Artículos de revistas
Off-shell distortions of multichannel atomic processes
Fecha
2017-02Registro en:
Barrachina Tejada, Raul Oscar; Clauser, Cesar Fernando; Off-shell distortions of multichannel atomic processes; Elsevier; Beam Interactions with Materials and Atoms; 408; 2-2017; 161-164
0168-583X
CONICET Digital
CONICET
Autor
Barrachina Tejada, Raul Oscar
Clauser, Cesar Fernando
Resumen
Any multichannel problem can be reduced to a succession of two-body events. However, these basic building blocks of many-body theories do not correspond to elastic processes but are off-the-energy-shell. In view of this difficulty, the great majority of the Distorted-Wave models includes a subsidiary approximation where these off-shell terms are arbitrarily forced to lie on the energy shell. At a first glance, since the energy deficiency is negligible for high enough velocities, the on-shell assumption seems to be completely justified. However, for the case of Coulomb interactions, the two-body off-shell distortions have branch-point singularities on the on-shell limit. In this article we demonstrate that these singularities might produce sizeable distortions of multiple scattering amplitudes, mainly when dealing with ion-ion collisions. Finally, we propose a method of including these distortions that might lead to better results that removing them completely.