Theory with correlations for ionization in ion-atom collisions

We perform the calculation of proton-hydrogen ionizing collisions based on the Φ₂ model recently proposed to describe the three-body final wave function. The transition matrix was evaluated analytically for a Born and a continuum distorted-wave initial state. The double-differential cross section was computed for the Born-Φ₂ approximation. Even when this is an undistorted initial-state theory, it introduces the asymmetries of the electron capture to continuum and soft electron peaks. It also takes into account the saddle electrons production in a more realistic way than other distorted-wave theories, presents the expected behavior in the forward direction for large electron energies, and shows the correct shift of the binary peak. Numerical results are compared with experimental data and other theoretical values.