Eur. Phys. J. D (2017) 71: 66
https://doi.org/10.1140/epjd/e2017-70714-9

Regular Article

Fragmentation of methane molecules by proton and antiproton impact^*

Department of Physics and Astronomy, York University, Toronto, Ontario, M3J 1P3, Canada

^a e-mail: tomk@yorku.ca

Received: 15 November 2016
Received in final form: 19 January 2017
Published online: 21 March 2017

Abstract

Proton and antiproton collisions with methane molecules have been investigated in the impact energy range of 20–5000 keV. To address the multi-centre nature of the system, a spectral representation of the molecular Hamiltonian is used in conjunction with the independent electron model. The initially populated molecular orbitals are expanded in terms of a single-centred basis and the two-centre basis generator method is employed to solve the time-dependent single-electron Schrödinger equations. The single-electron solutions are complemented with a dynamical decay-route fragmentation model based on fixed branching ratios from [H. Luna, E.G. Cavalcanti, J. Nickles, G.M. Sigaud, E.C. Montenegro, J. Phys. B 36, 4717 (2003)] to obtain the cross sections for the production of CH₄⁺, CH₃⁺, CH₂⁺, CH⁺ and C⁺ fragments. In the case of proton impact the calculations underestimate the measurements for CH₄⁺ and CH₃⁺, while good agreement is observed for the other fragments. A better consistency is found for antiprotons, particularly, for the production of CH₄⁺, CH₂⁺ and CH⁺.