Eur. Phys. J. D (2014) 68: 323
https://doi.org/10.1140/epjd/e2014-50409-7

Regular Article

Partial-wave analysis of particular peaks in total scattering cross sections caused by a single partial wave

¹ KTH-Mechanics, Royal Institute of Technology, 10044 Stockholm, Sweden
² CCDC, 12 Union Road, CB2 1EZ, Cambridge, UK

^a e-mail: ket@mech.kth.se

Received: 26 May 2014
Received in final form: 26 July 2014
Published online: 28 October 2014

Abstract

Certain broad low-energy peaks in the total cross sections relevant for electron-atom scattering are studied and found to be caused by a single partial wave. Such peaks are associated here with complex orbital angular momentum (Regge) pole trajectories. At the peak energies these S-matrix poles are in some neighborhood of an integer value and at the same time near its maximum real part value as a function of energy. Such peaks are found to have no time delays. Results are presented for the Dirac equation using three rational function Thomas-Fermi potential models, all with the same behavior at large and small radial distances.