Microscopic investigation of pair excitation and shape coexistence in even-even nuclei.

Abstract

Starting from shell structure and nuclear effective interaction among nucleons, a microscopic model investigating intruder states and shape coexistence in even-even nuclei near the closed shell has been established. Two methods of finding wave functions are also introduced. We present configuration mixing calculations within the model on {sup 112,114}Cd, {sup 114,116}Sn, and {sup 116,118,120}Te isotopes. Both methods give a good description of low-lying levels (energy spectra and {ital E}2 transition properties). We find that the mixing is not strong in these cases. We also point out the important roles of {ital np} interaction and {ital np} correlations in treating intruder states and shape coexistence.