The Tale of the Eta (Or More on C Invariance) Available to Purchase

The asymmetry that wouldn't go away could almost be the title of a detective novel. This time, however, it describes the latest chapter in the CP‐violation story. At the Washington APS meeting, Wonyong Lee and his Columbia collaborators (Mike Gormley, Emile Hyman, Tom Nash, John Peoples, Claude Schultz and Steve Stein) said that they had found a very small asymmetry in the decay of the η meson. If the asymmetry exists, it is evidence for violation of charge‐conjugation (C) invariance in the electromagnetic interaction or some other intermediate interaction. Although the effect is small, three‐standard‐deviations worth, Lee feels their data is very suggestive of C violation. But to really be sure, they will have to do a new experiment.