Related papers: Production of two electron-positron couples in ele…
A Monte Carlo program is presented for the computation of the most general cross section for two-photon production in e+e- collisions at fixed two-photon invariant mass W. Functions implemented for the five gamma* gamma* structure functions…
In this paper we consider the exclusive production of proton-antiproton pairs in the interaction between two quasireal photons in $e^+e^-$ collision. The differential and total cross section of the process $\gamma \gamma \to p\bar {p}$ at a…
At present paper we performed a detailed numerical analysis of four charged leptons photoproduction in frame of standard theory of electroweak interaction. Total and differential cross sections are obtained by using of the Monte-Carlo…
In this work we study the process $e^{+}+e^{-}\longrightarrow J/\Psi+\eta_{c} $ at energy $\sqrt{s}= 10.6 GeV$ observed recently at B-factories whose measurements were made by Babar and Belle groups. We calculate the cross section for this…
The cross section for different processes induced by $e^+e^-$ annihilation, in the kinematical limit $\beta_{\mu}\approx\beta_{\pi}=(1-m_{\pi}^2/\epsilon^2)^{1/2}\sim 1$, is calculated taking into account first order corrections to the…
Detailed numerical analysis of four charged leptons photoproduction in frame of standard theory of electroweak interaction is presented. Total and differential cross sections are obtained and investigated using the Monte-Carlo method of…
In this present paper, we investigate the muon pairs production in the interaction between two quasireal photons in $e^+e^-$ collision. The total and differential cross section of the process $\gamma \gamma \to \mu^+\mu^-$ at a beam energy…
The production of photon pairs in $e^+e^-\rightarrow f \bar f \gamma\gamma$ processes is studied using exact helicity amplitudes at tree level. Total cross sections, including initial state radiation effects, are given. They are presented…
A fast leading-order Monte Carlo generator for the process $e^+e^-\to\mu^+\mu^-\gamma$ is described. In fact, using the $e^+e^-\to\mu^+\mu^-\gamma $ process as an example, we provide a pedagogical demonstration of how a Monte Carlo…
Monte-Carlo generator with photon jets radiation in collinear regions for the process \eegg is described in detail. Radiative corrections in the first order of $\alpha$ are treated exactly. Large leading logarithmic corrections coming from…
The cross-section for the reaction $e^+e^- \rightarrow b\bar{b}\mu^+\mu^-$ is calculated with a semi-analytical integration of the phase space. Compact formulae are obtained for the total cross section and for invariant mass distributions…
The differential cross-section for the process e+e- -> \gamma\gamma is calculated assuming the presence of excited electrons with a chiral magnetic coupling. This calculation permits constraining the excited electron coupling using the same…
We present an estimate of the cross-section for the exclusive production of a rho_L^0-meson pair in e^+e^- scattering, which will be studied in the future high energy International Linear Collider. For this aim, we complete calculations of…
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1 at centre-of-mass energies lying between…
The reaction e+ e- -> e+ e- gamma* gamma* -> e+ e- hadrons is analysed for quasi-real virtual photons using data collected by the L3 detector during the LEP high energy runs at sqrt(s) = 183 and 189 GeV. Preliminary results on the cross…
The energy dependence of the electron - positron hadronic cross section can be measured not only by a straightforward energy scan, but also by means of the radiative return method. To provide extensive comparisons between theory and…
An extended version of the Monte Carlo program GALUGA is presented for the computation of two-photon production in $\e^+\e^-$ collisions. Functions implemented for the five $\gamma^\star\gamma^\star$ structure functions now include several…
A Monte Carlo generator has been constructed to simulate the reaction e+ e- --> gamma + 2 pions and gamma + 4 pions, where the photon is assumed to be observed in the detector. Predictions are presented for cms energies of 1GeV, 3GeV and…
We present the matrix element of gamma gamma ->4l process with four charge particles in final state. The constructions are performed in frame of Standard Model of electroweak interaction using the helicity amplitude method . Every possible…
The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a centre-of-mass energy of 183 GeV. The measured…