Energy dependence of the Rb 52S1/2–52P1/2 noble-gas collision shift

Abstract

Abstract For more than a century the study of optical-resonance collision shifts in thermal atomic vapors has provided a window into atom/atom and atom/molecule interactions at low energies (i.e. ∼30 meV). Overall, the agreement between theory and experiment has been good, suggesting that an understanding of these interactions at low energies is well in hand. Here, we present evidence that this is not the case. Using an isoclinic-point method we measure the energy dependence of the Rb D1 collision shift in the noble gases (NGs): He, Ne, Ar, Kr and Xe. While agreement between theory and experiment is quite good for the heavy NGs, it is quite poor for the lighter ones: He and Ne. In the case of Rb/He, not only are the theoretical values in gross disagreement with one another, but they are also in significant disagreement with experiment.