Latest results of the direct dark matter search with the EDELWEISS-2 experiment

TL;DR

This paper reports on the latest results from the EDELWEISS-2 experiment, a cryogenic Ge-bolometer setup in France, focusing on improved background rejection, muon-induced background identification, and increased data exposure for dark matter searches.

Contribution

It introduces new cryogenic detectors with enhanced background rejection and provides updated results with doubled data exposure, improving sensitivity in direct dark matter detection.

Findings

Improved sensitivity by about 15% over previous EDELWEISS-1 results.

Identification of muon-induced background events.

Measurements of muon-induced neutrons in the underground lab.

Abstract

EDELWEISS-2 is a Ge-bolometer experiment located in the underground laboratory Laboratoire Souterrain de Modane (LSM, France). For the second phase of the experiment, the collaboration has developed new cryogenic detectors with an improved background rejection (interleaved electrodes design, Phys. Lett. B681 (2009) 305). A continuous operation of ten of these bolometers at LSM together with an active muon veto shielding has been achieved. First results based on an effective exposure of 144 kg \dot d taken in 2009 have been published recently (Phys. Lett. B687 (2010) 29), the acquired data set has since then been doubled. The already published data correspond to an improvement in sensitivity of about 15 compared to EDELWEISS-1. We present and discuss the latest bolometer data including the identification of muon-induced background events and special measurements of muon-induced neutrons in LSM.