Averaged collision and reaction rates in a two-species gas of ultracold fermions

TL;DR

This paper investigates how quantum statistics influence ensemble-averaged collision rates in ultracold two-species fermionic gases, highlighting deviations from classical predictions especially in imbalanced systems.

Contribution

It provides a detailed analysis of how Fermi-averaged collision rates differ from Boltzmann averages in ultracold fermionic mixtures with varying masses and densities.

Findings

Fermi-averaged rates deviate from Boltzmann averages.

Deviations are significant in systems with mass or density imbalance.

Pauli blocking of final states is not considered in the analysis.

Abstract

Reactive or elastic two-body collisions in an ultracold gas are affected by quantum statistics. In this paper, we study ensemble-averaged collision rates for a two-species fermionic gas. The two species may have different masses, densities and temperatures. We investigate how averaged collision rates are affected by the presence of Fermi spheres in the initial states; Pauli blocking of final states is not considered. It is shown that, independently on the details of the collision, Fermi-averaged collision rates deviate from Boltzmann-averaged ones, particularly for a gas with strong imbalance of masses or densities.