Abstract
We discuss the effects of multiphonon excitations on heavy-ion fusion reactions at energies near and below the Coulomb barrier, focusing especially on the role of anharmonicities. We carry out a systematic study of those effects on the excitation function of the fusion cross section and on the fusion barrier distribution, by using the vibrational limit of the interacting boson model. We also analyze the recently measured high-precision data of the O + Sm fusion reaction with this model and discuss the anharmonic properties of the quadrupole as well as the octupole vibrations in Sm. Negative and positive static quadrupole moments are deduced for the first 2 and 3 states in Sm, respectively. It is shown that the fusion barrier distribution strongly depends on the sign of the quadrupole moments, suggesting that subbarrier fusion reactions offer an alternative method to extract the static quadrupole moments of phonon states in spherical nuclei.
- Received 5 November 1997
DOI:https://doi.org/10.1103/PhysRevC.57.1349
©1998 American Physical Society