SOLUBLE MODEL CALCULATIONS OF THE CONTINUUM STRUCTURE OF CLOSED-SHELL NUCLEI IN THE EIGENCHANNEL REACTION THEORY

摘要

An analysis of the eigenchannel formalism as applied to the reac-tion theory of photonuclear absorption processes is discussed and ana¬lyzed within the one-particle-one-hole framework. A method for eliminating these spurious components is derived and an analysis of the resultant 12C photoabsorption cross sections shows .relatively good agreement between the resonance peaks found by the eigenchannel analysis and those from experiment. The experi¬mental interpretation of resonance structure above the giant resonance as being attributable to single-particle excitations from low-lying closed shells is supported by the eigenchannel analysis of the 12C photoabsorption reaction. The fact that the eigenchannel theory can and does produce nuclear reaction information in good accord with exper¬iment tends to support its continued use. However, because of the ex¬cessive computer time involved in such a calculation and the preponder¬ance of numerical difficulties associated with it, extensive applications of the eigenchannel theory as presently formulated must be questioned.