Preferential population of magnetic sublevels of photodissociated atoms. I. Predissociation of Cs2

Preferential population of the magnetic sublevels of Cs(6p 2P3/2) atoms produced by predissociation of the C 1Πu state of the Cs2 molecule along the repulsive molecular state b 3Σ+u , has been found by observing the polarization of the atomic fluorescence Cs(6p 2Pm3/2→6s 2S1/2). By applying an external magnetic field, we have determined the population of the magnetic sublevels Cs(6p 2Pm3/2) directly from the intensities of the fluorescence lines Cs(6p 2Pm3/2 →6s 2Sm±11/2 ) split by the Zeeman effect. The results are analyzed theoretically by assuming the separability of electronic and nuclear motion for the dissociation along the repulsive potential curve. The effect of the external magnetic field on the photodissociation has been made clear, and the observed results could be fully explained on the basis of the adiabatic approximation.