Related papers: Four quark processes at LEP 200
The implementation of QED initial-state radiative corrections in the process of four-fermion production at LEP200 and higher-energy e+e- colliders is discussed. Because of the presence of charged-current processes, this is a nontrivial…
Four fermion processes at e+ e- colliders in a range of energy from 100 GeV to 1 TeV are discussed and examples of results obtained with an event generator presented. We also investigate the effects of the inclusion of initial state QED…
This report is a survey on QCD Event Generator issues of relevance for LEP 2. It contains four main sections: a summary of experience from LEP 1, extrapolations to LEP 2 energies, Monte Carlo descriptions and standardization issues.
We present the first results of next-to-leading order QCD corrections to three jet heavy quark production at LEP including mass effects. Among other applications, this calculation can be used to extract the bottom quark mass from LEP data,…
An important issue in the direct reconstruction method of determining the $W$ mass from $q\bar q Q\bar Q$ events at LEP2 concerns the impact of the relatively unknown QCD interconnection effects. It has been suggested that a study of `short…
Recent results on QCD studies in e+e- annihilations at LEP are presented. Data recorded by the LEP experiments at centre-of-mass energies between 91.2 to 206 GeV are included. The main topic is the measurement of alpha_s from event-shape…
In this talk we present the recent calculation of the NLO QCD corrections to the production of four b-quarks induced by initial state quarks at the CERN LHC. We describe the details of the calculation using the GOLEM approach for the…
Several preliminary QCD results from e+e- interactions at LEP are reported. These include studies of event shape variables, which are used to determine alpha_s and for studies of the validity of power corrections. Further, a study of color…
The activities of the QCD working group concentrated on improving the understanding and Monte Carlo simulation of multi-jet final states due to hard QCD processes at LEP, i.e. quark-antiquark plus multi-gluon and/or secondary quark…
Four-fermion processes with a particle lost in the beam pipe are studied at LEP to perform precision tests of the electroweak theory. Leading higher-order QED corrections to such processes are analyzed within the framework of the Structure…
This paper is a long write-up of ERATO. ERATO is a Monte Carlo event generator describing four fermion production at LEP2 and beyond. All tree-order processes leading to four fermions are included, taking into account all relevant QCD…
Next-to-leading order QCD corrections to three jet heavy quark production in $e^+ e^-$ collisions, including quark mass effects, are presented. The extraction of the b-quark mass form LEP data is considered and the first experimental…
The production of four fermions plus a visible photon in electron-positron collisions is analyzed, with particular emphasis on the LEP2 energy range. The study is based on the calculation of exact matrix elements, including the effect of…
The search for quartic anomalous gauge couplings at LEP requires appropriate predictions for the radiative processes e+ e- \to \nu\bar\nu \gamma\gamma, e+ e- \to q\bar{q}\gamma\gamma and e+ e- \to 4 fermions+\gamma. Matrix elements are…
I review few recent QCD results in $e^+e^-$, $ep$ and $p\bar{p}$ collisions. Furthermore, I discuss recent studies in power suppressed effects, ongoing progress in next-to-next-to-leading QCD calculations, and some recent puzzling results…
We briefly summarise the results for the four top-quark production process in the 4$\ell$ decay channel at NLO accuracy in perturbative QCD. We employ the narrow-width approximation for the treatment of the unstable particles, preserving…
The search for quartic anomalous gauge couplings (QAGC) at LEP requires appropriate predictions for the radiative processes e+ e- \to \nu\bar\nu \gamma\gamma, e+ e- \to q\bar{q}\gamma\gamma and e+ e- \to 4 fermions+\gamma. The current…
In quark-antiquark pair production at LEP, many features of the hadronic final state can be predicted by QCD. Using data collected by the OPAL experiment, we present the statistical distributions of fourteen "event shape observables," which…
The LHC provides new opportunities to improve our understanding of the b quark using high statistics data samples and the 14 TeV center-of-mass energy. The prospects to measure the cross section for inclusive b production in events…
The present status of four-fermion calculations and event generators for LEP2 physics is reviewed. Perspectives for future improvements are given.