The electronic system $(2{)}^2{\Sigma }^{+}$ and $(1{)}^2\Pi$ of LiCa

Abstract

High resolution Fourier transform spectroscopy and Laser induced fluorescence has been performed on LiCa in the infrared spectral range. We analyze rovibrational transitions of the $(2{)}^2{\Sigma }^{+}$--$X(1{)}^2{\Sigma }^{+}$ system of LiCa and find the $(2{)}^2{\Sigma }^{+}$ state to be perturbed by spin-orbit coupling to the $(1{)}^2\Pi$ state. We study the coupled system obtaining molecular parameters for the $(2{)}^2{\Sigma }^{+}$ and the $(1{)}^2\Pi$ state together with effective spin-orbit and spin-rotation coupling constants. The coupled system has also been evaluated by applying a potential function instead of rovibrational molecular parameters for the state $(2{)}^2{\Sigma }^{+}$. An improved analytic potential function of the $X(1{)}^2{\Sigma }^{+}$ state is derived, due to the extension of the observed rotational ladder.

15 pages, 4 figures 2 supplement files