Article

RPA calculation of K+-nucleus cross sections with a density-dependent Dirac-Brueckner NN interaction

Centre d'Etudes Nucléaires de Bordeaux-Gradignan, Université Bordeaux I, rue du Solarium, 33175 Gradignan Cedex, France22UMR CNRS 6426.
Nuclear Physics A (Impact Factor: 2.5). 07/1995; 589(4):609-619. DOI: 10.1016/0375-9474(95)00126-L

ABSTRACT In the calculation of the K+-nucleus cross sections, the coupling of the mesons exchanged between the K+ and the target nucleons to the polarization of the Fermi and Dirac seas has been taken into account. This polarization has been calculated in the one-loop approximation but summed up to all orders (RPA approximation). For this calculation a density-dependent relativistic NN interaction reproducing the saturation curve of a Dirac-Brueckner calculation providing a good description of nuclear matter has been used. The agreement with experiment is considerably improved.

0 Followers
 · 
48 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The momentum-space optical model of K+-nucleus scattering is analyzed and comparison with other conventional models is shown. The model is based on the multiple scattering formalism in which the optimal factorization approximation is used. Off-energy-shell extension of the elementary K+-nucleon amplitude is neglected which reduces non localities in the optical potential. Predictions of the model are sensitive to the definition of the K+-nucleon energy (energy shifts) but they are independent (1–2%) of a particular form of the covariant K+-nucleus scattering equation (relativistic Lippmann-Schwinger, Gross, Erkelenz-Holinde). The Coulomb distortion in the total cross section is important for28Si and40Ca at low momenta (≈10%). Off-energy-shell effects in the optical potential are discussed too. Results for the total and reaction cross sections are systematically below the data. The reaction cross sections are in a larger disagreement with the data than the total cross sections.
    Czechoslovak Journal of Physics 07/1998; 48(8):903-924. DOI:10.1023/A:1022873105513 · 0.57 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The attenuation cross sections measured in transmission experiments at the alternating-gradient synchrotron for K+ on 6Li, C, Si, and Ca at pL = 488, 531, 656, and 714 MeV/c are reanalyzed in order to derive total (σT) and reaction (σR) cross sections. The effect of plural (Molière) scattering is properly accounted for, leading to revised values of σT. We demonstrate the model dependence of these values, primarily due to the choice of K+ nuclear optical potential used to generate the necessary Coulomb-nuclear and nuclear elastic corrections. Values of σR are also derived, for the first time, from the same data and exhibit a remarkable degree of model independence. The derived values of σT and σR exceed those calculated by the first-order tρ optical potential for C, Si, and Ca, but not for 6Li, particularly at 656 and 714 MeV/c where the excess is 10–25%. Relative to 6Li, this excess is found to be nearly energy independent and its magnitude of 15–25% is not reproduced by any nuclear medium effect studied so far.
    Physical Review C 03/1997; 55(3). DOI:10.1103/PhysRevC.55.1304 · 3.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The longitudinal and transverse response functions as well as the Coulomb sum for quasielastic electron scattering on 12C, 40Ca, 48Ca, 56Fe and 208Pb have been calculated taking into account relativistic RPA correlations. For these calculations a density-dependent relativistic NN interaction reproducing the saturation curve of a Dirac-Brueckner calculation providing a good description of nuclear matter has been used. The agreement with experiment is considerably improved for nuclei ranging from 40Ca to 208Pb, but not for a relatively light nucleus like 12C.
    Nuclear Physics A 12/1995; 595(2-595):189-208. DOI:10.1016/0375-9474(95)00368-X · 2.50 Impact Factor

Preview (2 Sources)

Download
0 Downloads
Available from