Symmetry Violation in Heavy Nuclei

For a long time heavy nuclei were considered for the study of symmetry violations mostly due to enhancement factors related to the complex nuclear structure. Classical examples are experiments that measure parity violating correlations in nuclear decays and in nuclear reactions. It is well known that due to nuclear enhancements the parity violating effects in nuclei could be as large as ∼ 10 in comparison to its ”natural” scale ∼ 10 for the simplest few nucleon systems. This feature of heavy nuclei has been explored for the gathering of unique information about statistical properties of nuclei and for further development of the understanding of nuclear structure (see, for example ref.). However, it is practically impossible to obtain information about weak interactions using these precisely measured nuclear P -violating effects. The main reason for that is the extremely complicated structure of nuclear wave functions of the excited states of heavy nuclei. Therefore, P violating effects in heavy nuclei could be treated by using mainly statistical approaches. Time Reversal Invariance (TRI) is another example of a fundamental symmetry that could be enhanced in heavy nuclei. Since the origin of the possible TRI violation is not yet understood, and even a proof of the TRI violation (T -violation) does not exist, it is very important to search for T violation using all opportunities. To avoid a possible misunderstanding, we clarify the meaning of the proof of T -violation. From the point of view of a local Lorentz invariant field theory with ordinary relations between spin and statistics, T -violation can be related through the CPT theorem to CP -violation which was discovered experimentally in the K-meson decays. This kind of T -violating interaction violates parity,