Production of Slow Protonium in Vacuum

Authors :: Zurlo, N.
Amoretti, M.
Amsler, C.
Bonomi, G.
Carraro, C.
Cesar, C. L.
Charlton, M.
Doser, M.
Fontana, A.
Funakoshi, R.
Genova, P.
Hayano, R. S.
Jorgensen, L. V.
Kellerbauer, A.
Lagomarsino, V.
Landua, R.
Rizzini, E. Lodi
Macri', M.
Madsen, N.
Manuzio, G.
Mitchard, D.
Montagna, P.
Posada, L. G.
Pruys, H.
Regenfus, C.
Rotondi, A.
Testera, G.
Van der Werf, D. P.
Variola, A.
Venturelli, L.
Yamazaki, Y.
Source :: Hyperfine Interact.172:97-105,2006
Publication Year :: 2008
Abstract: We describe how protonium, the quasi-stable antiproton-proton bound system, has been synthesized following the interaction of antiprotons with the molecular ion H$_2^+$ in a nested Penning trap environment. From a careful analysis of the spatial distributions of antiproton annihilation events in the ATHENA experiment, evidence is presented for protonium production with sub-eV kinetic energies in states around $n$ = 70, with low angular momenta. This work provides a new 2-body system for study using laser spectroscopic techniques.<br />Comment: 9 pages with 5 figures and 1 table. Proceedings of the 4th International Conference on Trapped Charged Particles and Fundamental Physics (TCP 06), published in Hyperfine Interactions