Krems, Roman V.Dalgarno, Alexander2017-02-212003Krems, Roman V., and Alexander Dalgarno. 2003. “Threshold Laws for Collisional Reorientation of Electronic Angular Momentum.” Physical Review A 67 (5) (May 28). doi:10.1103/physreva.67.050704.1050-2947http://nrs.harvard.edu/urn-3:HUL.InstRepos:30403732It is shown that the velocity dependence of cross sections for projection-changing transitions in collisions of paramagnetic atoms or molecules with structureless targets near threshold has the form v2Δm when Δm is even and v2(Δm+1) when Δm is odd, where Δm is the change in the projection quantum number and v is the relative velocity.en-USJournal Article2017-02-2110.1103/PhysRevA.67.050704