Theoretical study of the quenching of NH (singlet Delta) molecules via collisions with Rb atoms: preliminary results

TL;DR

This paper presents a theoretical analysis of the quenching reaction between Rb atoms and NH molecules, showing that the reaction rate is large and near the quantum limit, with implications for ultracold molecule production.

Contribution

It provides the first ab initio quantum chemistry and scattering calculations including spin-orbit effects for this reaction, revealing a high reaction rate near the unitarity limit.

Findings

Reaction rate is large and approaches the quantum limit.

Near degeneracy of initial and final states enhances reaction probability.

Potential for experimental investigation of ultracold NH molecules.

Abstract

We examine the quenching reaction Rb (doublet S) + NH (singlet Delta) goes to Rb (doublet P one-half) + NH (ground triplet Sigma minus). This reaction may be utilized to produce ground state NH molecules for studies of ultracold physics or for other purposes, and is interesting in that it involves initial and final states that are nearly degenerate. This near degeneracy is expected to lead to a large reaction rate. We examine this system using ab initio quantum chemistry calculations and scattering calculations, which include spin-orbit effects, and find that the reaction rate is large and, in fact, approaches the quantum mechanical unitarity limit. We discuss the prospects for an experimental examination of this system.