A laser spectroscopic study of the X 1Σ+−C 1Π1 transition of MgAr: Evidence for Λ-type doubling

Abstract
The X 1Σ+0 and the C 1Π1 states of MgAr have been characterized spectroscopically. The MgAr van der Waals molecules, created in a new laser-vaporization, pulsed supersonic jet apparatus, were studied using laser-induced fluorescence. High-resolution spectra revealed lambda-type doubling consistent with the presence of the nearby higher-lying repulsive MgAr (D 1Σ+0) electronic state.