Measurement of the strange sea distribution using neutrino charm production

A high-statistics study by the Columbia-Chicago-Fermilab-Rochester Collaboration of opposite-sign dimuon events induced by neutrino-nucleon scattering at the Fermilab Tevatron is presented. A sample of 5044 ν_μ and 1062 {ν}_μ induced μ^∓{{{μ}}}^{±{}}$ events with ${P}_{{{μ}}1}≥9 GeV/c,{P}_{{{μ}}2}≥5 GeV/c, 30≤{E}_{{ν}}≤600 GeV, and 〈{Q}²$〉=22.2 ${GeV}²$/${c}²$ is observed. The data support the slow-rescaling model of charm production with a value of ${m}c=1.31±0.24{GeV}²$/${c}²$. The first measurement of the ${Q}²dependence of the nucleon strange quark distribution xs(x) is presented. The data yield the Cabibbo-Kobayashi-Maskawa matrix element{V}cd=0.209±0.012 and the nucleon fractional strangeness content{{{η}}}ₛ$=0.${064}_{{{-}}0.007}+0.008$.