Pulse shape discrimination in CUPID-Mo using principal component analysis

Abstract CUPID-Mo is a cryogenic detector array designed to search for neutrinoless double-beta decay (0νββ) of 100 Mo. It uses 20 scintillating Mo-enriched Li 2 MoO 4 bolometers instrumented with Ge light detectors perform active suppression α backgrounds, drastically reducing the expected background in 0νββ signal region. As result, pileup events and small instabilities that mimic normal signals become non-negligible potential backgrounds. These types can principle be eliminated based on their shapes, which are different from those regular bolometric pulses. We show purely data-driven principal component analysis approach able filter out these anomalous events, without aid response simulations.