A representation of the fusion barrier distributions has been deduced from the back angle quasielastic scattering cross section data in ${}^{16,18}\mathrm{O}{+}^{12,124}\mathrm{Sn}$ reactions, measured over a wide range of bombarding energies around the Coulomb barrier. The results have been compared with coupled channel calculations using the CCDEF code to study the effects of projectile and target inelastic excitations and nucleon transfer couplings on the representation of fusion barrier distributions in these systems. The present studies bring out the importance of coupling of $2n$ pickup in the ${}^{16}\mathrm{O}{+}^{120,124}\mathrm{Sn}$ reactions and $2n$ stripping in the ${}^{18}\mathrm{O}{+}^{120,124}\mathrm{Sn}$ reactions in explaining the observed barrier distributions.

• Received 4 December 2000

DOI:https://doi.org/10.1103/PhysRevC.64.024607