Parameter-free nonadiabatic correlation-polarization potential for vibrational excitation in electron-molecule scattering: Application to e-N2 collisions

This paper introduces a correlation-polarization potential for vibrational excitation in electron-molecule scattering. This potential generalizes a recently proposed model for elastic scattering [Bouferguene et al., Phys. Rev. A 59, 2712 (1999)]. Our potential contains no adjustable parameters and reflects known qualitative dependencies of correlation and polarization effects on the internuclear separation of the target molecule and on the position coordinate of the scattering electron. We test our potential on vibrationally elastic and inelastic scattering from N₂ in an energy range that includes the ²Π_g shape resonance. This resonance gives rise to intricate oscillatory structures in integral and differential cross sections; these structures are very sensitive to the correlation effects this potential is designed to model. Our e-N₂ cross sections agree well with experimental and other theoretical cross sections except at energies above the resonance, where experimental differential cross sections show a pronounced dip at scattering angles below about 60°. This dip is not present in the theoretical cross sections.