Magnetic Moments, Hadron Masses, and Quark Masses

Abstract

Two independent quark-model predictions of the $\Lambda$ 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) $\left(\frac{m_s}{m_u}\right)=\frac{(M_{{\Sigma }^{*}}-M_{\Sigma })}{(M_{\Delta }-M_N)}$; and (2) $m_s-m_u=M_{\Lambda }-M_N$. 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.