Related papers: Four fermion production in e+ e- annihilation
The dimension-four genuine anomalous quartic couplings are studied in processes of six-fermion production via e+e- collisions. Complete tree-level electroweak calculations are performed including initial-state-radiation and beamstrahlung.…
The collision of two intense, low-frequency laser beams is considered. The $e^-e^+$ pairs created in this field are shown to exhibit recollisions, which take place at high energy accumulated due to the wiggling of fermions. The resulting…
We study the effects of QCD corrections to the process $e^+e^-\rightarrow t\bar t+X\rightarrow b\ell^+\nu \bar b\ell^-\bar \nu+X$ above threshold. We show how to treat consistently to ${\cal O}(\alpha_s)$ the gluon radiation in both the…
Starting from the low-energy structure derived from QCD, we extend the amplitudes for four-pion production in e+ e- annihilation and tau decays up to invariant four-pion masses of 1 GeV. Cross sections and branching ratios BR(rho^0 -> 4 pi)…
Within the framework of nonrelativistic QCD, we make a detailed discussion on the doubly heavy baryon production through the $e^+ e^-$ annihilation channel, $e^{+}e^{-}\rightarrow\gamma/Z^0 \rightarrow \Xi_{QQ^{\prime}} +\bar{Q}…
The functional renormalization group equation is expanded to a two-loop form. This two-loop form equation involves one-loop effective action. An intermediate effective action perspective is adopted toward the one-loop effective action. That…
The past ten years of physics with e+e- colliding experiments at LEP and SLAC have shown the success of these experiments on not only impressively proving the theoretical predictions of the Standard Model (SM), but also to help provide…
The present knowledge on four-fermion production in electron-positron collisions is reviewed, with emphasis on W boson physics. Different methods to extract M_W from the data are presented and the role of QCD loop corrections discussed.
Top quark production in electron-positron annihilation is one of the benchmark reactions at a future linear collider. Both electroweak and QCD corrections are large, amounting to 10% or even more in specific kinematic regions. In this note…
We compute fermion pair production cross sections in $e^+e^-$ annihilation in models of electroweak symmetry breaking in warped 5-dimensional space. Our analysis is based on a framework with no elementary scalars, only gauge bosons and…
Hadronic final states in e+e- annihilitions at centre-of-mass energies from 14GeV up to 189GeV are studied in order to test recent predictions for power corrections to the mean values as well as the distributions of event shape variables.
Fermion compositeness and other new physics can be signalled by the presence of a strong four-fermion contact interaction. Here we present a study of $\ell\ell qq$ and $\ell\ell\ell'\ell'$ contact interactions using the reactions: $\ell^+…
High statistics Standard Model processes like fermion- and photon-pair production in e+e- collisions are studied at centre-of-mass energies up to 209 GeV. No significant deviation from the Standard Model is observed, leading to strong…
Recent results for the asymptotic behavior of fermion scattering amplitudes in the Sudakov limit are presented including next-to-leading logarithmic corrections. These are used for the analysis of the dominant electroweak corrections to the…
Fermion compositeness, and other types of new physics that can be described by the exchange of very massive particles, can manifest themselves as the result of an effective four-fermion contact interaction. In the case of the processes…
The instanton/sphaleron processes involve gauge fields with changing topology through a nonzero variation of the Chern-Simons number $\delta N_{CS}=\pm 1$. In QCD this leads to the production of $2N_f \delta N_{CS}$ units of axial charge,…
We present standard model predictions for a four fermion reaction e+ e- -> mu+ mu- bar_b b being one of the best detection channels of a low mass Higgs boson produced through the Higgsstrahlung mechanism at a linear collider. We include…
We describe the new version of the Monte Carlo event generator WOPPER for four fermion production through W-pairs including resummed leading logarithmic QED radiative corrections. Among the new features included are singly resonant…
A fully massive Monte Carlo program to compute all four-fermion processes in electron positron collisions, including Higgs boson production, is presented. Leading higher order effects are discussed and included.
It is shown that at muon colliders with the energy in the region of 100 TeV the process of coherent pair creation by the muon in the field of the opposing beam becomes important and imposes some limitations on collider parameters.