Backward scattering in the reaction KL0p→pKS0 is studied in the momentum interval 1.0 to 7.5 GeV/c. Comparison of KL0p→pKS0 and K+p→pK+ backward scattering, where respectively Σ exchange and Λ plus Σ exchange can contribute in the u channel, reveals that dσdΩ180°(KL0p→pKS0dσdΩ180°(K+p→pK+) above the resonance region. This result provides direct evidence for the dominance of the Λ contribution over the Σ contribution in the K+p→pK+ production amplitude.
No description provided.
We present results on vector-meson photoproduction via γp→Vp in the LBL-SLAC 82-in. hydrogen bubble chamber exposed to a linearly polarized photon beam at 2.8, 4.7, and 9.3 GeV. We find ρ0 production to have the characteristics of a diffractive process, i.e., a cross section decreasing slowly with energy and a differential cross section with slope of ∼ 6.5 GeV−2. Within errors the ρ0 production amplitudes are entirely due to natural-parity exchange. s-channel helicity is conserved to a high degree in the γ→ρ0 transition. We find evidence for small helicity-flip amplitudes for ππ pairs in the ρ0 region. Photoproduction of ω mesons is separated into its natural- (σN) and unnatural- (σU) parity-exchange contributions. The Eγ and t dependence and the spin density matrix of the unnatural-parity-exchange contribution are consistent with a one-pion-exchange process. The natural-parity-exchange part has characteristics similar to ρ0 production. At 9.3 GeV the ratio of σ(ρ0) to σN(ω) is ∼ 7. The slope of the φ differential cross section is ∼ 4.5 GeV−2, smaller than that of ρ0 and ω production. Natural-parity exchange is the main contributor to φ production. No evidence for higher-mass vector mesons is found in ππ, πππ, or KK¯ final states. The s and t dependences of Compton scattering as calculated from ρ, ω, and φ photoproduction using vector-meson dominance agree with experiment, but the predicted Compton cross section is too small by a factor of 2.
No description provided.
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Angular distributions of proton-proton elastic scattering have been measured for incident beam momenta of 10.0, 12.0, 14.2 and 24.0 GeV/ c over a range of lab scattering angles from 12 to 152 mrad. This is equivalent to a range of four-momentum transfer squared from about 0.1 to 6.7 GeV 2 at the highest momentum. Nucleon resonance production in the two-body reaction p + p → p + X has been studied at 24.0 GeV/ c incident momentum from 13.5 to 112 mrad by measuring the proton momentum spectra from the elastic peak down to a momentum corresponding to a missing mass of about 2.6 GeV. The new data are compared with previous results and theoretical models.
ESTIMATED 8 PCT RANDOM ERROR.
ESTIMATED 8 PCT RANDOM ERROR.
ESTIMATED 8 PCT RANDOM ERROR.
From 2728 events of 205-GeV pp interactions found in 15 000 pictures taken with the 30-in. hydrogen bubble chamber at the National Accelerator Laboratory, a total cross section of 39.5±1.1 mb was measured. The mean charged-particle multiplicity for inelastic pp collisions was measured to be 7.65±0.17. The prong distribution from 2 to 22 prongs is broader than a Poisson distribution and has a width parameter f2−=〈n−(n−−1)〉−〈n−〉2=0.95±0.21.
No description provided.
We have investigated the above processes at the CERN Intersecting Storage Rings (ISR). Results show a marked change of the slope parameter b ( t , s ) = (d/d t ) ln (d σ /d t ) around − t ≈ 0.10 GeV 2 . The s − and t − dependence of b ( t , s ) have been observed over the interval 460 GeV 2 < s < 2900 GeV 2 and 0.02 GeV 2 < t < 0.40 GeV 2 .
No description provided.
No description provided.
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As a partial result of an analysis of K + d interactions at 3 GeV/ c produced in the 81 cm Saclay bubble chamber, we present data on K + differential cross sections for the following reactions: K + d → K + d, K + d → K + pn, K + d → K 0 pp . A set of parameters describing the K + n elastic scattering has been obtained from a simulataneous fit, based on the Glauber model. to the three experimental differential cross sections and to the K + d total cross section, giving α n = 1.7 ± 0.5 GeV −2 for the slope α n of the differential cross section, and ρ n = −0.16 ± 0.3 for the ratio of the real to the imaginary part of the forward scattering amplitude. The D-wave function of the deuteron has been found to give a non-negligible contribution to the coherent reaction.
No description provided.
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Measurements of proton-deuteron scattering have been performed using an incident 24.0 GeV/ c proton beam. Momentum-loss spectra of forward-scattered protons were measured by a single-arm spectrometer over a range of proton angles from 13 to 107 mr. The contributions to the proton spectra of single and double scattering can be separated experimentally, thus allowing estimates of proton-neutron elastic cross sections to be deduced from the data over a range of four-momentum transfer squared, |t| 5.8 GeV 2 . Elastic p - d scattering, in which the proton and deuteron were detected in coincidence, has also been measured over a range of | t | from 0.6 to 1.8 GeV 2 .
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EXTRACTED FROM SINGLE AND DOUBLE PEAK DEUTERIUM DATA BY THE GLAUBER METHOD WITH FERMI MOTION CORRECTIONS.
We present results on the differential cross sections for the process K + n → K 0 p extracted from the reaction K + d → K 0 pp measured at 13 momenta between 0.64 and 1.51 GeV/ c .
THESE TOTAL CROSS SECTIONS WERE PRESENTED WITH MORE EXPERIMENTAL DETAILS IN G. GIACOMELLI ET AL., NP B37, 577 (1972).
REACTION HAS A SPECTATOR PROTON. THESE ARE NOT FREE NEUTRON CROSS SECTIONS. A 250 MEV/C MOMENTUM CUT IS APPLIED TO THE SPECTATOR MOMENTUM AND D(SIG)/DOMEGA THEN NORMALIZED TO THE UNCUT TOTAL CROSS SECTION FOR K+ DEUT --> K0 P P.
The reaction pn → pp π − at 7.0 GeV/ c is studied in a pd experiment. Observations on isobar production and low-mass enhancement are reported. The I = 1 2 isobars and the low-mass enhancement produced at the neutron vertex are discussed in terms of the diffraction dissociation plus duality model.
PART OF THE DIFFERENCE BETWEEN DEL PRODUCTION AT THE NEUTRON AND AT THE PROTON VERTICES COULD ARISE FROM DEUTERON EFFECTS.
Lambda production is studied in K − p interactions at 10.1 GeV/ c , where the dominant reaction is K − p → Λ + pions. General characteristics such as the distributions of the double differential cross section in the lab system, of the variable x = p L ∗ p max ∗ , of p ⊥ 2 and of the missing mass to the lambda are presented. Total cross sections for Λ production and for the various channels are given. Differential cross sections d σ d t , d σ d t′ and d σ d u′ are presented. Forward and backward peaks are observed in the d σ d t′ and d σ d u′ distributions, respectively. It is found that the exponential slope of these distributions decreases with increasing missing mass to the lambda and, for d σ d t′ , also for increasing multiplicity in the final state. The polarization of the lambdas is studied as a function of multiplicity, p L ∗ , (Λπ ± ) effective mass, t ′ and u ′. The forward lambdas show
No description provided.
POSSIBLE FORWARD DIP.
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