Revision 1

Accepted · first revision · record

Title: Why do chemically stable ultracold molecules disappear in collisions?
Plain: 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: 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.
Settled by: Species-by-species measurements of complex lifetimes and loss in light-free traps explained by a single model.
Kind: phenomenon
Answer type: mechanism
References: (empty)
Literature status: partially-resolved
Status note: 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).
Posed since: (empty)