Abstract
In the framework of the -phonon scheme and the interacting boson model a description of the and states is obtained. The wave vectors are written as an expansion in multiple -phonon excitations of the ground state. It is shown that the convergence of this expansion is fast and the main component already provides a good approximation of the wave vector. The accuracy of such a leading-order description exceeds 90% of the wave vector. By taking into account two -phonon configurations the accuracy of the description of the and states is increased to 98%. This is true for all collective nuclei with the exception of some rotors where the first excited band lies below or very close to the γ band and, due to band mixing, the wave vector of the state contains higher -phonon excitations. An application to some decay transitions is given.
- Received 26 June 1997
DOI:https://doi.org/10.1103/PhysRevC.57.150
©1998 American Physical Society