@article{oai:tsukuba.repo.nii.ac.jp:00028702,
author = {青木, 愼也 and Ohki, H. and Takeda, K. and Aoki, S. and Hashimoto, S. and Kaneko, T. and Matsufuru, H. and Noaki, J. and Onogi, T.},
issue = {3},
journal = {Physical review D},
month = {Feb},
note = {We calculate the strange quark content of the nucleon ⟨N, s̅ s, N⟩ in 2+1 -flavor lattice QCD. Chirally symmetric overlap fermion formulation is used to avoid the contamination from up and down quark contents due to an operator mixing between strange and light scalar operators, s̅ s and u̅ u+d̅ d. At a lattice spacing a=0.112(1) fm, we perform calculations at four values of degenerate up and down quark masses mud, which cover a range of the pion mass Mπ≃300–540 MeV. We employ two different methods to calculate ⟨N, s̅ s, N⟩. One is a direct method where we calculate ⟨N, s̅ s, N⟩ by directly inserting the s̅ s operator. The other is an indirect method where ⟨N, s̅ s, N⟩ is extracted from a derivative of the nucleon mass in terms of the strange quark mass. With these two methods we obtain consistent results for ⟨N, s̅ s, N⟩ with each other. Our best estimate fTs=ms⟨N, s̅ s, N⟩/MN=0.009(15)stat(16)sys is in good agreement with our previous studies in two-flavor QCD.},
title = {Nucleon strange quark content from Nf=2+1 lattice QCD with exact chiral symmetry},
volume = {87},
year = {2013}
}