Speaker
Description
The Cryogenic Underground Observatory for Rare Events (CUORE) is an experiment searching for neutrinoless double beta decay in a ton-scale detector, located at the Gran Sasso National Laboratory in Italy. Its proposed next-generation upgrade, CUPID, adopts a similar bolometer array operated at millikelvin temperatures, augmented with light detectors to enable particle identification and enhanced background rejection.
The signal of interest in neutrinoless double-beta decay consists of two electrons that predominantly deposit their energy within a single crystal. However, surface interactions can lead to energy sharing between adjacent absorbers. This motivates the study of multiplicity-2 (M2) events, in which two channels are coincidentally triggered. M2 events constitute approximately 5% of total events in the region of interest.
In this poster, we present a detailed characterization of M2 events using CUORE data and CUPID Monte Carlo simulations, outline background rejection strategies, and quantify M2 contribution to the overall sensitivity. We report the preliminary results of limits derived from M2 events in CUORE and provide a sensitivity projection for CUPID in the M2 event topology.