Physics using cold antiprotons

Recent progress of low-energy antiproton physics by atomic spectroscopy and collisions using slow antiprotons collaboration at CERN AD is presented. High-precision spectroscopy of antiprotonic helium—a neutral three-body system pe−He2+(=pHe+) produced when antiprotons (p) are stopped in various phases of helium—has tested 3-body QED theories as well as proton-vs-antiproton CPT to within ∼10−8. This was achieved by using a newly-developed radiofrequency quadrupole decelerator. Other ongoing and future experiments using low-energy antiprotons are discussed.