Tensor force and shape evolution of Si isotopes in the Skyrme-Hartree-Fock model

Much interest has recently been devoted to the shape evolution of neutron-rich Si isotopes both experimentally and theoretically. We present our study of 28-42Si using the Skyrme-Hartree- Fock model with the Bardeen-Cooper-Schrieffer approximation for the pairing channel. We use an empirical pairing parameter deduced from the experimental binding energy data for each nucleus and each Skyrme parametrization. The recent highlight of the deformation change from the prolate shape of 38Si to the oblate shape of 42Si is confirmed in the present model. We also emphasize the role of the tensor force in deformations of neutron-rich 30,32Si, and discuss its underlying physics.