Enhancing the light detection with the Neganov-Trofimov-Luke effect for the CUPID experiment.

CUPID (CUORE Upgrade with Particle IDentification) is a next-generation experiment designed to succeed CUORE and investigate neutrinos' Majorana nature by searching for neutrinoless double beta decay (0ν2β) in ¹⁰⁰Mo. The experiment will use Li₂​MoO₄​ scintillating crystals, operated at millikelvin temperatures, coupled with thin Ge bolometric light detectors to benefit from a dual heat and light readout. This presentation will highlight the recent advancements in the integration of Ge light detectors employing the Neganov-Trofimov-Luke (NTL) effect. This technology enhances the light channel signal-to-noise ratio. Therefore, it offers a crucial advantage to mitigate the contribution to the background of pile-up events—a dominant source of background in CUPID due to the slow bolometric response and the relatively fast ¹⁰⁰Mo 2ν2β decay. The NTL-enhanced light detectors have been incorporated into CUPID's baseline design, and ongoing efforts within the collaboration are focused on further optimizing their performance and validating their capability to meet the experiment's requirements.