An investigation of the natural line shape of the giant dipole resonance.

Abstract

An investigation of photoabsorption experiments in the spherical nucleus 141Pr, the quasispherical dynamically deformed 197Au, and the statically deformed 165Ho showed that the best function for the energy dependence of the reduced transition probability is given by the Breit-Wigner form rather than the Lorentz form of a resonance function. However, the form of the resulting measured cross section is of the Lorentz type. The dependence of the giant resonance width Gamma on the excitation energy was also investigated. The variation was found to be less than 1% per MeV if one considered the known isovector E2 resonances above the giant dipole resonance. Best fit values of the reduced transition probabilities for the three nuclei are given and compared to (e, e') results