Nuclear spectroscopy, nuclear clustering and exotic shapes

Abstract

Nuclear clustering has been a subject of intense study since the advent of heavy ion accelerators. Looking back more than 30 years, we are able today to see the connection between resonances in heavy ion reactions and extreme states in nuclei. In particular, excited states close to the decay thresholds into substructures show pronounced cluster structures. The ever repeated question about the possibility to describe such cluster phenomena in an extended (to a very large basis) and deformed shell model, has recently been revived in view of improved computational facilities. The new experimental facilities and the powerful new detector arrays for γ-spectroscopy and for charged particles have increased the sensitivity to study clustering phenomena by orders of magnitude. Today we are able to study nuclear structure at the limits of the mean field concept. With the advent of radioactive beams and the study of nuclei, which are weakly bound in their ground states, the question of the limits of mean field concepts has reached the low excitation energy region of nuclei.