Observation of photoassociation of ultracold sodium and cesium at the asymptote Na (3S1/2) + Cs (6P1/2)

Hyperfine structure of the NaCs b3Π2 state near the dissociation limit 3S1/2 + 6P3/2 observed with ultracold atomic photoassociation

We report new observations of the hyperfine structure in three ro-vibrational levels of the b³Π₂ state of NaCs near the dissociation limit 3S_1/2 + 6P_3/2. The experiment was done via photoassociation of ultracold atoms in a dual-species dark-spot magneto-optical trap, and the spectra were measured as atomic trap losses. The simulation of the hyperfine structure showed that the greater part of the observed structure belongs to almost isolated levels of the b³Π₂ state, but there are other parts of mixed character where the contribution from the ¹Σ symmetry dominates.