Resonant Rydberg-atom — Rydbert-atom collisions

Abstract

The experimental investigation of the resonant collision process $\mathrm{Na}ns+\mathrm{Na}\mathrm{ns}\ensuremath{\rightarrow}\mathrm{Na}np+\mathrm{Na}(n\ensuremath{-}1)p$ which occurs when the levels are tuned with an electric field so that the $\mathrm{ns}$ level lies midway between the two $p$ levels is described in detail. The observations are shown to be in good agreement with a long-range resonant dipole-dipole interaction.