Laser Studies of the Decay Chain of Metastable Antiprotonic Helium Atoms

In this paper we reported the first direct determination of the initial populations and level lifetimes of excited exotic atoms. We have since come to realize that an error was introduced in the normalization of the y axis of Fig. About 10% of the metastable P's are found in the u = n -I -1 = 3 sequence, instead of 30%.