Nucleon sigma term and strange quark content from lattice QCD with exact chiral symmetry

Journal Article · Mon Sep 01 00:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.78.054502· OSTI ID:21250737

Ohki, H ^[1]; Fukaya, H ^[2]; Hashimoto, S; Kaneko, T; Yamada, N ^[3]; Matsufuru, H; Noaki, J; Shintani, E ^[3]; Onogi, T ^[4]

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1. Department of Physics, Kyoto University, Kyoto 606-8501 (Japan)
2. Niels Bohr Institute, Niels Bohr International Academy Blegdamsvej 17 DK-2100 Copenhagen (Denmark)
3. High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan)
4. Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

We calculate the nucleon sigma term in two-flavor lattice QCD utilizing the Feynman-Hellman theorem. Both sea and valence quarks are described by the overlap fermion formulation, which preserves exact chiral and flavor symmetries on the lattice. We analyze the lattice data for the nucleon mass using the analytical formulae derived from the baryon chiral perturbation theory. From the data at valence quark mass set different from sea quark mass, we may extract the sea quark contribution to the sigma term, which corresponds to the strange quark content. We find that the strange quark content is much smaller than the previous lattice calculations and phenomenological estimates.

• OSTI ID: 21250737
• Journal Information: Physical Review. D, Particles Fields, Vol. 78, Issue 5; Other Information: DOI: 10.1103/PhysRevD.78.054502; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRAL SYMMETRY
FLAVOR MODEL
LATTICE FIELD THEORY
MASS
NUCLEONS
PERTURBATION THEORY
QUANTUM CHROMODYNAMICS
S QUARKS