Isotropic quantum beats

Previous theoretical work reviewed in [E.B. Alexandrov et al. Interference of atomic states (Springer, 1993)] has questioned the existence of isotropic quantum beats in atoms. The present work addresses this issue in dedicated experiments involving a pulsed pump-probe detection scheme. The thus obtained results show clear evidence of isotropic quantum beats for which a physical interpretation is given within the coupled-uncoupled state formalism. We suggest that assumptions made in the earlier theoretical work with respect to the structure of the light field make the predictions applicable to scattering only of single photons by atoms and not to scattering of the classical-like light pulses used in ordinary experiments

Photofragment space distribution in the photodissociation of NaI in the spectral range 315–370 nm: the role of molecular axis rotation

The first determination of translational anisotropy parameters β in the photodissociation of NaI molecules in the spectral range 315–370 nm is reported. The anisotropy parameters were determined by the analysis of Doppler resolved absorption profiles of Na(2S1/2) atoms produced in the photodissociation of NaI by linearly polarized light. The profiles were recorded for two orientations of the photolysis light: parallel and perpendicular to the direction of the probe beam. The value of the parameter β was obtained from a simultaneous fit of the profiles. The role of the rotation of the parent molecules on the branching ratio between parallel and perpendicular transitions in NaI during dissociation is discussed