Neutrino production of dimuons

Neutrino interactions with two muons in the final state have been studied using the Fermilab narrow band beam. A sample of 18v _μ like sign dimuon events withP _μ>9 GeV/c yields 6.6±4.8 events after backgroud subtraction and a prompt rate of (1.0±0.7)×10^?4 per single muon event. The kinematics of these events are compared with those of the non-prompt sources. A total of 437v _μ and 31 (bar v_mu ) opposite sign dimuon events withP _μ>4.3 GeV/c are used to measure the strange quark content of the nucleon: (kappa = {{2s} mathord{left/ {vphantom {{2s} {left( {bar u + bar d} right) = 0.52_{ - 0.15}^{ + 0.17} left( {oreta _s frac{{2s}}{{u + d}} = 0.075 pm 0.019} right) for 100< E_v< 230 GeVleft( {leftlangle {Q^2 } rightrangle = {{23 GeV^2 } mathord{left/ {vphantom {{23 GeV^2 } {c^2 }}} right. kern-0em} {c^2 }}} right)}}} right. kern-0em} {left( {bar u + bar d} right) = 0.52_{ - 0.15}^{ + 0.17} left( {oreta _s frac{{2s}}{{u + d}} = 0.075 pm 0.019} right) for 100< E_v< 230 GeVleft( {leftlangle {Q^2 } rightrangle = {{23 GeV^2 } mathord{left/ {vphantom {{23 GeV^2 } {c^2 }}} right. kern-0em} {c^2 }}} right)}}) using a charm semileptonic branching ratio of (10.9±1.4)% extracted from measurements ine ⁺ e ^? collisions and neutrino emulsion data.