Theoretical study of Na★ (3p) charge cloud orientation in Na + He collisions.

The Projected Valence Bond potential energies of NaHe system calculated by Courbin-Gaussorgues and Sidis are used in an 8-state model to study the direct excitation, deexcitation probabilities and the orientation of the charge cloud of Na★ (3p). The corresponding calculation are carried out using the impact parameter method in the 0.5 Kev < ECM < 100 Kev energy range. A comparison with the theoretical prediction of a 3-state model of Andersen and Nielsen is made and discrepancies are discussed.