Diffractive, Regge-pole, and distorted-wave Born-approximation description of theMg26(O16,C14)Sig.s.28transition between 33 and 128 MeV

Abstract

Angular distributions for the /sup 26/Mg(/sup 16/O, /sup 14/C)/sup 28/Si/sub g.s/ transition have been measured at incident energies of 33 and 40 MeV using a quadrupole-dipole-dipole-dipole spectrometer. These data together with previous measurements for this same transition at 45, 60, and 128 MeV incident energies have been analyzed in terms of a diffractive model, Regge poles, and the distorted-wave Born approximation. The shapes of the angular distributions at all incident energies are reproduced in each of the three analyses. Parameters required to fit the diffractive and Regge-pole models to the data are compared to equivalent quantities extracted from the distorted-wave Born-approximation analysis, and the relevant parameters are found to be consistent in all three models. This agreement is due principally to the peripheral nature of these reactions. To simultaneously reproduce the angular shape at the lowest and highest energies in the distorted-wave Born-approximation analysis, it was necessary to assume an energy dependent absorption in the vicinity of the nuclear surface. The use of such potentials removes much of the energy dependence of the normalization between the predicted and measured cross sections. (AIP)