Elastic differential cross sections for K + mesons scattered from nat C and 6 Li targets have been measured at an incident momentum of 715 MeV/c and at angles of 7° to 42° in the laboratory frame. The experimental cross sections agree, within errors, with two different parameter-free impulse approximation calculations. To reduce the effects of the systematic errors, the ratio of the experimental cross sections for nat C to 6 Li is compared to the theoretical values, and these ratios do not agree with theory. This discrepancy suggests either a density-dependent alteration of K + -nucleon amplitudes or a failure of the optical potential calculations to describe these nuclides adequately.
No description provided.
No description provided.
The pp → ppη reaction has been measured at six energies close to threshold, from 1258 MeV to 1352 MeV, using an internal cluster gas jet target in the CELSIUS storage ring. The η is detected through its decay photons, in an array of CsI detectors, and the forward-going protons are detected in a plastic scintillator spectrometer. A complete event reconstruction is obtained at the higher energies in the measured interval. The new data, together with earlier data, give an accurate determination of the energy dependence close to threshold. The influence of the η-proton FSI is seen in the total cross section data as well as in a Dalitz plot of the η-p invariant mass distributions.
No description provided.
The tensor analyzing power T 20 for the p ( d , p d) and p ( d , p ) pn reactions θ cm p = 180° have been measured at incident deuteron momenta from 3.5 to 6.5 GeV/ c . For both reactions T 20 remains negative up to internal momentum k ⋍ 0.85 GeV/ c and show a rich structure beyond the region where T 20 is expected to be determined by the S - and D -states of the deuteron. The T 20 data for deuteron breakup without pion production, close to the backward elastic kinematics, were obtained simultaneously with the elastic data.
K is the internal momentum of the nucleon.
Elastic scattering of linearly polarized photons on protons has been measured between 3.2 and 3.7 GeV for four-momentum transfers ranging from −0.1 to −0.7 (GeV/ c ) 2 . The observed cross section asymmetry in this range is consistent with zero within ±0.05.
No description provided.
The tensor analyzing power T 20 in inclusive deuteron breakup at 9 GeV/c and 0° on hydrogen and carbon targets up to internal momenta k of the proton in the deuteron of ∼ 1 GeV/c has been measured. The analyzing power remains negative up to the highest measured values of k , and is in definite disagreement with predictions from several theoretical models. A systematic difference between T 20 for deuteron breakup on hydrogen and carbon is observed.
No description provided.
No description provided.
Proton Compton scattering has been measured in a coincidence experiment at photon energies between 2.2 and 7 GeV and four-momentum transfers t between −0.06 and −0.85(GeV/ c ) 2 . For ∣ t ∣ ⩽ 0.4 (GeV/ c ) 2 fits of the form d σ /d t = ( A · exp( Bt )) yield forward cross sections A in good agreement with the values calculated from the total hadronic γ p cross section via the optical theorem and the forward dispersion relation. The slopes B do not show a significant energy dependence, the mean value being 5.7 ± 0.4 (GeV/ c ) −2 . The cross section is substantially larger than predicted by the vector-meson dominance model.
No description provided.
No description provided.
No description provided.
The measurements of the transmission regeneration amplitude on hydrogen in the momentum region of 14–42 GeV/ c indicate that in accordance with the Pomeranchuk theorem its magnitude |ƒ° − ƒ °|/k decreases as energy increases and its phase is approximately constant and equal to arg (ƒ° − ƒ °) = (−118 ± 13)° .
THE REGENERATION AMPLITUDE DECREASES OVER THIS ENERGY RANGE.
The reaction pp → pp π 0 has been measured using electron-cooled protons incident on an internal gas-jet target at seven different incident beam energies, from 280.7 MeV (1 MeV above the reaction threshold) up to 310.2 MeV. The pions were measured by their decay photons. In the overlapping energy region, the measured total cross sections agree with those measured in a recent Indiana experiment. The angular distributions are consistent with a 3 P 0 → 1 S 0 s 0 transition in the full energy range studied. The kinematical distributions are well described when taking into account the final state and the Coulomb interactions.
AN OVERALL 5 PCT ERROR IN NORMALIZATION IS NOT INCLUDED.
Compton scattering on protons has been measured at a mean photon energy of 6 GeV and four-momentum transfers − t between 0.06 and 0.60 (GeV/ c ) 2 . The differential cross section shows a diffraction-like behaviour. The cross section extrapolated to t =0 is in fair agreement with the optical point. Discrepancies with the vector meson dominance model are pointed out.
No description provided.
The polarization transfer κ 0 and the tensor analyzing power T 20 for the 1 H d p)d reaction have been measured up to an internal momentum of k = 0.58 GeV/c. Comparison of the same observables obtained in recent studies for 1 H d p)d reaction, as a function of k , show different behavior. However the data from these two reactions are almost identical when compared in T 20 versus κ 0 correlation plots. We discuss similarities and differences observed in the two reactions.
The authors use the Infinite Momentum Frame variable K= M( proton) * sqrt(1/(4*a*(1-a)) - 1), where a = (E(proton)+P_long(proton))/(E(deut)+P(deut)).
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