11th International Conference on Nucleus-Nucleus Collisions (NN), San-Antonio, Northern Mariana Islands, 27 May - 01 June 2012, vol.420, (Full Text)
We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies greater than or similar to 50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.