Unconditional tests of discrete symmetries by K mesons beyond the approximate Lee-Oehme-Yang theory

Unconditional tests of discrete symmetries CP, T, CPT are derived within the exact (rigorous) Quantum Theory. It was proved that usual tests, which were formulated in terms of the approximate lee- Oehm- Yang (LOY) theory must indicate quasi-violation of the discrete symmetries, in particular the CPT invariance. The new unexpected physical phenomena was derived- the dependence of the results the exact Quantum Theory (QTh) of the CP violation from the tails of mass distributions, but not only from the pole structure of the mass distributions, as it is in the LOY theory. (author)