相关论文: Non-resonant diagrams in radiative four-fermion pr…
The complete tree level cross section for the process $e^+e^- \to e^- \bar\nu_e u \bar{d}$ is computed using the GRACE system, a program package for automatic amplitude calculation. Special attention is brought to the gauge violation…
Several schemes to introduce finite width effects to reactions involving unstable elementary particles are given and the differences between them are investigated. The effects of the different schemes is investigated numerically for $W$…
The cross section of $e^+e^- \to b \bar{b} u \bar{d} \mu^- \bar{\nu}_\mu$ process with a complete set of tree diagrams, 232 diagrams in the unitary gauge, was calculated at the energy range of $\sqrt{s}$ = 340 - 500 GeV by using GRACE…
We compute the total cross section as well as angular and energy distributions for process $e^+e^-\to\gamma\gamma\gamma$ with both unpolarized and polarized beams in the framework of noncommutative quantum electrodynamics (NCQED). The…
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…
The relevance of radiative corrections to 4f production at LEP2 and future e+e- colliders is emphasized, and their treatment in the event generator RacoonWW is briefly discussed. In particular, the non-universal corrections are compared…
We study the effects of non-commutative QED (NCQED) in fermion pair production, gamma + gamma -> f + bar{f} and Compton scattering, e + gamma -> e + gamma. Non-commutative geometries appear naturally in the context of string/M-theory and…
We describe the salient features of precise predictions for the processes e+ e- -> WW -> 4f(gamma) as obtained with the Monte Carlo generator RacoonWW, including the complete O(alpha) electroweak radiative corrections in the double-pole…
We present numerical results for total cross sections and various distributions for e+e- --> WW --> 4f(+gamma) at a future 500GeV linear collider, obtained from the Monte Carlo generator RACOONWW. This generator is the first one that…
grc4f is a Monte-Carlo package for generating e+e- to 4-fermion processes in the standard model. All of the 76 LEP-2 allowed fermionic final state processes evaluated at tree level are included in version 1.1. grc4f addresses event…
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…
grc4f is a Monte-Carlo package for generating e+e- to 4-fermion processes in the standard model. All of the 76 LEP-2 allowed fermionic final state processes evaluated at tree level are included in version 1.0. grc4f addresses event…
We present the Monte Carlo generator RacoonWW that computes cross sections to all processes e^+ e^- -> 4f and e^+ e^- -> 4f + gamma and calculates the complete O(alpha) electroweak radiative corrections to e^+ e^- -> W W -> 4f in the…
A new event generator is proposed for two processes e+e- -> nu nu-bar gamma and e+e- -> nu nu-bar gamma gamma where nu includes all the neutrino species. The exact matrix elements of single- and double-photon emission, generated by the…
We present an efficient generator for the process e+e- to 4 fermions + gamma through off-shell W pairs. It is based on a massless matrix element with leading order(m^2) corrections. Only the resonant WW graphs are included. We have tested…
An electromagnetic response of a single graphene layer to a uniform, arbitrarily strong electric field $E(t)$ is calculated by solving the kinetic Boltzmann equation within the relaxation-time approximation. The theory is valid at low…
The vanishing of the cross section for particular points in phase space - radiation zeros - is examined for the process $ q \bar q \to W^+W^- \gamma$ at high energy. Unlike the process $q \bar q' \to W^\pm \gamma$, actual zeros only occur…
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…
The process e^+e^-\to\pi^0\gamma in the energy range \sqrt{s}=0.60-1.06 GeV was studied at VEPP-2M collider with SND detector using 14 pb^{-1} of integrated luminosity. Data were analyzed in the framework of the vector meson dominance…
Optimal conditions to acomplish amplification without inversion in three-level schemes based on quantum nonlinear interference effects are analyzed. Specific features of relaxation processes in optical transitions seting these conditions…