Evidence for Corrections to Soft-PionS-Wave Nonleptonic Hyperon-Decay Amplitudes

Abstract

Evidence is found for corrections to the soft-pion $S$-wave nonleptonic hyperon-decay amplitudes from the observed deviation from the generalized Lee-Sugawara relation $2A({\ensuremath{\Xi}}_{\ensuremath{-}}^{\ensuremath{-}})+A({\ensuremath{\Lambda}}_{\ensuremath{-}}^{0})+{(\frac{3}{2})}^{\frac{1}{2}}A({\ensuremath{\Sigma}}_{\ensuremath{-}}^{\ensuremath{-}})=0$. These corrections, assumed to come from the low-lying ${\mathrm{\textonehalf{}}}^{\ensuremath{-}}$ excited baryon intermediate states, are estimated experimentally with use of the expressions suggested by the quark model and are found to reduce significantly the soft-pion results.