English

Quark mass difference effects in hadronic Fermi matrix elements from first principles

High Energy Physics - Phenomenology 2023-11-01 v2 High Energy Physics - Experiment High Energy Physics - Lattice Nuclear Experiment Nuclear Theory

Abstract

It was recently estimated that the strong isospin-symmetry breaking (ISB) corrections to the Fermi matrix element in free neutron decay could be of the order 10410^{-4}, one order of magnitude larger than the na\"{\i}ve estimate based on the Behrends-Sirlin-Ademollo-Gatto theorem. To investigate this claim, we derive a general expression of the leading ISB correction to hadronic Fermi matrix elements, which takes the form of a four-point correlation function in lattice gauge theory and is straightforward to compute from first principles. Our formalism paves the way for the first determination of such correction in the neutron sector with fully-controlled theory uncertainties.

Keywords

Cite

@article{arxiv.2306.10199,
  title  = {Quark mass difference effects in hadronic Fermi matrix elements from first principles},
  author = {Chien-Yeah Seng and Vincenzo Cirigliano and Xu Feng and Mikhail Gorchtein and Luchang Jin and Gerald A. Miller},
  journal= {arXiv preprint arXiv:2306.10199},
  year   = {2023}
}

Comments

Version accepted by PLB

R2 v1 2026-06-28T11:07:43.508Z