Why do chemically stable ultracold molecules disappear in collisions?
In plain words
Even molecules that cannot react vanish from traps when they collide. They seem to stick together for a while and are then lost, but the full story is not settled.
Precise statement
Bialkali molecules (RbCs, NaK, NaRb, NaCs) in their absolute ground state with no exothermic reaction channel show two-body loss at near-universal rates. Identify all loss channels of the four-atom complex (trap-light photoexcitation, collisions with a third molecule, other) and account for measured rates quantitatively for each species. Answer: a channel-by-channel budget matching data.
What would settle it
Species-by-species measurements of complex lifetimes and loss in light-free traps explained by a single model.
Status in the literature
Photoexcitation by trap light explains loss in several species, but some measured complex lifetimes differ from statistical estimates by large factors (review arXiv:2211.10223).
Related problems
- More general than First-principles lifetime of the four-atom collision complex