Survey of Resonance Reaction Theories

Abstract

Resonances, will play a central role in the discussions of this Conference. On the one hand we shall be concerned with the extraction of the parameters describing a resonance, its energy, its half width, etc., from experiment. On the other hand we shall want to be able to interpret these results in terms of the structure of the interacting nuclear systems--ultimately in terms of the wave function of the system or (a lesser but physically as significant a goal) for statistical parameters suitably related to that wave function. Ancient as these problems (the description of a resonance, the extraction of resonance parameters from experiment, their interpretation) are, their solution has remained the subject of a debate which has been argued by some with fanatical fervor. One of my objectives in today’s talk is to take the heat out of this quarrel. It is my thesis that each of the methods (although they may have had some deficiencies in their original formulation) have been or can be adapted by sufficiently clever men so as to become equivalently valid. I will not therefore, be an advocate for any particular formalism. I like my own [1,2,3,4] but all that means is that I am more comfortable in using its constructs and concepts, not that it is superior. The final expressions obtained for experimental observables are in fact very similar so that, as far as fitting the data is concerned, the experimentalist or theorist can choose whichever suits his fancy. In passing, it would however, be useful to have programs which would translate between possible forms.