Magnetic Moments, Hadron Masses, and Quark Masses

Abstract

Two independent quark-model predictions of the $\ensuremath{\Lambda}$ magnetic moments, in agreement with one another and with experiment to 1%, are obtained by using two different inputs for SU(3) breaking in quark masses: (1) $(\frac{{m}_{s}}{{m}_{u}})=\frac{({M}_{{\ensuremath{\Sigma}}^{*}}\ensuremath{-}{M}_{\ensuremath{\Sigma}})}{({M}_{\ensuremath{\Delta}}\ensuremath{-}{M}_{N})}$; and (2) ${m}_{s}\ensuremath{-}{m}_{u}={M}_{\ensuremath{\Lambda}}\ensuremath{-}{M}_{N}$. I discuss the implications of the surprising sucess of a description of quark magnetic moments as Dirac moments with quark masses related so simply to hadron masses.