Threshold anomaly in the elastic scattering ofHe6onBi209

Abstract

The energy dependence of the optical potential for the elastic scattering of $^{6}\mathrm{He}$ on $^{209}\mathrm{Bi}$ at near and subbarrier energies is studied. Elastic angular distributions and the reaction cross section were simultaneously fitted by performing some modifications in the ECIS code. A phenomenological optical model potential with the Woods-Saxon form was used. There are signatures that the so-called breakup threshold anomaly (BTA) is present in this system having a halo projectile $^{6}\mathrm{He}$, as it had been found earlier for systems involving stable weakly bound nuclei.