Light hadron spectroscopy using domain wall valence quarks on an asqtad sea

Journal Article · Sun Mar 01 04:00:00 EST 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.054502· OSTI ID:21260090

Walker-Loud, A; Lin, H -W; Richards, D G; Edwards, R G; Engelhardt, M; Fleming, G T; Haegler, Ph; Musch, B; Lin, M F; Meyer, H; Negele, J W; Pochinsky, A V; Procura, M; Syritsyn, S; Morningstar, C J; Orginos, K; Renner, D B; Schroers, W ^[1]

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1. Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)

We calculate the light hadron spectrum in full QCD using two plus one flavor asqtad sea quarks and domain wall valence quarks. Meson and baryon masses are calculated on a lattice of spatial size L{approx_equal}2.5 fm, and a lattice spacing of a{approx_equal}0.124 fm, for pion masses as light as m{sub {pi}}{approx_equal}300 MeV, and compared with the results by the MILC Collaboration with asqtad valence quarks at the same lattice spacing. Two- and three-flavor chiral extrapolations of the baryon masses are performed using both continuum and mixed action heavy baryon chiral perturbation theory. Both the three-flavor and two-flavor functional forms describe our lattice results, although the low-energy constants from the next-to-leading order SU(3) fits are inconsistent with their phenomenological values. Next-to-next-to-leading order SU(2) continuum formulae provide a good fit to the data and yield an extrapolated nucleon mass consistent with experiment, but the convergence pattern indicates that even our lightest pion mass may be at the upper end of the chiral regime. Surprisingly, our nucleon masses are essentially linear in m{sub {pi}} over our full range of pion masses, and we show this feature is common to all recent dynamical calculations of the nucleon mass. The origin of this linearity is not presently understood, and lighter pion masses and increased control of systematic errors will be needed to resolve this puzzling behavior.

• OSTI ID: 21260090
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 5 Vol. 79; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
CHIRALITY
COMPUTERIZED SIMULATION
CONTROL
CONVERGENCE
EXTRAPOLATION
FLAVOR MODEL
LATTICE FIELD THEORY
MASS
MESONS
MEV RANGE 100-1000
NUCLEONS
PERTURBATION THEORY
PIONS
QUANTUM CHROMODYNAMICS
QUARKS
SPECTRA
SPECTROSCOPY
SU-2 GROUPS
SU-3 GROUPS