High-resolution spectroscopy of Rydberg molecular states of Rb285 near the 5s+7p asymptote

Rydberg molecules, often exemplified by long-range "trilobite" molecules, are a subject of much recent interest at high principal quantum number n. States that use the same bonding mechanism can exist at much lower n and less-extreme internuclear separations that are still quite long range. We use a high-resolution pulsed amplifier to study previously detected transitions to a low-n Rydberg molecular state near the 5s + 7 p asymptote in Rb-85(2). The observed line structure is modeled using precise ground-state positions and a lower bound of tau > 1.1 x 10(-9) s is set on the excited-state autoionization lifetime.