Related papers: Top Quark Pair Production in the Threshold Region
The measurement of the top quark polarization, sensitive to the electroweak coupling structure, in t-channel single-top production is presented. Events are analyzed corresponding to an integrated luminosity of approximately…
We study pair production of leptoquarks in e+e- annihilation at linear colliders. A detailed simulation including beamstrahlung and initial state radiation, leptoquark decay and hadronization, as well as detector smearing, is performed.…
We analyze the four-fermion reactions e+e- -> 4f containing a single top quark and three other fermions, a possible decay product of the resonant anti-top quark, in the final state. This allows us to estimate the contribution of the…
For top-quarks produced via the subprocess $q\bar q\to t\bar t$, the longitudinal t-quark polarization ($P_{\parallel}$) vanishes in QCD. $P_{\parallel}$ can be measured by the angular distribution of the lepton in $t$-quark semileptonic…
We investigate a possible CP violating effect in $e^+e^-$ annihilation into $t\bar t$ top quark pairs. As an illustrative example, we assume the source of the CP nonconservation is in the Yukawa couplings of a neutral Higgs boson which…
The study of the properties of the top quark is one of the main goals of the Large Hadron Collider (LHC) physics program. The experimental precision expected at the LHC requires the calculation of several top-quark related observables…
A search is presented for the pair production of new heavy resonances, each decaying into a top quark (t) or antiquark and a gluon (g). The analysis uses data recorded with the CMS detector from proton-proton collisions at a center-of-mass…
In the presence of an electric dipole coupling of $t \bar t$ to a photon, and an analogous ``weak" dipole coupling to the $Z$, $CP$ violation in the process $e^+e^- \rightarrow t \bar t$ leads to the polarization of the top and anti-top.…
In our previous work, we studied the polar distribution of the scaled energy of bottom-flavored hadrons from polarized top quark decays $t(\uparrow)\rightarrow W^++b(\rightarrow X_b)$, using two different helicity coordinate systems.…
The process of electron-positron pair production by two photons in a strong magnetic field has been studied. The process kinematics is considered, and the probability amplitude for arbitrary polarizations of particles is found. The…
We show that a precise measurement of the single-top production cross section at the Tevatron and the LHC can strongly constrain the model parameters of the Littlest Higgs model with T-parity. A reduction in the single-top production rate…
In the presence of an electric dipole coupling of t-tbar to a photon, and an analogous "weak" dipole coupling to the Z, CP violation in the process e+e- --> t tbar results in modified polarization of the top and anti-top. This polarization…
Heavy quark productions in high energy polarized scatterings are reviewed from a personal point of view. After mentioning why heavy quark physics is so interesting, I concentrate on two rather specific subjects: (1) polarized…
An overview of recent results on top quark properties and interactions is given, obtained using data collected with the CMS and ATLAS experiments during the years 2011 and 2012 at 7 TeV and 8 TeV centre-of-mass energies. Measurements of top…
We present a detailed study, at the fast detector simulation level, of top-pair photoproduction in semileptonic mode at the LHeC and FCC-he future colliders. We work in full tree-level QED, not relying on the equivalent-photon…
We discuss the degree of spin polarization of single top quarks produced via $Wg$ fusion process in $ep$ collision at TESLA+HERAp and CLIC+LHC energies $\sqrt{s}=1.6$ and 5.3 TeV. A description on how to combine the cross sections of…
We present results of phenomenological studies for top-quark pair production at the LHC at the center of mass energy $\sqrt{S} = 7$ TeV. The transverse momentum and rapidity distributions for final-state top quarks are calculated in…
We show that the measurement of the $Z$ polarization in the $e^+e^-\to t\bar t Z$ process would allow an interesting determination of the role of the top quark mass. This can be used for testing the possibility of top compositeness or of…
We investigate spin properties of single top quark production at hadron colliders. Based on an analogy with single top production and polarized top quark decay, we reproduce in a simple way the results by G.Mahlon and S.Parke on the…
We study the production and decay of a heavy charged Higgs boson in the $bg\to tH^-$ and $H^-\to b\bar t$ processes at the Large Hadron Collider (LHC). We show that the chiral structure of the $H^-t\bar b$ vertex entering both stages is…