Determination of Strong-Interaction Widths and Shifts of Pionic X-Rays with a Crystal Spectrometer

Abstract

Pionic $3d\ensuremath{-}2p$ atomic transitions in F, Na, and Mg have been studied using a bent crystal spectrometer. The pionic atoms were formed in the production target placed in the external proton beam of the Space Radiation Effects Laboratory synchrocyclotron. The observed energies and widths of the transitions are $E=41679(3)$ eV and $\ensuremath{\Gamma}=21(8)$ eV, $E=62434(18)$ eV and $\ensuremath{\Gamma}=22(80)$ eV, $E=74389(9)$ eV and $\ensuremath{\Gamma}=67(35)$ eV, in F, Na, and Mg, respectively. The results are compared with calculations based on a pion-nucleus optical potential.