On the stereodynamics of cold and ultracold H + D₂ and D + HD chemical reactions

Stereodynamic control of rotational quenching of vibrationally excited HD molecules, by means of cold inelastic collisions with H₂, D₂ and He, has recently been demonstrated by combining intra-beam technologies with Stark-induced adiabatic Raman passage techniques for the preparation of molecular states [1-2]. Control of the angular distribution of the scattered molecules in these processes has also been addressed in recent theoretical studies [3-5]. In this work we examine the stereodynamics of H + D₂↔ D + HD chemical reactions in the cold and ultracold regimes with vibrational excitation of the molecules to the v=4 level. The trend in stereodynamic preference is analyzed in terms of polarization of the initial and final rotational angular momenta of the reactant and product molecules.

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