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 ${\nu }_{\mu }d\to {\mu }^{-}p{p}_s$. The events were obtained from a 2.4×${10}^6$-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 $M_A=1.00\mathrm{}\pm 0.05$ 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 $M_A=0.80\mathrm{}\pm 0.10$ GeV/${\mathit{c}}^2$ and $M_V=0.96\mathrm{}\pm 0.04$ GeV/${\mathit{c}}^2$.