A Search of Low-Mass WIMPs with p-type Point Contact Germanium Detector in the CDEX-1 Experiment

TL;DR

This paper reports on the CDEX-1 experiment's search for low-mass WIMPs using a germanium detector, setting new constraints on WIMP interactions with matter based on 335.6 kg-days of data.

Contribution

It presents the first results from the CDEX-1 experiment using a p-type point-contact germanium detector at a low energy threshold for low-mass WIMP detection.

Findings

No excess events observed, consistent with background expectations.

Established new exclusion limits on WIMP-nucleon spin-independent couplings.

Set constraints on WIMP-nucleon spin-dependent interactions.

Abstract

The CDEX-1 experiment conducted a search of low-mass (< 10 GeV/c2) Weakly Interacting Massive Particles (WIMPs) dark matter at the China Jinping Underground Laboratory using a p-type point-contact germanium detector with a fiducial mass of 915 g at a physics analysis threshold of 475 eVee. We report the hardware set-up, detector characterization, data acquisition and analysis procedures of this experiment. No excess of unidentified events are observed after subtraction of known background. Using 335.6 kg-days of data, exclusion constraints on the WIMP-nucleon spin-independent and spin-dependent couplings are derived.