State-to-state differential cross-sections for the reactive scattering of H*(n) with o-D2

Abstract

Full quantum-state resolved differential cross-sections of the H*(n) + o-D₂ → HD + D*(n′) reaction have been measured for the first time using the Rydberg H-atom time-of-flight method. Experimental results show that the angular distributions of HD product rotational states show a strong preference for forward scattering. This result is considerably different to that predicted by full quantum mechanical calculations on the corresponding ion–molecule reaction, suggesting that the ionic core and Rydberg electron coupling cannot be neglected in the Rydberg H-atom reactive scattering with D₂ and, therefore, that the Fermi independent-collider model is not valid in describing the dynamics of Rydberg atom reactions with molecules.