High resolution laser excitation spectroscopy of the B1-X¹Σ⁺ transition of PbS

Abstract

Several vibrational bands of the B1-X ¹Σ⁺ electronic transition of PbS were observed using laser excitation spectroscopy on a collimated molecular beam. For the B1 state highly accurate molecular constants were derived and a small Ω doubling was analysed. Isotopic field shift parameters are compared to those of the A0⁺-X ¹Σ⁺ transition. The hyperfine splitting observed for ²⁰⁷Pb³²S depends on the parity of the levels and is interpreted in terms of Ω hyperfine doubling.