First data from the CUPID-Mo neutrinoless double beta decay experiment

TL;DR

The CUPID-Mo experiment utilizes cryogenic scintillating detectors to search for neutrinoless double beta decay in $^{100}$Mo, demonstrating excellent background suppression and setting new decay half-life limits.

Contribution

This work presents the first data from CUPID-Mo, showcasing detector performance, radiopurity, and initial decay half-life limits, advancing the technology for future neutrinoless double beta decay searches.

Findings

Achieved 6.7 keV energy resolution at 2615 keV

Alpha event discrimination better than 99.9%

Set a half-life limit of >3×10^{23} years for $^{100}$Mo

Abstract

The CUPID-Mo experiment is searching for neutrinoless double beta decay in $^{100}$Mo, evaluating the technology of cryogenic scintillating Li$_{2}^{100}$MoO$_4$ detectors for CUPID (CUORE Upgrade with Particle ID). CUPID-Mo detectors feature background suppression using a dual-readout scheme with Li$_{2}$MoO$_4$ crystals complemented by Ge bolometers for light detection. The detection of both heat and scintillation light signals allows the efficient discrimination of $\alpha$ from $\gamma$&$\beta$ events. In this proceedings, we discuss results from the first 2 months of data taking in spring 2019. In addition to an excellent bolometric performance of 6.7$\,$keV (FWHM) at 2615$\,$keV and an $\alpha$ separation of better than 99.9\% for all detectors, we report on bulk radiopurity for Th and U. Finally, we interpret the accumulated physics data in terms of a limit of $T_{1/2}^{0\nu}\,> 3\times10^{23}\,$yr for $^{100}$Mo and discuss the sensitivity of CUPID-Mo until the expected end of physics data taking in early 2020.