Supplementary evidence for T violation.

Abstract

The only significant experimental evidence for T violation is based on the data on CP violation and other measured properties of the decay amplitudes of neutral K mesons and their combined use in an analysis based on the Bell-Steinberger unitarity relation or its equivalent. It has been pointed out by Kenny and Sachs that there is a technical possibility that this conclusion can be evaded because the argument depends on the assumption that the effective (phenomenological) weak-interaction Hamiltonian from which the decay amplitudes are derived is Hermitian. The purpose of this paper is to show that this assumption can be circumvented by making use of additional data on the unitarity of the decay amplitudes of both the neutral and charged K mesons to establish an upper limit on the magnitude of amplitudes associated with T-invariant anti-Hermitian interactions. It is assumed that the order of magnitude of such terms is in conformity with the values expected on the basis of the usual approximate isotopic spin selection rules for the weak interactions. Then it is found that if all the relevant weak interactions are T invariant, the data on unitarity would place an upper limit on the CP-violation parameter Vertical Bareta/sub +/-Verticalmore » Bar of Vertical Bareta/sub +/-Vertical Bar<0.34 x 10/sup -3/, which is an order of magnitude smaller than the observed value. It is therefore found that the possibility of including in the analysis a non-Hermitian effective weak Hamiltonian up to the limit permitted by the data on unitarity does not alter the conclusion that T invariance is violated.« less