Sub-GeV Dark Matter Searches with EDELWEISS: New results and prospects

TL;DR

The EDELWEISS collaboration reports new results in sub-GeV dark matter searches using germanium bolometers with advanced sensor technology, achieving unprecedented sensitivity and paving the way for future low-mass dark matter detection.

Contribution

First cryogenic germanium detector with TES sensors demonstrating high sensitivity for sub-GeV dark matter searches, enabling new detection techniques and improved performance.

Findings

Achieved RMS resolution of 4.46 electron-hole pairs.

Excluded WIMP cross-sections down to 10^{-29} cm^2 for masses as low as 32 MeV/C^2.

First measurement in cryogenic germanium with TES sensors.

Abstract

The Edelweiss collaboration performs light Dark Matter (DM) particles searches with germanium bolometer collecting charge and phonon signals. Thanks to the Neganov-Trofimov-Luke (NTL) effect, a RMS resolution of 4.46 electron-hole pairs was obtained on a massive (200g) germanium detector instrumented with a NbSi Transition Edge Sensor (TES) operated underground at the Laboratoire Souterrain de Modane (LSM). This sensitivity made possible a search for WIMP using the Migdal effect down to 32 MeV/C$^{2}$ and exclude cross-sections down to 10$^{-29}$ cm$^2$. It is the first measurement in cryogenic germanium with such thermal sensor, proving the high relevance of this technology. Furthermore, such TES have shown sensitivity to out-of-equilibrium phonons, paving the way for EDELWEISS new experience CRYOSEL. This is an important step in the development of Ge detectors with improved performance in the context of the EDELWEISS-SubGeV program.