Neutral-current coupling in high-energy neutrino interactions

Abstract

We present measured hadron energy distributions for the reactions $\nu \left(\overline{\nu }\right)+N\to \nu \left(\overline{\nu }\right)+\mathrm{hadrons}$ at high energy, as well as for the similar charged-current interactions. Insofar as possible, the determination of these distributions avoids any a priori assumptions about either the neutral-current or the charged-current interactions. We further analyze the neutral-current distributions within the framework of specific models, particularly the scaling model, to obtain a positive-helicity component $P=0.36\mathrm{}\pm 0.10$, which lies between pure $V-A$ and pure $V$ or $A$, and a coupling strength of $g_0=0.31\mathrm{}\pm 0.03$ relative to the charged-current interaction. These coupling parameters agree well with the predictions of the Weinberg-Salam model with ${{sin}^2\theta }_W=0.33\mathrm{}\pm 0.07$.