Effect of projectile breakup and target deformation on complete fusion cross section

Study of nuclear reaction dynamics involving weakly bound or halo nuclei is a field of current interest because of its application to research in astrophysics, nuclear structure and production of super heavy elements. There exist different conclusions about the enhancement or suppression of the fusion cross section over the predictions of single barrier fusion model in the reactions induced by weakly bound stable nuclei such as ⁶,⁷Li and ⁹Be at energies around the Coulomb barrier. The fusion cross section for ^6,7Li+¹⁴⁴,¹⁵²Sm systems was studied. The activation technique was used to separate the complete fusion (CF) and incomplete fusion (ICF) cross sections. The effect of target deformation on the fusion cross section was studied using ¹⁵²Sm, as it is deformed target. Comparing the results of ^6,7Li+¹⁴⁴Sm, the effect of projectile break up threshold on fusion cross section as ⁷Li has more break up threshold (2.478 MeV) than ⁶Li(1.47 MeV). It is also important to span the energy from sub barrier to two or three times the barrier, because there are evidence that the role of the break on the fusion depends on the energy. At above barrier energies the CF being larger for ⁷Li than ⁶Li induced reactions. It confirms that due to larger breakup threshold of the former the effect of breakup is lower, hence less suppression and the results are consistent with systematic. It also shows that the CF at subbarrier energies for ⁷Li+¹⁵²Sm is much more enhanced than for ⁷Li+^144,152Sm due to target deformation. Thus, it can be concluded that the effect of both projectile breakup and target deformation co-exist on the CF excitation function involving a weakly bound projectile and a deformed target. (author)