Testing CPT with antiprotonic helium and antihydrogen – the ASACUSA experiment at CERN-AD Original Research Article

The precision spectroscopy of antiprotonic helium has steadily advanced in recent years, yielding a CPT test of the difference of antiproton and proton charge and mass of < 10 ppb. Experiments with a new laser system currently under way promise to improve the accuracy by a factor 5–10. An experiment being developed to measure the hyperfine splitting of antihydrogen is described.