Distributions of leptons in decays of polarised heavy quarks

Abstract

Analytic formulae are given for QCD corrections to the lepton spectra in decays of polarised up and down type heavy quarks. These formulae are much simpler than the published ones for the corrections to the spectra of charged leptons originating from the decays of unpolarised quarks and polarised up type quarks. Distributions of leptons in semileptonic ${\Lambda }_c$ and ${\Lambda }_b$ decays can be used as spin analysers for the corresponding heavy quarks. Thus our results can be applied to the decays of polarised charm and bottom quarks. For the charged leptons the corrections to the asymmetries are found to be small in charm decays whereas for bottom decays they exhibit a non-trivial dependence on the energy of the charged lepton. Short life-time enables polarisation studies for the top quark. Our results are directly applicable for processes involving polarised top quarks.

Karlsruhe Univ. preprint TTP 93-40, 19 pages, 1 figure included as the postscript file fig1.ps after the Latex file

References in corpus (10)

• QCD Predictions for Lepton Spectra in Inclusive Heavy Flavour Decays
• Inclusive Semileptonic B and Polarized Lambda_b Decays from QCD
• On the Motion of Heavy Quarks inside Hadrons: Universal Distributions and Inclusive Decays
• Analysis of the Photon Spectrum in Inclusive $B\to X_s\gamma$ Decays
• V-a Tests Through Leptons from Polarised Top Quarks
• Heavy Quark Fragmentation into Heavy Mesons
• QCD Corrections and the Endpoint of the Lepton Spectrum in Semileptonic B Decays
• The Top Width - Theoretical update
• QCD corrections to decays of polarised charm and bottom quarks
• Effects of non-standard couplings, radiative corrections and neutrino masses on the lepton spectrum in $\mu$ and $\tau$ decays

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