2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/124503Weak decays of beauty baryons like Lambda_b into Lambda V(J^P=1^-), where the produced resonances are polarized, offer interesting opportunity to perform tests of Time-Reversal Invariance. This paper emphasizes the particular role of the resonance polarization-vectors and their physical properties by symmetry transformations. In particular, it is shown that the normal component of a polarization-vector, as defined in the Jackson's frame, is Lorentz invariant and could get large values, notably in the case of J/psi production.11 pages, 3 figures, 1 table. Submitted to Phys. Lett. BHigh Energy Physics - Phenomenologytext