Recent shell-model results for exotic nuclei

¹ Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
² Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
³ Department of Physics, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
⁴ National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, Bunkyo-ku, East Lansing MI 48824, USA
⁵ Center for Mathematical Sciences, University of Aizu, Ikki-machi, Aizu-Wakamatsu, Fukushima 965-8580, Japan .
⁶ Institute for Natural Sciences, Senshu University, Tokyo, 101-8425, Japan .

^a e-mail: utsuno.yutaka@jaea.go.jp

Published online: 20 March 2014

Abstract

We report on our recent advancement in the shell model and its applications to exotic nuclei, focusing on the shell evolution and large-scale calculations with the Monte Carlo shell model (MCSM). First, we test the validity of the monopole-based universal interaction (V_MU) as a shell-model interaction by performing large-scale shell-model calculations in two different mass regions using effective interactions which partly comprise V_MU. Those calculations are successful and provide a deeper insight into the shell evolution beyond the single-particle model, in particular showing that the evolution of the spin-orbit splitting due to the tensor force plays a decisive role in the structure of the neutron-rich N ∼ 28 region and antimony isotopes. Next, we give a brief overview of recent developments in MCSM, and show that it is applicable to exotic nuclei that involve many valence orbits. As an example of its applications to exotic nuclei, shape coexistence in ³²Mg is examined.