Lattice calculation of the strangeness magnetic moment of the nucleon

We report on a lattice QCD calculation of the strangeness magnetic moment of the nucleon. Our result is GMˢ(0)=-0.36±0.20. The sea contributions from the u and d quarks are about 80% larger. However, they cancel to a large extent due to their electric charges, resulting in a smaller net sea contribution of -0.097±0.037μN to the nucleon magnetic moment. As far as the neutron to proton magnetic moment ratio is concerned, this sea contribution tends to cancel out the cloud-quark effect from the Z graphs and results in a ratio of -0.68±0.04 which is close to the SU(6) relation and the experiment. The strangeness Sachs electric mean-square radius 〈rₛ²〉E is found to be small and negative.