Electroweak radiative corrections to neutrino--nucleon scattering at NuTeV

Abstract

A dedicated effort by both the experimental and theoretical communities is crucial for achieving a precise determination of Standard Model parameters such as the $W$ mass ($M_W$). $M_W$ is measured directly at the CERN LEP2 $e^+ e^-$ and the Fermilab Tevatron $p \bar p$ colliders, resulting in a precision of $\delta M_W/M_W=0.03%$. A complementary $M_W$ measurement is provided by the NuTeV collaboration, who extract $\sin^2 \theta_W$, and thus $M_W$, from the ratio of deep-inelastic neutral and charged-current neutrino(anti-neutrino)-Nucleon ($\nu N(\bar \nu N)$) scattering cross sections. However, their result differs from direct measurements performed at LEP2 and the Tevatron by about three standard deviations. Possible sources for the origin of this discrepancy have been extensively studied in the literature, among them the impact of electroweak radiative corrections. Here we provide first (preliminary) results of a new calculation of electroweak ${\cal O}(\alpha)$ corrections with emphasis on the effects of non-zero muon and charm quark masses. We find non-negligible shifts in $\sin^2\theta_W$ due to these mass effects but more detailed studies including detector resolution effects are needed to determine their impact on $M_W$ as extracted by the NuTeV collaboration.