Lattice Calculation of Nucleon Isovector Axial Charge with Improved Currents

Abstract

We employ dimension-4 operators to improve the local vector and axial-vector currents and calculate the nucleon isovector axial coupling $g_A^3$ with overlap valence on $2+1$-flavor Domain Wall Fermion sea. Using the equality of $g_A^3$ from the spatial and temporal components of the axial-vector current as a normalization condition, we find that $g_A^3$ is increased by a few percent towards the experimental value. The excited-state contamination has been taken into account with three time separations between the source and sink. The improved axial charges $g_A^3(24I)=1.22(4)$ and $g_A^3(32I)=1.21(3)$ are obtained on a $24^3\times 64$ lattice at pion mass of 330 MeV and a $32^3\times 64$ lattice at pion mass 300 MeV are increased by $3.4\%$ and $1.7\%$ from their unimproved values, respectively. We have also used clover fermion on the same DWF configurations and find the same behavior for the local axial charge as that of the overlap fermion.

25 pages, 11 figures, matched to the version accepted by PRD

References in corpus (7)

• Extraction of Spin-Dependent Parton Densities and Their Uncertainties
• A first unbiased global determination of polarized PDFs and their uncertainties
• Continuum Limit Physics from 2+1 Flavor Domain Wall QCD
• Nucleon isovector couplings from $N_f=2$ lattice QCD
• Precision Measurement of the Neutron Beta-Decay Asymmetry
• Overlap Valence on 2+1 Flavor Domain Wall Fermion Configurations with Deflation and Low-mode Substitution
• Meson Mass Decomposition from Lattice QCD

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• Nucleon structure from basis light-front quantization
• Nucleon axial and pseudoscalar form factors from lattice QCD at the physical point
• Solving the PCAC puzzle for nucleon axial and pseudoscalar form factors
• Extraction of nucleon axial charge and radius from lattice QCD results using baryon chiral perturbation theory
• Lattice Calculation of Pion Form Factor with Overlap Fermions
• Review of experimental and theoretical status of the proton radius puzzle
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• Distillation at High-Momentum
• Sea Quarks Contribution to the Nucleon Magnetic Moment and Charge Radius at the Physical Point
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• Roper State from Overlap Fermions
• The nucleon isovector tensor charge from lattice QCD using chiral fermions
• Nucleon mass and isovector couplings in 2+1-flavor dynamical domain-wall lattice QCD near physical mass
• Ratio of strange to $u/d$ momentum fraction in disconnected insertions
• Holographic estimate of the meson cloud contribution to nucleon axial form factor
• Quark spin content of SU(3) light and singly heavy baryons
• Nucleon isovector scalar charge from overlap fermions
• Chiral Analysis of the Nucleon Mass and Sigma Commutator
• Nucleon Structure from Basis Light-Front Quantization : Status and Prospects
• Nucleon Matrix Elements at Physical Pion Mass and Cost Comparison
• Proton momentum and angular momentum decompositions with overlap fermions