Number 167 (Story #2), March 3, 1994 by Phillip F. Schewe and Ben Stein SEARCHING FOR ANTIPROTON DECAY is harder than searching for proton decay. Proton stability can be studied by using vast underground tanks of fluids; such experiments have pushed the proton's measured lifetime to at least 10**32 years. Antiprotons, in contrast, must be created artificially at accelerators and can be stored in comparatively small numbers. The most stringent previous antiproton lifetime limit was 3.4 months. Now scientists at Fermilab has established new higher limits for a variety of possible decay modes, such as 1848 years for antiproton decay into a positron plus a photon and 554 years for decay into a positron and a pion. Theorists expect that the lifetime of the proton and antiproton would be identical, but this has to be confirmed experimentally. (S. Geer et al., UPCOMING ARTICLE in Physical Review Letters, 14 Mar. 1994.)