SU(3)-breaking corrections to the hyperon vector coupling $f_1(0)$ in covariant baryon chiral perturbation theory

TL;DR

This paper calculates SU(3)-breaking corrections to hyperon vector couplings using covariant baryon chiral perturbation theory, including octet and decuplet contributions, and finds positive corrections consistent with other theoretical approaches.

Contribution

It provides the first comprehensive calculation of SU(3)-breaking corrections to $f_1(0)$ up to $ ext{O}(p^4)$, incorporating dynamical decuplet effects in covariant baryon chiral perturbation theory.

Findings

Decuplet contributions are comparable or larger than octet contributions.

All four $f_1(0)$) corrections are positive.

Results agree with large $N_c$ fits, chiral quark models, and lattice QCD.

Abstract

We calculate the SU(3)-breaking corrections to the hyperon vector coupling $f_1(0)$ up to $\mathcal{O}(p^4)$ in covariant baryon chiral perturbation theory with dynamical octet and decuplet contributions. We find that the decuplet contributions are of similar or even larger size than the octet ones. Combining both, we predict positive SU(3)-breaking corrections to all the four independent $f_1(0)$'s (assuming isospin symmetry), which are consistent, within uncertainties, with the latest results form large $N_c$ fits, chiral quark models, and quenched lattice QCD calculations.