Hadronic shift in pionic hydrogen
arXiv:1406.6525 · doi:10.1140/epja/i2014-14190-x
Abstract
The hadronic shift in pionic hydrogen has been redetermined to be $ε_{1s}=7.086\,\pm\,0.007(stat)\,\pm\,0.006(sys)$\,eV by X-ray spectroscopy of ground state transitions applying various energy calibration schemes. The experiment was performed at the high-intensity low-energy pion beam of the Paul Scherrer Institut by using the cyclotron trap and an ultimate-resolution Bragg spectrometer with bent crystals.
10 pages, 6 figures