Test of SU(3) Symmetry in Hyperon Semileptonic Decays

TL;DR

This paper investigates SU(3) symmetry breaking in hyperon semileptonic decays, deriving a GMO-like relation for axial vector current matrix elements, and finds symmetry breaking effects of 5-11%, supporting the Cabibbo model.

Contribution

It introduces a generalized GMO relation for hyperon semileptonic decay axial vector currents and quantifies SU(3) symmetry breaking effects.

Findings

SU(3) symmetry breaking in hyperon decays is 5-11%

The generalized GMO relation supports the Cabibbo model

Evidence for small SU(3) symmetry breaking

Abstract

Existing analyzes of baryon semileptonic decays indicate the presence of a small SU(3) symmetry breaking in hyperon semileptonic decays, but to provide evidence for SU(3) symmetry breaking, one would need a relation similar to the Gell-Mann--Okubo (GMO) baryon mass formula which is satisfied to a few percents, showing evidence for a small SU(3) symmetry breaking effect in the GMO mass formula. In this talk, I would like to present a similar GMO relation obtained in a recent work for hyperon semileptonic decay axial vector current matrix elements. Using these generalized GMO relations for the measured axial vector current to vector current form factor ratios, it is shown that SU(3) symmetry breaking in hyperon semileptonic decays is of $5-11%$ and confirms the validity of the Cabibbo model for hyperon semi-leptonic decays.