Next-to-leading-order QCD corrections to nucleon Dirac form factors

Abstract: The leading-order perturbative QCD (pQCD) predictions to nucleon electromagnetic form factors were first made in late 70s. Nearly half a century later, we accomplish the calculation of the next-to-leading-order (NLO) QCD corrections to proton and neutron's Dirac form factors at large momentum transfer, to the leading-twist accuracy in collinear factorization. The NLO hard-scattering kernel is computed in the Krankl and Manashov renormalization scheme. The effect of NLO perturbative corrections turns out to be positive and substantial. Confronting our state-of-the-art pQCD predictions with the available data for nucleon Dirac form factors, in both space-like and time-like regions, imposes a stringent test on the validity of the parameterized forms of nucleon leading-twist light-cone-distribution amplitudes (LCDAs), which have been predicted by a class of QCD sum rules-based models and lattice QCD simulation.