Study of opposite-sign dimuon production in high-energy neutrino-nucleon interactions

Results are presented of a study of opposite-sign dimuon events observed in a fine-grained neutrino detector exposed to the Fermilab Tevatron wide-band neutrino beam. A total of 300 background-corrected μ⁺μ^- events induced by incident neutrinos and antineutrinos with energies up to 500 GeV were accumulated. The data were analyzed in terms of a model based on charmquark production followed by semileptonic decay of the charmed meson. The Cabibbo-Kobayashi-Maskawa matrix terms were found to be |Ucd|²=0.0378±0.0127 (stat)_-0.0082+0.0099 (syst), and κ|Ucs|²=0.391±0.076 (stat)_-0.066+0.097 (syst). The ratio of the strange to nonstrange sea in the nucleon, κ=2S(Ū+D̄), was measured to be 0.407±{}0.075 (stat)_-0.069+0.103 (syst).