We are doing laser spectroscopy of the 2S-2P energy difference (Lamb shift) in muonic hydrogen, muonic deuterium and muonic helium-3 and -4 ions. The physics motivation includes

  • measurement of the charge radii of the lightest nuclei (proton, deuteron, helium-3 and -4 nuclei)
  • improved determination of the Rydberg constant
  • test of bound-state quantum electrodynamics (QED)
  • Zemach radius (magnetization) of the proton
  • nuclear polarizabilities and test of few-nucleon models

Our Proposal on muonic helium gives you all the details.