Testing CP and Time Reversal Symmetries with Λ_b to Λ V(1-) Decays

In this letter, an overview is given for interesting tests of both CP and Time Reversal symmetries with the beauty baryon $\Lambda_b $. Extensive use of the helicity formalism and HQET is done for all calculations. Then, emphasis is put on sophisticated methods like analysis of resonance polarizations and particular angle distributions which can exhibit a clear signal of TR violation.