Limits on variances from symmetry in neutral kaon decays

Abstract

An analysis is made o f the limits on the possible departures from CP -, T -, and TCP -invariance, both in the structure of K L and K S states and in the decay amplitudes to xx and xIv channels. A small violation of the requirements of CP - and T -invariance on the structure of K L and K S states can be deduced under quite plausible assumptions, but there is no evidence of any other departure from the requirements of CP -, or T -, or TCP -in variance. However, the present limit for one measure 8 of TCP -noninvariance is several times larger than the estim ated value of the corresponding CP - and T -noninvariance parameter or = Re<K L |K S >. Taking a conservative view of the experimental data, symmetry-violating parts of decay amplitudes are lim ited to better than 1 % for the I = 0 channel and to within a small percentage for the I = 2 channel, in relative magnitude. The corresponding limits which can be deduced for leptonic decay amplitudes are som ewhat larger but there are indications that symmetry-violating amplitudes are unlikely to exceed a small percentage in relative magnitude.