Determination of the Strange Quark Content of the Nucleon from a Next-to-Leading-Order QCD Analysis of Neutrino Charm Production

TL;DR

This paper presents a next-to-leading-order QCD analysis of neutrino-induced charm production, revealing the strange quark content of the nucleon and providing measurements of the charm quark mass and CKM matrix element.

Contribution

It provides the first NLO QCD analysis of neutrino charm production, improving understanding of the strange quark distribution and related parameters.

Findings

Strange quark content is about 47.7% of non-strange sea.

Strange sea x-dependence resembles non-strange sea.

Charm quark mass measured at 1.70 GeV/c^2.

Abstract

We present the first next-to-leading-order QCD analysis of neutrino charm production, using a sample of 6090 $\nu_\mu$- and $\bar\nu_\mu$-induced opposite-sign dimuon events observed in the CCFR detector at the Fermilab Tevatron. We find that the nucleon strange quark content is suppressed with respect to the non-strange sea quarks by a factor $\kappa = 0.477 \: ^{+\:0.063}_{-\:0.053}$, where the error includes statistical, systematic and QCD scale uncertainties. In contrast to previous leading order analyses, we find that the strange sea $x$-dependence is similar to that of the non-strange sea, and that the measured charm quark mass, $m_c = 1.70 \pm 0.19 \:{\rm GeV/c}^2$, is larger and consistent with that determined in other processes. Further analysis finds that the difference in $x$-distributions between $xs(x)$ and $x\bar s(x)$ is small. A measurement of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cd}|=0.232 ^{+\:0.018}_{-\:0.020}$ is also presented. uufile containing compressed postscript files of five Figures is appended at the end of the LaTeX source.