Low-Energy Electron and Positron Scattering by para-Difluorobenzene

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Scattering Theory

Background:

• Understanding electron and positron interactions with molecules is crucial for various fields, including radiation chemistry and materials science.
• Para-difluorobenzene (1,4-C6H4F2) is a molecule with potential applications, necessitating detailed studies of its collision dynamics.
• Previous experimental data provides a benchmark for theoretical calculations.

Purpose of the Study:

• To calculate elastic integral and differential cross sections for low-energy electron and positron collisions with para-difluorobenzene.
• To investigate the presence and nature of resonances in electron-para-difluorobenzene scattering.
• To determine the scattering characteristics, such as Ramsauer-Townsend minima and virtual states, for both electron and positron collisions.

Main Methods:

• Employed the Schwinger multichannel method for theoretical calculations.
• Performed electron scattering calculations using static-exchange and static-exchange plus polarization approximations.
• Conducted positron scattering calculations using the static plus polarization approximation at multiple polarization levels.

Main Results:

• Identified three low-energy π*-resonances and one higher-energy σ*-resonance in electron scattering.
• Observed a Ramsauer-Townsend minimum in the calculated integral cross section for electron scattering.
• Indicated the presence of a virtual state in the integral cross section for positron scattering.
• Achieved reasonable agreement between calculated and experimental total cross sections for both electrons and positrons.

Conclusions:

• The Schwinger multichannel method provides accurate predictions for electron and positron scattering with para-difluorobenzene.
• The study elucidates the complex scattering dynamics, including resonance phenomena and the Ramsauer-Townsend effect.
• The findings contribute to a deeper understanding of molecular interactions relevant to physics and chemistry.