Evidence for Coulomb effects on the fusion barrier distribution for deformed projectile nuclei

Abstract

Coulomb effects during the interaction of light deformed projectile nuclei with a heavy collision partner have been predicted to modify the fusion barrier distribution leading to a hindrance in the sub-barrier fusion cross section. In order to verify this experimentally, we have determined the fusion barrier distributions from the measurement of quasielastic excitation functions for $^{16}\mathrm{O}$(spherical)+$^{115}\mathrm{In}$, $^{28}\mathrm{Si}$(oblate)+ $^{115}\mathrm{In}$, and $^{30}\mathrm{Si}$(prolate)+ $^{115}\mathrm{In}$ systems. For $^{16}\mathrm{O}+^{115}\mathrm{In}$ system, the fusion barrier distribution is single peaked, whereas for $^{28}\mathrm{Si}+^{115}\mathrm{In}$ and $^{30}\mathrm{Si}+^{115}\mathrm{In}$ systems, one observes broadening and well defined structures in fusion barrier distribution, which could be explained by coupled-channel calculations performed using the CCFULL code after including deformation and Coulomb effects on the projectile in the field of target nucleus.