Breakup threshold anomaly in the elastic scattering for the ⁶Li+⁹⁰Zr system

Abstract

Measurements of elastic scattering for the ⁶Li+⁹⁰Zr system has been performed at various energies, namely, 11, 12, 13, 15, 17, 19, 21, 25, and 30 MeV, to study the energy dependence of the interaction potential. Angular distributions have been measured in a wide angular range to extract the behavior of the potential reliably. The data have been analyzed using the phenomenological Woods-Saxon shaped optical potential and the double folding potential. The potential behavior shows the characteristics of the breakup threshold anomaly, namely, the increase in the imaginary potential near the barrier with a small reduction in the real part. Continuum-discretized-coupled-channel (CDCC) calculations give a good description of the measured elastic scattering data and predict large breakup coupling effects. The polarization potentials extracted from the CDCC calculations have been studied for the present system along with those for the ⁶Li+²⁰⁸Pb, and ⁶Li+²⁸Si systems, and a similar energy dependence has been obtained for all the cases considered.