Hyperon forward spin polarizability gamma0 in baryon chiral perturbation theory

TL;DR

This paper calculates the hyperon forward spin polarizability gamma0 using baryon chiral perturbation theory, including spin 3/2 states, and compares predictions with experimental data, extending to SU(3) hyperons.

Contribution

It provides the first pure chiral perturbation theory predictions for gamma0 of hyperons, incorporating decuplet states and extending the framework to SU(3).

Findings

SU(2) results agree well with experimental data

Predictions for Sigma^- and Xi^- gamma0 values are provided

Explicit decuplet inclusion improves theoretical accuracy

Abstract

We present the calculation of the hyperon forward spin polarizability gamma0 using manifestly Lorentz covariant baryon chiral perturbation theory including the intermediate contribution of the spin 3/2 states. As at the considered order the extraction of gamma0 is a pure prediction of chiral perturbation theory, the obtained values are a good test for this theory. After including explicitly the decuplet states, our SU(2) results have a very good agreement with the experimental data and we extend our framework to SU(3) to give predictions to the hyperons' gamma0 values. Prominent are the Sigma^- and Xi^- baryons as their photon transition to the decuplet is forbidden in SU(3) symmetry and therefore they are not sensitive to the explicit inclusion of the decuplet in the theory.