$SU(3)$ vs. $SU(3) \times SU(3)$ Breaking in Weak Hyperon Decays
Open Access Publications from the University of California

## $SU(3)$ vs. $SU(3) \times SU(3)$ Breaking in Weak Hyperon Decays

• Author(s): Luty, Markus A
• White, Martin
• et al.
Abstract

We consider the predictions of chiral perturbation theory for $SU(3)$ breaking in weak semileptonic and $s$-wave nonleptonic hyperon decays. By defining an expansion sensitive only to $SU(3)$ breaking, we show that the leading corrections give rise to moderate corrections to $SU(3)$ relations ($\lsim 20\%$), even though the {\it chiral} symmetry $SU(3) \times SU(3)$ appears to be rather badly broken. This explains why $SU(3)$ fits to weak hyperon decays work well even though chiral-symmetry breaking corrections are large. Applying these $SU(3)$-breaking corrections to the analysis of the EMC data, we find that the predicted value of $\bra p\mybar s\gamma_\mu\gamma_5 s\ket p$ is reduced by $\simeq 35\%$, suggesting that the EMC effect'' may be less striking than commonly thought.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.