The hadronic shift in pionic hydrogen has been redetermined to be $epsilon_{1s}=7.086,pm,0.007(stat),pm,0.006(sys)$,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.
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