Study of the reactionνμd→μ−pps

Abstract

This paper reports a determination of the axial-vector form factor of the nucleon using the momentum-transfer distribution for 1737 events of the type ${\ensuremath{\nu}}_{\ensuremath{\mu}}d\ensuremath{\rightarrow}{\ensuremath{\mu}}^{\ensuremath{-}}p{p}_{s}$. The events were obtained from a 2.4\ifmmode\times\else\texttimes\fi{}${10}^{6}$-frame exposure of the Argonne 12-foot bubble chamber to a neutrino beam at the Argonne Zero Gradient Synchrotron. After fitting and applying selection criteria, the background was estimated to be at the 2% level. The axial-vector mass in the dipole parametrization was measured to be ${M}_{A}=1.00\ifmmode\pm\else\textpm\fi{}0.05$ GeV/${\mathit{c}}^{2}$, in good agreement both with earlier measurements from this experiment and with other recent results. A test of the conserved-vector-current hypothesis, made by simultaneously fitting ${M}_{A}$ and ${M}_{V}$ using dipole form factors, gave ${M}_{A}=0.80\ifmmode\pm\else\textpm\fi{}0.10$ GeV/${\mathit{c}}^{2}$ and ${M}_{V}=0.96\ifmmode\pm\else\textpm\fi{}0.04$ GeV/${\mathit{c}}^{2}$.