Shell-model study of the N=82 isotonic chain with a realistic effective Hamiltonian

We have performed shell-model calculations for the even- and odd-mass N = 82 isotones, focusing attention on low-energy states. The single-particle energies and effective two-body interaction both have been determined within the framework of the time-dependent degenerate linked-diagram perturbation theory, starting from a low-momentum interaction derived from the CD-Bonn nucleon-nucleon potential. In this way, no phenomenological input enters our effective Hamiltonian, whose reliability is evidenced by the good agreement between theory and experiment.