Laser spectroscopy of the X 1Σ+ and B 1Π states of the LiRb molecule

We have studied the X 1Σ+ and B 1Π states of 7Li85Rb using Laser Induced Fluorescence (LIF) Spectroscopy and Fluorescence Excitation Spectroscopy (FES). We extract molecular constants for levels v″ = 0–2 of the X 1Σ+ state and levels v′ = 0–20 of the B 1Π state. For the B 1Π state, we have observed rotational perturbations in the e-parity component of the v′ = 2 level, and determined the dissociation energy. We discuss implications of our measurements in finding efficient photoassociation pathways for production of ultracold ground state LiRb molecules, and their detection via state selective ionization.