Predissociation dynamics of the A2Σ+ state of SH radical: Fine-structure state distributions of the S(3PJ) products

Abstract

Photo-predissociation of rovibrational levels of SH (A2Σ+, v′ = 0–6) is studied using the high-n Rydberg atom time-of-flight technique. Spin–orbit branching fractions of the S(3PJ=2,1,0) products are measured in the product translational energy distributions. The SH A2Σ+v′ = 0 state predissociates predominantly via coupling to the 4Σ− repulsive state. As the vibrational level v′ increases, predissociation dynamics change drastically, with all three repulsive states (4Σ−, 2Σ−, and 4Π) involved in the dissociation. Nonadiabatic interactions and quantum interferences among these dissociation pathways affect the fine-structure state distributions of the S(3PJ=2,1,0) products.