相关论文: T-Odd Gluon-Top-Quark Couplings at LHC
The top quark pairs produced at a polarized muon collider are in a (nearly) pure spin configuration. This result holds for all center-of-mass energies, and is insensitive to the next-to-leading order QCD radiative corrections. The decay…
We analyze the pair-production of top quarks in polarized $e^+e^-$ scattering in the presence of electroweak dipole moments. For this, we consider two $CP$-odd observables which probe both the real and the imaginary parts of these moments.…
The first evidence for the standard model production of a top quark in association with a W boson and a Z boson is reported. The measurement is performed in multilepton final states, where the Z boson is reconstructed via its decays to…
The International Linear Collider (ILC) will be able to precisely measure the electroweak couplings of the top in e+e- -> tt~. We compare the limits which can be achieved at the ILC with those which can be obtained in tt~gamma$ and tt~Z…
In this paper we study new-physics contributions to the top-quark decay $t \to b \bar b c$. We search for ways of detecting such new physics via measurements at the LHC. As top quarks are mainly produced at the LHC in $t \bar t$ production…
The top-antitop quark (t t-bar) production cross section is measured in proton-proton collisions at sqrt(s) = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 inverse femtobarns.…
Little Higgs models are often endowed with a T-parity in order to satisfy electroweak precision tests and give at the same time a stable particle which is a candidate for cold dark matter. This type of models predicts a set of new T-odd…
CP violating dipole moments of leptons vanish at least to three loop order and are estimated to be $({m_l\over Mev})\times 1.6\times 10^{- 40}$ e-cm in the standard model (SM), where $m_l$ is the mass of the lepton. However they can receive…
CP violating effects in top quark pair production at the future 2 TeV $p\bar p$ Tevatron and 14 TeV $pp$ LHC colliders are investigated. We study three kinds of CP violating sources:the supersymmetric CP-odd phase of the stop trilinear soft…
A measurement of the top quark pole mass $m_\mathrm{t}^\text{pole}$ in events where a top quark-antiquark pair ($\mathrm{t\bar{t}}$) is produced in association with at least one additional jet ($\mathrm{t\bar{t}}$+jet) is presented. This…
We study the same-sign top pair production mediated by the first Kluza-Klein (KK) excitation of the gluon in the Randall-Sundrum (RS) model with flavor violation at the Large Hadron Collider (LHC), in which the nonuniversal couplings…
A search is performed for top-quark pairs ($t\bar{t}$) produced together with a photon ($\gamma$) with transverse energy greater than 20 GeV using a sample of $t\bar{t}$ candidate events in final states with jets, missing transverse…
We explore the possibility that the right-handed top quark is composite, identifying possible signatures of compositeness and how they might manifest themselves at the LHC and Tevatron. We perform a complete analysis of the dimension six…
The anomalous magnetic moment of the tau lepton $a_\tau = (g_\tau -2)/2$ strikingly evades measurement, but is highly sensitive to new physics such as compositeness or supersymmetry. We propose using ultraperipheral heavy ion collisions at…
Recent experimental results from the CDF collaboration which study the top forward-backward asymmetry have strengthened the case that new physics is playing a role in t-tbar production. Here we propose a set of measurements, built from the…
The couplings of axion-like particles (ALPs) to Standard Model fermions are proportional to the fermion masses, making the interaction with the top quark particularly significant. In this study, we consider an ALP that is a mixture of…
A measurement is performed of the cross section of top quark pair production in association with a W or Z boson using proton-proton collisions at a center-of-mass energy of 13 TeV at the LHC. The data sample corresponds to an integrated…
We propose to observe the top spin correlation effect at Tevatron through the measurement of the correlated asymmetries of the charged lepton momenta using the dilepton decay events of top and anti-top quark pairs. The possibility of…
In the supersymmetric models, the dominant sources of the hadronic flavor-diagonal CP violation at low energy are the theta term and the chromoelectric dipole moments of quarks. Using QCD sum rules, we estimate the preferred range and the…
The normalized differential cross section for top-quark pair production in association with at least one jet is studied as a function of the inverse of the invariant mass of the $t \bar{t}+1$-jet system. This distribution can be used for a…