A Variational Approach to Nuclear Reactions

Abstract

The formalism of Wigner and Eisenbud for nuclear reactions is carried out by means of a variation principle. A variation principle of the Hulth\'en type is derived for the $R$ matrix and applied to trial wave functions written in terms of the resonance functions, ${X}_{\ensuremath{\lambda}}$, of the Wigner-Eisenbud formalism. As a result, a finite level formula for the $R$ matrix is directly obtained.