Work

Coupled-channel method for the scattering hypervolume in ultracold atomic three-body collisions

Year: 2026

Type: article

Abstract: We introduce a coupled-channel method for elastic three-body scattering in systems of identical bosonic alkali-metal atoms. The approach relies on the numerically exact two-body off-the-energy-shell transition matrix, constructed from realistic multichannel molecular interaction potentials that support many bound states. By rigorously accounting for this off-shell structure, the method captures both the short-range physics as well as multichannel couplings characteristic of alkali-metal potentials without resorting to model pseudopotentials. The central output is the complex three-body scattering hypervolume—the three-body analog of the two-body scattering length—which we obtain with controlled and verifiable numerical accuracy. As a realistic benchmark, we apply our framework to spin-polarized potassium-39, performing full coupled-channel three-body scattering calculations and extracting the hypervolume over experimentally relevant conditions. The method is general and transferable to other atomic species and interaction models featuring deep molecular potentials with an arbitrarily large number of bound states.

Source: Physical Review A

DOI: 10.1103/xzwl-qlbj

Authors: P. J. P. Kersbergen, J. van de Kraats, D. J. M. Ahmed-Braun, S. J. J. M. F. Kokkelmans

Institutions: Eindhoven University of Technology, University of Antwerp

Language: English

Topic: Cold Atom Physics and Bose-Einstein Condensates

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,675