Folding model analysis of the excitation of low-lying states and the high energy octupole resonance in Sn-116 by 240 MeV alpha scattering

Abstract

The sum rule strength of the high energy octupole resonance (HEOR) and the transition rates of low-lying 2(+) and 3(-) states of Sn-116, excited by 240 MeV alpha scattering, have been determined from deformed potential and folding model analyses. Deformed potential cross sections for both the low-lying 3(-) state and the HEOR are greater than folding cross sections by a factor of 1.18. The high energy octupole resonance was found to exhaust (70+/-15)% and (83 +/- 15)% of the E3 energy-weighted sum rule from the two analyses, respectively. The data for the low-lying states are fit well by the calculations made with both models using electromagnetic values for the transition rates. Optical-model parameters were obtained from fits to elastic scattering data. The differential cross sections for the elastic scattering and inelastic scattering exciting the low-lying 2(+) and 3(-) states in Sn-116 were measured over the angle range from theta(c.m.)=1.6 degrees to 35.2 degrees.