Deeply bound 1s and 2p states in pionic atoms

Abstract

New results were obtained on pionic 1s levels in 24Mg, 27Al and 28Si, on 2p states in 93Nb and natRu, as well as on 3d states in 93Nb, natRu, natAg and natCd. For the first time the predicted repulsive shifts for the pionic 2p level have been observed. The following values were obtained for the strong-interaction shifts and widths (all values in keV); 24Mg: ε 1s 0 = −80.5 ± 0.6 and Γ 1s 0 = 24.3 ± 1.6; 27Al: ε 1s 0 = −115.5 ± 1.4 and Γ 1s 0 = 28.8 ± 1.2, 28Si: ε 1s 0 = −131.6 ± 2.0 and Γ 1s 0 = 41 ± 4; 93Nb: ε 2p 0 = −11 ± 3, Γ 2p 0 = 64 ± 8, ε 3d 0 = 0.74 ± 0.02 and Γ 3d 0 = 0.402 ± 0.016; natRu: ε 2p 0 = −48 ± 7, Γ 2p 0 = 77 ± 24, ε 3d 0 = 1.39 ± 0.08 and Γ 3d 0 = 0.75 ± 0.08; natAg: ε 3d 0 = 1.94 ± 0.07 and Γ 3d 0 = 1.44 ± 0.05 and natCd: ε 3d 0 = 2.14 ± 0.09 and Γ 3d 0 = 1.65 ± 0.07. The results are in reasonable agreement with the predictions of the standard optical potentials.