A study of the weak neutral current and the electromagnetic properties of the muon neutrino

Measurements of the total cross sections were performed. In addition, limits were obtained on the electromagnetic properties of the muon neutrino. The elastic scattering events were observed in a large mass, finely segmented detector at the BNL AGS wide band neutrino beam. A total of (159.5 ± 17.3 ± 7.3) νμe → νμe reactions and (96.7 ± 13.2 ± 8.8) νμ e → νμe reactions were observed. The observation together with quasielastic normalization yielded the cross sections: (1.87±0.21[stat]±0.27[syst]) x 10-42 cm2/GeV for (νμe → νμe); (1.20 ±0.17[stat]±0.16[syst]) x 10-42cm2/GeV for (νμe → νμe). By taking the correlated systematic errors into account, the ratio of the two cross sections was determined to be: 1.56-0.25-0.21+0.31+0.24. The weak neutral current coupling constants of the electron were determined to be: gν = -0.17-0.054+0.053; ga = -0.510-0.037+0.040. The ratio of the neutral to charge current coupling was determined to be: ρ = 1.008 ± 0.064. By using the predictions of the Weinberg-Salam theory for gν, ga, and ρ, the Weinberg angle was determined to be: sin2Θω = 0.197-0.021+0.020[stat]-0.017+0.017[syst]. Limits were placed on the muon neutrino magnetic moment and charge radius by examining deviations of the cross sections from the Standard Model values, determined by using the value of sin2Θω given by the measured masses of the intermediate vector bosons