Effect of the charged-lepton's mass on the quasielastic neutrino cross sections

Martini et al. [Phys. Rev. C 94, 015501 (2016)] recently observed that when the produced-lepton's mass plays an important role, the charged-current quasielastic cross section for muon neutrinos can be higher than that for electron neutrinos. Here I argue that this effect appears solely in the theoretical descriptions of nuclear effects in which nucleon knockout requires the energy and momentum transfers to lie in a narrow range of the kinematically allowed values.