%0 Journal Article
%A Hirtl, A.
%A Anagnostopoulos, D. F.
%A Covita, D. S.
%A Fuhrmann, H.
%A Gorke, H.
%A Gotta, D.
%A Gruber, A.
%A Hennebach, M.
%A Indelicato, P.
%A Jensen, Th. S.
%A Bigot, E.-O. Le
%A Liu, Y.-W.
%A Markushin, V. E.
%A Marton, J.
%A Nekipelov, M.
%A Santos, J. M. F. dos
%A Simons, L. M.
%A Strauch, Th.
%A Trassinelli, M.
%A Veloso, J. F. C. A.
%A Zmeskal, J.
%T Redetermination of the strong-interaction width in pionic hydrogen
%J The European physical journal / A
%V 57
%N 2
%@ 1434-601X
%C Heidelberg
%I Springer
%M FZJ-2021-01193
%P 70
%D 2021
%X The hadronic width of the ground state of pionic hydrogen has been redetermined by X-ray spectroscopy to be  meV. The experiment was performed at the high-intensity low-energy pion beam of the Paul Scherrer Institute by using the cyclotron trap and a high-resolution Bragg spectrometer with spherically bent crystals. Coulomb de-excitation was studied in detail by comparing its influence on the line shape by measuring the three different transitions K, K, and K at various hydrogen densities. The pion-nucleon scattering lengths and other physical quantities extracted from pionic-atom data are in good agreement with the results obtained from pion-nucleon and nucleon-nucleon scattering experiments and confirm that a consistent picture is achieved for the low-energy pion-nucleon sector with respect to the expectations of chiral perturbation theory.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000623308200001
%R 10.1140/epja/s10050-021-00387-x
%U https://juser.fz-juelich.de/record/890777