Relationship Between Differential Interference Angle and Parameter of Experiment in Molecular Beam

Collisional quantum interference (CQI)was observed in the intramolecularrotational energy transfer in the experiment of the static cell,and the integral interference angles were measured. To observemore precise information, the experiment in the molecular beamshould be taken, from which the relationship between the differentialinterference angle and the scattering angle can be obtained. In this paper, the theoretical model of CQI is described in an atom-diatom system in the condition of the molecular beam, based on the first-Born approximation of time-dependent perturbationtheory, taking into accounts the long-range interaction potential.The method of observing and measuring correctly the differentialinterference angle is presented. The changing tendency of thedifferential interference angle with the impact parameter andrelative velocity is discussed. The changing tendencies of thedifferential interference angle with the parameter of experimentin the molecular beam, including the impact parameter and thevelocity are discussed. This theoretical model is important to understand or perform the experiment in the molecular beam.