Hyperon Decays in Chiral Perturbation Theory Revisited

TL;DR

This paper revisits hyperon decay analyses using heavy baryon chiral perturbation theory, improving P-wave predictions by including previously omitted diagrams and performing a correlated fit to chiral parameters.

Contribution

It introduces a revised approach with additional diagrams in chiral perturbation theory to better match hyperon decay data, especially for P-waves.

Findings

P-wave predictions are significantly improved

S-wave results remain unchanged

Correlated fit yields consistent chiral parameters

Abstract

The discrepancies found between S-wave and P-wave fits for hyperon decays are reinvestigated using the heavy baryon chiral Lagrangian formalism. The agreement is found to improve through the inclusion of previously omitted diagrams. The S-waves are unaffected by this, but the P-wave predictions are modified. A correlated fit to the chiral parameters is performed and the results discussed.