Upper bound to the ionization energy of 85 Rb 2

International audienceWe report an upper bound to the ionization energy of 85Rb2 of 31348.0(6) cm-1, which also provides a lower bound to the dissociation energy D0 of 85Rb+2 of 6307.5(6) cm-1. These bounds were measured by the onset of autoionization of the excited states of 85Rb2 below the 5s+7p atomic limit. We form 85Rb2 molecules via photoassociation of ultracold 85Rb atoms and subsequently excite the molecules by single-photon uv transitions to states above the ionization threshold