• DOI:10.1140/EPJA/S10050-021-00387-X
• Corpus ID: 234031492

Redetermination of the strong-interaction width in pionic hydrogen

@article{Hirtl2021RedeterminationOT,
  title={Redetermination of the strong-interaction width in pionic hydrogen},
  author={Albert Hirtl and Dimitrios F. Anagnostopoulos and Daniel S. Covita and Hermann Fuhrmann and Hubert Gorke and Detlev Gotta and A. Gruber and Maik Hennebach and Paul Indelicato and Thomas S. Jensen and E.-O. Le Bigot and Yi-Wei Liu and V. E. Markushin and Johann Marton and Michael Nekipelov and Jmf dos Santos and Leopold M. Simons and T. Strauch and Martino Trassinelli and Jo{\~a}o Veloso and Johann Zmeskal},
  journal={The European Physical Journal A},
  year={2021}
}

• A. Hirtl, D. Anagnostopoulos, +18 authors J. Zmeskal
• Published 1 February 2021
• Physics
• The European Physical Journal A

The hadronic width of the ground state of pionic hydrogen has been redetermined by X-ray spectroscopy to be $$\varGamma ^{\pi \mathrm {H}}_{1s}=(856\,\pm \,16_\mathrm{stat}\,\pm \,22_\mathrm{sys})$$

Γ

1
s

π
H

=

(
856

±

16
stat

±

22
sys

)

 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$$\alpha $$
α
, K$$\beta $$
β
, and K$$\gamma $$
γ
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.