Probing particle and nuclear physics models of neutrinoless double beta decay with different nuclei

TL;DR

This paper explores how future neutrinoless double beta decay data across various nuclei can differentiate between standard and nonstandard physics models, despite nuclear uncertainties, aiding in understanding underlying decay mechanisms.

Contribution

It demonstrates that future measurements can distinguish between different particle physics models of decay using multiple nuclei, even with current nuclear physics uncertainties.

Findings

Future data can differentiate decay models at 95% confidence level.

Multiple nuclei measurements help discriminate decay mechanisms.

Nuclear uncertainties do not prevent model discrimination with prospective data.

Abstract

Half-life estimates for neutrinoless double beta decay depend on particle physics models for lepton flavor violation, as well as on nuclear physics models for the structure and transitions of candidate nuclei. Different models considered in the literature can be contrasted - via prospective data - with a "standard" scenario characterized by light Majorana neutrino exchange and by the quasiparticle random phase approximation, for which the theoretical covariance matrix has been recently estimated. We show that, assuming future half-life data in four promising nuclei (Ge-76, Se-82, Te-130, and Xe-136), the standard scenario can be distinguished from a few nonstandard physics models, while being compatible with alternative state-of-the-art nuclear calculations (at 95% C.L.). Future signals in different nuclei may thus help to discriminate at least some decay mechanisms, without being spoiled by current nuclear uncertainties. Prospects for possible improvements are also discussed.