Elastic scattering and Li7 production in the Li8+Sn120 reaction

Abstract

The ${}^8\mathrm{Li}+{}^{120}\mathrm{Sn}$ collision has been investigated at laboratory energies of 21.7 and 25.8 MeV ($V_{\mathrm{CB}}^{\mathrm{lab}}=20.5$ MeV). The ${}^8\mathrm{Li}+{}^{120}\mathrm{Sn}$ elastic scattering and the ${}^7\mathrm{Li}$ fragment angular and energy distributions from the ${}^{120}\mathrm{Sn}({}^8\mathrm{Li},{}^7\mathrm{Li})X$ reaction have been measured. The elastic scattering angular distributions were analyzed by optical model and coupled reaction channels (CRC) calculations considering the coupling with the neutron stripping channel. The effect of the projectile breakup on the elastic scattering distributions has been studied via continuum-discretized coupled-channels (CDCC) calculations. The experimental ${}^7\mathrm{Li}$ energy distribution presents characteristics similar to a neutron transfer reaction populating a wide range of excited states in the recoil system, from the ground state up to states above the neutron threshold, with a maximum in the excitation energy predicted by $Q$-optimum arguments. These energy distributions, as well as the corresponding ${}^7\mathrm{Li}$ angular distributions, are well described using the Ichimura, Austern, and Vincent (IAV) model, which includes the neutron transfer to bound and unbound states of the target nucleus. The total reaction cross sections from the elastic scattering angular distributions and total breakup cross sections have been obtained from the IAV plus CDCC and CRC calculations. A comparison with previous measurements of the ${}^8\mathrm{Li}$ scattering on ${}^9\mathrm{Be}$ and ${}^{58}\mathrm{Ni}$ targets is presented. A dominance of the transfer to bound states over the breakup channel is seen in the present case.