We report nucleon mass, isovector vector and axial-vector charges, and tensor and scalar couplings, calculated using two recent $2+1$-flavor dynamical domain-wall fermion lattice-QCD ensembles generated jointly by the RIKEN-BNL-Columbia and UKQCD Collaborations. These ensembles were generated with Iwasaki $\times$ dislocation-suppressing-determinant-ratio gauge action at an inverse lattice spacing of 1.378(7) GeV and pion mass values of 249.4(3) and 172.3(3) MeV. The nucleon mass extrapolates to a value $m_N=0.950(5)\mathrm{GeV}$ at the physical point. The isovector vector charge renormalizes to unity in the chiral limit, narrowly constraining excited-state contamination in the calculation. The ratio of the isovector axial-vector to the vector charges shows a deficit of about 10%. The tensor coupling no longer depends on mass and extrapolates to 1.04(5) in $\overline{\mathrm{MS}}2\mathrm{GeV}$ renormalization at the physical point, in a good agreement with the value obtained at the lightest mass in our previous calculations and other calculations that followed. The scalar charge, though noisier, does not show mass dependence and is in agreement with other calculations.

• Received 8 November 2019
• Accepted 21 January 2020

DOI:https://doi.org/10.1103/PhysRevD.101.034510

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Published by the American Physical Society