The cross section for the production of Ξ + particles in K + p interactions at 12.7 GeV/ c is 10 ± 3 μ b; the Ξ − production cross section is 2.5 ± 1.0 μ b; the upper limit on Ω − or Ω + production is 0.4 μb. The Ξ − are produced preferentially in the backward direction in the CM system while the Ξ + are produced mainly forward. The mass and lifetime of the Ξ + agree with the accepted values for the Ξ − hyperon.
Cross sections have been corrected for the detection probability of all observed hyperons involved in these reactions.
Approximately 700 events of the reaction K − d → K − π − pp s produced by 5.5 GeV/ c kaons were used to measure the cross section for Kπ elastic scattering in the T = 3 2 state by a Chew-Low extrapolation. The cross section does not exceed 2.1 mb and has no structure for Kπ masses from threshold up to 2.0 GeV.
Chew-Low extrapolation is used for evaluation of the K- P elastic cross section.
A systematic search for exotic states produced in K − d interactions at 3 GeV/ c is reported. From the analysis of the mass spectra of strange mesons, non-strange mesons, hyperons with S = −1 and S = −2, upper limits for the production cross sections of exotic resonances may be placed at one or two orders of magnitude smaller than for the production of normal resonances of same strangeness and baryon number.
No description provided.
An experiment has been carried out to determine the imaginary part of the two-photon exchange amplitude by measuring the polarisation of the recoil proton in elastic electron-proton scattering. The polirisation was found to be −0.006 ± 0.030 at q 2 = 1.3 (GeV/ c ) 2 , +0.052 ± 0.55 at 1.5 (GeV/ c ) 2 and +0.065 ± 0.087 at 1.9 (GeV/ c ) 2 .
No description provided.
Neutron-proton total cross-sections were measured in the momentum range from 8 GeV/ c to 21 GeV/ c with an accuracy of better than 2% using a 0 o neutron beam at the CERN Proton Synchrotron. The np total cross-section drops from 39.7 mb at 8 GeV/ c at 21 GeV/ c , and thus follows closely the pp total cross-sections in this momentum interval.
No description provided.
We have measured elastic electron-proton scattering cross sections in the range of four-momentum transfers from 7 F−2[0.27 (GeV/c)2] to 150 F−2 [5.84 (GeV/c)2] and at scattered electron angles of between 20° and 34° in the laboratory. The estimated errors in the cross sections range from ±2.1% at the lowest momentum transfer to ±9.6% at the highest. Both the scattered electron and the recoil proton were detected, resulting in an overdetermination of the kinematics. When the constraint of a coincident proton is removed, there is no significant change in the estimated cross sections.
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The differential cross sections for the γ + n → π O + n reaction have been measured at the photon energies of 500–900 MeV. The ratios, R oo = [ d δ d Ω(γ n → π o n ) ] [ d δ d Ω(γ p → π o p ) ] , have been obtained at the c.m. pion angles of 60 O , 90 O , 105 O , 120 O , and 140 O .
Axis error includes +- 0.0/0.0 contribution (8 TO 11////).
Axis error includes +- 0.0/0.0 contribution (8 TO 11////).
Axis error includes +- 0.0/0.0 contribution (8 TO 11////).
abstract only
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Differential cross sections for neutral-pion photoproduction on hydrogen in the region of the first resonance have been measured by two independent experiments detecting the recoil protons. The results of both measurements have been combined into one set of cross sections covering the photon energy range from 200 to 440 MeV at pion c.m. angles between 50 and 160 degrees.
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We present results of measurements on photoproduction of ρ mesons. Analysis of 106 measured ρ events in a four-dimensional data matrix dσ(A, m, p, t⊥)dΩdm with dimensions 14×20×10×20 yields precise information on nuclear density distributions for ρ production. We obtain for the Woods-Saxon radii R(A)=(1.12±0.02)A13 and, using the vector dominance model, σρN=26.7±2.0 mb and γρ24π=0.57±0.10.
No description provided.
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