Related papers: EKHARA Monte Carlo generator for e+e- to e+e-pi0 a…
The class of six-fermion production processes at e+e- colliders comprises very interesting particle reactions, such as the production of top-quark pairs and of Higgs bosons in the intermediate Higgs mass range, the scattering of massive…
A review of the status of the Monte Carlo event generator PHOKHARA, developed for experiments using the radiative return method. The four-pion production in electron-positron annihilation and in tau-lepton decays and the narrow resonances…
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…
ExDiff2.0 is a Monte Carlo event generator for simulation of Exclusive Diffractive processes in proton-proton collisions. The present version includes reactions: elastic scattering $pp\to pp$ at 7, 8, 13, 14~TeV; $pp\to p+R+p$, $R =…
Recent theoretical studies of the e+ e- --> K + K- gamma process are described. Three main reaction mechanisms are considered: the initial state radiation, the final state radiation and the strong interaction between the outgoing K+ K-…
Muon pair production through the radiative return is of importance for a measurement of the hadronic production cross section in two ways: it provides an independent calibration and it may give rise to an important background for a…
We summarise the motivation for, and the status of, the tools developed by CEDAR/MCnet for validating and tuning Monte Carlo event generators for the LHC against data from previous colliders. We then present selected preliminary results…
Experiments at high luminosity electron-positron colliders allow to study the kaon and the pion form factors in the time-like region up to high energies. Also the kaon and the pion pair production at and around the narrow resonances J/psi…
We present a new, model-independent method to analyze radiative decays of mesons to a vector, isovector pair of pions of invariant mass square below the first significant pion-pion threshold in the vector channel. It is based on a…
Dalitz decays of $\omega$ and $\rho$ mesons, $\omega\to \pi^0\gamma^*\to\pi^0 e^+e^-$ and $\rho^0\to \pi^0\gamma^*\to\pi^0 e^+e^-$, produced in $pp$ collisions are calculated within a covariant effective meson-nucleon theory. We argue that…
The transverse polarization of a quark is a degree of freedom that is not taken into account in the most commonly used Monte Carlo generators. For the case "e^+e^- -> hadrons" I show that it is possible to use these generators to simulate…
We present a dynamical study of $e^+e^-$ production in $\pi^-$A reactions at 1.3 and 1.7 GeV on the basis of the Coupled-Channel-BUU approach. The contributions from vector mesons ($\rho,\omega$) are calculated taking into account the…
We present consistent theoretical descriptions of the $\pi N \to e^+e^- N$ and $\gamma N \to e^+e^- N$ reactions on proton and neutron targets for total center of mass energies $\sqrt s$ ranging between 1.50 GeV and 1.75 GeV. These…
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…
We describe the Monte Carlo event generator for quantum black hole production and decay in proton-proton collisions -- QBH version 1.03.
We discuss the theoretical approach and practical algorithms for simulation of radiative events in elastic ep-scattering. A new Monte Carlo generator for real photon emission events in the process of elastic electron-proton scattering is…
The Monte Carlo program {\tt WWGENPV}, designed for computing distributions and generating events for the four-fermion process $e^+ e^- \to W^+ W^- \to 4f$, is described. It is based on the calculation of the exact tree-level matrix element…
Quark spin effects in $e^+e^-$ annihilation to pseudoscalar and vector mesons are implemented for the first time in the PYTHIA Monte Carlo event generator. The spin-dependent fragmentation of the string stretched between the produced…
In view of the forthcoming experiments at high energy $e^+ e^-$ colliders, LEP2 and beyond, the process $e^+ e^- \to W^+ W^- \to 4f$ has been investigated for {\it off-shell} $W$'s. After deriving the matrix element for the process within…
We discuss two processes, the $\pi N \to e^+e^- N$ and the $\gamma N \to e^+e^- N$ reactions, below and close to the vector meson production threshold ($1.40<\sqrt s <1.75$ GeV). The aim is to gain understanding of the coupling of vector…