SIGNATURE OF 3-BODY INTERACTIONS IN LOW-ENERGY (E,2E) REACTIONS IN COPLANAR ASYMMETRIC ENERGY-SHARING GEOMETRY

In this work the multiply differential cross section for the low-energ y electron-impact ionization of atomic hydrogen is considered in the c oplanar asymmetric energy-sharing kinematics at an incident energy of 27.2 eV. The emergence of structures in the measured spin-unresolved c ross sections is explained in terms of isolated two-body final-state i nteractions and three-body coupling. The cross section shows two peaks originating from 'classical' sequential two-body collisions. The posi tion of these peaks is determined by two-body final-state interactions . In addition, it is demonstrated that the signature of three-body int eractions is carried by the magnitude and ratio of these two peaks. Th e direct and exchange amplitudes as well as the spin asymmetry are als o considered.