Eur. Phys. J. D 62, 379-388 (2011)
https://doi.org/10.1140/epjd/e2011-10693-3

Regular Article

Positronium formation in Debye plasma

¹ Department of Mathematics, Visva-Bharati University, Santiniketan 731235, W Bengal, India
² Department of Physics, Ramakrishna Mission Vivekananda University, Belur Math, Howrah 711202, W Bengal, India

^a e-mail: puspajit.mandal@visva-bharati.ac.in

Received: 6 December 2010
Received in final form: 30 January 2011
Published online: 25 March 2011

Abstract

Positronium (Ps) formation during positron-hydrogen collisions in Debye plasma has been studied in detail by using the second-order distorted-wave approximation with the inclusion of the adiabatic dipole polarization potential. Reliable results have been reported at several incident positron energies in the range from the Ps formation threshold to 500 eV for different values of the Debye screening parameter μ. Resonances for S-, P- and D-wave partial Ps formation cross sections appear to exist for 0.03 ≤ μ ≤ 0.3. Interesting structures in the differential cross sections are displayed in the surface plots. It is reported here for the first time that there is a huge probability of Ps formation in dense plasma corresponding to Debye screening parameter μ ≥ 0.3.