First measurement of a long-lived ${\pi }^{+}{\pi }^{-}$ atom lifetime

B. Adeva, L. Afanasyev, A. Anania +56

The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogen-like ${\pi }^{+}{\pi }^{-}$ atoms, produced by protons hitting a beryllium target. A part…