Leading-order QCD analysis of neutrino-induced dimuon events

The results of a leading-order QCD analysis of neutrino-induced charm production are presented. They are based on a sample of 4111 $\nu_\mu$ - and 871 $\bar \nu_\mu$ -induced opposite-sign dimuon events with $E_{\mu 1},E_{\mu 2} > 6{\rm GeV}$ , $35 < E_{\nu} < 290{\rm GeV}$ and $Q^2> 5.5\,{\rm GeV^2}$ , observed in the CHARM II detector exposed to the CERN wide band neutrino and antineutrino beams. The analysis yields the value of the charm quark mass $m_c=1.79\pm0.38\,{\rm GeV}/c^2$ and the Cabibbo–Kobayashi–Maskawa matrix element $|V_{cd}|=0.219\pm0.016$ . The strange quark content of the nucleon is found to be suppressed with respect to non-strange sea quarks by a factor $\kappa =0.39\pm0.09$ .