Nucleon axial, scalar, and tensor charges using lattice QCD at the physical pion mass

Abstract

We report on lattice QCD calculations of the nucleon isovector axial, scalar, and tensor charges. Our calculations are performed on two 2+1-flavor ensembles generated using a 2-HEX-smeared Wilson-clover action at the physical pion mass and lattice spacings $a\approx$ 0.116 and 0.093 fm. We use a wide range of source-sink separations - eight values ranging from roughly 0.4 to 1.4 fm on the coarse ensemble and three values from 0.9 to 1.5 fm on the fine ensemble - which allows us to perform an extensive study of excited-state effects using different analysis and fit strategies. To determine the renormalization factors, we use the nonperturbative Rome-Southampton approach and compare RI'-MOM and RI-SMOM intermediate schemes to estimate the systematic uncertainties. Our final results are computed in the MS-bar scheme at scale 2 GeV. The tensor and axial charges have uncertainties of roughly 4%, $g_T=0.972(41)$ and $g_A=1.265(49)$. The resulting scalar charge, $g_S=0.927(303)$, has a much larger uncertainty due to a stronger dependence on the choice of intermediate renormalization scheme and on the lattice spacing.

24 pages, 13 figures, 9 tables. v2: added references. v3: additional discussion of systematics and summary plot showing calculations by other groups

References in corpus (7)

• Adaptive multigrid algorithm for the lattice Wilson-Dirac operator
• Nucleon isovector couplings from $N_f=2$ lattice QCD
• Massless correlators of vector, scalar and tensor currents in position space at orders alpha_s^3 and alpha_s^4: explicit analytical results
• RI'/SMOM scheme amplitudes for quark currents at two loops
• Fourier Accelerated Conjugate Gradient Lattice Gauge Fixing
• Chiral Corrections to Nucleon Two- and Three-Point Correlation Functions
• Chiral perturbation theory and nucleon-pion-state contaminations in lattice QCD

Cited by in corpus (20)

• FLAG Review 2021
• Precision Nucleon Charges and Form Factors Using 2+1-flavor Lattice QCD
• FLAG Review 2024
• The Present and Future of QCD
• Status of Lattice QCD Determination of Nucleon Form Factors and their Relevance for the Few-GeV Neutrino Program
• Updated QCD global analysis of single transverse-spin asymmetries I: Extracting $\tilde{H}$, and the role of the Soffer bound and lattice QCD
• Octet baryon isovector charges from $N_f=2+1$ lattice QCD
• Transversity distributions and tensor charges of the nucleon: extraction from dihadron production and their universal nature
• First simultaneous global QCD analysis of dihadron fragmentation functions and transversity parton distribution functions
• CP violating effects in ${}^{210}$Fr and prospects for new physics beyond the Standard Model
• Nucleon isovector couplings in Nf = 2 + 1 lattice QCD at the physical point
• Excited states in nucleon structure calculations
• Detailed analysis of excited state systematics in a lattice QCD calculation of $g_A$
• RI/MOM and RI/SMOM renormalization of quark bilinear operators using overlap fermions
• Weak interaction axial form factors of the octet baryons in nuclear medium
• Moments of Nucleon Unpolarized, Polarized, and Transversity Parton Distribution Functions from Lattice QCD at the Physical Point
• Extraordinary nature of the nucleon scalar charge and its densities as a signal of nontrivial vacuum structure of QCD
• Off-shell quark bilinear operator Green's functions at two loops
• The isoscalar octet axial form factor of the nucleon from lattice QCD
• Nucleon axial-vector form factor and radius from future neutrino experiments