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Title: Nucleon Axial Charge in Full Lattice QCD

Abstract

The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm){sup 3}. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 7% statistical errors.

Authors:
;  [1];  [2];  [3];  [4]; ;  [5];  [1];  [6];  [6];  [7];  [8]
  1. Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)
  2. Sloane Physics Laboratory, Yale University, New Haven, Connecticut 06520 (United States)
  3. Department of Physics and Astronomy, Vrije Universiteit, 1081 HV Amsterdam (Netherlands)
  4. (Germany)
  5. Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)
  6. (United States)
  7. Department of Physics, University of Arizona, 1118 East 4th Street, Tucson, Arizona 85721 (United States)
  8. John von Neumann-Institut fuer Computing NIC/DESY, D-15738 Zeuthen (Germany)
Publication Date:
OSTI Identifier:
20777016
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevLett.96.052001; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CHIRALITY; ERRORS; LATTICE FIELD THEORY; MASS; MEV RANGE 100-1000; NUCLEONS; PERTURBATION THEORY; PIONS; QUANTUM CHROMODYNAMICS; QUARKS; VALENCE

Citation Formats

Edwards, R.G., Richards, D.G., Fleming, G.T., Haegler, Ph., Institut fuer Theoretische Physik, TU Muenchen, D-85747 Garching, Negele, J.W., Pochinsky, A.V., Orginos, K., Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, Renner, D.B., and Schroers, W.. Nucleon Axial Charge in Full Lattice QCD. United States: N. p., 2006. Web. doi:10.1103/PhysRevLett.96.052001.
Edwards, R.G., Richards, D.G., Fleming, G.T., Haegler, Ph., Institut fuer Theoretische Physik, TU Muenchen, D-85747 Garching, Negele, J.W., Pochinsky, A.V., Orginos, K., Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, Renner, D.B., & Schroers, W.. Nucleon Axial Charge in Full Lattice QCD. United States. doi:10.1103/PhysRevLett.96.052001.
Edwards, R.G., Richards, D.G., Fleming, G.T., Haegler, Ph., Institut fuer Theoretische Physik, TU Muenchen, D-85747 Garching, Negele, J.W., Pochinsky, A.V., Orginos, K., Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, Renner, D.B., and Schroers, W.. Fri . "Nucleon Axial Charge in Full Lattice QCD". United States. doi:10.1103/PhysRevLett.96.052001.
@article{osti_20777016,
title = {Nucleon Axial Charge in Full Lattice QCD},
author = {Edwards, R.G. and Richards, D.G. and Fleming, G.T. and Haegler, Ph. and Institut fuer Theoretische Physik, TU Muenchen, D-85747 Garching and Negele, J.W. and Pochinsky, A.V. and Orginos, K. and Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 and Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795 and Renner, D.B. and Schroers, W.},
abstractNote = {The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm){sup 3}. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 7% statistical errors.},
doi = {10.1103/PhysRevLett.96.052001},
journal = {Physical Review Letters},
number = 5,
volume = 96,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2006},
month = {Fri Feb 10 00:00:00 EST 2006}
}
  • The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm)3. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 5% statistical errors.
  • We present results for the nucleon axial charge g_A at a fixed lattice spacing of 1/a=1.73(3) GeV using 2+1 flavors of domain wall fermions on size 16^3x32 and 24^3x64 lattices (L=1.8 and 2.7 fm) with length 16 in the fifth dimension. The total length of the Monte Carlo trajectory at the lightest quark mass is 7360 units, including 900 for thermalization. We find finite volume effects are larger than the pion mass dependence at the smallest value of m_\pi (= 330 MeV) in our calculation. We also find that g_A exhibits a scaling with the single variable m_\pi L whichmore » can also be seen in previous two-flavor domain wall and Wilson fermion calculations. Using this scaling to eliminate the finite-volume effect, we obtain g_A = 1.20(6)(4) at the physical pion mass, m_\pi = 135 MeV, where the first and second errors are statistical and systematic. The observed finite-volume effects also appear in similar quenched simulations, but disappear when V>(2.4$ fm)^3. We argue this is a dynamical quark« less
  • We present results for the nucleon axial charge g{sub A} at a fixed lattice spacing of 1/a=1.73(3) GeV using 2+1 flavors of domain wall fermions on size 16{sup 3}x32 and 24{sup 3}x64 lattices (L=1.8 and 2.7 fm) with length 16 in the fifth dimension. The length of the Monte Carlo trajectory at the lightest m{sub {pi}} is 7360 units, including 900 for thermalization. We find finite volume effects are larger than the pion mass dependence at m{sub {pi}}=330 MeV. We also find a scaling with the single variable m{sub {pi}}L which can also be seen in previous two-flavor domain wallmore » and Wilson fermion calculations. Using this scaling to eliminate the finite-volume effect, we obtain g{sub A}=1.20(6)(4) at the physical pion mass, m{sub {pi}}=135 MeV, where the first and second errors are statistical and systematic. The observed finite-volume scaling also appears in similar quenched simulations, but disappear when V{>=}(2.4 fm){sup 3}. We argue this is a dynamical quark effect.« less