One-loop corrections to light neutrino masses in gauged U(1) extensions of the standard model

We consider gauged U(1) extensions of the standard model of particle physics with three right-handed sterile neutrinos and a singlet scalar. The neutrinos obtain mass via the type I seesaw mechanism. We compute the one-loop corrections to the elements of the tree-level mass matrix of the light neutrinos and show explicitly the cancellation of the gauge-dependent terms. We present a general formula for the gauge-independent, finite one-loop corrections for arbitrary number new U(1) groups, new complex scalars, and sterile neutrinos. We estimate the size of the corrections relative to the tree-level mass matrix in a particular extension, the superweak model.