SHAPE TRANSITIONS IN EVEN MO AND SM ISOTOPES - STUDY IN A NEW MICROSCOPIC INTERACTING BOSON MODEL SCHEME

A simple dynamic procedure, based on the deformed Hartree-Fock solution of a nucleus, is presented to construct the IBM operators in microscopic basis. The parameters of these operators are evaluated by establishing a Marumori mapping from the truncated shell model space onto the boson space. The transitions from spherical to axial-rotor shape observed in the low-lying levels of even(96-108) Mo and Sm-146-154 isotopes are reproduced qualitatively by applying this procedure with a fixed set of fermion input parameters to each chain. Variation of a few parameters in fermion space leads to quantitative agreement.