Latest Results from Calibrating Six Months of Cryogenic Germanium Detectors for RICOCHET Neutrino Scattering Experiment

The RICOCHET collaboration is an international effort that collects data from de tectors near a 58.3 MW nuclear reactor at the Institut Laue-Langevin (ILL) in Greno ble, France [1]. It seeks to measure Coherent Elastic Neutrino-Nucleus Scattering (CEvNS), the process by which a neutrino interacts with a nucleus by exchanging a Z boson, causing the nucleus to recoil and the neutrino to scatter [2]. Studying this interaction and the energy spectral shape of CEvNS offers a look into physics be yond the standard model and provides a background process for dark matter searches. RICOCHET has deployed 42-gram Germanium targets sensitive to a 40 electron-volt equivalence energy signal to detect phonon propagation and ionization signals from these events [3]. We calibrated and reprocessed RUN015 data from January 2025 to June 2025 using pulse shape characterization algorithms to find a baseline for the spec tral shape of the CEvNS signal. We present our reprocessed results.

[1] “The ILL high-flux reactor- ILL Neutrons for Society,” Www.ill.eu, 2024. https://www.ill.eu/a-unique-facility/the-worlds-most-intense-neutron source/the-ill-high-flux-reactor (accessed Oct. 13, 2025).

[2] M. Abdullah et al., “Coherent elastic neutrino-nucleus scattering: Terrestrial and astrophysical applications,” arXiv (Cornell University), Mar. 2022, doi: https://doi.org/10.48550/arxiv.2203.07361 (accessed Oct. 13, 2025). ‌

[3] A. Armatol et al., “Characterization of mini-cryocube detectors from the Ric ochet Experiment Commissioning at the Institut Laue-Langevin,” arXiv.org, https://doi.org/10.48550/arXiv.2507.22751 (accessed Oct. 13, 2025).