Speaker
Description
Resonance parametrizations of nuclear scattering and reaction observables are useful for applications in nuclear astrophysics, nuclear energy and nuclear safety and security. Such parametrizations derived from the phenomenological $R$-matrix -- a Green-function approach -- afford compact and accurate descriptions of the relevant observables and their uncertainties as determined by the observed data. The equivalence of various representations of resonance parameters is discussed and a unified view of these is presented in terms of the theory of resolvent operators. Recent work on minimal sets of resonance parameters is demonstrated by studying the $^5$He compound system in terms of sets of resonance parameters derived from a complete $R$-matrix study. [LA-UR-21-29550]