相关论文: Off shell W pair production in e+ e- annihilation:…
We calculate the production cross sections for $D^{*+}D^{*-}$, $D^+D^{*-}$ and $D^+D^-$ in $e^+e^-$ annihilation through one virtual photon in the framework of perturbative QCD with constituent quarks. The calculated cross sections for…
Direct, resonant production of the charmonium states $\chi_{c1}$ and $\chi_{c2}$ in electron-positron annihilation is investigated. Depending on details of the model, a sizeable variation of the prediction for the production cross section…
We calculate the double charmonium production cross section within the framework of $4\times 4$ Bethe-Salpeter Equation in the electron-positron annihilation, at center of mass energy $\sqrt{s}= 10.6$GeV, that proceeds through the exchange…
We present a new analysis of double charmonium production in e^+ e^- annihilation. The observation of the processes e^+ e^- -> J/psi eta_c, J/psi chi_c0, and J/psi eta_c(2S) is confirmed using a dataset more than three times larger than…
A simple extension of the QCD inspired potential model which includes dynamical quarks first proposed by Eichten et al. is remarkably successful in accounting both for the observed narrow state heavy quarkonium spectroscopy and experimental…
We give a short review of the results for four fermion production, which have been obtained by the semi-analytical approach. The angular degrees of freedom (typically five or more) are integrated over analytically while the integrations…
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 give rise to 3- and 4-point photon vertices and to…
A total and differential cross-section calculation for the Electroweak Standard Model reaction $e^+ e^- \rightarrow (Z^0 Z^0) \rightarrow f_1\bar{f_1}f_2\bar{f_2}(\gamma)$\ including the effects of the finite $Z^0$\ width and, for the first…
A cross-section calculation for the Standard Model reaction $e^+e^- \rightarrow (Z^0Z^0) \rightarrow f_1\bar{f_1}f_2\bar{f_2}$ including the effects of the finite $Z^0$~width and initial state radiative corrections is presented. The angular…
We investigated the effect of the light fermion masses on cross sections for e^+e^- into 4 fermions in the Fermion Loop scheme defined in hep-ph/9612260, and approximations to it. The effects are found to be very small, except of course in…
The chargino pair production in $e^-e^-$ collisions with their subsequent decays are considered within SUSY models with R-parity violation and with lepton number non-conservation. The production process ($\sqrt{s}=1$ TeV) is predicted to be…
We investigate a contribution of the $d$ wave to the cross section of $e^+e^-$ annihilation to the pair of charged leptons or nucleons close to threshold of the process. In contrast to the point of view accepted in literature, due to the…
If the Dark Matter is the neutral Majorana component of a multiplet which is charged under the electroweak interactions of the Standard Model, its main annihilation channel is into W+W-, while the annihilation into light fermions is…
We analytically calculate the total and differential cross sections for the pair production of doubly heavy baryons in the framework of diquark model. The processes of electron-positron and quark-antiquark annihilations are considered. The…
Using 3.07 ${pb}^{-1}$ of data collected in the energy range 0.60-0.97 GeV by CMD-2, about 150 events of the process $\epm \to \pch$ have been selected. The energy dependence of the cross section agrees with the assumption of the $a_1(1260)…
We present a general classification of all four fermion final states in $\gamma\gamma$~collisions and a calculation of cross sections below the $W^+W^-$-threshold.
The cross sections of high-energy $\mu^+\mu^-$ pair production and paradimuonium production by a relativistic electron in the atomic field are discussed. The calculation is performed exactly in the parameters of the atomic field. Though the…
The cross-section for the production of $t\bar{t}$ pairs in $e^+e^-$-annihilation via a virtual photon is determined up to order $\alpha_s^2$. For the cm-energies of interest the effect of the top mass may not be considered as a small…
We make a detailed study on the typical production channel of double charmoniums, $e^+e^-\to J/\psi+\eta_c$, at the center-of-mass collision energy $\sqrt{s}=10.58$ GeV. The key component of the process is the form factor $F_{\rm VP}(q^2)$,…
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…