@article{53b0e4b2ed6643cbb1f3a24ddc88f513,
title = "Pionic and muonic X-ray transitions in liquid helium",
abstract = "Energies and intensities of pionic and muonic X-rays in liquid 4He have been measured with a Si (Li) detector. The energy shift due to strong interaction effects of the pionic 1s level in 4He was determined to be -75.7±2.0 eV. The natural line width of this level is 45±3 eV. These values are compared with different theoretical predictions. Cascade calculations, including external Auger effect and sliding transitions, have been performed to reproduce the yields of the muonic and pionic transitions. The pionic 2p level width is deduced: Γ2p = (1.1 ± 0.5) × 1012 sec-1 = (7.2±3.3) × 10-4 eV.",
author = "G. Backenstoss and J. Egger and {von Egidy}, T. and R. Hagelberg and Herrlander, {C. J.} and H. Koch and Povel, {H. P.} and A. Schwitter and L. Tauscher",
note = "Funding Information: We wish to thankI . BergstromH, . Daniel, M. Ericson,T . E. 0. Ericson,J . Htifner, M. Krell, N. J. Mang and E. Zavattini for many heIpfu1d iscussionsW. e are very much indebtedt o L. Mazzone and his hydrogent arget group at CERN for the perfect construction of the target and for assistanced uring the operation. The technicals upporto f A. Engstriim,N . Hasslera ndK. Rolli is gratefullya cknowledged. This work wass upportedb y the GermanB undesministeriumfu r Bildungu nd Wissen-schaft.",
year = "1974",
month = nov,
day = "4",
doi = "10.1016/0375-9474(74)90637-X",
language = "English",
volume = "232",
pages = "519--532",
journal = "Nuclear Physics, Section A",
issn = "0375-9474",
publisher = "Elsevier B.V.",
number = "2",
}