REFERENCES AND NOTES 1. S. Ospelkaus et al., Science 327, 853–857 (2010).

has a small, yet nonzero, quantum defect. The corresponding lifetime of Cs(36F) is t36F ≈ 18 ms (25). The fact that the decay of the molecular state is different from the purely radiative decay of the Cs(nS) Rydberg state, and closer to the nearby (n – 4)F state, is another indication of the degenerate mixing involved in the formation of the hybrid trilobite molecules. The class of ultralong-range molecule observed here is an advantageous cross between a tradi-tional “trilobite ” molecule and a low-l ultralong-range Rydberg molecule (7–12). The discovery of the trilobite ultralong-range Rydberg mole-cule could open opportunities in ultracold chem-istry and strongly correlated many-body physics