Study of the cross-section of a direct nuclear reaction in the vicinity of its singularities

Abstract

The simplest graphs corresponding to direct nuclear reactions are studied. The position of the singularities of simply connected graphs with no more than 2 incoming and outgoing particles at each vertex has been determined. The residue at these poles has been calculated and related to the level width or to the relative weight of cluster configurations of the interacting nuclei. The calculations have been made in the general case of two incoming particles and of two or three outgoing particles with spins different from zero.