Related papers: Excited electron contribution to the e+e- -> \gamm…
The differential cross section and some polarization observables have been calculated for the $e^+\,e^-\to \gamma\,\gamma$ reaction taking into account the contribution of the heavy excited electron and the general form…
We study the potential of $\gamma \gamma$ option of future high energy linear $e^{+}e^{-}$ colliders to search for excited electrons with spin-1/2. We calculate single production cross sections, give the angular distributions and $f-m^*$…
The amplitude for the anomalous transitions gamma pi(+) -> pi(0) pi(+) is analyzed within Chiral Perturbation Theory including electromagnetic interactions. The presence of a t-channel one-photon exchange contribution induces sizeable e^2…
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…
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…
The integrated cross sections of high-energy $e^+e^-$ electroproduction by an electron in an atomic field is studied. Importance of various contributions to these cross sections is discussed. It is shown that the Coulomb corrections are…
The possibility of single and pair excited neutrino production in high energy e+e-, gamma-e and gamma-gamma collisions on linear colliders is studied. The integrated cross sections of these subproceses are calculated. Special attention is…
Electron-impact cross sections for the dissociation process of vibrationally excited He2+ molecular ion, as a function of the incident electron energy are calculated for the dissociative transition X2\Sigma+u \to A2\Sigma+g by using the…
We analyze the capability of the next generation of linear electron--positron colliders to unravel the spin and couplings of excited leptons predicted by composite models. Assuming that these machines will be able to operate both in the…
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 effect of anomalous gauge couplings on polarized $e^- e^-$ scattering cross sections is examined. It turns out that different combinations of beam polarizations provide constraints that are complementary to each other and to those…
Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes $e^-\gamma \to e^-X\bar{X}$ with $X=\mu,\,\gamma$ or $e$ at arbitrary energies. For the first two processes our…
We give the amplitude for $\gamma\gamma \rightarrow \pi^+\pi^-\pi^0$ in leading order chiral perturbation theory. For the case of real photons we calculate the total and differential cross section. Furthermore, we give the dependence of the…
We analyzed the potential of the LC with $\sqrt{s}=0.5$ TeV, LC$\times$LHC based ep collider with $\sqrt{s}=3.74$ TeV and LHC with $\sqrt{s}=14$ TeV to search for excited electrons through transition magnetic type couplings with gauge…
The ability of high energy $e^+e^-$ colliders to indirectly probe the existence of heavy new charged gauge bosons via their exchange in the reaction $e^+e^-\to \nu\bar\nu\gamma$ is investigated. It is shown that examination of the resulting…
Direct detection experiments utilizing electronic excitations are spearheading the search for light, sub-GeV, dark matter (DM). It is thus crucial to have accurate predictions for any DM-electron interaction rate in this regime. EXCEED-DM…
The form factor \pi^0\gamma^*\gamma^* is obtained to the next leading order of derivative expansion of the chiral anomaly and the VMD. As a test the form factor has been used to calculate the cross section of ee^+-->\pi^0\gamma. Theory…
This paper presents a theoretical investigation of the cross sections for dissociative electron attachment and dissociative excitation processes in vibrationally excited CH radicals induced by electron impact. Resonant electron-CH…
A search for excited electron e* production is described in which the electroweak decays e*->e gamma, e*->e Z and e*->nu W are considered. The data used correspond to an integrated luminosity of 120 pb^(-1) taken in e^(+-)p collisions from…
We calculate the cross-section for the diffractive exclusive process gamma*_L (Q_1^2) gamma*_L(Q_2^2) -> rho^0_L rho^0_L, in view of its study in the future high energy e+e- linear collider. The Born order approximation of the amplitude is…