Contributions of strange quarks to the magnetic moment of the proton

Abstract

Using the Gerasimov-Drell-Hearn sum rule and experimental total cross sections for photoproduction of $\eta$, $K$ and $\phi$ mesons on the proton, we obtain upper bounds for the contribution of strange quarks to the anomalous magnetic moment of the proton, $|\kappa_{s}| \le 0.20 \kappa_{p}$. The proposed experiments to measure the spin-dependence of the absorption cross section are expected to lower these bounds considerably. The existing data on $\eta$ production and phenomenological models for $K$ production agree with a negative sign for $\kappa_{s}$.