In this paper we have investigated the properties of the D(1285) and E(1420) meson resonances using the five-body annihilation channels p p → K K πππ obtained in a large statistics experiment (28 events/μb). The analysis favours the 1 + spin-parity assignment for the D(1285) meson. The dominant decay mode of the D(1285) into K K π is found to be δ(970)π. The situation concerning the E(1420) meson remains confused although not inconsistent with previous analyses. Partial cross sections on resonance production are also presented.
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A study of the inclusive production of π − , η , ϱ 0 , ω ad f mesons in p p annihilation at 0.7 GeV/ c is presented. Topological and channel cross sections are determined. Longitudinal and transversal momentum distributions of non-strange mesons are studied. It is deduced that nearly 48% of all negative pions arise from the decay of η , ϱ 0 , ω and f mesons.
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Experimental results are presented for the available channels in the 1.2 GeV/ c π + p interaction. An isobaric model with incoherent addition of the amplitudes is used to determine the π, Δ and N ∗ abundance rates in the π + π o p final state. The multipole parameters in the density matrix of the Δ ++ are determined as functions of its production angle.
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LEGENDRE POLYNOMIAL FIT USED TO CORRECT FOR ELASTIC EVENTS LOST FROM THE FORWARD BIN.
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Two--kaon production in proton--deuteron collisions has been studied at three energies close to threshold using a calibrated magnetic spectrograph to measure the final $^3$He and a vertex detector to measure the $K^+K^-$ pair. Differential and total cross sections are presented for the production of $\phi$--mesons, decaying through $\phi\to K^+K^-$, as well as for prompt $K^+K^-$ production. The prompt production seems to follow phase space in both its differential distributions and in its energy dependence. The amplitude for the $pd\to ^3${He}$ \phi$ reaction varies little for excess energies below 22 MeV and the value is consistent with that obtained from a threshold measurement. The angular distribution of the $K^+K^-$ decay pair shows that near threshold the $\phi$--mesons are dominantly produced with polarization $m=0$ along the initial proton direction. No conclusive evidence for $f_0(980)$ production is found in the data.
Total cross section for K+ K- production.
Total cross section for PHI production.
Differential cross section as a function of the excitation energy of the K+ K- pair.
Full angular distributions of the polarization parameter in elastic K+p scattering at 1.37, 1.45, 1.60, 1.71, 1.80, 1.89, 2.11, and 2.31 GeV/c are presented. These data were obtained in an experiment at the Zero Gradient Synchrotron using a polarized proton target with arrays of scintillation and Čerenkov counters to detect the scattered particles.
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Elastic scattering of hadrons on protons has been measured at momenta of 50, 100, and 200 GeV/c. The meson-proton scattering is found to be independent of momentum and meson type for −t>0.8 (GeV/c)2. The momentum dependence of the pp dip at −t=1.4 (GeV/c)2 was investigated. Slope parameters are given.
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Backward elastic scattering of π± on protons has been measured for incident pion momenta between 30 and 90 GeV/c and 0≤−u≤0.5 (GeV/c)2. The u dependence of the cross sections is similar to that observed at lower momenta, and Regge models give acceptable fits to the data.
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From a 98000-photograph exposure of the BNL 80-in. deuterium-filled chamber to a 14.6-GeV/c p¯ beam we have extracted those events that fit the channel p¯n→p¯pπ−. The cross section for this channel is measured to be 730 ± 50 μb. The cross section for the reaction p¯n→Δ¯−−(1238)p is determined to be 130 ± 30 μb. Evidence for target dissociation is presented. A comparison with the reaction π−n→π−pπ− at the same energy indicates agreement with factorization.
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Energy spectra and angular distributions of protons emitted from the inclusive (d,xp) reaction on 9Be, 12C, 27Al, 58Ni, 93Nb, 181Ta, 208Pb, and 238U were measured at an incident deuteron energy of 100 MeV. The protons were detected at laboratory scattering angles of 6° to 120° and 8° to 120° for the targets with 9<~A<~27 and A>~58, respectively. Two triple-element and three double-element detector telescopes allowed for a low energy detection threshold of 4 to 8 MeV. The experimental results are presented in double-differential as well as angle- and energy-integrated cross sections. For all the nuclei studied, the energy spectra at forward angles show pronounced deuteron breakup peaks centered around approximately half of the incident deuteron energy. Qualitatively the energy spectra are similar for all nuclei at a given angle except in the region of the low-energy evaporation peak. As a function of target mass the evaporation cross sections are found to increase up to A=58 after which they decrease again. The total preequilibrium proton cross section is roughly (280±60)A1/3 mb. The angular distributions at the high emission energies are strongly forward peaked while the distributions of the low-energy protons are almost isotropic. The LAHET code system (LCS) was applied to calculate the proton production cross sections. Standard LCS calculations are found to underpredict the experimental cross sections at the very forward angles on the heavy target nuclei (A≳58). By adding incoherently the Coulomb breakup cross section of the deuteron to the LCS calculations the experimental cross sections are reproduced to within 10%. Although preequilibrium processes are a necessary ingredient in the LCS calculations of the large-angle cross sections, this code still fails to predict the experimental evaporation distributions.
All Cross Sections has errors 10 pct (for PB208 and U238 errors >10 pct) including systematic uncertainties. Tabulated proton multiplicities extracted from the experimental data by dividing proton cross section by reaction cross section using the empirical expression pi*(1.58A**(1/3)+.671*Ad**(1/3))**2 (taken from PR B348, 697).
Charged particle multiplicities from high multiplicity central interactions of 158 GeV/nucleon Pb ions with Pb target nuclei have been measured in the central and far forward projectile spectator regions using emulsion chambers. Multiplicities are significantly lower than predicted by Monte Carlo simulations. We examine the shape of the pseudorapidity distribution and its dependence on centrality in detail.
Q(NAME=B) parameter is the total sum of the individual charges of the projectile fragments.
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