EDELWEISS-II Dark Matter Search : status and first results

TL;DR

The EDELWEISS-II experiment employs cryogenic germanium detectors to search for WIMPs, achieving low background conditions and demonstrating detectors capable of probing extremely low WIMP-nucleon cross-sections, with initial results indicating progress in dark matter detection.

Contribution

This paper reports the first results from EDELWEISS-II using advanced detectors with active surface event rejection, improving sensitivity to low cross-section WIMP interactions.

Findings

Low radioactive background achieved in underground lab

Detectors sensitive to WIMPs with cross-sections below 10^-8 pb

Preliminary WIMP search results presented

Abstract

The EDELWEISS II experiment is devoted to the search for Weakly Interacting Massive Particles (WIMP) that would constitute the Dark Matter halo of our Galaxy. For this purpose, the experiment uses cryogenic germanium detectors, cooled down at 20 mK, in which the collision of a WIMP with an atomic nucleus produces characteristic signals in terms of ionization and elevation of temperature. We will present the preliminary results of the first operation of the detectors installed in the underground laboratory of the Frejus Tunnel (LSM), attesting to the very low radioactive background conditions achieved so far. New detectors, with a special electrode design for active rejection of surface events, have been shown to be suited for searches of WIMPs with scattering cross-sections on nucleon well below 10-8 pb. Preliminary results of WIMP search performed with a first set of these detectors are presented.