Understanding nuclear dynamics in the SD-pair shell model: From pre-vibration to collective rotation

. Influences of some important residual interactions considered in the shell model on nuclear dynamics and the shape phase evolution have been investigated in the SD-pair shell model for an identical nucleon system. The results indicate that the collective modes including the spherical vibration, prolate rotation, and X(5)-like critical dynamics are mainly driven by the competition between the monopole-pairing interaction and the quadrupole-quadrupole interaction, and the main features of the U(5)-SU(3) phase transition can be well reproduced within the SD-pair model. In addition, it is also shown that the quadrupole-pairing interaction cannot be ignored in reproducing an ideal rotational spectrum with a realistic single-particle configuration.