$O({\alpha }_s)$ corrections to polarized top decay into a charged Higgs $t(\uparrow )\to H^{+}+b$

Abstract

We calculate the $O({\alpha }_s)$ radiative corrections to polarized top quark decay into a charged Higgs boson and a massive bottom quark in two variants of the two-Higgs-doublet model. The radiative corrections to the polarization asymmetry of the decay may become as large as $25$. We provide analytical formulae for the unpolarized and polarized rates for $m_b\ne 0$ and for $m_b=0$. For $m_b=0$ our closed-form expressions for the unpolarized and polarized rates become rather compact.

24 pages, 5 figures in the text, content modified, comments added, appendices added, references updated, replaced with published version