Neutrino production of opposite sign dimuons in the NOMAD experiment

Abstract The NOMAD Collaboration presents a study of opposite sign dimuon events in the framework of Leading Order QCD. A total of 2714 neutrino- and 115 antineutrino-induced opposite sign dimuon events with E μ 1 , E μ 2 >4.5 GeV, 15 E ν Q 2 >1 ( GeV / c ) 2 are observed in the Front-Calorimeter of NOMAD during the 1995 and 1996 runs. The analysis yields a value for the charm quark mass of m c =1.3 +0.3+0.3 −0.3−0.3 GeV / c 2 and for the average semileptonic branching ratio of B c =0.095 +0.007+0.014 −0.007−0.013 . The ratio of the strange to non-strange sea in the nucleon is measured to be κ =0.48 +0.09+0.17 −0.07−0.12 . The measured rate of charm-induced dimuon relative to single muon, as a function of neutrino energy, is consistent with the slow rescaling hypothesis of heavy quark production.