Recent results on the $\Lambda \rightarrow p\ell \bar{\nu}_\ell$ semileptonic decay
Abstract
We present a lattice-QCD determination of the vector and axial-vector form factors, providing theoretical input for studies of the semileptonic decay . The calculation is carried out on a single gauge ensemble with physical light, strange, and charm quark masses and delivers a precise determination of the complete set of transition form factors, including second-class contributions. Using these form factors, we compute decay rates for both the electronic and muonic channels, as well as their ratio, which offers a sensitive test of lepton-flavor universality and possible non-standard scalar or tensor interactions. This decay mode provides a theoretically well-controlled avenue for extracting the CKM matrix element from the baryon sector. Our estimate of is obtained by combining our recent lattice-QCD results with recent measurements of the relevant branching fraction reported by BESIII and LHCb.
Cite
@article{arxiv.2602.16560,
title = {Recent results on the $\Lambda \rightarrow p\ell \bar{\nu}_\ell$ semileptonic decay},
author = {Simone Bacchio and Andreas Konstantinou},
journal= {arXiv preprint arXiv:2602.16560},
year = {2026}
}