None
No description provided.
No description provided.
Measurements of the ν and ν¯ weak hadronic neutral-current total cross sections and hadron energy distributions are consistent with a V−A form for this current. They are three standard deviations from pure V, pure A, or a pure T form and unambiguously exclude V+A and any linear combination of S and P.
DATA FOR VARIOUS BEAM FOCUSING.
No description provided.
We report on the analysis of inclusive neutral current events produced in neutrino and antineutrino narrow band beams. We find for incident neutrino energies in the range 12–200 GeV and for hadron energies above 12 GeV a neutral to charged current cross-section ratio of R v = 0.293 ± 0.010 for incident neutrinos, and R v = 0.35 ± 0.03 for antineutrinos. These ratios are consistent with the Weinberg-Salam model, with sin 2 θ w = 0.24 ± 0.02.
No description provided.
No description provided.
Samples of 9200 muon-neutrino and 3800 muon-antineutrino interactions on nuclei were obtained with the fine-grain calorimeter of the CHARM Collaboration at the CERN 200 GeV narrow-band neutrino beam. The interactions were classified as either neutral-current or charged-current processes on an event-by-event basis. Neutral-current and charged-current cross sections in neutrino and antineutrino interactions are presented. From these results we deduce a statistically significant contribution of right-handed coupling to the neutral hadronic current, and a value of the electroweak mixing angle corresponding to sin 2 θ = 0.220 ± 0.014.
Measured charged current total cross section.
Measured charged current total cross section.
No description provided.
Distributions of the Bjorken scaling variables x and y, and the structure function F+(x), are presented both for neutral-current and for charged-current νμ interactions. The data were obtained by use of the Fermilab 15-ft neon bubble chamber exposed to a narrow-band νμ beam. Results are based on 151 neutral-current and 683 charged-current events. An important feature of the neutral-current analysis is the event-by-event reconstruction of the outgoing neutrino.
No description provided.
DATA REQUESTED FROM C.BALTAY ON 20/9/91.
DATA REQUESTED FROM C.BALTAY ON 20/9/91.
The ratio Rν of the neutral- to charged-current cross sections of neutrinos in iron has been measured in an exposure of the CERN-Dortmund-Heidelberg-Saclay neutrino detector to a 160-GeV/c neutrino narrow-band beam at the CERN Super Proton Synchrotron. The result is Rν=0.3072±0.0025(stat)±0.0020(syst), for hadronic energy greater than 10 GeV. The electroweak mixing parameter is sin2θW=0.225±0.005(expt)±0.003(theor)+0.013(mc−1.5 GeVc2), where mc is the charm-quark mass.
No description provided.
New measurements of the total crosssections of charged-current interactions of muonneutrinos and antineutrinos on isoscalar nuclei have been performed. Data were recorded in an exposure of the CHARM d
No description provided.
No description provided.
The final results from the WA 1/2 neutrino experiment in the 1984 CERN 160 GeV narrow band beam are presented. The ratiosRν and\(R_{\bar v} \) of neutral to charged current interaction rates of neutrinos and antineutrinos in iron are measured to beRν=0.3072±0.0033 and\(R_{\bar v} \)=0.382±0.016. A value of the electroweak parameter sin2 θw = 1 −mW2/mZ2 is extracted fromRν. The result is sin2 θw =0.228+0.013(mc−1.5)±0.0003 (theor.) wheremc is the mass of the charmed quark in GeV formt=60 GeV,MH=100 GeV, ρ=1. CombiningRν and\(R_{\bar v} \) one obtains a value for ρ=0.991+0.023(mc−1.5)±0.020(exp.). Alternatively,Rν and\(R_{\bar v} \) yield a precise value of the ratio of intermediate vector boson massesmW/mZ=0.880−0.007(mc−1.5)±0.002(exp.)±0.002(theor.). Comparison of these results with those from direct measurements of the vector boson masses are presented. In a model-independent analysis the left- and right-handed neutral current coupling constants,gL2 andgR2, are determined.
No description provided.
No description provided.
No description provided.
The rate of neutrino- and antineutrino-induced prompt same-sign dimuon production in steel was measured using a sample of μ−μ− events and 25 μ+μ+ events withPμ>9 GeV/c, produced in 1.5 millionvμ and 0.3 million\(\overline {v_\mu}\) induced charged-current events with energies between 30 GeV and 600 GeV. The data were obtained with the Chicago-Columbia-Fermilab-Rochester (CCFR) neutrino detector in the Fermilab Tevatron Quadrupole Triplet Neutrino Beam during experiments E 744 and E 770. After background subtraction, the prompt rate of same-sign dimuon production is (0.53±0.24)×10−4 pervμ charged-current event and (0.52±0.33)×10−4 per\(\overline {v_\mu}\) charged-current event. The kinematic distributions of the same-sign dimuon events after background subtraction are consistent with those of the non-prompt background due to meson decays in the hadron shower of a charged-current event. Calculations ofc\(\bar c\) gluon bremsstrahlung, based on improved measurements of the charm mass parameter and nucleon structure functions by the CCFR collaboration, yield a prompt rate of (0.09±0.39)×10−4 pervμ charged-current event. In this case,c\(\bar c\) gluon bremsstrahlung is probably not an observable source of prompt same-sign dimuons.
Rate of dimuon production per charged current event.
Rate of dimuon production per charged current event.
Charged vector D*+(2010) meson production is studied in a high energy neutrino bubble chamber experiment with mean neutrino energy of 141 GeV. The D*+ are produced in (5.6±1.8)% of the neutrino charged current interactions, indicating a steep increase of cross section with energy. The mean fractional hadronic energy of the D*+ meson is 0.55 ± 0.06.
No description provided.