The analyzing powers of π+ and π− were measured using an incident 22−GeV/c transversely polarized proton beam at the Brookhaven Alternating Gradient Synchrotron. A magnetic spectrometer measured π± inclusive asymmetries on a hydrogen and a carbon target. An elastic polarimeter with a CH2 target measured pp elastic-scattering asymmetries to determine the beam polarization using published data for the pp elastic analyzing power. Using the beam polarization determined from the elastic polarimeter and asymmetries from the inclusive spectrometer, analyzing powers AN for π± were determined in the xF and pT ranges (0.45–0.8) and (0.3–1.2 GeV/c), respectively. The analyzing power results are similar in both sign and character to other measurements at 200 and 11.7 GeV/c, confirming the expectation that high-energy pion inclusive analyzing powers remain large and relatively energy independent. This suggests that pion inclusive polarimetry may be a suitable method for measuring future beam polarizations at BNL RHIC or DESY HERA. Analyzing powers of π+ and π− produced on hydrogen and carbon targets are the same. Various models to explain inclusive analyzing powers are also discussed.
We report on double-differential inclusive cross-sections of the production of secondary protons, deuterons, and charged pions and kaons, in the interactions with a 5% nuclear interaction length thick stationary beryllium target, of a +8.9 GeV/c proton and pion beam, and a -8.0 GeV/c pion beam. Results are given for secondary particles with production angles between 20 and 125 degrees.
Double differential inclusive cross section for the reaction P BE --> PI- Xwith an 8.9 GeV beam and production angle 75 to 90 degrees.
We report measurements of the ratios K+π+, pπ+, K−π−, p¯π−, π−π+, K−K+, and p¯p for hadrons with 0.19<xt<0.62 produced in p−Be and p−W collisions at s=38.8 GeV. The K+π+ ratio at high xt gives the fragmentation-function ratio DuK+Duπ+ at high z. The high-xt K−π− ratio gives an upper limit for DdK−Ddπ− at high z. The pt dependence of pπ+ suggests that scattered constituent diquarks are the primary source of protons with pt<6 GeV/c. We also present species correlations in high-mass h+h− pairs. Strong K+K− and pp¯ correlations were observed.
No description provided.
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No description provided.
The emission of protons from targets of Li6, Li, C12, Al27, Ca40, V51, Zr90, and Pb under bombardment from 800 MeV protons has been studied using a high resolution proton spectrometer. Spectra were measured at laboratory scattering angles of 5°, 7°, 9°, 11°, 13°, 15°, 20°, 25°, and 30° with special emphasis on the quasifree region. Outgoing momenta corresponding to the region of pion production were examined at 11° and 15°. Absolute cross sections have been derived by reference to known (p,p) scattering data at 800 MeV. The quasifree scattering has been compared to a distorted-wave impulse approximation analysis by summing over the unobserved (struck) nucleon. The systematics of proton production and the applicability of the distorted-wave impulse approximation analyses are discussed. NUCLEAR REACTIONS (p,p′) on Li6, Li, C12, Al27, Ca40, V51, Zr90, Pb; Ep=800 MeV, θL=5° to 30°; quasielastic scattering, DWIA analysis.
APPROXIMATE SYSTEMATIC CROSS SECTION ERROR IS EQUAL TO +-5.9%.
Particle production in proton-induced reactions at 14.6 GeV/c on Be, Al, Cu, and Au targets has been systematically studied using the E-802 spectrometer at the BNL-Alternating Gradient Synchrotron. Particles are measured in the angular range from 5° to 58° and identified up to momenta of 5, 3.5, and 8 GeV/c for pions, kaons, and protons, respectively. Mechanisms for particle production are discussed in comparison with heavy-ion-induced reactions at the same incident energy per nucleon.
No description provided.
The excitation of theΔ resonance is observed in proton collisions on C, Nb and Pb targets at 0.8 and 1.6 GeV incident energies. The mass E0 and widthΓ of the resonance are determined from the invariant mass spectra of correlated (p, π±)-pairs in the final state of the collision: The mass E0 is smaller than that of the free resonance, however by comparing to intra-nuclear cascade calculations, this reduction is traced back to the effects of Fermi motion, NN scattering and pion reabsorption in nuclear matter.
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Invariant cross sections for hadron production (π±,K±,p and\(\bar p\)) by protons off C, Al, Cu, Sn and Pb nuclei have been measured at 70 GeV for theP∧ range from 1 up to 4.65 GeV/c. TheA-dependence of the invariant cross section is not described by the exponentialAα(P∧), which points to the presence of secondary hadron absorption in nuclei.
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The measurement of invariant cross sections for the production of protons by 400 GeV protons from a variety of nuclear targets is described. Results are given for Li6, Be, C, A1, Cu, and Ta at 70°, 90°, 118°, 137° and 160° for detected protons from 0.4 to 1.4 GeV/c. Some angular distributions are given over a wider selection of angles. Comparisons are made with observed experimental results at other energies. NUCLEAR REACTIONS Inclusive cross section, 400 GeV, Li6, Be, C, A1, Cu, and Ta.
No description provided.
Cross sections of cumulative K exp + and K exp - -meson production in the 200-1000 MeV kinetic energy range at 90 deg, 120 deg, 168 deg (l.c.s.) are measured. The ranges of kinetic energies and emission angles mean that, according to the hypothesis of cum ...
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