Diabatic models for weakly bound states and cold collisions of ground-state alkali-metal atoms

Abstract

We apply a simplified description to weakly bound states and cold-collision continuum states of pairs of ground-state alkali-metal atoms, which complements the usual more elaborate coupled-channel treatment. It is based on a diabatic treatment of the transition region between the exchange-dominated interatomic distance range at small $r$ and the hyperfine-dominated range at large $r$. The models contain the degenerate internal states approximation for H atoms as a special case.