Radiative Corrections to the Nucleon Isovector gV and gA

Electroweak, QCD, and QED radiative corrections to the nucleon low-energy coupling constants gV and gA are enhanced by large perturbative logarithms between the electroweak and hadronic scale, as well as between the hadronic scale and the low-energy MeV scale. Additionally, higher-order pion-mass splitting corrections to the nucleon axial-vector charge might be large. By consistently incorporating these effects, we provide an updated relation between the lattice-QCD and physical gA, finding a total radiative correction of 3.5(2.1)% (5.6(0.7)%). This leads to an expected lattice-QCD result of gAQCD=1.265(26) (gAQCD=1.240(9)) when based on a combination of lattice-QCD and data-driven (or only data-driven) inputs, respectively. Future phenomenological, chiral perturbation theory, and lattice-QCD studies can improve both the central value and the uncertainty of this estimate.