The analyzing power A N of proton-proton, proton-hydrocarbon, and antiproton-hydrocarbon, scattering in the Coulomb-nuclear interference region has been measured using thhe 185 GeV/ c Fermilab polarized-proton and -antiproton beams. The results are found to be consistent with theoretical predictions within statistical uncertainties.
No description provided.
The ratio of the analysing powers for quasi-elastic pp scattering in carbon and for elastic scattering on free protons was measured fromT = 0.52 to 2.8 GeV by scattering of the SATURNE II polarized proton beam on carbon and CH2. It was found to have a maximum at about 0.8 GeV. The energy dependence for quasielastic scattering on carbon had not been measured before above 1 GeV. The observed effect was not expected from simple models.
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Results are presented from experiment WA7 at the CERN SPS, which has measured the elastic differential cross sections of π ± p, K ± p, p p and pp at incident momen ta of 20, 30 and 50 GeV/ c . The measurements cover the momentum transfer range 0.5 < | t | < 8 (GeV/ c ) 2 , corresponding to c.m. scattering angles between 10° and 50°. The experimental set-up, trigger logic and data analysis are described. The experimental results are compared with existing meson-proton and nucleon-proton data at lower and higher energies covering the medium- and large-| t | region. Some prominent models and their predictions for elastic scattering at WA7 energies and beyond are reviewed, with emphasis on geometrical scaling, factorizing eikonal models, lowest-order QCD and other dynamical exchange-type models. Results for p p two-body annihilation into π − π + and K − K + at 30 and 50 GeV/ c , obtained in parallel with the elastic p p data, are also presented.
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The elastic scattering of 3.55 GeV/ c π + and π − mesons by protons was measured at centre-of-mass angles between 165° and 177°. The angular distributions for 864 events show a steeply rising backward peak for π + p, while the shape is less clear for π − p.
No description provided.
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Extrapolations.
Backward elastic scattering has been measured for π + p at 2.85 and 3.30 GeV/ c and for π − p at 3.30 GeV/ c . The π + p angular distributions show steep backward peaks, whereas the π − p distribution is flatter. At 2.85 GeV/ c the π + p differential cross section close to 180° is more than twice that at 3.30 GeV/ c , supporting the assignment J P = 11 2 + for Δ δ (2420) resonance. The π + p data at 2.85 GeV/ c indicate the onset of a dip at cos θ c.m. ≈ −0.97.
The data for cos(theta) = 1 is the extrapolation.
The data for cos(theta) = 1 and U = 0 are the extrapolations.
The data for cos(theta) = 1 and U = 0 are the extrapolations.
A total of 24 360 events having two charged particles in the final state from π−+p interactions at an incident π− momentum of 2.7 GeVc have been analyzed. The final states π−π+n and π−π0p are found to be dominated by rho-meson production, and in addition, significant N*(1238) production is seen. The partial cross sections for the dominant resonant channels are σ=(pρ−)=(1.3±0.2) mb, σ(nρ0)=(2.3±0.2) mb, and σ[π−N*+(→pπ0)]=(0.5±0.2) mb. The production of the ρ− and ρ0 and the decay of the ρ− agree very well with the predictions of an absorption-modified one-pion-exchange model. The production angular distributions of the ρ0 and ρ− follow an exponential of the form Ae+Bt. The results from a least-squares fit give B(ρ−)=9.32±0.08 (GeVc)−2, B(ρ0)=10.26±0.06 (GeVc)−2. A similar analysis for the elastic-scattering events gave B(el)=7.77±0.05 (GeVc)−2. The ρ0 decay distributions are asymmetric and they have been analyzed using a simple model which includes S−P-wave interference. No clear evidence is seen for a T=0, J=0 resonance at a mass near that of the ρ. The N*(1238) resonance production is found to be in agreement with the ρ-exchange model of Stodolsky and Sakurai. Indication of other resonance production with small cross section is seen, such as A1 and A2 production in the multiple missing neutral events. The masses and widths of the ρ0 and ρ− as a function of the four-momentum transfer squared to the nucleon have been determined.
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Results are reported based on a study of 3114 π−p events at 205 GeV/c in the National Accelerator Laboratory 30-in. bubble chamber. The measured π−p total and elastic cross sections are 24.0 ± 0.5 and 3.0 ± 0.3 mb, respectively. The elastic differential cross section has a slope of 9.0 ± 0.7 GeV−2 for 0.03≤−t≤0.6 GeV2. The average charged-particle multiplicity for the inelastic events is 8.02 ± 0.12.
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A phase shift analysis of the K<sup loc="post">+</sup>p elastic scattering at 780 MeV/c has been performed. The experimental differential cross section is best explained by a solution with dominant s wave, negative s wave phase shift (−42.7 ± 1 deg.) and small contributions of p and d waves.
Corrected for PI+ P events and scanning efficiency.
Results are presented concerning topological cross-sections and multiplicity distribution for a π−p experiment at 11.2 GeV/c. The statistics used are one-half of the total ones (106 bubble chamber pictures). Comparison with data at different energies and theoretical predictions are made, and satisfactory agreement is obtained.
TABLE ALSO QUOTES PRONG CROSS SECTIONS FOR PRODUCTION OF VEE(S).
We present the final results of a measurement of the polarization parameter P 0 in high-energy n~-p and p-p elastic scattering, performed using a target which contained polarized protons. Data were taken at beam momenta of 6.0, 8.0, 10.0 and 12.0 GeV/c for n-, and of 6.0, 10.0 and 12.0 GeV/c for n+ and p, in the interval of invariant four-momentum transfer squared-t from 0.1 to 0.75 (GeV/c)2.
No description provided.
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