Simple Scaling Law for Rotational-Energy Transfer inNa2*-Xe Collisions

We have measured the thermally averaged rate constants for rotationally inelastic collisions of ${\mathrm{Na}}_2$* and Xe for six values of initial angular momentum $j_0$ and for changes in $j$ up to 30. We propose a new scaling law which fits all these rates within 20%. This scaling law implies that $m_j$ is conserved in the collision, and shows that the square of the $T$ matrix has a power-law dependence on the energy transferred. These results suggest the importance of dynamical effects in rotationally inelastic collisions.