Effects of exchange terms in relativistic HF and RPA approaches

por Nguyen Van Giai (Institut de Physique Nucleaire Orsay)

miércoles 20 feb. 2008 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

The relativistic mean field (RMF) theory is quite popular and successful in nuclear structure studies. The nucleon-nucleon in-medium interactions are mediated by effective mesons. The RMF approach amounts to a Hartree approximation where direct (Hartree) interactions create the mean field whereas exchange (Fock) interactions are omitted and simulated by a renormalization of the meson-nucleon couplings. However, this approach has its limitations: effects related to interaction components such as the pion-nucleon pseudo-vector coupling, or rho-nucleon tensor coupling, cannot be described by the RMF approach. These effects can be seen for example in the evolution of single-particle energies along an isotopic or isotonic chain, the shell modifications, or in spin-isospin (Gamow-Teller, spin dipole) excitation modes. In this talk, we will present recent results obtained in relativistic Hartree-Fock and Random Phase Approximation.