Constraints on Inelastic Dark Matter Signal using ZEPLIN-II Results

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.