Related papers: Spin-dependent energy distribution of B-hadrons fr…
We calculate the ${\cal O}(\alpha_s)$ radiative corrections to the spin dependent differential decay rates of the process $t\rightarrow b+W^+$. These are needed to study the angular distribution of the energy of hadrons produced in…
We consider the decay of a polarized top quark into a stable $W^+$ boson and charmed-flavored (D) or bottom-flavored (B) hadrons, via $t(\uparrow)\rightarrow W^++D/B+X$. We study the angular distribution of the scaled-energy of B/D-hadrons…
We consider the decay of a polarized top quark into a polarized W-boson plus a bottom quark, followed by the decay of the W-boson into a pair of leptons or quarks. The polar angle distribution of the top spin relative to the W-momentum and…
We present the analytical expressions for the next-to-leading order corrections to the partial decay width $t(\uparrow) \rightarrow bW^+$, followed by $b\rightarrow H_bX$, for nonzero b-quark mass ($m_b\neq 0$) in the fixed-flavor-number…
The polarisation of top quarks produced in high energy processes can be a very sensitive probe of physics beyond the Standard Model. The kinematical distributions of the decay products of the top quark can provide clean information on the…
In recent years, searches for the light and heavy charged Higgs bosons have been done by the ATLAS and the CMS collaborations at the Large Hadron Collider (LHC) in proton-proton collision. Nevertheless, a definitive search is a program that…
Angular and energy distributions for leptons and bottom quarks in the process e^+e^- --> t t-bar --> l^{+-}/b(b-bar) ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on…
Top quark decays before hadronization and its information transfer to final products. The top quark decays via the weak interaction, hence the azimuthal polarized decay rate is zero in the leading order of SM. Therefore the study of top…
We calculate the density matrix for the decay of a polarised top quark into a polarised W boson and a massive b quark, for the most general Wtb vertex arising from dimension-six gauge-invariant effective operators. We show that, in addition…
We calculate the O(alpha_s) radiative corrections to the three spin independent and five spin dependent structure functions that describe the angular decay distribution in the decay of a polarized top quark into a W-boson (followed by the…
We study the inclusive production of bottom-flavored hadrons from semileptonic decays of polarized top quarks at next-to-leading order in QCD using fragmentation functions recently determined from a global fit to $e^+e^-$ data. We provide…
We analyze the energy distribution of the leptons coming from the top decay $t\ra b\hc,\ bW^+\ra bl^+\nu$. The correlation between the lepton energy distribution and the top spin may be useful for distinguishing the $\hc$ signature from the…
We present the energy distribution of b-flavoured hadrons in top quark decay using the PYTHIA and HERWIG event generators, which we tune to LEP and SLD data. We find that fitting the string and cluster models is essential to reproduce the…
We present results for the differential distributions of jets from non-leptonic decays of polarized top quarks within the Standard Model, including QCD radiative corrections. Our work extends existing results which are only available for…
The polarization of a top quark can be sensitive to new physics beyond the standard model. Since the charged lepton from top quark decay is maximally correlated with the top quark spin, it is common to measure the polarization from the…
We analyse the semileptonic decay of a polarised top-quark with a large velocity based on the perturbative QCD factorisation framework. Thanks to the factorisation and the spin decomposition, the production part and the decay part can be…
We investigate the effects of new physics scenarios containing a high mass vector resonance on top pair production at the LHC, using the polarization of the produced top. In particular we use kinematic distributions of the secondary lepton…
We study the fragmentation of the b quark in top decay in NLO QCD, within the framework of perturbative fragmentation, which allows one to resum large logarithms $\sim\log (m_t^2/m_b^2)$. We show the b-energy distribution, which we compare…
We calculate the QED and QCD radiative corrections to the charged lepton energy distributions in the dominant semileptonic decays of the top quark $t \to b W^+ \to b(\ell^+ \nu_\ell)$ $(\ell=e, \mu, \tau)$ in the standard model(SM), and for…
The longitudinal polarization of hyperons in $e^+e^-$ annihilation at high energies depends on the longitudinal polarization of the quark produced at the $e^+e^-$ annihilation vertex whereas the spin alignment of vector mesons is…