Quantum action variable description of bound and scattering states
We present generalized definitions of the classical and quantum radial action variables for both bound and scattering states of a particle moving in the Yukawa potential. The classical action variable is defined as an integral over a contour in the complex radial coordinate plane of the classical momentum function. The quantum action variable is similarly defined as an integral over the same contour of the quantum momentum function. The extension of these definitions of the action variable to other central potentials is discussed.