B-mesons from top-quark decay in presence of the charged-Higgs boson in the Zero-Mass Variable-Flavor-Number Scheme

Abstract: We study the energy spectrum of the inclusive bottom-flavored mesons in top-quark decay into a charged-Higgs-boson and a massless bottom quark at next-to-leading order (NLO) in the two-Higgs-doublet model. To extract the result we work in the Zero-Mass Variable-Flavor-Number scheme(ZM-VFNs) using realistic nonperturbative fragmentation functions obtained through a global fit to $e^+e^-$ data from CERN LEP1 and SLAC SLC on the Z-boson resonance. We study both the contribution of the bottom-quark fragmentation and the gluon fragmentation to produce the bottom-flavored meson (B-Meson). We find that the contribution of the gluon leads to an appreciable reduction in decay rate at low values of the B-meson energy. It means the NLO corrections are significant.