We calculate the strange quark content of the nucleon directly from its disconnected three-point function in N_f=2+1 QCD. Chiral symmetry is crucial to avoid a possibly large contamination due to operator mixing, and is exactly preserved by employing the overlap quark action. We also use the all-to-all quark propagator and the low-mode averaging technique in order to accurately calculate the relevant nucleon correlator. Our preliminary result extrapolated to the physical point is f_{T_s} = 0.013(12)(16). This is in good agreement with our previous estimate in N_f=2 QCD as well as those from our indirect calculations using the Feynman-Hellmann theorem.
@article{arxiv.1012.1907,
title = {Nucleon strange quark content in 2+1-flavor QCD},
author = {JLQCD Collaboration and K. Takeda and S. Aoki and S. Hashimoto and T. Kaneko and T. Onogi and N. Yamada},
journal= {arXiv preprint arXiv:1012.1907},
year = {2010}
}
Comments
7pages, talk presented at The XXVIII International Symposium on Lattice Field Theory, Lattice2010