Probing the mechanism of neutrinoless double-beta decay in multiple isotopes

• Published in: The journal of high energy physics Vol. 2023; no. 2; pp. 172 - 30
• Main Authors: Agostini, Matteo, Deppisch, Frank F., Van Goffrier, Graham
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 16.02.2023; Springer Nature B.V; SpringerOpen
• Subjects: Baryon/Lepton Number Violation; Bayesian analysis; Beta decay; Classical and Quantum Gravitation; Elementary Particles; High energy physics; Isotopes; Neutrino Interactions; Neutrinos; Parameters; Particle physics; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Specific BSM Phenomenology; Standard model (particle physics); String Theory; Neutrino Interactions; Baryon/Lepton Number Violation; Specific BSM Phenomenology
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP02(2023)172

A bstract A large experimental program is being mounted to search for neutrinoless double-beta decay over the next decade. Multiple experiments using different target isotopes are being prepared to explore the whole parameter space allowed for inverted-ordered light neutrinos, and have the potential to make discoveries in several other scenarios, including normal-ordered light neutrinos and other exotic mechanisms. We investigate to what extent long-range and exotic short-range contributions may be distinguished by combining measurements of the decay half-life across isotopes in the framework of a global Bayesian analysis. We demonstrate how measurements in two isotopes will constrain the parameter space up to a two-fold degeneracy, and how a further measurement in a third isotope removes such a degeneracy. We also discuss the impact of uncertainties and correlations in nuclear matrix element calculations. Our work motivates an experimental program measuring neutrinoless double-beta decay in more than one isotope, as this would break parameter degeneracies and advance our understanding of particle physics beyond the Standard Model.