Light-particle emission in the reaction ⁶ He + ⁶⁴ Zn around the Coulomb barrier

Abstract

The elastic-scattering, neutron transfer and projectile break-up channels have been studied for the reaction 6 He + 64 Zn at energies around the Coulomb barrier. The results show a very large break-up and transfer cross-section corresponding to the largest fraction of the total reaction cross-section. No evidence of threshold anomaly emerged from the elasticscattering optical-model analysis.

Reaction studies with low-energy weakly-bound beams at INFN-LNS

“…On medium mass targets very few experiments have been performed. The measurement of elastic scattering of 6 He+ 64 Zn was reported in [6,7]. Although the elastic cross-section is overall suppressed when compared to the one for 4 He+ 64 Zn, the Coulomb-nuclear interference pattern is not as much reduced as it was observed in the case of heavy targets.…”

“…Recently, the 11 Li+ 208 Pb elastic scattering around the Coulomb barrier was reported and compared with the scattering of 9 Li on the same target [13]. A huge suppression of the 11 Li elastic cross-section was found with respect to the 9 Li one, much larger than the one observed in the case of 6 He on similar mass targets [8][9][10]. CDCC calculations show that coupling to continuum via the Coulomb-dipole interaction gives an important contribution to the disappearance of the Coulomb-nuclear interference peak.…”

“…Elastic scattering with halo nuclei, 6 He, 11 Be and 11 Li, at energies around the Coulomb barrier has been measured by different authors mostly on heavy targets [6][7][8][9][10][11][12][13]. In collisions induced on heavy nuclei the data showed a suppression of the elastic cross-section in the region of the Coulomb-nuclear interference peak when compared with the scattering induced by the corresponding stable isotope at similar c.m.…”

“…Although the elastic cross-section is overall suppressed when compared to the one for 4 He+ 64 Zn, the Coulomb-nuclear interference pattern is not as much reduced as it was observed in the case of heavy targets. More recently, the 4,6 He+ 64 Zn measurements were extended to higher c.m. energies E c.m.…”

“…The study of nuclear collisions around the Coulomb barrier induced by halo and, more in general, weakly bound nuclei such as the stable 6 Li, 7 Li, 9 Be, has been widely investigated over the last twenty years. Results have shown that the very low breakup threshold of such nuclei, combined with the halo or cluster structure of the ground state, will strongly affect the reaction dynamics around the Coulomb barrier.…”