Quantum Interference In Collision-Induced Energy Transfer Within Co (A (1)Pi Similar To E(3)Sigma(-) ) Mixed States - Temporal Behavior Of Transition Amplitude And Phase Angle

A further study on the temporal behavior of collision-induced transition amplitude and phase angle within CO (A similar to e) mixed states is carried out based on the first order Born approximation of time dependent perturbation theory for He or HCl as the collision partners. The calculation shows that the transition amplitudes appear some damped oscillation with the period reciprocally proportional to the energy gap between the initial and final states while the damping time is determined by the inter-molecular potential of the collision system. For a given impact parameter and collisional velocity, the transition of CO from an initial rotational state J to the final state J' may proceed through many channels with different quantum numbers M of CO and different J and M quantum numbers of the collision partner. So the experimental transition amplitudes with its real and imaginary parts are the average of all the possible channels. It is interesting to note that in the case of He as the collision partner, all the transition amplitude vectors for both singlet and triplet channels are located in the 1st quadrant of the complex plane, whereas for HCl as the collision partner the transition vectors of singlet and triplet channels are located respectively in the 4th and 1st quadrants. These results well explain the experimental fact that the interference phase angle is smaller than 90degrees for He as the collision partner, whereas it is larger than 90degrees for HCl as the collision partner.