The differential cross sections of the combined elastic and break-up K − d reaction have been measured at 1.21, 1.42 and 2.61 GeV/ c incident K − momentum. The measurements have been performed at the CERN PS using multiwire proportional chambers. The values of the invariant momentum transfer t explored (0.0005<| t |<0.1 GeV 2 ) include the Coulomb-nuclear interference region. The differential cross sections have been analysed in the framework of the Glauber impact-parameter formalism. The observed interference effects have been used to derive the ratio of the real to imaginary part of the forward K − n nuclear amplitude.
SUM OF COHERENT AND BREAK-UP SCATTERING.
SUM OF COHERENT AND BREAK-UP SCATTERING.
SUM OF COHERENT AND BREAK-UP SCATTERING.
The invariant cross section for the inclusive production of π+, π−, K+, K−, p, and p¯ is presented for proton-nucleon interactions at plab=28.5 GeV/c. Beryllium, titanium, and tungsten targets were used and the yields were extrapolated to A=1 using the power law σ∼Aα. The exponent α increases with pT, except for protons. The pT dependence of the cross sections is compared with a simple fireball model.
No description provided.
No description provided.
The two coherent reactions π+d → dπ+π+π− and π+d → → dπ+π+π+π0 are studied in the 2 m DBC at the incoming momentum of 11.7 GeV/c. The production cross-sections are measured:σ=(0.37±±0.06) mb andσ=(0.24±0.05) mb respectively. The two reactions are analysed in the different LPS configurations. The dσ/dt′ distribution for the two reactions displays the same exp[−At′] shape withA⋍37 (GeV/c)−2 in both cases, thus indicating that the differential cross-sections are dominated by the deuteron form factor. The coherent inclastic interaction contains the channel π+d → θ0π+d with a cross-sectionσ==(20±5) µb and a signal for the B+-meson of about 12 µb. The four-pion masses display structures below 2 GeV/c.
No description provided.
No description provided.
Differential cross sections for the elastic scattering of protons on 2 H, 3 H, 3 He and 4 He have been measured at 600 MeV. Proton-deuterium elastic scattering is investigated in a four-momentum transfer square t -range corresponding to Coulomb-nuclear interference in order to determine the nucleon-nucleon amplitudes at 600 MeV. For the other nuclei, we investigate the t -range corresponding to the first and second maximum, in order to determine the mechanism of the nuclear process. A few physical comments on the results are made.
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We have studied ω photoproduction using 7.5- to 10.5-GeV tagged photons. Cross sections from hydrogen lie 22% below the bubble chamber results of Ballam et al., but have a similar slope. Density matrices indicate approximate s-channel helicity conservation. The proton-neutron cross-section difference is midway between zero and the value suggested by the γp−γn total-cross-section difference. Fits to the cross sections for D, Be, and Cu and those for Be, C, Al, Cu, and Pb from a previous experiment yield σωN=25.4±2.7 mb and γω24π=7.6±1.2.
No description provided.
FORWARD CROSS SECTION IS 366 +- 49 MUB/GEV**2 AND SLOPE IS 47.1 +- 8.0 GEV**-2.
The angular distribution of the inclusive reaction 4 He + p → 3 He + X was measured with 6.85 GeV/ c incident alphas. At large angles, the observed kinematics corresponds to the elastic scattering on the target proton of an 3 He present in the incoming 4 He, the remaining neutron being a spectator. This shows the presence of an important component of 3 He in 4 He. The integrated cross section for 3 He production is σ 3He = 24.1 ± 1.9 mb.
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The differential cross section in the very forward direction has been measured for K − and K + scattering (break-up and coherent) on a deuterium target at an incident momentum of 10 GeV/ c . From these measurements and using a model for the scattering and re-scattering effects in deuterium, we have exploited the Coulomb-nuclear interference to deduce the real part of the K ± n scattering amplitude at a momentum transfer t = 0. The measurements are the first ever obtained for the K + n reaction and the first at this energy for the K − n reaction. A comparison has been made between our results and those predicted from dispersion relations. A new dispersion-relation fit including all the existing K ± n values at different energies has been performed.
SUM OF COHERENT AND BREAK-UP SCATTERING ON DEUTERIUM.
FROM FIT TO D(SIG)/DT OVER -T=0.0018 TO 0.074 GEV**2 ALLOWING FOR COULOMB SCATTERING, DOUBLE SCATTERING, INTERFERENCES AND FERMI MOTION. CORRELATION BETWEEN SLOPE AND RE(AMP)/IM(AMP) IS REFLECTED IN THE GIVEN SYSTEMATIC E RRORS.
We have searched for production of charmed mesons in the reaction π−+N→D*−+X, D*−→π−+D¯0, D¯0→K++π− at a beam momentum of 10.5 GeV/c. We measure the cross section times branching ratio to be 7±20 nb/nucleon.
No description provided.
The cross section for elastic scattering of 794-MeV neutrons by deuterium has been measured for neutron center of mass angles from 139° to 179°. The angular distribution is fitted very well both by an empirical function αeβ(μ−μ180∘) and by a calculation that uses the one parameter Craigie-Wilkin triangle diagram technique. [NUCLEAR REACTION nH2→H2n, E=794 MeV; measured σ(θ). Calculated σ(θ) with triangle diagram techniques.]
X ERROR H = 12.60 CM. X ERROR D(THETA) = 2.0000 DEG.
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