Inclusive decays and lifetimes of doubly charmed baryons

We extend the analysis of weak decays of heavy hadrons to the case of doubly charmed baryons, \Xi_{cc}^{++}, \Xi_{cc}^{+} and \Omega_{cc}^{+}. Doubly charmed baryons are modeled as a heavy-light system containing a heavy cc-diquark and a light quark. Such a model leads to preasymptotic effects in semileptonic and nonleptonic decays which are essentially proportional to the meson wave function. Very clear predictions for semileptonic branching ratios and lifetimes of doubly charmed baryons are obtained.