Stereodynamic control of overlapping resonances in cold molecular collisions

Abstract

Stereodynamic control of resonant molecular collisions has emerged as a new frontier in cold molecule research. Recent experimental studies have focused on weakly interacting molecular systems such as HD collisions with H2, D2, and He. We report here the possibility of such control in strongly interacting systems taking rotational relaxation in cold collisions of HCl and H2. Using explicit quantum scattering calculations in full six dimensions it is shown that robust control of the collision dynamics is possible even when multiple (overlapping) shape resonances coexist in a narrow energy range, indicating that cold stereochemistry offers great promise for many molecules beyond simple systems. We demonstrate a striking case where two prominent peaks in overlapping resonances are switched off simultaneously by suitable alignment of the HCl molecule.