15min:

A. J. ORR-EWING AND R. A. ROSE, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.; C.-H. YANG, K. VIDMA AND D. H. PARKER, Institute for Molecules and Materials, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, the Netherlands.

Velocity map imaging of the S(³P_J=0,1,2) fragments from the predissociation of selected ro-vibrational levels of the A^{2 +} state of SH has been used to determine photofragment recoil anisotropies, branching into spin-orbit levels, and the electronic angular momentum polarization of the S atoms. The photofragment recoil anisotropies will be compared with predictions from a model by Houston and coworkers that accounts for the effects of excited state lifetimes. These vibrational and rotational level dependent lifetimes were previously measured by cavity ring-down spectroscopy and modelled using Fermi Golden rule calculations. The spin-orbit level branching and populations of m_J states, derived from the angular momentum polarization measurements, depend on the correlation of the repulsive states responsible for the A^{2 +} state predissociation to the asymptotic H(²S_1/2) + S(³P_J) limits and non-adiabatic dynamics during the fragmentation.