Blue satellite bands of KRb molecule: Intermediate long-range states

Three distinct satellite bands at 730–736 nm and a single shoulder at 755.5 nm that we assigned to KRb heteronuclear molecule are found in absorption measurements of hot K + Rb vapor. The interpretation of these bands is discussed in terms of recent ab initio calculations of the relevant potential curves. Semiclassical spectral simulations were performed with ab initio potentials and approximate transition dipole moment functions showing a good agreement with observations. The probabilities of cold molecule photoassociative formation into the external well of the double minimum (5)0+ state and decay to the ground state are discussed, and relative yields of molecular formation were estimated by using quantum mechanical calculations.