Hyperfine dependent atom-molecule loss analyzed by the analytic solution of few-body loss equations

TL;DR

This study investigates hyperfine-dependent atom-molecule inelastic collisions in ultracold mixtures, providing analytic solutions to loss equations and revealing loss rates below the universal limit.

Contribution

It introduces an analytic approach to model few-body loss dynamics in ultracold atom-molecule systems, highlighting hyperfine dependence and sub-universal loss rates.

Findings

Atom-molecule loss rates depend on hyperfine states.

Loss rates are significantly below the universal limit.

Analytic solutions effectively describe the loss dynamics.

Abstract

We prepare mixtures of ultracold $^{39}$K atoms in various hyperfine spin states and $^{23}$Na$^{39}$K molecules in an optical dipole trap at a fixed magnetic field and study inelastic two-body atom-molecule collisions. We observe atom-molecule losses that are hyperfine dependent with a two-body loss rate far below the universal limit. We analyze the two-body loss dynamics based on the derivation of general and easy applicable analytic solutions for the differential equations describing the loss of an arbitrary number $\gamma$ of particles in a single collisional event.