SEMIMICROSCOPIC ALGEBRAIC CLUSTER MODEL OF LIGHT-NUCLEI .1. 2-CLUSTER-SYSTEMS WITH SPIN ISOSPIN-FREE INTERACTIONS

The relation of the phenomenological algebraic cluster model, i.e., of the vibron model and its extensions, to the microscopic description i s discussed. Based on this connection a semimicroscopic approach is fo rmulated, in which the internal cluster degrees of freedom are treated in terms of the SU(3) shell model, and the relative motion is describ ed by the vibron model. For a two-cluster system this model has a grou p structure of U(C1)ST,(4) x U(C1)(3) x U(R)(4) x U(C2)(3) x U(C2)ST(4 ), and the phenomenological interactions are obtained in terms of the group generators. The model space is constructed to be free from the P auli-forbidden states and spurious center of mass motion, similar to t hat of the SU(3) cluster model. Three examples, the C-12 + alpha, the C-12+ C-12 and the C-14 + alpha systems are presented to demonstrate v arious aspects of the semimicroscopic algebraic cluster model. (C) 199 4 Academic Press, Inc.