Classical and quantal collisional Stark mixing at ultralow energies - art.no. 032701

Exact classical and quantal solutions are presented for the full array Of i ntrashell transitions nl-->nl', between any angular momentum states, induce d by slow distant collisions with a charged particle. The collisions are ad iabatic with respect to the orbital frequency of the atomic electron and th e transitions are induced by the weak ion-atom dipole field generated by th e ion moving along a classical path. The rich symmetry of the problem allow s a unified approach and is the source of the excellent agreement, beyond t he usual Ehrenfest's correspondence principle, between the classical and qu antal treatments. A classical transition probability is defined. Probabilit ies for transition between any angular momentum states within a high Rydber g energy level are derived in exact analytic forms and are analyzed for a l arge number of numerical examples. The transition probabilities obtained fr om the three methods-quantal and classical formulations and Monte Carlo cla ssical simulations-are directly compared to provide excellent agreement.