Semileptonic bc to cc and bb to bc Baryon Decays and Heavy Quark Spin Symmetry

We study the semileptonic decays of the lowest-lying $bc$ baryons to the lowest-lying $cc$ baryons (${\mathrm{\Xi }}_{bc}^{(\mathrm{\prime }\ast )}\to {\mathrm{\Xi }}_{cc}^{(\ast )}$ and ${\mathrm{\Omega }}_{bc}^{(\mathrm{\prime }\ast )}\to {\mathrm{\Omega }}_{cc}^{(\ast )}$), in the limit $m_b, m_c \gg \Lambda_$\mathrm{Q}\mathrm{C}\mathrm{D}$$ and close to the zero recoil point. The separate heavy quark spin symmetries make it possible to describe all these decays using a single form factor. We also show how these constraints can be used to test the validity of different quark model calculations. $bb$ to $bc$ baryon decays are also discussed.