The permanent electric dipole moments and magnetic hyperfine interaction in the [formula omitted] state of yttrium monosulfide

Abstract

The optical Stark effect in the (0,0) A 2 Π–X 2 Σ + band systems of a yttrium monosulfide, YS, supersonic molecular beam sample have been analyzed to produce the magnitude of the permanent electric dipole moments, | μ|, for the A 2 Π 3/2 , and A 2 Π 1/2 states of 5.9(2), and 6.8(1) D, respectively. Small splittings in the field free A 2 Π 3/2–X 2 Σ + and A 2 Π 1/2–X 2 Σ + spectra were analyzed to produce the magnetic hyperfine spectroscopic parameters a=−36(6), c=111(7), and d=−107(6) MHz for the A 2 Π state. Transition frequencies of the low rotational lines in the (0,0) A 2 Π r–X 2 Σ + band system were measured and analyzed to produce the first complete set of fine structure parameters for the A 2 Π r state. A comparison with YO and other isovalent molecules is made.