Heavy quark fragmentation into double heavy baryons in the quark-diquark model

In the framework of nonrelativistic QCD and the quark-diquark model of baryons we have obtained the fragmentation functions for heavy quarks that split into spin-12 and spin-32 double heavy baryons. We predict the production rates as well as the shape of the energy spectra for cc- and bc-baryons in the region of the Z0 peak at the LEP collider.