Heavy quark fragmentation to baryons containing two heavy quarks

We discuss the fragmentation of a heavy quark to a baryon containing two heavy quarks of mass $m_Q>>{\Lambda }_{\mathrm{QCD}}$. In this limit the heavy quarks first combine perturbatively into a compact diquark with a radius small compared to $\frac{1}{{\Lambda }_{\mathrm{QCD}}}$, which interacts with the light hadronic degrees of freedom exactly as does a heavy antiquark. The subsequent evolution of this $\mathrm{QQ}$ diquark to a $\mathrm{QQq}$ baryon is identical to the fragmentation of a heavy antiquark to a meson. We apply this analysis to the production of baryons of the form $\mathrm{ccq}$, $\mathrm{bbq}$, and $\mathrm{bcq}$.