Related papers: $e^+ e^- \to e^- {\bar \nu_e} u {\bar d}$ from LEP…
The complete tree level cross section for $e^+e^- \to e^- \bar\nu_e u \bar{d} \gamma$ is computed and discussed in comparison with the cross sections for $e^+e^- \to e^- \bar\nu_e u \bar{d} $ and $e^+e^- \to \bar{u} d u \bar{d}$. Event…
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…
GRAPE-Dilepton is a Monte Carlo event generator for dilepton production in ep collisions. The cross-section calculation is based on the exact matrix elements in the electroweak theory at tree level. The dilepton productions via $\gamma…
The process e^+e^- --> Z gamma, where the Z boson decays into hadrons or neutrinos, is studied with data collected with the L3 detector at LEP at centre-of-mass energies from 189 GeV up to 209 GeV. The cross sections are measured and found…
Large scale calculation for the radiative corrections required for the current and future collider experiments can be done automatically using the GRACE-LOOP system. Here several results for e+e- --> 3-body processes are presented including…
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…
The process e+e- -> W+W-gamma is analysed using the data collected with the L3 detector at LEP at a centre-of-mass energy of 188.6GeV, corresponding to an integrated luminosity of 176.8pb^-1. Based on a sample of 42 selected W+W- candidates…
Using the automatic system GRACE-LOOP, the full $O(\alpha)$ electroweak corrections has been calculated for the process $e^+e^- \to W^+\mu \bar{\nu}_{\mu}$. The total correction to the cross section is found to be typically -6.4% at…
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…
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…
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…
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…
The complete matrix element for $e^+e^-\ar W^+W^-\bar b b$ is computed at tree level and applied to: {\bf a)} $\bar t t$ production and decay ; {\bf b)} $ZH$ production followed by $Z\ar \bar bb$ and $H\ar WW$. In both cases we include…
We study the process $e^+ e^- \to \gamma \gamma \nu \bar{\nu}$ in the context of a strong electroweak symmetry breaking model, which can be a source of events with two photons and missing energy at LEP2. We investigate bounds on the model…
Much theoretical effort and automatization are required to confront new physics models with experimental data for many types of particle reactions at future colliders. In this context, we extend GRACE, an automatic calculation system for…
We perform a detailed study of the process $e^+e^-\to \mu^+\mu^-\nu_l\bar\nu_l$ including all contributions. The contributions other than from real gauge boson production leads to a rich phenomenology. We explore the use of the process as a…
We present the full O(alpha) corrections to single Higgs production in e+e- collision. The computation is performed with the help of GRACE-LOOP where a generalized non-linear gauge fixing condition is implemented. The numerical results are…
We present a study of single-W production ($e^+e^-\to e^-\bar{\nu}_e W^+$) as a new probe of the anomalous couplings at the LEP energy region. We introduce simple cuts to separate the single-W process from W-pair production and have…
The total cross section of the process $e^+e^- \to p\bar{p}$ is calculated within the energy range close to the mass of $\psi(3770)$ charmonium state. It was shown that the main contribution to this cross section comes from three gluon…