Relativistic models for quasielastic neutrino scattering

Abstract

We present quasielastic neutrino-nucleus cross sections in the energy range from 150 MeV to 5 GeV for the target nuclei $^{12}\mathrm{C}$ and $^{56}\mathrm{Fe}$. A relativistic description of the nuclear dynamics and the neutrino-nucleus coupling is adopted. For the treatment of final-state interactions we rely on two frameworks succesfully applied to exclusive electron-nucleus scattering: a relativistic optical potential and a relativistic multiple-scattering Glauber approximation. At lower energies, the optical-potential approach is considered to be the optimum choice, whereas at high energies a Glauber approach is more natural. Comparing the results of both calculations, it is found that the Glauber approach yields valid results down to the remarkably small nucleon kinetic energies of 200 MeV. We argue that the nuclear transparencies extracted from $A(e,{e}^{'}p)$ measurements can be used to obtain realistic estimates of the effect of FSI mechanisms on quasielastic neutrino-nucleus cross sections. We present two independent relativistic plane-wave impulse approximation (RPWIA) calculations of quasielastic neutrino-nucleus cross sections. They agree at the percentage level, showing the reliability of the numerical techniques adopted and providing benchmark RPWIA results.