Preferential population of magnetic sublevels of photodissociated atoms. Photodissociation of alkali-metal dimers and the effect of magnetic field

Abstract

By applying an external magnetic field, we have determined the population of the magnetic sublevels of photodissociated atoms from the intensities of atomic fluorescence lines split by the Zeeman effect. A preferential population of the magnetic sublevels of the atomic fragment Na(3 ²P_3/2), which arises from the direct photodissociation through the D¹Π(continuum) state of the NaK molecule, has been observed. The results are explained by assuming the separability of electronic and nuclear motion during the dissociation. The observed results could be rationalized by the sum of the photodissociation amplitudes caused by excitation of the P, Q and R branches. The population of the magnetic sublevels of Rb(5 ²P_3/2) atoms produced by predissociation of the C¹Π_u state of the Rb₂ molecule by the repulsive molecular state c³Σ⁺_u has been determined from the Zeeman spectra of the emission Rb(5 ²P_3/2→ 5 ²S^m′_1/2). The observed results are interpreted by including the spin-orbit coupling between an excited level of the C¹Π_u state and levels of the c³Σ⁺_u state and the effect of the external magnetic field.