5,624 research outputs found
Single Top production at LHC
The Production of single top quarks at LHC provides an ideal framework to
investigate the properties of electroweak interaction, in particular of the
{\it tWb} coupling. Moreover, single top is a powerful mean to identify physics
beyond the standard model. All three different production mechanisms of single
top are expected to be observed at LHC. Recent studies from ATLAS and CMS are
presented.Comment: 5 pages, Presented at the XLIrst Rencontres de Moriond - QCD and High
Energy Hadronic Interaction
Secondary particles spectra in the decay of a polarized top quark with anomalous coupling
Analytic expression for energy and angular dependence of a secondary charged
lepton in the decay of a polarized top quark with anomalous couplings in
the presence of all anomalous couplings are derived. The angular distribution
of the b-quark is derived as well. It is presented that the charged lepton spin
correlation coefficient is not very sensitive to the anomalous couplings.
However, the b-quark spin correlation coefficient is sensitive to anomalous
couplings and could be used as a powerful tool for searching of non-SM
coupling.Comment: 9 pages, 5 figure
Study of anomalous top quark FCNC interactions via -channel of single top
The potential of the LHC for investigation of anomalous top quark
interactions with gluon () through the production of -channel of
single top quark is studied. In the Standard Model, the single top quarks in
the -channel mode are charge symmetric meaning that . However, the presence of anomalous FCNC
couplings leads to charge asymmetry. In this paper a method is proposed in
which this charge asymmetry may be used to constrain anomalous FCNC couplings.
The strength of resulting constraints is estimated for the LHC for the center
of mass energies of 7 and 14 TeV.Comment: 13 pages, 4 figures, new references adde
Semi-Leptonic Decay of a Polarized Top Quark in the Noncommutative Standard Model
In this paper we study the noncommutative effects to the lepton spectrum from
the decay of a polarized top quark. It is shown that the lowest contribution
comes from the quadratic terms of the noncommutative parameter. The deviations
from the standard model are significant for small values of the noncommutative
characteristic scale. However, the charged lepton spin correlation coefficient
has a remarkable deviation from the standard model from very low values of the
noncommutative characteristic scale to 1 TeV.Comment: 8 pages, 4 figure
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