Complete fusion in7Li+144,152Sm reactions

Abstract

Complete fusion cross sections for ${}^{7}$Li+${}^{144,152}$Sm reactions have been measured at energies around the Coulomb barrier by offline $\ensuremath{\gamma}$-counting technique. Measured cross sections for the above two reactions are found to be similar at energies well above the Coulomb barrier, however, at sub-barrier energies the cross sections for the ${}^{7}$Li+${}^{152}$Sm system are much higher compared to the ${}^{7}$Li+${}^{144}$Sm system, manifesting the effect of target deformation. Cross sections for the present reactions at above-barrier energies are found to be larger than previously measured reactions involving ${}^{6}$Li projectile with the same targets, possibly due to smaller breakup probability of ${}^{7}$Li than ${}^{6}$Li. Coupled-channels calculations show that the experimental fusion cross sections for both the systems are enhanced at subbarrier energies and suppressed at above-barrier energies compared to the respective one-dimensional barrier penetration model predictions. The calculations by different models show that the measured complete fusion cross sections at above-barrier energies are suppressed up to $\ensuremath{\sim}$25% compared to the theoretical predictions. It also reveals that a large part of the suppression could be due to inelastic and transfer coupling.