Measurement of neutrino-proton and antineutrino-proton elastic scattering

Abstract

Measurements of the semileptonic weak-neutral-current reactions ${\nu }_{\mu }$p→${\nu }_{\mu }$p and ν${¯}_{\mu }$p→ν${¯}_{\mu }$p are presented. The experiment was performed using a 170-metric-ton high-resolution target detector in the BNL wide-band neutrino beam. High-statistics samples yield the absolute differential cross sections dσ(${\nu }_{\mu }$p)/${\mathrm{dQ}}^2$ and dσ(ν${¯}_{\mu }$p)/${\mathrm{dQ}}^2$. A measurement of the axial-vector form factor $G_A$($Q^2$) is also presented. The results are in good agreement with the standard model SU(2)×U(1). The weak-neutral-current parameter ${\sin }^2$ ${\mathrm{theta}}_{\mathrm{W}}$ is determined to be ${\sin }^2$ ${\mathrm{\theta }}_{\mathit{W}}$=0.220±0.016(stat${)}_{\mathrm{-}0.031}^{+0.023\mathrm{}}$(syst).