The study of the J ψ transverse momentum distribution in oxygen-uranium reactions at 200 GeV/nucleon shows that 〈 P T 〉 and 〈 P T 2 〉 increase with the transverse energy of the reaction. Muon pairs in the mass continuum do not exhibit the same behaviour. The comparison of the J ψ production rates in central and peripheral collisions shows a significant diminution for low P T central events.
Two parametrization of the D(SIG)/D(PT) are used: first is : PT*exp(-SLOPE*PT**CONST(C=PT)) and second is : PT*exp(-2*MT/CONST(C=MT)).
D(SIG)/D(PT) is parameterized as PT*exp(-SLOPE*PT**CONST).
D(SIG)/D(PT) is parameterized as PT*exp(-SLOPE*PT**CONST).
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.
A single-spin asymmetry in the inclusive π 0 production at small x F was measured. In the experiment 40 GeV/c π − mesons were incident on transversely polarized protons and deutrons. An asymmetry of (40–50)% has been revealed in the hard scattering region.
No description provided.
The inclusive production of neutral kaons is studied inK+p and π+p interactions at 250 GeV/c. Total and semi-inclusive cross sections and average kaon multiplicities are presented and compared with the data at lower energies. The longitudinal and transverse momentum distributions and their energy dependence are analyzed. The results are interpreted in the framework of recent parton models.
No description provided.
No description provided.
No description provided.
We report on a study of ρ0, ρ+, ω,\(\bar K^{*0} (892)\) andK*0 (892) inclusive production in π+p interactions at 250 GeV/c, for ρ+,\(\bar K^{*0} (892)\) for the first time in a π+p experiment. The data are compared withK+p data in the same experiment, with results of other experiments and with quark-parton models. Interesting differences are found between ρ+,0 and ω production.
Inclusive cross sections and average multiplicity per inelastic collision.
No description provided.
No description provided.
None
Data from Run 1. There is an additional overall systematic uncertainty of 5.2 pct.
Data from Run 2. There is an additional overall systematic uncertainty of 5.2 pct.
Average R value.
We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from C12 nuclei. Our result is Aexpt=0.60±0.14±0.02 ppm, where the first error is statistical and the second is systematic. With a beam polarization of 0.37, we compute the isoscalar vector hadronic coupling constant γ̃ to be 0.136±0.032±0.009. The standard model predicts γ̃=0.155 at the tree level, in agreement with our data.
No description provided.
The total cross section for the reaction pp→ppπ0 was measured at nine center-of-mass energies from 1.5 to 23 MeV above threshold. The experiment was carried out with the Indiana Cooler, a recently constructed storage ring. The experimental advantages of an electron-cooled proton beam were utilized. The data cover an energy range where only the lowest possible angular momentum state contributes in the exit channel. The measured energy dependence of the total cross section is not compatible with that predicted by models of s-wave pion production and rescattering.
No description provided.
We have observed four unambiguous decays of the charmed strange baryon Ξ c o in the NA32 experiment at CERN. Charge- coupled devices and silicon microstrip detectors were used to reconstruct the decay mode Ξ c o → pK − K ∗ (892) o seen in events produced by the interaction of 230 GeV/ c negative poins and kaons on a copper target. We present the first measurement of the lifetime of the Ξ c o , together with a determination of its mass and production cross section. The resonant components of the Ξ c o decay are studied. We use our earlier measurement of the mass of the Ξ c + in the determination of the isospin mass splitting of the Ξ c states.
No description provided.
Results on the photoproduction of 10 000 fully reconstructed charmed particles from the 108 recorded triggers of Fermilab experiment E691 have been analyzed in the photon-gluon-fusion model. We find that the total cross section, its rise with energy, and the pT2 and xF distributions can be explained by a high mass for the charm quark (mc=1.74−0.18+0.13 GeV/c2) and a soft-gluon distribution [G(x)∼(1-x)gn, where ng=7.1±2.2].
Data can be found in the record RED = 4080.
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