Light pseudoscalar decay constants, quark masses, and low energy constants from three-flavor lattice QCD

Journal Article · Wed Dec 01 00:00:00 EST 2004 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.70.114501· OSTI ID:20698150

Aubin, C; Bernard, C; DeTar, C; Osborn, J; Gottlieb, Steven; Gregory, E B; Toussaint, D; Heller, U M; Hetrick, J E; Sugar, R ^[1]

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1. Department of Physics, Washington University, St. Louis, Missouri 63130 (United States)

As part of our program of lattice simulations of three-flavor QCD with improved staggered quarks, we have calculated pseudoscalar meson masses and decay constants for a range of valence quark masses and sea-quark masses on lattices with lattice spacings of about 0.125 and 0.09 fm. We fit the lattice data to forms computed with ''staggered chiral perturbation theory.'' Our results provide a sensitive test of the lattice simulations, and especially of the chiral behavior, including the effects of chiral logarithms. We find: f{sub {pi}}=129.5{+-}0.9{+-}3.5 MeV, f{sub K}=156.6{+-}1.0{+-}3.6 MeV, and f{sub K}/f{sub {pi}}=1.210(4)(13), where the errors are statistical and systematic. Following a recent paper by Marciano, our value of f{sub K}/f{sub {pi}} implies |V{sub us}|=0.2219(26). Further, we obtain m{sub u}/m{sub d}=0.43(0)(1)(8), where the errors are from statistics, simulation systematics, and electromagnetic effects, respectively. The partially quenched data can also be used to determine several of the constants of the low energy chiral effective Lagrangian: In particular, we find 2L{sub 8}-L{sub 5}=-0.2(1)(2)x10{sup -3} at chiral scale m{sub {eta}}, where the errors are statistical and systematic. This provides an alternative (though not independent) way of estimating m{sub u}; the value of 2L{sub 8}-L{sub 5} is far outside the range that would allow the up quark to be massless. Results for m{sub s}{sup MS}, m-circumflex{sup MS}, and m{sub s}/m-circumflex can be obtained from the same lattice data and chiral fits, and have been presented previously in joint work with the HPQCD and UKQCD collaborations. Using the perturbative mass renormalization reported in that work, we obtain m{sub u}{sup MS}=1.7(0)(1)(2)(2) MeV and m{sub d}{sup MS}=3.9(0)(1)(4)(2) MeV at scale 2 GeV, with errors from statistics, simulation, perturbation theory, and electromagnetic effects, respectively.

• OSTI ID: 20698150
• Journal Information: Physical Review. D, Particles Fields, Vol. 70, Issue 11; Other Information: DOI: 10.1103/PhysRevD.70.114501; (c) 2004 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA). MILC Collaboration; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CHIRAL SYMMETRY
CHIRALITY
COMPUTERIZED SIMULATION
ERRORS
FLAVOR MODEL
GEV RANGE
KAONS
LAGRANGIAN FIELD THEORY
LAGRANGIAN FUNCTION
LATTICE FIELD THEORY
LEPTONIC DECAY
MASS RENORMALIZATION
MEV RANGE
PERTURBATION THEORY
PIONS
QUANTUM CHROMODYNAMICS
REST MASS
STATISTICS
U QUARKS