Scattering of electron and positron by methane

This work provides a comprehensive theoretical investigation of \({e^-}-CH_4\) and \({e^+}-CH_4\) scattering systems over a wide range of projectile energies, from 1 eV to 1 MeV. The single scattering independent atom model (IAM) and the screening correction (IAMS), arising from a semi-classical analysis of atomic geometrical overlap, are used within the same framework for the present analysis. A broad spectrum of scattering observable quantities is calculated, such as differential, integrated elastic, momentum transfer, viscosity, inelastic, grand total and total ionization cross sections along with the Sherman function. For this spin-dependent and relativistic scattering study, the Dirac equation is solved using a complex optical potential model (OPM) by partial wave phase-shift analysis to generate the scattering cross-sections data. A satisfactory level of concordance is observed when our computed results are compared to both experimental data and other theoretical calculations available in the literature. The screening corrected independent atom model (IAMS) has been found to produce results with greater accuracy than the IAM.

Comparison of scattering cross sections (a) DCS in units of \(a_0^2/sr\) at 90°scattering angle, (b) Sherman function S(θ) at 90°scattering angle, (c) TCS, (d) IECS, (e) TICS and (f) MTCS in units of \(a_0^2\).