A renormalized approach to neutrinoless double-beta decay
Abstract
The process at the heart of neutrinoless double-beta decay, induced by a light Majorana neutrino, is investigated in pionless and chiral effective field theory. We show in various regularization schemes the need to introduce a short-range lepton-number-violating operator at leading order, confirming earlier findings. We demonstrate that such a short-range operator is only needed in spin-singlet -wave transitions, while leading-order transitions involving higher partial waves depend solely on long-range currents. Calculations are extended to include next-to-leading corrections in perturbation theory, where to this order no additional undetermined parameters appear. We establish a connection based on chiral symmetry between neutrinoless double-beta decay and nuclear charge-independence breaking induced by electromagnetism. Data on the latter confirm the need for a leading-order short-range operator, but do not allow for a full determination of the corresponding lepton-number-violating coupling. Using a crude estimate of this coupling, we perform ab initio calculations of the matrix elements for neutrinoless double-beta decay for He and Be. We speculate on the phenomenological impact of the leading short-range operator on the basis of these results.
Cite
@article{arxiv.1907.11254,
title = {A renormalized approach to neutrinoless double-beta decay},
author = {V. Cirigliano and W. Dekens and J. de Vries and M. L. Graesser and E. Mereghetti and S. Pastore and M. Piarulli and U. van Kolck and R. B. Wiringa},
journal= {arXiv preprint arXiv:1907.11254},
year = {2019}
}