The application of the absorption-edge technique to broadened pionic X-ray lines

A modification of the standard absorption edge technique is shown to be useful for determining the energy of broadened X-ray lines such as are observed for the last transitions in pionic atoms where the broadening is due to the strong pion-nucleus interaction. The technique offers an alternative and independent means of energy calibration for K transitions in pionic helium, lithium, beryllium and boron, and hence can be used for determining the strong interaction shift for such pion-nucleus systems. (Auth.)