  Light and heavy charged Higgs bosons are predicted by many models with an
extended Higgs sector such as the two-Higgs-doublet model (2HDM). Searches for
the charged Higgs bosons have been done by the ATLAS and the CMS experiments at
the Large Hadron Collider (LHC) in proton-proton collision. However, a
definitive search is a program that still has to be carried out so this belongs
to the LHC experiments. The experimental observation of charged Higgs bosons
would indicate physics beyond the Standard Model. In the present work we study
the ${\cal O}(\alpha_s)$ correction to the energy spectrum of the inclusive
bottom-flavored mesons $(X_b)$ in polarized top quark decays into a light
charged Higgs boson ($m_{H^+}<m_t$) and a massless bottom quark followed by the
hadronization process $b\to X_b$ in the 2HDM, i.e. $t(\uparrow)\to H^+b\to
H^+X_b+Jet$. This spin-dependent energy distribution is studied in two
different helicity coordinate systems. This study could be considered as a new
channel to search for the charged Higgs bosons. To present our phenomenological
predictions, we restrict ourselves to the unexcluded regions of the MSSM
$m_{H^+}-\tan\beta$ parameter space determined by the recent results of the CMS
and the ATLAS collaborations.
