Hyperon Nonleptonic Decays in Chiral Perturbation Theory Reexamined

TL;DR

This paper reevaluates hyperon nonleptonic decay amplitudes using chiral perturbation theory, identifying new terms and discrepancies with prior calculations, but confirming the persistent challenge of matching experimental data.

Contribution

It provides a revised calculation of decay amplitudes, including previously omitted terms, highlighting ongoing issues in theoretical-experimental agreement.

Findings

Partial disagreement with previous calculations

Identification of new terms in P-wave amplitudes

Numerical significance of modifications

Abstract

We recalculate the leading nonanalytic contributions to the amplitudes for hyperon nonleptonic decays in chiral perturbation theory. Our results partially disagree with those calculated before, and include new terms previously omitted in the P-wave amplitudes. Although these modifications are numerically significant, they do not change the well-known fact that good agreement with experiment cannot be simultaneously achieved using one-loop S- and P-wave amplitudes.