Total cross sections of K± and p¯ on hydrogen and deuterium were measured in a standard transmission experiment with statistical precisions of the order of 0.05-0.25%. Data were obtained in the momentum range 2.45-3.30 GeV/c for K−N, 1.55-3.30 GeV/c for K+N, and 1.00-3.30 GeV/c for p¯N. Cross sections for the pure isotopic spin states are obtained using a procedure for the deuterium data which takes into account Fermi motion and the shadow effect. Evidence for the following new structures was found: Y1*(2455), Y1*(2620), Y0*(2585), Z1*(2150), Z1*(2500), π1*(2290), π1*(2350), and π0*(2375).
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In a new measurement of proton total cross sections at 3.00 GeV/c, the p−d total cross section is found to be lower than a previous measurement by 1.17±0.09 mb. This implies a corresponding new value for the total cross section for I=0 which is 2.18±0.27 mb lower than the previous value. Possible sources of systematic error are discussed.
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A measurement of the differential cross section for the reaction np→ π 0 d has been made at the Lawrence Radiation Laboratory 184-inch cyclotron. A neutron beam with kinetic energies up to 720 MeV was incident on a liquid hydrogen target. The angle and momentum of the deuterons were measured using an analyzing magnet and wire spark chambers with a magnetostrictive readout. Deuterons were separated from protons by time-of-flight. The photons from the decaying π 0 were not detected. The neutron energy was calculated from the measured deuteron angle and momentum.
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A measurement of the differential cross section for the reaction n + p → d + π° has been made using a neutron beam with kinetic energies up to 720 MeV. The angle and momentum of the deuterons were measured using an analyzing magnet and wire spark chambers with a magnetostrictive readout. The photons from the decaying π° were not detected. The neutron energy was calculated from the measured deuteron angle and momentum. The cross sections are compared to those for the reaction π + + d ⇆ p + p as a test of isotopic spin invariance in strong interactions. The symmetry of the cross sections about 90° is also investigated, and an upper limit of about 1% is placed on the real part of the ratio of isospin-violating to isospin-conserving amplitudes.
EKIN IS 325 TO 675 MEV.
We give new experimental results on ρω interference and two-body cross sections in p¯p annihilation at 2.3GeVc. These are used, together with ρω interference results from lower energies, to argue that the annihilation process is not mediated by discrete s-channel mesonic resonances in the mass range 2.1-2.6 GeV.
No description provided.
Complete angular distributions for the reactions p p → π − π + and other two meson states at 2.3 GeV/ c are presented. The extraordinary π − π + angular distribution is contrasted with the other final states and the predictions of simple models. A favourable comparison is made with the qualitative features of a dual model involving high mass meson states with a strong degeneracy with respect to I -spin.
SOME ANGULAR DISTRIBUTIONS ALSO PRESENTED.
K* NEUTRAL TO CHARGED PRODUCTION RATIO.
Measurements have been carried out of total cross sections of positive kaons on hydrogen and deuterium to a statistical precision of better than ± 0.1 mb for most points in the range of laboratory momentum from 410 to 1065 MeV / c in intervals of approximately 50 MeV/ c . A very broad elastic structure in the I = 0 state is inferred.
No description provided.
High statistics data on p p annihilation into five and more pions at 2.32 GeV/ c are presented. Cross sections for various final states and for the production of meson resonances have been determined. The Dalitz plot asymmetry for some 4 800 ω decay events produced in p p → 2π + 2π − π 0 is found to be consistent with zero. Upper limits for the production of exotic meson resonances are presented.
No description provided.
Total cross sections of p¯p and p¯d have been measured between 360 and 1050 MeV/c, with high statistical precision. Structures are observed in both cross sections at about the same momenta. For p¯p, the central mass is 1932±2 MeV/c2, and a fit to the data with a simple Breit-Wigner resonance plus background gives Γ=9−3+4 MeV/c2. The data suggest that the structures are in the isospin-1 state.
No description provided.
Total cross sections of π± and K± on protons and deuterons have been measured at 50, 100, 150, and 200 GeV/c. All of the cross sections rise with increasing momentum.
No description provided.
PARTICLE-ANTIPARTICLE CROSS SECTION DIFFERENCES - SOME COMMON ERRORS CANCEL.
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