Strange quark polarization of the nucleon: A parameter-independent prediction of the chiral potential model

We perform a one-loop calculation of the strange quark polarization (Deltas) of the nucleon in an SU(3) chiral potential model. We find that if the intermediate quark excited states are summed over in a proper way, i.e., summed up to a given energy instead of given radial and orbital quantum numbers, Deltas turns out to be almost independent of all the model parameters: quark masses and potential strengths. The contribution from the quark-antiquark pair creation and annihilation ''Z diagrams is found to be significant. Our numerical results agree quite reasonably with experiments and lattice QCD calculations.