Atoms made of a particle and an antiparticle are unstable, usually surviving less than a microsecond. Antihydrogen, made entirely of antiparticles, is believed to be stable, and it is this longevity that holds the promise of precision studies of matter-antimatter symmetry. We have recently demonstrated trapping of antihydrogen atoms by releasing them after a confinement time of 172 ms. A critical question for future studies is: how long can anti-atoms be trapped? Here, we report the observation of anti-atom confinement for 1,000 s, extending our earlier results by nearly four orders of magnitude. Our calculations indicate that most of the trapped anti-atoms reach the ground state. Further, we report the first measurement of the energy distribution of trapped antihydrogen, which, coupled with detailed comparisons with simulations, provides a key tool for the systematic investigation of trapping dynamics. These advances open up a range of experimental possibilities, including precision studies of charge-parity-time reversal symmetry and cooling to temperatures where gravitational effects could become apparent.
Andresen, G. B.Ashkezari, M. D.Baquero-Ruiz, M.Bertsche, W.Bowe, P. D.Butler, E.Cesar, C. L.Charlton, M.Deller, A.Eriksson, S.Fajans, J.Friesen, T.Fujiwara, M. C.Gill, D. R.Gutierrez, A.Hangst, J. S.Hardy, W. N.Hayano, R. S.Hayden, M. E.Humphries, A. J.Hydomako, R.Jonsell, SvanteKemp, S. L.Kurchaninov, L.Madsen, N.Menary, S.Nolan, P.Olchanski, K.Olin, A.Pusa, P.Rasmussen, C. O.Robicheaux, F.Sarid, E.Silveira, D. M.So, C.Storey, J. W.Thompson, R. I.van der Werf, D. P.Wurtele, J. S.Yamazaki, Y.