Trap loss in a two-species Na-Cs magneto-optical trap: Intramultiplet mixing in heteronuclear ultracold collisions

We describe a comprehensive investigation of trap loss in a two-species Na-Cs magneto-optical trap. Observed losses, due to the interspecies interactions, are attributed to collisions in which a change in the fine-structure state of the Na partner causes the escape of atoms from the trap. Results are described in terms of the heteronuclear pair potentials and the interaction of the colliding pairs with the radiatively active environment.