Effect Of N = 40 Shell Closure On Barrier Distributions In [sup 18]O+[sup 58,60]Ni Reactions

The quasi-elastic scattering measurements for {sup 18}O+{sup 58,62}Ni systems have been carried out at {theta}{sub lab} = 150 deg. around Coulomb barrier energies to investigate the effect of nuclear shell closure on the barrier distributions. The {sup 18}O+{sup 58}Ni system leads to N = 40 neutron shell closure and {sup 18}O+{sup 62}Ni system is having N = 44 in the compound system. It is observed that target 2{sup +} and 3{sup -}, projectile 2{sup +} inelastic and 2n-transfer couplings are required in coupled-channels fusion model (CCFULL) calculations to get good comparison with the experimental barrier distribution of {sup 18}O+{sup 62}Ni system, whereas projectile 2{sup +} inelastic state coupling is not required for {sup 18}O+{sup 58}Ni system. However, the low energy structure observed in the barrier distribution of {sup 18}O+{sup 58}Ni system is not reproduced by coupled-channels calculations. This suggests, a possible additional effect due to N = 40 shell closure in the compound system not accounted for in coupled-channels calculations.