Spherical-deformed shape coexistence for the pf shell in the nuclear shellmodel - art. no. 044306

A spherical-deformed shape coexistence for semimagic pf-shell nuclei is inv estigated. Deformed states can arise by breaking the f(7/2) submagic shell, and coexist with spherical yrast states for Fe-54. These states are shown to be primarily two-particle two-hole excitations on top of the respective correlated ground states. In addition to these modes, a four-particle-four- hole excitation can be found for Fe-54, which is related to the deformed ba nd of doubly magic Ni-56. To investigate this shape coexistence, we use the conventional shell-model diagonalization, constrained Hartree-Fock, genera tor coordinate, variation-after-projection, and Monte Carlo shell-model met hods.