Related papers: ee4fgamma, A program for e+e- -> 4f, 4fgamma with …
We compute several total and differential cross sections relevant to top and WWZ physics at future $e^+e^-$ colliders taking into account the full set of Feynman diagrams for six fermion final states. We also include in our calculations…
The measurements of four-fermion production rates performed at LEP2 in e+e- collisions at centre-of-mass energies ranging from 161 to 209 GeV are presented. The focus is put on processes that involve the production and decay of W or Z…
The top-quark, $W$ and $Z^0$ bosons have widths that are a sizable fraction of their masses and will be produced copiously at upcoming accelerators. Yet S-matrix theory cannot treat unstable particles as external states. Dealing with…
We describe the physics potential of $e^+e^-$ linear colliders in this report. These machines are planned to operate in the first phase at a center-of --mass energy of 500 GeV, before being scaled up to about 1 TeV. In the second phase of…
A generator with $\alpha^2$ order radiative correction effects, including both the initial state radiative corrections and the photon vacuum polarization corrections, is built for the full simulation of $e^+e^- \to hadrons $ in cross…
In this paper it is shown that the final state radiation process $e^{+}e^{-}\rightarrow\mu^{+}\mu^{-}\gamma$ at tree level is not associated with any IR divergence in the soft photon high energy limit if the calculation is done using a…
The presence of a heavy fermion doublet of fourth generation in the standard model would lead to a anomalous decay with fermion number non-conservation. The anomalous decay path in the background of the electroweak instanton is demonstrated…
The e+e- --> pi+pi-pi0pi0 reaction cross section as a function of the incident energy is calculated using a model that is an extension of our recently published model of the e+e- annihilation into four charged pions. The latter considered…
A model independent formalism for the electron positron annihilation reaction $e^++e^-\to a_1(1260)+\pi $ has been derived. The differential and total cross sections and the elements of the spin--density matrix of the $a_1$-meson were…
A computer program is presented which calculates the elastic and inelastic scattering in intermediate and high energy nuclear collisions. A coupled-channels method is used for Coulomb and nuclear excitations of E1, E2, E3, M1, and M2…
The BFKL dynamics can be successfully tested at the future high energy $e^+e^-$ linear collider. The total $\gamma^*\gamma^*$ cross-section is calculated in the Leading Log QCD dipole picture of BFKL dynamics, and compared with the one from…
We perform a dedicated study of the four-fermion production process e- e+ -> mu- nubar_mu u dbar X near the W pair-production threshold in view of the importance of this process for a precise measurement of the W boson mass. Accurate…
The $O(\alpha)$ corrections to $\gamma\gamma --> f \bar f$ in the Standard Model are calculated for arbitrary, light fermions $f$. The relevant analytical results are listed in a form that is appropriate for practical applications, and…
The program {\tt TOPAZ0} is designed for computing $Z^0$ parameters, de-convoluted and QED-dressed cross sections and forward-backward asymmetries of $e^+ e^-$ annihilation into fermion pairs and of Bhabha scattering around the $Z^0$ peak,…
We study the effects of non-commutative QED (NCQED) in fermion pair production, $\gamma + \gamma \to f + \bar{f}$ and Compton scattering, $e + \gamma \to e + \gamma$. Non-commutative geometries appear naturally in the context of…
We study bottom-quark fragmentation in e+e- annihilation, top and Higgs decay H -> b bbar, using Monte Carlo event generators, as well as calculations, based on the formalism of perturbative fragmentation functions, which resum soft- and…
The longitudinal (e,e') response function of 4He is calculated precisely with full final state interaction. The explicit calculation of the four-body continuum states is avoided by the method of integral transforms. Precision tests of the…
We use a recent O(alpha_s^2) calculation of the differential cross section for the production of heavy quarks in e+e- annihilation to compute a few moments of the heavy quark single-inclusive production cross section. We verify that,…
A fast and simple Monte Carlo program is presented that simulates single Bremsstrahlung in Bhabha scattering, e+e- --> e+e-gamma, without constraints on scattering angles. This allows the study of this process at arbitrarily small, or even…
We present the calculation of gamma gamma -> 2e+e- process cross section. The construction are perfomed using both helicity amplitude method and method of precision covariant calculation. The magnitude of cross section is obtained by the…