Elastic and inelastic scattering of 1.37 GeV α particles from ¹²C and ^40,42,44,48Ca

Elastic and inelastic scattering data of 1.37 GeV α particles on ¹²C and ^40,42,44,48Ca are analyzed within the framework of the Glauber theory. Collective excitations to one-phonon levels are treated using the Tassie model. The effect of the coupling between the elastic and inelastic channels is considered. It is shown that a phase variation of the nucleon-nucleon elastic scattering amplitude leads to a large increase in the calculated differential cross section. The presence of a phase variation leads to a substantial improvement.