Related papers: Structure-dependent radiative corrections to $e^+ …
We use the unitary and analytic model of the pion electromagnetic form factor in order to evaluate in the lowest order the $e^{+}e^{-}\to\pi^{+}\pi^{-}$ contribution into the muon magnetic anomaly. We demonstrate, that this technique…
We calculate the leading-order QED radiative corrections to the process $e^- p\rightarrow e^- p l^- l^+ $ in the soft-photon approximation, in two different energy regimes which are of relevance to extract nucleon structure information. In…
Based on the S-matrix approach, we introduce a modified formula for the $\pi^{\pm}$ electromagnetic form factor which describes very well the experimental data in the energy region $2m_{\pi} \leq \sqrt{s} \leq 1.1$ GeV. Using the CVC…
A Monte Carlo generator has been constructed to simulate the reaction e^+e^- \to \gamma + 4 \pi, where the photon is assumed to be observed in the detector. Only initial state radiation is considered. Additional collinear photon radiation…
The differential cross section for the process $\gamma \gamma \to \pi^0 \pi^0$ has been measured in the kinematic range 0.6 GeV $< W < 4.1$ GeV, $|\cos \theta^*|<0.8$ in energy and pion scattering angle, respectively, in the $\gamma\gamma$…
The differential cross sections for the process $\gamma \gamma \to \pi^0 \pi^0$ have been measured in the kinematic range 0.6 GeV $< W < 4.1$ GeV, $|\cos \theta^*|<0.8$ in energy and pion scattering angle, respectively, in the…
The nonresonant mechanism in the reactions $e^+\,e^-\to \pi^-\,p\,\bar{n}$ and $e^+\,e^-\to \pi^+\,n\,\bar{p}$ is investigated in frame of the one-photon exchange approximation. The description of the hadronic phase space and the invariant…
We present a high-precision QED calculation, with 0.1% theoretical accuracy, of two photon production in $e^+ e^-$ annihilation, as required by more and more accurate luminosity monitoring at flavour factories. The accuracy of the approach,…
The study of the charge asymmetry of produced particles allows to investigate the interference of different production mechanisms and to determine new features of the corresponding amplitudes. In the process $e^- e^+ \to e^- e^+ \pi^+…
We present a detailed analysis of $e^+e^-\to\pi^+\pi^-$ data up to $\sqrt{s}=1\,\text{GeV}$ in the framework of dispersion relations. Starting from a family of $\pi\pi$ $P$-wave phase shifts, as derived from a previous Roy-equation analysis…
We study the one-loop radiative corrections to pair production of the supersymmetric scalar partners of the standard fermions in e+e- annihilation. Both electroweak and SUSY-QCD corrections are considered. Applications are for production of…
We have measured the cross section $\sigma(e^+e^-\to\pi^+\pi^-\gamma)$ with the KLOE detector at DA$\Phi$NE, at an energy $W=M_\phi=1.02$ GeV. From the dependence of the cross section on $m(\pi^+\pi^-)=\sqrt{W^2-2WE_\gamma}$, where…
We employ a dispersion relation that allows to recover the phase of the electromagnetic form factor of the pion from its absolute value above threshold. Compared to alternative approaches building on the phase, this approach builds on…
We calculate in chiral perturbation theory the double-pion photoproduction processes $\pi^-\gamma \to \pi^- \pi^0\pi^0$ and $\pi^-\gamma\to \pi^+\pi^-\pi^-$ at low energies. At leading order these reactions are governed by the chiral…
We complement studies of the neutral pion transition form factor pi^0 --> gamma^(*) gamma^(*) with calculations for the electromagnetic decay widths of the processes pi^0 --> e^+ e^-, pi^0 --> e^+ e^- gamma and pi^0 --> e^+ e^- e^+ e^-.…
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…
Final state radiation (FSR) in pion--pair production cannot be calculated reliably because of the composite structure of the pions. However, FSR corrections have to be taken into account for a precise evaluation of the hadronic contribution…
We estimate the isospin-violating QED radiative corrections to the charged-to-neutral ratios of the decay rates for B^+ and B^0 in non-leptonic B meson decays. In particular, these corrections are potentially important for precision…
We study the 1-loop corrections to the charged Higgs production both in the Minimal Supersymmetric Standard Model (MSSM) and in a more general type II two-Higgs-doublet model (THDM-II). We consider the full set of corrections (including…
We discuss an inclusive approach to the measurement of the e+e- --> pi+ pi- cross--section by the radiative return method without photon tagging. The essential part of this approach is the choice of rules for event selection which provide…