I shall overview how the single-particle and collective (shape) properties of atomic nuclei are driven/controlled by certain characteristic features of nuclear forces. The tensor force then shows unique and substantial effects. The tensor force has been known and studied extensively for decades, but its crucial contributions to these properties are being clarified with new aspects. Regarding single-particle nature, the shell evolution oocurs due to the monopole components of the central and tensor forces, changing magic/shell structure in going to exotic nuclei. Examples can be found in many nuclei including those studied in ANL. The same mechanism works within a given nucleus (Type II shell evolution). Advanced Monte Carlo Shell Model calculation can describe heavy nuclei up to Hg isotopes, exhibiting the 1st (2nd) order quantum phase transition in Zr (Sn) isotopes, and the multiple 1st order transitions in Hg isotopes. I shall survey the underlying mechanism for these phenomena, and discuss a possible general mechanism, quantum self-organization, where the interplay between single-particle states and collective modes can exhibit a variety of shapes.

Argonne Physics Division Colloquium Schedule