Radiative corrections for the decay $\Sigma^0\to\Lambda e^+e^-$

TL;DR

This paper calculates QED radiative corrections for the decay aa^0d7b4b1e^+e^- to better understand hyperon structure through a process where phase space limitations make radiative effects significant.

Contribution

It provides a comprehensive evaluation of QED radiative corrections for aa^0d7b4b1e^+e^- decay beyond the soft-photon approximation, covering the entire Dalitz plot without energy restrictions.

Findings

QED corrections are significant in aa^0d7b4b1e^+e^- decay.

Corrections are evaluated over the full Dalitz plot.

Results improve understanding of hyperon electromagnetic structure.

Abstract

Electromagnetic form factors serve to explore the intrinsic structure of nucleons and their strangeness partners. With electron scattering at low energies the electromagnetic moments and radii of nucleons can be deduced. The corresponding experiments for hyperons are limited because of the unstable nature of the hyperons. Only for one process this turns to an advantage: the decay of the neutral Sigma hyperon to a Lambda hyperon and a real or virtual photon. Due to limited phase space the effects caused by the Sigma-to-Lambda transition form factors compete with the QED radiative corrections for the decay $\Sigma^0\to\Lambda e^+e^-$. These QED corrections are addressed in the present work, evaluated beyond the soft-photon approximation, i.e., over the whole range of the Dalitz plot and with no restrictions on the energy of the radiative photon.