The Fermilab 15-ft bubble chamber has been exposed to a quadrupole triplet neutrino beam produced at the Tevatron. The ratio of ν to ν¯ in the beam is approximately 2.5. The mean event energy for ν-induced charged-current events is 150 GeV, and for ν¯-induced charged-current events it is 110 GeV. A total of 64 dimuon candidates (1 μ+μ+, 52 μ−μ+ and μ+μ−, and 11 μ−μ−) is observed in the data sample of approximately 13 300 charged-current events. The number and properties of the μ−μ− and μ+μ+ candidates are consistent with their being produced by background processes, the important sources being π and K decay and punchthrough. The 90%-C.L. upper limit for μ−μ−/μ− for muon momenta above 4 GeV/c is 1.2×10−3, and for momenta above 9 GeV/c this limit is 1.1×10−3. The opposite-sign-dimuon–to–single-muon ratio is (0.62±0.13)% for muon momenta above 4 GeV/c. There are eight neutral strange particles in the opposite-sign sample, leading to a rate per dimuon event of 0.65±0.29. The opposite-sign-dimuon sample is consistent with the hypothesis of charm production and decay.
No description provided.
No description provided.
No description provided.
Neutrino and antineutrino total charged current cross sections on iron were measured in the 100, 160, and 200 GeV narrow band beams at the CERN SPS in the energy range 10 to 200 GeV. Assuming σ/E to be constant, the values corrected for non-isoscalarity are σv/E = (0.686 ± 0.019) * 10−38 cm2/ (GeV · nucleon) and σv/E = (0.339 ± 0.010) * 10−38 cm2/ (GeV·nucleon). Between 50 and 150 GeV no energy dependence of σ/E was observed within ±3% for neutrino and ±4% for antineutrino interactions.
Measured charged current total cross section.
Measured charged current total cross section.
No description provided.
Using the freon filled bubble chamber SKAT in the (anti)neutrino wide band beam of the Serpukhov accelerator we determine the neutral to charged current cross section ratios for neutrinos and antineutrinos below 30GeV. From these ratios we calculate in leading order a mixing parameter of the standard model of Θw=0.215±0.029.
Axis error includes +- 0.0/0.0 contribution (?////TOTAL SYSTEMATICS).
Axis error includes +- 0.0/0.0 contribution (?////TOTAL SYSTEMATICS).
Axis error includes +- 0.0/0.0 contribution (?////TOTAL SYSTEMATICS).
The ratios of neutral current to charged current cross sections of neutrino and antineutrino interactions in heavy Ne/H 2 mixture have been measured in BEBC. The beam was the CERN SPS 200 GeV/ c narrow band beam. The ratios were obtained using a cut in the transverse momentum of the hadronic system. In the standard Glashow-Salam-Weinberg model, our results correspond to the value of sin 2 θ w = 0.182 ± 0.020 ± 0.012. By combining this experiment with data from a hydrogen target the coupling constants u L 2 and L 2 are found to be 0.15 ± 0.04 and 0.19 ± 0.05, respectively.
No description provided.
No description provided.
Exposures of the Ne/H 2 filled Big European Bubble Chamber (BEBC) to a dichromatic neutrino (antineutrino) beam produced by 400 GeV protons of the CERN SPS yielded ∼ 3100 events with a negative, and ∼ 1100 with a positive, muon. The neutrino flux is determined from the muon flux in the shielding. Assuming a linear energy dependence of the cross section, the values σ E between 20 and 200 GeV are found to be 0.657 ± 0.012 (stat.) ± 0.027 (syst.) and 0.309 ± 0.009 (stat.) ± 0.013 (syst.) cm 2 (GeV nucleon) −1 , for neutrinos and antineutrinos, respectively. The scaling variable q 2 E decreases significantly with increasing energy both for neutrinos and antineutrinos.
Measured charged current total cross section.
Measured charged current total cross section.
No description provided.
Total neutrino and antineutrino cross sections in the energy range 15 to 150 GeV, and the nucleon structure functions, F 2 ( x , Q 2 ) and xF 3 ( x , Q 2 ) in the Q 2 range 0.5 to 50 (GeV/ c ) 2 have been measured using a data sample of 3000 neutrino and 3800 antineutrino events. The structure functions show a weak Q 2 dependence at different x values.
Measured charged current total cross section.
Measured charged current total cross section.
ERRORS CONTAIN 10 P.C. SYSTEMATIC ERROR WHICH HAS BEEN LINEARLY ADDED TO THE STATISTICAL ERROR.
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.
Charged-current neutrino and antineutrino interaction cross sections have been measured in the energy range 10 to 50 GeV using BEBC filled with a neon-hydrogen mixture. At these energies, σ/E was measured to be (0.73±0.08) 10−38 cm2/GeV per nucleon for neutrinos and (0.32±0.06) 10−38 cm2/GeV per nucleon for antineutrinos.
Axis error includes +- 9/9 contribution (NEUTRAL CURRENT EVENTS AND NEUTRAL HADRON INDUCED REACTIONS, LOSSES OF EVENTS WITH ONLY ONE VISIBLE CHARGED PARTICLE).
Axis error includes +- 9/9 contribution (NEUTRAL CURRENT EVENTS AND NEUTRAL HADRON INDUCED REACTIONS, LOSSES OF EVENTS WITH ONLY ONE VISIBLE CHARGED PARTICLE).
Average total cross sections are given for neutrino charged current interactions at neutrino energies of 2.87 GeV and 9.05 GeV. The ratios 〈σ〉 〈E〉 are 0.69 ± 0.05 and 0.61 ± 0.06 in units of 10 −38 cm 2 /GeV nucleon, respectively The errors include both statistical and systematic uncertainties.
Measured charged current total cross section.
Measured charged current total cross section.
The charged-current cross sections for neutrinos and antineutrinos on nucleons in the energy range 20–200 GeV are given. Taken in conjunction with the previous Gargamelle results, they show that σ E is almost constant with energy for antineutrinos, and falls with energy for neutrinos. The value of 〈q 2 〉 E decreases with energy for both neutrinos and antineutrinos, and these deviations from exact Bjorken scaling are consistent with those observed in electron and muon inelastic scattering. We find no evidence for new heavy quark states with right-handed coupling.
Measured charged current total cross section.
Measured charged current total cross section.
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