Doppler polarization spectroscopy of the photofragments from an in-plane rotation of water: Demonstration of unperturbed vector correlations

The μ-v, v-J, and μ-v-J vector correlations of the OH fragments ejected from the photodissociation at 193 nm of the 3₀₃ in-plane rotational state of the fundamental symmetric stretch of water, H₂O (1,0,0), are probed by Doppler polarization spectroscopy. The observed correlations are close to the limiting values expected for an idealized orientation (with minimal influence of the parent rotation) where the transition dipole moment of the parent is parallel to the fragment angular momentum and perpendicular to its velocity. This is the first time that these correlations are measured for the photodissociation of an initially prepared, vibrationally excited molecule in a specific rotational state.