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π±p elastic differential cross sections in the momentum range 1.72-2.80 GeV/c have been measured at the proton synchrotron "NIMROD" of the Rutherford High Energy Laboratory. The results are tabulated, and analyses of the differential cross sections employing optical models and Legendre polynomial expansions are advanced. A critical discussion of a recent interpretation of differential-cross-section structure in terms of interference between resonant and background amplitudes is presented.
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Elastic π−+p differential cross-section data are presented at the incident-pion momenta 1.72, 1.89, 2.07, 2.27 and 2.46 GeV/c. Resonant behaviour in the coefficients of a Legendre polynomial expansion indicates G- or H-wave resonance. Further analysis using an energy-dependent parametrization of G- and H-waves shows the results to be compatible with the 7−/2 assignment for the , but equally acceptable solutions are obtained with the inclusion of an additional 9+/2 resonance contribution.
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We report measurements of the proton elastic form factors, G E p and G M p , extracted from electron scattering in the range 1⩽ Q 2 ⩽3(GeV/ c ) 2 . The uncertainties are <15% in G E p and <3% in G M p . The values of G E p are larger than indicated by most theoretical parameterizations, The ratio of Pauli and Dirac form factors, Q 2 F 2 p / F 1 p , is lower and demonstrates less Q 2 dependence than most of these parameterizations. Comparisons are made to theoretical models, including those based on perturbative QCD and vector-meson dominance.
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We report measurements of the proton form factors GEp and GMp extracted from elastic scattering in the range 1≤Q2≤3 (GeV/c)2 with total uncertainties < 15% in GEp and < 3% in GMp. Comparisons are made to theoretical models, including those based on perturbative QCD, vector-meson dominance, QCD sum rules, and diquark constituents in the proton. The results for GEp are somewhat larger than indicated by most theoretical parametrizations, and the ratios of the Pauli and Dirac form factors Q2(F2pF1p) are lower in value and demonstrate a weaker Q2 dependence than those predictions. A global extraction of the elastic form factors from several experiments in the range 0.1 0.1<Q2<10 (GeV/c)2 is also presented.
Point-to-point systematic uncertainty is 0.5%, overall normailzation uncertainty is 1.9%.
Point-to-point systematic uncertainty is 0.5%, overall normailzation uncertainty is 1.9%.
Point-to-point systematic uncertainty is 0.5%, overall normailzation uncertainty is 1.9%.
Inclusive cross sections and invariant single-particle distributions are presented for positive pions and protons produced in 8.05-GeV/c π−p and 18.5-GeV/c π±p inclusive reactions. Distributions in pT2 and in the longitudinal variables x, y (c.m.) and pl (lab) are shown. Comparisons are made with inclusive distributions for other particles produced in the same reactions.
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The reactions e + d → e ' + p S + p + π − and e + d → e ' + n S + n + π + were measured detecting electron and pion in coincidence at an invariant hadronic mass of 2.19 GeV. The measurements were performed at electron four-momentum transfer squared of f 2 = 0.70 and 1.35 GeV 2 in the range of t = ( γ v − π ) 2 between t min and −1.0 GeV 2 . The cross section d 2 σ / dtdφ of the reaction e + n → e' + p + π − was determined.
ACTUALLY RATIO OF PI- TO PI+ PRODUCTION OFF DEUTERIUM.
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Results are given for the production differential cross sections and the ω decay angular distribution in terms of the ω spin density matrix elements.
PAPER ALSO GIVES OFF-DIAGONAL ELEMENTS OF THE ERROR COVARIANCE MATRIX.
PAPER ALSO GIVES OFF-DIAGONAL ELEMENTS OF THE ERROR COVARIANCE MATRIX.
Measurements have been made on Compton scattering for photon energies between 5 and 17 GeV and t values from -0.06 to -1.1 (GeVc)2. The data were obtained by performing a coincidence between the Stanford Linear Accelerator Center 1.6-GeVc spectrometer and a Lucite shower counter. The scattering appears diffractive out to high t values, but the cross sections seem not to be in good agreement with the prediction of a strict vector-meson-dominance model.
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Elastic electron-proton scattering cross sections have been measured using the internal beam of the 6-BeV Cambridge Electron Accelerator at laboratory scattering angles between 31° and 90° for values of the four-momentum transfer squared ranging from q2=0.389 to 6.81 (BeV/c)2 (q2=10 to 175F−2). Incident electron energies ranged from 1.0 to 6.0 BeV. Scattered electrons from an internal liquid-hydrogen target were momentum-analyzed using a single quadrupole spectrometer capable of momentum analysis up to 3.0 BeV/c. Čerenkov and shower counters were used to help reject pion and low-energy background. The cross sections presented are absolute cross sections with experimental errors ranging from 6.8% to 20%. Separation of proton electromagnetic form factors have been made for all but the two highest momentum transfer points, using the Rosenbluth formula. Both form factors, GEp and GMp, were observed to continue to decrease as the momentum transfer increases. An upper limit to the possible asymptotic values of the proton electromagnetic form factors has been established.
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