Ultracold Rb-OH collisions and prospects for sympathetic cooling

Abstract

We have computed ab inito cross sections for cold collisions of Rb atoms with OH radicals. We predict collision rate constants of order 10^{-11} cm^3/s at temperatures in the range 10-100 mK at which molecules have already been produced experimentally. However, we also find that in these collisions the molecules have a strong propensity for changing their internal state, which could make sympathetic cooling of OH in a Rb buffer gas problematic in magnetostatic or electrostatic traps.

submitted to PRL