The discovery of the lepton number violation would be a smoking gun signal for physics beyond the Standard Model, and its most sensitive probe is the search for neutrinoless double beta decay (0νββ). Working in the framework of the Standard Model Effective Field Theory (SMEFT), we show that one-loop effects can remarkably improve the tree-level bounds on the new-physics scales for several dimension-7 operators. Using ultraviolet model examples, we then showcase the competition among 0νββ contributions induced by dimension-7 and loop-level dimension-5 SMEFT operators.
@article{arxiv.2504.00081,
title = {Importance of Loop Effects in Probing Lepton Number Violation},
author = {Lukáš Gráf and Chandan Hati and Ana Martín-Galán and Oliver Scholer},
journal= {arXiv preprint arXiv:2504.00081},
year = {2025}
}
Comments
Minor changes and typos corrected, 6+2 pages, 3+1 figures