Fully differential cross-sections in single ionization of helium by 2 MeV/amu C6+ impact: The role of correlated wave functions

Abstract

We study the effect of final-state dynamic correlation in single ionization of helium atom by 2 MeV/amu C6+ impact analyzing the fully differential cross-sections (FDCS). The transition matrix is introduced using a correlated continuum wave (CCW) and that for the initial state by an undistorted Born-approximation. The final state is modeled by the CCW function so that both the correlation and the interaction between the projectile and the residual target ion (PT interaction) are treated. The analytical expression of the transition matrix has been obtained through a series representation of the CCW function. Illustrative computations are performed in the scattering plane. A comparison of fully differential results using the present model with other theories and experimental data reveals that the dynamic correlation is responsible for the enhancement of the FDCS structure. The PT interaction is also checked in our model. We observe a satisfactory, although not perfect, agreement of the CCW calculations with experimental findings. Large discrepancies between the experimental data and theoretical predictions are found, which can at least be partly attributed to the inclusion of dynamic correlation effects.