Signature of three-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-energy electron-impact ionization of atomic hydrogen is considered in the coplanar asymmetric energy-sharing kinematics at an incident energy of 27.2 eV. The emergence of structures in the measured spin-unresolved cross sections is explained in terms of isolated two-body final-state interactions and three-body coupling. The cross section shows two peaks originating from `classical' sequential two-body collisions. The position of these peaks is determined by two-body final-state interactions. In addition, it is demonstrated that the signature of three-body interactions is carried by the magnitude and ratio of these two peaks. The direct and exchange amplitudes as well as the spin asymmetry are also considered.