Dispersive estimate of the electromagnetic charge symmetry violation in the octet baryon masses

TL;DR

This paper uses a dispersion relation approach to estimate electromagnetic contributions to charge symmetry breaking in octet baryon masses, refining previous analyses and aligning with recent lattice QCD+QED results.

Contribution

It introduces a dispersive analysis based on the Cottingham formula for hyperon mass splittings, incorporating lattice QCD and SU(3) symmetry breaking constraints.

Findings

Results agree with recent lattice QCD+QED determinations.

Uncertainties mainly due to limited knowledge of hyperon inelastic structure.

Provides refined estimates for proton-neutron mass splitting.

Abstract

We explore the electromagnetic contribution to the charge symmetry breaking in the octet baryon masses using a subtracted dispersion relation based on the Cottingham formula. For the proton-neutron mass splitting we report a minor revision of the recent analysis of Walker-Loud, Carlson and Miller. For the electromagnetic structure of the hyperons we constrain our analysis, where possible, by a combination of lattice QCD and SU(3) symmetry breaking estimates. The results for the baryon mass splittings are found to be compatible with recent lattice QCD+QED determinations. The uncertainties in the dispersive analysis are dominated by the lack of knowledge of the hyperon inelastic structure.