Analytic Formulae for the Matrix Elements of the Transition Operators in   the Symplectic Extension of the Interacting Vector Boson Model
  The tensor properties of all the generators of Sp(12,R) - the group of dynamical symmetry of the Interacting Vector Boson Model (IVBM), are given with respect to the reduction chain Sp(12,R) $\supset $ U(6) $\supset $ U(3) x U(2) $\supset $ O(3) x U(1). Matrix elements of the basic building blocks of the model are evaluated in symmetry adapted basis along the considered chain. As a result of this, the analytic form of the matrix elements of any operator in the enveloping algebra of the Sp(12,R), defining a certain transition operator, can be calculated. The procedure allows further applications of the symplectic IVBM for the description of transition probabilities between nuclear collective states. 
H. G. Ganev, A. I. Georgieva, and V.P.Garistov