Pionic Hydrogen @ PSI       Physics for open minds    



  • To measure the strong interaction width and shift of the ground state of pionic hydrogen with high precision: better than 1% for the shift and about 2% for the width.


  • Use the PSI cyclotron trap to produce the pionic hydrogen atoms in controlled environment.
  • Use crystal spectrometers and CCD detectors to measure the X-ray lines.
  • Perform measurements at different hydrogen densities.
  • Perform simultaneous measurements of the pionic and muonic hydrogen X-ray lines.
  • Use the atomic cascade code to determine the Doppler broadening corrections to the widths of the X-ray lines.


  • The pion-nucleon scattering lengths will be determined with the accuracy of about 1%.
  • The pion-nucleon coupling constant will be calculated.
  • The isospin breaking effects will be evaluated.
Home | Objectives | People | Technology | Milestones | References | About 

Pionic Hydrogen @ PSI
Webmaster.    Last modified: January 13, 2001.