Within the framework of chiral effective field theory we discuss the leading contributions to the neutrinoless double-beta decay transition operator induced by light Majorana neutrinos. Based on renormalization arguments in both dimensional regularization with minimal subtraction and a coordinate-space cutoff scheme, we show the need to introduce a leading-order short-range operator, missing in all current calculations. We discuss strategies to determine the finite part of the short-range coupling by matching to lattice QCD or by relating it via chiral symmetry to isospin-breaking observables in the two-nucleon sector. Finally, we speculate on the impact of this new contribution on nuclear matrix elements of relevance to experiment.
@article{arxiv.1802.10097,
title = {A new leading contribution 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 U. van Kolck},
journal= {arXiv preprint arXiv:1802.10097},
year = {2018}
}