2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/42178We review the weak-decay and spectroscopy properties of baryons with two charmed quarks. We also present the convergent speculations on exotic mesons $(QQ\bar{q}\bar{q})$ with two heavy quarks and two light antiquarks.9 pages, 5 figures, latex with cernrep.cls, Contribution to the Compass Workshop, CERN, Sept. 26-27, 2002, Proc. to appear as a CERN Yellow ReportHigh Energy Physics - Phenomenologytext