Predissociation dynamics of the A(2)Sigma(+) state of SH and SD

The technique of cavity ring-down spectroscopy has been used to investigate predissociation in the A (2) Sigma(+) state of the SH and SD radicals. Spectra were recorded of the A-X (1,0) band of SH and the (1,0), (2,0) bands of SD. Linewidth measurements of transitions to individual rovibrational levels of the A state revealed increasing predissociation rates with vibrational and rotational quantum number. These and all other available data have been reproduced, quantitatively, by Fermi Golden Rule calculations employing the best (experimentally determined) analytic potential for the A state and ab initio repulsive potentials and spin-orbit coupling matrix elements. (C) 1997 American Institute of Physics.