Rotational excitation of H

We present rotational excitation cross sections for low energy scattering of positrons by H2, below positronium formation threshold (≈8.2 eV). The cross sections were computed from fixed-nuclei scattering amplitudes generated with the Schwinger multichannel method using the adiabatic rotational approximation. Comparison with other similar theoretical results shows that the magnitude of the cross section associated to the transition Ji = 0 → Jf = 2 is strongly affected by the methodology used to model the correlation-polarization effects