出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We calculate the strange quark content of the nucleon hNj ¯ ssjNi directly from its disconnected three-point function in Nf =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 fTs =ms hNj ¯ ssjNi/MN = 0.013(12)(16), where ms and MN are the masses of strange quark and nucleon. This is in good agreement with our previous estimate in Nf =2 QCD as well as those from our indirect calculations using the Feynman-Hellmann theorem.
