New Values for K° Decay Rate Still Disagree with the Old

For followers of CP violation (PHYSICS TODAY, April 1968, page 80 and November 1967, page 73) a recent Princeton experiment (reported by M. Banner, James W. Cronin, J. K. Liu and J. E. Pilcher in Phys. Rev. Letters 21, 1107, 1968) offers another value for $|η00|2,$ the ratio of the two‐neutralpion decay rate of $K20$ to the two‐neutral‐pion decay rate of $K10.$As the table (based on reports at the Vienna high‐energy physics conference in September) shows, not only do various experimenters disagree with each other, but also with their own earlier measurements. Errors have been found in the first and second Cronin experiments; so Cronin III is the only valid entry for the group.