Λb decays into Λ-vector

A complete study of the angular distributions of the processes, Λb→ΛV(1−), with Λ→pπ− and V(J/Ψ)→ℓ+ℓ− or V(ρ0)→π+π−, is performed. Emphasis is put on the initial Λb polarization produced in the proton-proton collisions. The polarization density-matrices as well as angular distributions are derived and help to construct T-odd observables which allow us to perform tests of both time-reversal and CP violation.