2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/198608We study the polarization of the J/ψmeson of the B_c -> J/ψmu nu decay process, followed by J/ψ-> mu+ mu-, with the help of the heavy-quark spin symmetry formalism (HQSS). We adapt the ISGW wave function. Due to the clean signature of the decay mode, measurements of the polarization of the J/ψmeson can play a special role in extracting |V_{cb}|, the quark mixing-matrix element. We compare the results with the predictions of other quark models.12 pages, 2 figures, RevTeXHigh Energy Physics - Phenomenologytext