Göran Fäldt

Fermi motion in pion deuteron scattering at high energies

Abstract The Fermi motion plays an important role in resonant multiple scattering. Its conclusion restores the agreement between experiments and Glauber theory.

DISPERSION RELATIONS AND GLAUBER MODEL FOR PION--DEUTERON SCATTERING.

Abstract Forward dispersion relations are used to calculate the real part of the elastic amplitude for forward pion-deuteron scattering. The same real part is also calculated from the Galuber multiple scattering model. The results of the two approaches are critically compared in the light of present experiments. A theoretically deduced value for the pion-deuteron scattering length is also given. A theoretical prediction for the pion-deuteron total cross section for energies below 450 MeV is found to agree rather well with experiments.

Low-energy pion--nucleus optical potentials

Abstract We discuss the local and non-local pion-nucleus optical potentials. We find that the local potential becomes non-local when two-nucleon correlations are included. The two potentials (including correlations) can be made local through a transformation on the wave function. The new local potentials agree up to quadratic terms when expanded in powers of the density. The influence of finite-range correlations and off-shell pion-nucleon form factors is also investigated.

Symmetries in inelastic proton--nucleus scattering

Abstract Various symmetries of inelastic proton-nucleus scattering within the Glauber model are discussed. They are obtained from symmetries of the corresponding proton-nucleon amplitude. In particular, it is shown that the polarization and analyzing power are in general not equal.

Threshold π0 Photoproduction on Deuterium

We investigate the multiple scattering contributions to π0 photoproduction on deuterium at threshold. A consistent evaluation of all the double scattering terms shows that the static approximation is quite reliable. Corrections to this result come mainly from the off-shell form factors in the nucleon amplitudes and the small P-wave contribution to the single scattering terms. The effect of the mass difference between the charged and the neutral pion is found to be small.

Optical Model and Glauber Model Calculations for Elastic 12C-12C Scattering at 1016 MeV

The elastic scattering cross-section for 12C + 12C at 1016 MeV is analyzed in the optical model and in the Glauber model. Radial parameters characterizing the scattering are discussed.

The pion mass difference in threshold pion reactions on light nuclei

Abstract We investigate the effect of the pion mass difference in scattering and photoproduction of pions on light nuclei near threshold. The effect is found to be most easily described in a nuclear K -matrix formalism where the nuclear K -matrix elements are shown to be independent of the mass difference.

Threshold Pion Photoproduction in Break-up Reactions on Deuterium

The break-up reactions ?d ? ?+nn and ?d ? ?0np are studied for energies close to threshold. The dependence of the ?+ cross section on the neutron-neutron scattering length is investigated and the ?0 cross section calculated in the energy range 0-20 MeV above threshold.

Radial Parameters in Nucleon-Nucleus Scattering

We investigate the effect of the strength of the nucleon-nucleon interaction on the nucleon-nucleus reaction cross section and on the diffractive angular pattern of the elastic differential cross section.

The Coulomb Interaction and Spin Effects in Elastic Proton-Nucleus Scattering at 800 MeV

We describe a method to include the Coulomb interaction in Glauber calculations for elastic proton-nucleus scattering. We show that at 800 MeV the polarization is sensitive to the electromagnetic spin-orbit interaction in a wide angular range. We also show that if the charge distribution is approximated by a uniformly charged sphere serious errors may appear for large momentum transfers.