Corrections to the Alder-Winther theory of Coulomb excitation

Abstract

An expansion scheme is developed for studying corrections to the Alder-Winther theory of Coulomb excitation. The zeroth-order term in the expansion of the excitation cross section is identical to the expression provided by the Alder-Winther theory and there are several kinds of first-order corrections. All of these can be calculated by making simple changes in existing computer programs for the Alder-Winther theory. These corrections can be interpreted as a change in the deflection function for the relative motion and a change in the excitation probabilities due to the deviations of the relative motion from a Rutherford orbit. Some of the terms that describe the change in the excitation probabilities correspond to an energy symmetrisation and others can be interpreted as an angular momentum symmetrisation. Numerical comparisons with results of full quantal coupled-channels calculations are presented.