Calculation of nucleon strange quark content with dynamical overlap quarks

Abstract

We calculate the nucleon strange quark content directly from disconnected three-point functions. Numerical simulations are carried out in two-flavor QCD using the overlap quark action with up and down quark masses down to a fifth of the physical strange quark mass. To improve the statistical accuracy, we calculate the nucleon two-point functions with the low-mode averaging technique, whereas the all-to-all quark propagator is used for the disconnected quark loop. We obtain the y parameter, which is the ratio of the strange and light quark contents, y = 0.024(45) at the physical point. This is in a good agreement with our earlier calculation from the nucleon spectrum through the Feynman-Hellmann theorem.