Unusual threshold anomaly in the Li-6+(208) Pb system

The angular distributions of elastic scattering for the Li-6 + Pb-208 system have been measured at several energies around the Coulomb barrier. The parameters of optical potential are extracted by means of a phenomenological optical model analysis. It is found that the real and imaginal potentials show a pronounced energy dependence. The behaviour of the potential at the nearly especially sub-barrier energies in the Li-6 + Pb-208 system is quite different from the results of some previous reports observed in other systems, such as F-19 + Pb-208 and O-16 + Pb-208. This unusual threshold phenomenon indicates that breakup channel is strongly coupled with the elastic channel and has obvious effects on optical potential.Physics, MultidisciplinarySCI(E)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)2ARTICLE51146-11492