Differential cross section (angular distribution) for the reaction H+H₂(v=j=0)→H₂(v′, ODD j′)+H in the energy range 0.90-1.35 eV

Calculations are reported of the differential cross section for the reaction H+H₂(v=j=0)→H₂(v′, odd j′)+H for total energy E from 0.9 to 1.35 eV. Total angular momentum values up to J=24 are included in the partial wave summations, and in all respects these results should be the essentially exact (i.e. to a few percent) values for this (LSTH) potential energy surface. Complete differential cross sections are reported at several energies for final vibrational states v′=0 and 1, and for various final rotational states j′. Of particular interest is the energy dependence of the differential cross section for back-scattering. Specifically, it is seen that the energy dependence of the J=0 reaction probability is qualitatively similar to that of the differential cross section for back-scattering, so that resonance structure which is quite apparent in the former shows up to some extent in the latter. Even this structure, though, is not as pronounced as that reported in recent experimental results for the integral cross section. The lack of agreement between theory and experiment with regard to resonance structure in the energy dependence of these cross sections thus remains unaccounted for.