Constraints on Inelastic Dark Matter Signal using ZEPLIN-II Results

TL;DR

This paper uses ZEPLIN-II detector data to set new constraints on inelastic dark matter models, excluding large parameter spaces and challenging previous claims for WIMPs over 100 GeV.

Contribution

It provides the first strong experimental limits on inelastic dark matter using ZEPLIN-II data with background discrimination and background subtraction techniques.

Findings

ZEPLIN-II data excludes significant iDM parameter space.

Limits suggest >99% confidence exclusion of previous iDM claims.

Constraints are especially strong for WIMP masses over 100 GeV.

Abstract

There has been an increasing interest on the concept of Inelastic Dark Matter (iDM) - motivated in part by some recent data. We describe the constraints on iDM from the results of the two phase dark matter detector ZEPLIN-II, which has demonstrated strong background discrimination capabilities (>98%). Using previously published estimates of the ZEPLIN-II residual background, the iDM limits presented here exclude a significantly larger iDM parameter space than the limits derived without background subtraction. Moreover, assuming standard xenon quenching factor (qXe) of 0.19, our ZEPLIN-II limits strongly suggest the exclusion of iDM signal claims at >99% C.L., for Weakly Interacting Massive Particles (WIMPs) masses >100 GeV.