New Measurements of the Neutral Kaon Parameters

This paper presents new determinations of the Ks lifetime, the mass diA'erence between the Kg and KL, the difference in the phases of tioo and q~-, and the phase of ri+ itself. The following paper [1] in this issue presents the result for c'/c from the same data set. CPT symmetry is a cornerstone of local quantum field theory and hence is worth probing, particularly given the nonlocal character of candidate (string) theories. In the neutral kaon system, CPT symmetry coupled with unitarity [2] leads to the curious fact that the Kc and Kz lifetimes and the Kg-KL mass difI'erence h, m are related to the phases of the CP-violating nn decay amplitudes @+and @00 via e+ —moo = tan ' [2t),m/(I g —r z )],