EXA2011

From the discovery of metastable states in the antiprotonic helium [1, 2] a spectacular progress has been achieved in precision spectroscopy of He^+pbar atoms [3, 4]. This talk will be devoted to advances in theory, which is an indispensable constituent for studying properties of antiproton and (!) electron via the spectroscopy of antiprotonic helium. Particularly, the following topics will be...

We review the latest results of precision spectroscopy of antiprotonic helium, and the determination of the antiproton-to-electron mass ratio carried out by the ASACUSA collaboration of CERN.

We shall review the current status of the theory of collisional processes of antiprotonic helium. The following questions will be discussed: 1. Formation and cascade transitions of exotic atoms. Primary populations of metastable states of antiprotonic helium. 2. Collisional quenching of metastable antiprotonic helium. 3. Shift and broadening of E1 spectral lines in antiprotonic...

Antiprotonic helium is a neutral exotic atom, consisting of a helium nucleus, an electron and an antiproton. The interactions of the angular momenta and spins of these constituents cause a splitting within the principle states. The spin magnetic moment of the antiproton can be determined by comparing the measured hyperfine transition frequencies with three-body quantum electrodynamics (QED)...