QCD corrections to decays of polarized charm and bottom quarks

Distributions of leptons in semileptonic ${\mathrm{\Lambda }}_{\mathit{c}}$ and ${\mathrm{\Lambda }}_{\mathit{b}}$ decays can be used as spin analyzers for the corresponding heavy quarks. QCD corrected charged lepton spectra are known for polarized up-type quarks. The analogous formulas are derived for polarized down-type quarks. These results are applied to the decays of polarized charm and bottom quarks. For charged leptons in charm decays the corrections to asymmetries are small. For bottom decays they exhibit a nontrivial dependence on the energy of the charged lepton.