None
No description provided.
No description provided.
We present a new determination of the nonsinglet structure function ${\mathit{F}}_{2}^{\mathit{p}}$ - ${\mathit{F}}_{2}^{\mathit{n}}$ at ${\mathit{Q}}^{2}$=4 ${\mathrm{GeV}}^{2}$ using recently measured values of ${\mathit{F}}_{2}^{\mathit{d}}$ and ${\mathit{F}}_{2}^{\mathit{n}}$/${\mathit{F}}_{2}^{\mathit{p}}$. A new evaluation of the Gottfried sum is given, which remains below the simple quark-parton model value of 1/3.
Errors of F2(D) are the estimated total uncertainties and those on the ratio and difference are statistical only.
Values of the Gottfried Sum Rule integral (GS) defined as the integral between X(C=MIN) and X = 0.8 of (F2(P)-F2(N))DX/X.
No description provided.
Data on multiplicities of charged particles produced in proton-nucleus and nucleus-nucleus collisions at 200 GeV per nucleon are presented. It is shown that the mean multiplicity of negative particles is proportional to the mean number of nucleons participating in the collision both for nucleus-nucleus and proton-nucleus collisions. The apparent consistency of pion multiplicity data with the assumption of an incoherent superposition of nucleon-nucleon collisions is critically discussed.
No description provided.
No description provided.
No description provided.
An analysis has been performed of neutrino and antineutrino interactions with protons and neutrons in a deuterium bubble chamber. The interactions under study are quasielastic neutrino-neutron scattering and one-, two- and three-pion production reactions. Results are presented on cross sections, effective mass distributions, resonance production, momentum transfer distributions and coefficients of the decay angular distributions. Where possible, comparisons are made with existing theoretical models and predictions.
No description provided.
Numerical values supplied by A.Tenner.
Numerical values supplied by A.Tenner.
None
No description provided.
No description provided.
No description provided.
The ratios of neutral-current to charged-current cross sections of v and v interactions, seperately, on proton and neutron targets have been measured. The Big European Bubble Chamber (BEBC), filled with deuterium and equipped with an external muon identifier (EMI) and an internal picket fence (IPF), was exposed to the CERN SPS (anti)neutrino wide-band beam. The measured ratios are R v p= = 0.405 ± 0.024 ± 0.021 , R v n = 0.243 ± 0.013 ± 0.016, R v p = 0.301 ± 0.027 ± 0.024 and R v n = 0.490 ± 0.050 ± 0.037 . (The first error is statistical and the second systematic). From combinations of these ratios the following neutral-current chiral coupling constants have been determined: u L 2 = 0.099 ± 0.018 ± 0.008, d L 2 = 0.202 ± 0.020 ± 0.019, u R 2 = 0.020 ± 0.016 ± 0.009 and d R 2 = 0.002 ± 0.017 ± 0.010. These results agree with the predictions of the SU(2) × U(1) standard electroweak model. Assuming ϱ = 1, the corresponding value of sin 2 θ w is found to be 0.247 ± 0.029, whereas a two-parameter fit to the data yields sin 2 θ w = 0.243 ± 0.046 and ϱ = 0.996 ± 0.041.
No description provided.
No description provided.
No description provided.
The cross-section ratio of neutral-current and charged-current semileptonic interactions of muon-neutrinos on isoscalar nuclei has been measured with the result:Rv=0.3093±0.0031 for hadronic energy larger than 4 GeV. From this ratio we determined the electroweak mixing angle sin2θW, wheremc is the charm-quark mass in GeV/c2. Comparison with direct measurements ofmw andmz determines the radiative shift of the intermediate boson mass Δr=0.077±0.025(exp.)±0.038(syst.), in agreement with the prediction. Assuming the validity of the electroweak standard theory we determined ϱ=0.990−0.013(mc−1.5)±0.009(exp.)±0.003(theor.).
No description provided.
No description provided.
STATISTICAL ERROR IN THE VALUE CITED IS REDUCING, WHEN CUT IS MORE STRINGENT?.
Data obtained with the bubble chamber BEBC at CERN are used for the first significant test of Adler's prediction for the neutrino and antineutrino-proton scattering cross sections at vanishing four-momentum transfer squaredQ2. An Extended Vector Meson Dominance Model (EVDM) is applied to extrapolate Adler's prediction to experimentally accessible values ofQ2. The data show good agreement with Adler's prediction forQ2→0 thus confirming the PCAC hypothesis in the kinematical region of high leptonic energy transfer ν>2 GeV. The good agreement of the data with the theoretical predictions also at higherQ2, where the EVDM terms are dominant, also supports this model. However, an EVDM calculation without PCAC is clearly ruled out by the data.
No description provided.
No description provided.
No description provided.
None
No description provided.
No description provided.
No description provided.
Topological cross sections and characteristics of charged particle multiplicity distributions for¯nn andnn interactions and¯nn annihilations at 6·1 GeV/c are presented. KNO-distributions for¯nn andnn interactions are very similar. Characteristics for¯nn and¯pp annihilations are identical at equal energies.
No description provided.
No description provided.
No description provided.
Forum