Heavy deformed nuclei in the shell model Monte Carlo method

We extend the shell model Monte Carlo approach to heavy deformed nuclei using a new proton-neutron formalism. The low excitation energies of such nuclei necessitate low-temperature calculations, for which a stabilization method is implemented in the canonical ensemble. We apply the method to study a well-deformed rare-earth nucleus, (162)Dy. The single-particle model space includes the 50-82 shell plus 1f(7/2) orbital for protons and the 82-126 shell plus 0h(11/2), 1g(9/2) orbitals for neutrons. We show that the spherical shell model reproduces well the rotational character of (162)Dy within this model space. We also calculate the level density of (162)Dy and find it to be in excellent agreement with the experimental level density, which we extract from several experiments.