Low-energy electron scattering from molecular hydrogen: Excitation of the X 1Σg + to b 3Σu+ transition

We present time-of-flight differential cross-section measurements and convergent close-coupling calculations of differential cross sections for the electron-impact excitation of the X- 1 Sigma(+)(g) -> b (3)Sigma(+)(u) transition in molecular hydrogen. A part of this work was recently published [M. Zawadzki et al., Phys. Rev. A 97, 050702(R) (2018)]. In this work, agreement between theory and experiment is excellent overall, and marks a transition in electron-molecule scattering where differential scattering of excitation is found to be in such precise agreement. We also present total electron-impact excitation differential cross sections for H-2 for which agreement between theory and experiment is found to be excellent.