass using the complementarity between direct and indirect searches and the ILC
• The median recoil direction as a WIMP directional detection signal
• Observation of the 'head-tail' effect in nuclear recoils of low-energy neutrons
• First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches
• MIMAC : A Micro-TPC Matrix of Chambers for direct detection of Wimps
• The Maximum Patch Method for Directional Dark Matter Detection

Cited by in corpus (4)

• Markov Chain Monte Carlo analysis to constrain Dark Matter properties with directional detection
• Micromegas detector developments for Dark Matter directional detection with MIMAC
• Exploring SUSY light Higgs boson scenarios via dark matter experiments
• Directional detection of non-baryonic dark matter with MIMAC