Product-state distribution after isotopic substitution in ultracold atom-molecule collisions

We theoretically investigate the isotopic substitution reactions in gaseous samples at ultracold temperature (T ≪ 1 K) during atom-molecule collisions where one of the constituent atoms of the molecule is replaced by its isotope. We focus on molecular species that can be created experimentally in this range. We show that the molecular products are translationally cold, which could allow their trapping and thus their detection in order to shed new light on ultracold molecular collisions. We also demonstrate that in a few cases, the molecular products may occupy only the lowest rotational states. We discuss the possibility of controlling the kinetic energy release of such chemical reactions by an external electric field.