Abstract
It is shown that the derivative of the scattering phase shift with respect to energy, , must exceed a certain limit if the interaction of scattered particle and scatterer vanishes beyond a certain distance. This limitation of is, fundamentally, a consequence of the principle of causality; it is derived, however, from a property of the derivative matrix .
- Received 10 December 1954
DOI:https://doi.org/10.1103/PhysRev.98.145
©1955 American Physical Society