PIONIC 4F -] 3D TRANSITION IN TA-181, NATURAL RE, AND BI-209 AND THE STRONG INTERACTION LEVEL SHIFT AND WIDTH OF THE PIONIC 3D STATE

Owing to a powerful Compton-suppression technique it was possible to observe for the first time the pionic 4f → 3d X-ray transition in elements heavier than A = 150. The strong interaction monopole shifts ε0 and widths Γ0 as well as the quadrupole splitting of the 3d levels have been measured in Ta, Re and Bi. Thus in addition to the strongly shifted and broadened 5g → 4f transitions, a second, strongly affected line is available for these elements. For the pionic 4f levels, standard optical potentials fit the strong interaction shifts and broadenings quite well. The now observed, deeper-lying 3d states in Ta, Re and Bi have shifts and widths that differ by a factor of 2 or more from the standard optical potential predictions. From the observed relative X-ray intensities of the pionic cascade we also extract the strong interaction widths of the 5g and 4f levels. © 1979.