None
No description provided.
No description provided.
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Topological distributions of charged and neutral hadrons from the reaction e + e − → multihadrons are studied at √ s of about 30 GeV. An excess of planar events is observed at a rate which cannot be explained by statistical fluctuations in the standard two-jet process. The planar events, mostly consisting of a slim jet on one side and a broader jet on the other, are shown actually to possess three-jet structure by demonstrating that the broader jet itself consists of two collinear jets in its own rest system. Detailed agreement between data and predictions is obtained if the process e + e − →q q ̄ g is taken into account. This strongly suggests gluon bremsstrahlung as the origin of the planar three-jet events. By comparison of the data with the qq̄g-model we obtain a value for the strong coupling constant of α S ( q 2 = 0.17 ± 0.04.
THRUST AND PLANARITY DISTRIBUTIONS. FINAL (BETTER) THRUST DISTRIBUTIONS WITH DETECTOR CORRECTIONS TO BE PUBLISHED LATER.
No description provided.
We have measured π+p, π−p, and pp elastic scattering at an incident-beam momentum of 200 GeV/c in the region of −t, four-momentum transfer squared, from 0.021 to 0.665 (GeV/c)2. The data allow an investigation of the t dependence of the logarithmic forward slope parameter b≡(ddt)(lndσdt). In addition to standard parametrization, we use functional forms suggested by the additive quark model to fit the measured dσdt distributions. Within the context of this model we estimate the size of the clothed quark in the pion and proton. Limits on the elastic-scattering amplitude derived from unitarity bounds are checked, and no violations are observed.
No description provided.
No description provided.
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The charged-particle multiplicity distribution from 250-GeV/c π−p interactions in the Fermilab 15-ft bubble chamber is presented. The corrections to the raw data are described. Fits to these data along with other high-energy bubble-chamber data show that cluster models with two components—a low-multiplicity, diffractive component and a high-multiplicity, nondiffractive component—describe the data fairly well. The charged multiplicity of each cluster is found to be ∼2, while the number of clusters for each component grows linearly with ln(s). The multiplicity moments are consistent with other experiments. We find 〈nc〉=8.427±0.059, f2cc=8.66±0.11, 〈nc〉D=2.038±0.023. The total inelastic cross section is σI=21.42±0.50 mb.
No description provided.
We have examined the inclusive production of nonstrange particle resonances in νp interactions using the Fermilab 15-ft bubble chamber. A sample of 2437 charged-current events with visible longitudinal momentum greater than 10 GeV/c was obtained. The ρ0 and Δ++(1232) are seen. An overall rate of 0.21±0.04 ρ0 per event is found. For five-prong events, the rate is 0.44±0.08 ρ0 per event. The ρ0Z distribution falls rapidly for Z greater than 0.4. The production of Δ++ is seen clearly in events with an identified proton. No evidence is seen for Δ0 production. An upper limit of 0.34 is placed on the ratio of ηπ0 (90% confidence level).
NO CLEAR DEL0 SIGNAL.
None
No description provided.
DATA FOR EVNENT WITHOUT PAIRS FROM INTERFIERENCE REGION - YF 27, 1556.
No description provided.
The charged multiplicity distribution is presented for K − p interactions produced in the hydrogen bubble chamber, BEBC, using an r.f. separated, tagged K − beam of 110 GeV/ c momentum. A comparison with K + p, πp and pp data at lower energies shows that the main features of the multiplicity distributions depend on energy and charge of the incident particles, but not on their strangeness. At high energies, only the energy is important.
No description provided.
No description provided.
No description provided.
Hadron production by e + e − annihilation has been studied for c.m. energies W between 13 and 31.6 GeV. As a function of 1n W the charged particle multiplicity grows faster at high energy than at lower energies. This is correlated with a rise in the plateau of the rapidity distribution. The cross section s d σ /d x is found to scale within ±30% for x > 0.2 and 5 ⩽ W ⩽ 31.6 GeV.
CHARGED PARTICLE MULTIPLICITIES.
RAPIDITY DISTRIBUTION.
RAPIDITY DISTRIBUTION.
Virtual photoproduction of J/ ψ mesons has been measured for 280 GeV muon iron interactions in an iron/scintillator calorimeter target. The J/ψ's were identified by their decay into muon pairs. 315 events were observed, about half of which were elastic. The t , Q 2 and v distributions of these elastic events are presented. The v dependence is measured between 40 and 180 Mev and compared with lower energy photoproduction results. The Q 2 dependence is compared with the predictions of the vector dominance model.
TPRIME DISTRIBUTION OF ELASTIC J/PSI EVENTS FOR ALL Q2 AND NU WITH 280 GEV MUON BEAM.
NORMALIZED Q**2 DISTRIBUTION OF ELASTIC J/PSI EVENTS FOR ALL NU AND T WITH 280 GEV MUON BEAM.
EXTRAPOLATION OF Q**2 AND T DEPENDENCE TO CALCULATE D(SIG)/DT AT Q**2=0 AND T=0 FOR ELASTIC J/PSI PHOTOPRODUCTION PER NUCLEON.
Results are presented on vector meson production in the hypercharge exchange reactions: π + p → K ∗+ (890) Y + and K − p→ ρ − Y + where Y + is either Σ + or Y ∗+ (1385). These reactions have been studied at 7 GeV/ c and 11.5 GeV/ c using the SLAC Hybrid Facility. Total and differential cross sections, hyperon polarization, and vector meson decay angular distributions are presented. We find that reactions with Σ + production are dominated by natural parity exchange. The Y ∗ (1385) reactions are consistent with substantial natural parity exchange contributions but also show significant unnatural parity exchange. The differential cross sections and polarization measurements for the vector meson production are compared to the pseudoscalar production reactions.
Axis error includes +- 20/20 contribution.
Axis error includes +- 20/20 contribution.
Axis error includes +- 20/20 contribution.
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