Direct WIMP identification: Physics performance of a segmented noble-liquid target immersed in a Gd-doped water veto

TL;DR

This paper assesses a segmented noble-liquid detector with Gd-doped water veto for direct WIMP detection, demonstrating its potential to significantly reduce neutron backgrounds and probe very low WIMP-nucleon cross sections.

Contribution

It introduces a novel detector design combining noble liquids and Gd-doped water for improved background rejection in WIMP searches.

Findings

Neutron background can be reduced to about 1 event per year per tonne.

A 1-tonne-year exposure can exclude WIMP-nucleon cross sections down to 10^{-10} pb.

The detector design is effective for direct dark matter detection with low background levels.

Abstract

We evaluate background rejection capabilities and physics performance of a detector composed of two diverse elements: a sensitive target (filled with one or two species of liquefied noble gasses) and an active veto (made of Gd-doped ultra-pure water). A GEANT4 simulation shows that for a direct WIMP search, this device can reduce the neutron background to O(1) event per year per tonne of material. Our calculation shows that an exposure of one tonne $\times$ year will suffice to exclude spin-independent WIMP-nucleon cross sections ranging from $10^{-9}$ pb to $10^{-10}$ pb.