Simple relations among E2 matrix elements of low-lying collective states

A method is developed to derive simple relations among the reduced matrix e lements of the quadrupole operator between low-lying collective states. As an example, the fourth-order scalars of Q are considered. The accuracy and validity of the proposed relations is checked for the ECQF Hamiltonian of t he IBM-1 in the whole parameter space of the Casten triangle. Furthermore t hese relations are successfully tested for low-lying collective states in n uclei for which all relevant data is available. (C) 2001 Elsevier Science B .V. All rights reserved.