Related papers: Total cross sections of $e\gamma\to e X\bar{X}$ pr…
The processes $e^+e^-\to e^+e^-X$, with $X$ being either the $\eta$ meson or $\pi^0\pi^0$, are studied at DA$\Phi$NE, with $e^+e^-$ beams colliding at $\sqrt{s}\simeq1$ GeV, below the $\phi$ resonance peak. The data sample is from an…
The process $e^{+}e^{-}\rightarrow\gamma^{*}\rightarrow \pi^{0}\gamma$ was considered using time-like pion transition form factor, obtained in the approach of the Anomaly Sum Rules(ASR). The total cross section and angular distribution of…
We calculate the next-to-next-to-leading order (NNLO) QED corrections to the $C$-odd part of the differential cross section of the $e^+e^-\to\mu^+\mu^-$ process. This part contributes to the angular and forward-backward asymmetry. Together…
The results on e+e- --> W+W- --> 4f(+gamma) obtained by different groups are compared with each other. Differences in the results for the total cross section of up to about 0.6% are traced back to different ways of implementing the…
We study the processes e+ e- --> 3(pi+pi-)gamma, 2(pi+pi-pi0)gamma and K+ K- 2(pi+pi-)gamma, with the photon radiated from the initial state. About 20,000, 33,000 and 4,000 fully reconstructed events, respectively, have been selected from…
The energy reconstruction of high-energy muons depends on the energy loss characteristics. Accurate knowledge of the cross sections of the energy loss processes is necessary for precise measurements of the energy spectrum of muons and…
The Born cross sections of $e^{+}e^{-}\to \Sigma^{0}\bar{\Sigma}^{0}$ are measured at center-of-mass energies from $2.3864$ to $3.0200$ GeV using data samples with an integrated luminosity of $328.5$ pb$^{-1}$ collected with the BESIII…
A Monte Carlo program is presented for the computation of the most general cross section for two-photon production in e+e- collisions at fixed two-photon invariant mass W. Functions implemented for the five gamma* gamma* structure functions…
We calculate the NNLO QED corrections to the $C$-even part of differential cross section of $e^+e^- \to \mu^+\mu^-$ process. We neglect power corrections in the electron mass and obtain the result in terms of Goncharov's polylogarithms.
Based on $e^{+}e^{-}$ annihilation data collected with the BESIII detector at the BEPCII collider, searches for the $e^{+}e^{-}\to\Sigma_{c}\bar{\Sigma}_{c}$ ($\Sigma_{c}^{+}\bar{\Sigma}_{c}^{-}$, $\Sigma_{c}^{0}\bar{\Sigma}_{c}^{0}$ and…
First correction to the high-energy asymptotics of the total $e^+e^-$ photoproduction cross section in the electric field of a heavy atom is derived with the exact account of this field. The consideration is based on the use of the…
The cross section of the process $e^+e^- \rightarrow \omega \chi_{c0}$ is measured at center-of-mass energies from $\sqrt{s} =$ 4.178 to 4.278 GeV using a data sample of 7 fb$^{-1}$ collected with the BESIII detector operating at the BEPCII…
We derive an analytic representation of the ten-particle, two-loop double-box integral as an elliptic integral over weight-three polylogarithms. To obtain this form, we first derive a four-fold, rational (Feynman-)parametric representation…
A covariant method is proposed for calculating the amplitudes of processes involving polarized spin 1/2 particles. It is suitable for calculating the interference terms in the cross sections of such processes. As an illustration,…
Helicity amplitudes and differential cross section of high-energy $e^+e^-$ photoproduction accompanied by bremsstrahlung in the electric field of a heavy atom are derived. The results are exact in the nuclear charge number and obtained in…
Using data samples with a total integrated luminosity of $20.1~\rm fb^{-1}$ collected by the BESIII detector operating at the BEPCII collider, the cross section of the process $e^+e^- \rightarrow \pi^+\pi^-\psi(3686)$ is measured at…
The total cross section for top quark pair production close to threshold in e+e- annihilation is investigated. Details are given about the calculation at next-to-next-to-leading logarithmic order. The summation of logarithms leads to a…
The cross sections of the process $e^{+}e^{-} \to K_{S}^{0}K_{L}^{0}$ are measured at fifteen center-of-mass energies $\sqrt{s}$ from $2.00$ to $3.08~{\rm GeV}$ with the BESIII detector at the Beijing Electron Positron Collider (BEPCII).…
The distributions of the bottom quark in the process $e^+ e^- \to t \, \bar{t} \to b \, W^+ \, \bar{t}$ are considered at the $e^+ e^-$ energy corresponding to the first construction stage of the Compact Linear Collider. The cross sections…
The cross section of the process $e^+e^-\to\pi^+\pi^-\pi^0$ is measured with a precision of 1.6% to 25% in the energy range between $0.7$ and 3.0 GeV using the Initial State Radiation method. A data set with an integrated luminosity of…