Investigation of KRb and Rb2 formed on cold helium nanodroplets

KRb and Rb-2 dimers are formed on cold helium nanodroplets. Laser excitation and emission spectra from the transition (1)(3) Pi(g)-(3)Sigma(+)(u) of Rb-2 and the transition (2)(3)Pi-(3)Sigma(+) of KRb have been measured. A thorough analysis of the emission, which takes place after desorption of the dimers from the surface of the helium cluster, has been performed. It allows us to determine the redistribution of vibrational population on the droplet surface. A comparison of the experimental spectra with simulations, obtained with the potential energy curves and dipole moments calculated by Aymar and Dulieu, allows a test of the accuracy of the ab initio potentials.