A multi-isotope $0\nu2\beta$ bolometric experiment

TL;DR

This paper proposes a multi-isotope bolometric experiment for neutrinoless double beta decay, demonstrating that combining data from multiple isotopes enhances the sensitivity to Majorana neutrino mass within a shared detector environment.

Contribution

It introduces a novel multi-isotope bolometric approach for $0 u2eta$ decay detection, enabling simultaneous study of four isotopes and improving mass sensitivity compared to single-isotope experiments.

Findings

Multi-isotope detectors can study up to four isotopes simultaneously.

Combined data from multiple isotopes is competitive with single-isotope sensitivity.

The approach is compatible with the CUPID project and enhances experimental robustness.

Abstract

There are valuable arguments to perform neutrinoless double beta ($0\nu2\beta$) decay experiments with several nuclei: the uncertainty of nuclear-matrix-ele\-ment calculations; the possibility to test these calculations by using the ratio of the measured lifetimes; the unpredictability of possible breakthroughs in the detection technique; the difficulty to foresee background in $0\nu2\beta$ decay searches; the limited amount of isotopically enriched materials. We propose therefore approaches to estimate the Majorana neutrino mass by combining experimental data collected with different $0\nu2\beta$ decay candidates. In particular, we apply our methods to a next-generation experiment based on scintillating and Cherenkov-radiation bolometers. Current results indicate that this technology can effectively study up to four different isotopes simultaneously ($^{82}$Se, $^{100}$Mo, $^{116}$Cd and $^{130}$Te), embedded in detectors which share the same concepts and environment. We show that the combined information on the Majorana neutrino mass extracted from a multi-candidate bolometric experiment is competitive with that achievable with a single isotope, once that the cryogenic experimental volume is fixed. The remarkable conceptual and technical advantages of a multi-isotope investigation are discussed. This approach can be naturally applied to the proposed CUPID project, follow-up of the CUORE experiment that is currently taking data in the Gran Sasso underground laboratory.