Looking at radiative corrections to the ${\Sigma }^{\pm }\to \Lambda e^{\pm }\bar{\nu }$ semileptonic decay-rate ratio

Abstract

We investigate the impact of radiative corrections on the ratio of the semileptonic decay rates ${\Sigma }^{\pm }\to \Lambda e^{\pm }\bar{\nu }$. Phenomenological analyses point to sizable radiative effects on the experimentally measured ratio. From a theoretical perspective, this observable is particularly appealing because several hadronic and electroweak contributions partially cancel in the ratio, providing a cleaner probe of electromagnetic effects. We identify the dominant contributions to the radiative corrections and develop the framework for a dedicated calculation. This represents a first step toward a precise theoretical description of baryon semileptonic decays, helping to assess their potential as precision tests of the Standard Model.

arXiv commentProceedings for The 43rd International Symposium on Lattice Field Theory (Lattice 2026)