Fusion and quasi-elastic scattering in theLi6,7+Au197

Abstract

Fusion and quasi-elastic scattering measurements have been carried out for 6,7 Li + 197 Au systems in the energy range E/V b ∼ 0.7 to 1.5. Coupled-channel calculations including coupling to inelastic states of the target and projectiles are able to explain an enhancement in measured fusion cross sections at energies below the barrier. At energies above the barrier the complete fusion cross sections are found to be suppressed compared to the coupled-channel predictions for both systems. A systematic comparison of fusion cross sections of the weakly bound stable nuclei 6,7 Li and halo nuclei 6,8 He on a 197 Au target is presented. Barrier distributions from quasi-elastic scattering are seen to shift towards higher energies with respect to fusion after inclusion of the breakup-α channel for both 6 Li and 7 Li.

Systematic study of breakup effects on complete fusion at energies above the Coulomb barrier

“…In the last few years, CF cross sections for many reactions involving weakly bound nuclei have been measured Fusion Function [ [21][22][23][24][25]. The suppression of complete fusion cross sections above the Coulomb barrier due to the breakup has been observed in these reaction systems.…”

“…* sgzhou@itp.ac.cn Several methods have been adopted to investigate the influence of the breakup on fusion reactions around the Coulomb barrier [15][16][17][18][19][20]. One of the most widely employed approaches is to compare the data with either the predictions of coupled channel (CC) calculations without the breakup channels [10,11,[21][22][23][24][25] or the predictions of a single barrier penetration model (SBPM) [5,[12][13][14]. It was found that the CF cross sections are suppressed at energies above the Coulomb barrier.…”

“…Therefore, further systematic study of the influence of the breakup on CF cross sections is needed. Particularly, in the last few years, new experiments with weakly bound nuclei were performed and the corresponding CF cross sections were measured [21][22][23][24][25]. Moreover, evidences of breakup for tightly bound projectiles ( 11 B, 12,13 C and 16 O) were also found [14,[27][28][29][30].…”

Recent developments in fusion and direct reactions with weakly bound nuclei

“…These distributions are clearly different. The difference can be seen more clearly in the work of Palshetkar et al [96], where the QEBD and the CFBD are plotted together. The barrier distributions for the 6 α particles.…”

Systematic study of suppression of complete fusion in reactions involving weakly bound nuclei at energies above the Coulomb barrier

“…This shortcoming can be avoided within a new dynamical quantum approach that includes SCF as well as ICF from the bound state(s) of the projectile [26]. In addition, the comparison of experimental fusion cross sections with either the predictions of coupled-channel (CC) calculations without the breakup and transfer channels [12][13][14][15][16][27][28][29][30][31] or the predictions of a single barrier penetration model (SBPM) [9][10][11] shows that CF cross sections are suppressed owing to the breakup at energies above the Coulomb barrier.…”