Spin-flipping transitions in [Formula Presented] molecules induced by collisions with structureless atoms

Abstract

It is shown that spin-flipping transitions in low energy collisions of [Formula Presented] diatomic molecules in the lowest rotational [Formula Presented] level with structureless atoms proceed through coupling to the rotationally excited [Formula Presented] levels, and are determined by the spin-rotation interaction in the rotationally excited molecule. We carry out calculations for collisions of CaH and [Formula Presented] For the spin-flip rate coefficient corresponding to an interaction potential that does not generate a shape resonance, we obtain [Formula Presented] at a temperature of 0.4 K consistent with the measured value of [Formula Presented] We make predictions as to which molecules should have the least probability of spin-flipping in collisions with atoms. © 2003 The American Physical Society.