Relevance of Two Boson Exchange Effect in Quasi-Elastic Charged Current Neutrino-Nucleon Interaction

Abstract

Two boson exchange (TBE) correction to the cross section for the quasi-elastic charged current $\nu n$ and $\bar{\nu }p$ scattering is evaluated. The TBE is given by $W\gamma$ box diagrams. The calculations are performed for 1 GeV neutrinos. The averaged TBE correction is of the order of $2÷4$ (with respect to Born contribution) in the case of ${\nu }_e$ and ${\bar{\nu }}_e$ and $1÷2$ in the case of ${\nu }_{\mu }$ and ${\bar{\nu }}_{\mu }$. The impact of the TBE effect on the systematic discrepancy between the ${\nu }_e$ and ${\nu }_{\mu }$ cross sections is discussed.

Comments: 6 pages, 7 figures