Test of the universality of the electron-neutrino and muon-neutrino coupling to the charged weak current

Abstract A measurement of the ratio of electron-neutrino and muon-neutrino charged-current cross sections is reported. Using data collected in an exposure of the CHARM detector to a 160 GeV narrow-band neutrino beam at CERN we obtained σ νe ( CC ) σ νμ ( CC ) = 1.20 ± 0.11 . A ratio of the coupling constants g eνe g μνμ = 1.10 ± 0.05 at 〈Q 2 〉 ∽ 16 GeV 2 was derived in agreement with the universal coupling strength of the electron and muon families to the charged weak current.