The Strange Quark Contribution to the Proton’s Magnetic Moment

Abstract

We report a new determination of the strange quark contribution to the proton’s magnetic form factor at a four-momentum transfer Q2 = 0.1(GeV/c)2 from parity-violating e-p elastic scattering. The result uses a revised analysis of data from the SAMPLE experiment which was carried out at the MIT-Bates Laboratory. The data are combined with a calculation of the proton’s axial form factor GeA to determine the strange form factor GsM (Q2=0.1)=0.37±0.20±0.26±0.07. The extrapolation of GsM to its Q2 = 0 limit and comparison with calculations is also discussed.