Related papers: Fermion pair production at LEP2 and interpretation…
We review the status of theoretical predictions for W-pair production at high energies. We discuss a systematic scenario towards a Monte-Carlo generator for e^+e^- --> 4f(\gamma), which meets the experimental requirements. In particular we…
I give an overview of the ability of a high energy $\mu^+\mu^-$ collider to discover new particles and interactions. I start with heavy fermions which will be the most straightforward to produce and observe. I then discuss single leptoquark…
Effects of four-Fermi-type new interactions are studied in top-quark pair production and their subsequent decays at future e^+e^- colliders. Secondary-lepton-energy distributions are calculated for arbitrary longitudinal beam polarizations.…
We study Standard Model four-fermion production in e+ e- annihilation at LEP2 energies and above using a semi-analytical approach. We derive the complete QED initial state corrections (ISR) to the reactions e+e- -> ZZ ->…
We derive limits on a class of new physics effects that are naturally present in grand unified theories based on extended gauge groups, and in particular in $E_6$ and $SO(10)$ models. We concentrate on $i$) the effects of the mixing of new…
The status of the LEP 1 results, the LEP 2 perspectives and some recent developments in the high energy behavior of electron-positron annihilation are briefly discussed.
Results on W-pair productions at LEP2 are reviewed and their consistency with standard electroweak expectations is summarised. Special interest is given to measurements of W polarisation, and to new studies of spin and decay-plane…
We present a theoretical study of a double lepton pair production in ultra--relativistic collision between two bare ions. Special emphasis is placed to processes in which creation of (at least one) $e^+ e^-$ pair is accompanied by the…
We investigate the quantum properties of heavy-fermion pairs, such as $t\bar t$ or $\tau^+\tau^-$, produced in lepton-lepton collisions with polarised beams. Focusing on spin correlations, entanglement, Bell-inequality violation, and…
We study possible observational effects of the two Higgs doublets in the $e^+e^- \to b \bar{b} Z^0$ at the LEP II energy. We have found that the observational values can be obviously different from that predicted by the minimal Standard…
The many-parametric fit of the LEP2 data on e^+e^-\to e^+e^-, \mu^+\mu^-, \tau^+\tau^- processes is performed to estimate signals of the Abelian Z'-boson beyond the standard model. The model-independent relations between the Z' couplings to…
I report on recent results for the total production cross section of the process e- e+ -> mu- nubar_mu u dbar X near the W-pair production threshold up to next-to-leading order in GammaW/MW alpha v^2 obtained in the framework of…
The process of the lepton pair production by a neutrino propagating in an external electromagnetic field is investigated in the framework of the Standard Model. Relatively simple exact expression for the probability as the single integral…
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…
This report summarises the results of the four-fermion working group of the LEP2-MC workshop, held at CERN from 1999 to 2000. Recent developments in the calculation of four-fermion processes in electron-positron collisions at LEP-2…
Precise measurements of electroweak processes at the International Linear Collider (ILC) will provide unique opportunities to explore new physics beyond the Standard Model. Fermion pair productions are sensitive to a new contact interaction…
In its second phase, LEP has allowed to study four fermion processes never observed before. Results are presented on the charged triple gauge boson couplings (TGC) from the W-pair, Single W and Single gamma production. The anomalous quartic…
We constrain the parameters of dynamical torsion, namely, the torsion-fermion coupling and the torsion mass, by making a careful analysis of current LEP-2 data at several energies, as well as CDF and D0 data from Run-I of the Tevatron. We…
Various precision determinations of the Fermi constant are compared. Included are muon and (leptonic) tau decays as well as indirect prescriptions employing $\alpha, m_Z, m_W, \ssthwmzms, \Gamma(Z\to\ell^+\ell^-)$, and $\Gamma(Z \to \nu\bar…
This talk summarizes recent progress in top quark physics studies for high energy linear electron-positron colliders as presented at the LCWS2000 Workshop at Fermilab. New results were presented for top pair production at threshold and in…