Near-threshold collisional dynamics in the e⁻e⁺p system

Authors

H. B. Ambalampitiya, Quantemol Ltd., University of Nebraska–LincolnFollow
J. Stallbaumer, University of Nebraska–Lincoln
Ilya I. Fabrikant, University of Nebraska-LincolnFollow
I. Kalinkin, Curtin University
D. V. Fursa, Curtin University
A. S. Kadyrov, Curtin University, Institute of Nuclear Physics
I. Bray, Curtin University

Date of this Version

9-8-2023

Citation

PHYSICAL REVIEW A 108, 032808 (2023). 10.1103/PhysRevA.108.032808

Comments

Used by permission.

Abstract

We study e⁺-H(n) and Ps(n)-p collisions near the three-body breakup threshold and thresholds for the charge-transfer processes.We show that classical trajectoryMonte Carlo (CTMC) simulations for the three-body breakup agree reasonably well in this energy region with quantum-mechanical convergent close-coupling (CCC) calculations even if the initial hydrogen atom or positronium atom is in the ground state. The threshold behavior of the three-body breakup cross section in e⁺-H(1s) and Ps(1s)-p collisions agrees with the Wannier law with Klar’s exponent and obeys the classical scaling laws, although some deviation from the Klar-Wannier behavior is observed in the CCC results. Below the threshold the agreement between CTMC and CCC disappears. In particular the CTMC method fails completely for the processes of H formation in Ps(1s)-p collisions and Ps formation in e⁺-H collisions well below the three-body breakup threshold. For higher initial states the CTMC results below the threshold improve substantially, in accordance with the correspondence principle. This is explained by comparing the quantum-mechanical threshold laws with the classical laws.