Glory effect in the optical-model analysis of 39K(α, α) 39K elastic scattering

Abstract

An optical-model analysis of the 39K(α, α) 39K scattering data in the angular range up to 179° and for nine α-particle energies from 22.1 to 28.2 MeV has been performed in order to investigate whether the so-called nuclear glory effect is contained in the optical model. Six four-parameter potentials describing the elastic scattering were found with a depth of the real part ranging from 100 to 300 MeV. Only potentials with a real part deeper than 200 MeV can reproduce the backward scattering. The radius parameters corresponding to these deep potentials are rather small ( r 0 = 1.1 fm. It has been shown in an additional study that partial waves corresponding to the surface region of the target nucleus play an essential role in the backward scattering.