We have measured differential cross sections (DCSs) for the HD products of the exchange reaction at five different collision energies in the range . The contribution from the less energetic H atoms formed upon spin-orbit excitation of Br in the photolysis of the HBr precursor is taken into account for two collision energies, and , allowing us to disentangle the two different channels. The measured DCSs agree well with new time-dependent quantum-mechanical calculations. As the product rotational excitation increases, the DCSs shift from backward to sideward scattering, as expected. We also find that the shapes of the DCSs show only a small overall dependence on the collision energy, with a notable exception occurring for HD , which appears bimodal at high collision energies. We suggest that this feature results from both direct recoil and indirect scattering from the conical intersection.
Differential cross section for the reaction as a function of collision energy
Konrad Koszinowski, Noah T. Goldberg, Jianyang Zhang, Richard N. Zare, Foudhil Bouakline, Stuart C. Althorpe; Differential cross section for the reaction as a function of collision energy. J. Chem. Phys. 28 September 2007; 127 (12): 124315. https://doi.org/10.1063/1.2771157
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