The Paschos-Wolfenstein relation in a hadronic picture

Abstract The Paschos-Wolfenstein (PW) relation joins neutraland charged-current (anti)neutrino cross sections into an expression that depends on the weak mixing angle sin θW in a straightforward way. Contrary to the traditional approach with partonic degrees of freedom, in this work, we adopt a model built on hadronic degrees of freedom to perform a study of the PW relation at intermediate energies (100 MeV 2 GeV). We show that the Weinberg-angle dependence of the PW relation at medium energies is to a good approximation the same as in the deep inelastic scattering regime. Employing a relativistic mean-field nucleon knock-out model for the description of quasi-elastic neutrino-nucleus reactions, the influence of nuclear effects on the PW relation is investigated. The impact of the strangeness content of the nucleon and the neutron excess in the target nucleus are discussed. The combination of neutron excess in heavy target nuclei with a non-zero strangeness content of the nucleon largely influences the PW relation. Results are presented for 16O and 56Fe target nuclei.