High-energy limit of neutrino quasielastic cross section

Abstract

It's a common knowledge that the quasielastic neutrino-neutron and antineutrino-proton cross sections tend to the same constant as (anti)neutrino energy becomes high. In this paper we calculate the exact expression of the limit in terms of the parameters describing quasielastic scattering. We check that even at very high energies only small absolute values of the four-momentum transfer contribute to the cross section, hence the Fermi theory can be applied. The dipole approximation of the form factors allows to perform analytic calculations. Obtained results are neutrino-flavour independent.