nuclear spin relaxation in cold atom-molecule collisions

We use rigorous quantum scattering calculations to explore the quantum dynamics of nuclear spin relaxation in cold collisions of ¹³CO (¹Σ⁺) molecules with ⁴He atoms in an external magnetic field. We find that collision-induced nuclear spin relaxation in the ground rotational manifold of ¹³CO occurs extremely slowly as long as the temperature remains small compared to the spacing between the ground and the first excited rotational levels.