2,181 research outputs found
Spin-dependent energy distribution of B-hadrons from polarized top decays considering the azimuthal correlation rate
In our previous work, we studied the polar distribution of the scaled energy
of bottom-flavored hadrons from polarized top quark decays
, using two different helicity
coordinate systems. Basically, the energy distributions are governed by the
unpolarized, polar and azimuthal rate functions which are related to the
density matrix elements of the decay . Here we
present, for the first time, the analytical expressions for the radiative corrections to the differential azimuthal decay rates
of the partonic process in two helicity
systems, which are needed to study the azimuthal distribution of the energy
spectrum of the B-hadron produced in polarized top quark decays. Our
predictions of the hadron energy distributions enable us to deepen our
knowledge of the hadronization process and to determine the polarization states
of top quarks
Charged Higgs production from polarized top-quark decay in the 2HDM considering the general-mass variable-flavor-number scheme
Charged Higgs bosons are predicted by some non-minimal Higgs
scenarios, such as models containing Higgs triplets and two-Higgs-doublet
models, so that the experimental observation of these bosons would indicate
physics beyond the Standard Model. In the present work, we introduce a new
channel to indirect search for the charged Higgses through the hadronic decay
of polarized top quarks where a top quark decays into a charged Higgs and
a bottom-flavored hadron via the hadronization process of the produced
bottom quark, . To obtain the energy
spectrum of produced -hadrons we present, for the first time, an analytical
expression for the corrections to the differential decay
width of the process in the presence of a massive b-quark
in the General-Mass Variable-Flavor-Number Scheme (GM-VFNS). We find that the
most reliable predictions for the B-hadron energy spectrum are made in the
GM-VFN scheme, specifically, when the Type-II 2HDM scenario is concerned
Next-to-leading order corrections to the spin-dependent energy spectrum of hadrons from polarized top quark decay in the general two Higgs doublet model
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 still has to be carried out at the LHC. The experimental
observation of charged Higgs bosons would indicate physics beyond the Standard
Model. In the present work, we study the scaled-energy distribution of
bottom-flavored mesons () inclusively produced in polarized top quark decays
into a light charged Higgs boson and a massless bottom quark at next-to-leading
order in the two-Higgs-doublet model; . This
spin-dependent energy distribution is studied in a specific helicity coordinate
system where the polarization vector of the top quark is measured with respect
to the direction of the Higgs momentum. The study of these energy distributions
could be considered as a new channel to search for the charged Higgs bosons at
the LHC. For our numerical analysis and phenomenological predictions, we
restrict ourselves to the unexcluded regions of the MSSM
parameter space determined by the recent results of the CMS \cite{CMS:2014cdp}
and ATLAS \cite{TheATLAScollaboration:2013wia} collaborations.Comment: 10 pages, 6 figures. arXiv admin note: text overlap with
arXiv:1611.0801
Effect of hypoxia on myocardium in heart-lung preparation
Effect of hypoxia on myocardium in starling heart lung preparations ventilated with mixtures of oxygen, nitrogen, and carbon dioxid
Effect of Blood Ph and CO2 Tension on the Performance of the Heart-lung Preparation
Blood pH and carbon dioxide tension effect on performance of heart-lung preparatio
Heavy quark fragmentation functions at next-to-leading perturbative QCD
It is well-known that the dominant mechanism to produce hadronic bound states
with large transverse momentum is fragmentation. This mechanism is described by
the fragmentation functions (FFs) which are the universal and
process-independent functions. Here, we review the perturbative FFs formalism
as an appropriate tool for studying these hadronization processes and detail
the extension of this formalism at next-to-leading order (NLO). Using the
Suzuki's model, we calculate the perturbative QCD FF for a heavy quark to
fragment into a S-wave heavy meson at NLO. As an example, we study the LO and
NLO FFs for a charm quark to split into the S-wave -meson and compare our
analytic results both with experimental data and well-known phenomenological
models
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