XENON10/100 dark matter constraints in comparison with CoGeNT and DAMA: examining the Leff dependence

TL;DR

This paper evaluates the compatibility of various dark matter detection experiments, focusing on how uncertainties in scintillation efficiency affect constraints on low-mass WIMPs, and finds XENON10 provides the strongest bounds conflicting with DAMA/LIBRA and CoGeNT results.

Contribution

It systematically analyzes the impact of Leff uncertainties on XENON constraints and compares their implications with DAMA/LIBRA and CoGeNT findings for low-mass WIMPs.

Findings

XENON10 provides the strongest bounds among XENON experiments.

XENON100 results are insensitive to low-energy Leff extrapolation.

XENON10 constraints are incompatible with DAMA/LIBRA and limit CoGeNT's low-mass WIMP region.

Abstract

We consider the compatibility of DAMA/LIBRA, CoGeNT, XENON10 and XENON100 results for spin-independent (SI) dark matter Weakly Interacting Massive Particles (WIMPs), particularly at low masses (~ 10 GeV), assuming a standard dark matter halo. The XENON bounds depend on the scintillation efficiency factor Leff for which there is considerable uncertainty. Thus we consider various extrapolations for Leff at low energy. With the Leff measurements we consider, XENON100 results are found to be insensitive to the low energy extrapolation. We find the strongest bounds are from XENON10, rather than XENON100, due to the lower energy threshold. For reasonable choices of Leff and for the case of SI elastic scattering, XENON10 is incompatible with the DAMA/LIBRA 3$\sigma$ region and severely constrains the 7-12 GeV WIMP mass region of interest published by the CoGeNT collaboration.