CORRELATIONS IN THE IN-MEDIUM NUCLEON-NUCLEON CROSS-SECTION

The influence of the ground state correlations on the in-medium nucleo n-nucleon cross section is investigated in the framework of an extende d Brueckner-Hartree-Fock theory of nuclear matter. The effect of the c orrelations is to overwhelm the suppression of the in-medium NN cross section already established in previous approximations. Moreover the r esulting cross section exceeds largely, particularly for neutron-proto n scattering, the free-space values in the low energy range (up to 200 -250 MeV) for nuclear medium densities up to two times the saturation density.