Cold collisions between argon atoms and hydrogen molecules

Collisions between argon atoms and hydrogen molecules are investigated at very low temperatures. Quantum-mechanical calculations are performed using two different potential-energy surfaces. Rate coefficients for all possible combinations of initial vibrational and rotational level have been computed in the limit of zero temperature. Resonant and quasiresonant behavior is found using both potential-energy surfaces. The results are interpreted and estimates are made of the reliability of the calculations.