相关论文: Longitudinal top quark polarization
Vector Leptoquarks (VLQs) have emerged as primary candidates for resolving discrepancies in the Standard Model, specifically within $B$-meson decay channels and the anomalous magnetic moment of the muon. This work presents a rigorous…
Radiative corrections due to pair production in process of electron-positron annihilation are considered. The main attention is paid to the corrections of the third order. Simultaneous emission of photons and pairs is taken into account.…
At future $\gamma \gamma$ colliders copious production of $t \bar{t}$ pairs is possible. This would allow a detailed investigation of the interactions involving the top quark. We propose some orrelations which are sensitive to $t \bar{t}$…
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…
The production of four top quarks is a rare process in the Standard Model that provides unique opportunities and sensitivity to Standard Model observables including potential enhancement from many popular new physics extensions. This…
Longitudinal polarization of Lambda produced in $e^+e^-$ annihilation at LEP energies is calculated in a picture for the spin content of Lambda which is consistent with the polarized deep inelastic lepton-nucleon scattering data and SU(3)…
Coulomb corrections to perturbation theory for producing electron-positron pairs in ultrarelativistic heavy ion collisions are considered in a part-analytical, part-numerical approach. Production probabilities are reduced from perturbation…
Top-quark physics plays an important role at hadron colliders such as the Tevatron at Fermilab or the LHC at CERN. Given the planned precision at these colliders, precise theoretical predictions are required. In this paper we present the…
We calculate the next-to-next-to-leading order correction to the cross section for top quark pair production in e+e- annihilation in the threshold region, resumming all O [ (alpha_s/beta)^n (alpha_s^2, beta^2, alpha_s beta) ] terms of…
Unlike other examples of fermion pair production in e+ e- collisions, we show that top-quark pairs are produced in an essentially unique spin configuration in polarized e+ e- colliders at all energies. Since the directions of the…
I give an introduction to the effective field theory description of top pair production at threshold in e+e- annihilation. The impact of the summation of logarithms of the top quark velocity including most recent results at…
An overview of top physics and phenomenology at a high-energy linear collider is presented. A comprehensive study of top quark physics is possible at such a facility. The unique threshold production of top pairs would provide measurements…
I review a few selected topics concerning heavy-quark fragmentation, taking particular care about bottom- and charm-quark production in $e^+e^-$ annihilation and the inclusion of non-perturbative corrections. In particular, I discuss recent…
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…
A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in t-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8 TeV corresponding…
Partons produced in the early stage of non-central heavy-ion collisions can develop a longitudinal fluid shear because of unequal local number densities of participant target and projectile nucleons. Under such fluid shear, local parton…
The complete set of matrix elements for all polarization configurations in top quark decays is presented including higher order QCD corrections. The analysis is done in the framework of the helicity formalism. The results can be used in a…
Recent analytical and numerical results for the three-loop polarization function allow to present a phenomenological analysis of the cross section for massive quark production in electron positron annihilation to order $\alpha_s^2$.…
Electroweak corrections associated with the instability of the top quark to the next-to-next-to-leading logarithmic (NNLL) total top pair threshold cross section in e+e- annihilation are determined. Our method is based on absorptive parts…
The current status of top quark studies at the Large Hadron Collider (LHC) and at the Linear Collider (LC) is summarized. Expectations on the measurements of the top mass, couplings and decays, of the top spin polarization and of the single…