Related papers: Total cross sections of $e\gamma\to e X\bar{X}$ pr…
Using data samples collected at center-of-mass energies between 2.000 and 3.080 GeV with the BESIII detector operating at the BEPCII collider, a partial-wave analysis is performed on the process $e^+e^-\to\eta\pi^+\pi^-$. In addition to the…
Using recent BABAR, CMD-3 and SND data, the sum of $e^+e^- \to 3(\pi^+\pi^-), 2(\pi^+\pi^-\pi^0), p\bar{p}, n\bar{n}$ cross sections is obtained. Unlike $e^+e^- \to 3(\pi^+\pi^-)$ and $e^+e^- \to 2(\pi^+\pi^-\pi^0)$ processes, no structures…
The $\epsilon$-expansion of several two-loop self-energy diagrams with different thresholds and one mass are calculated. On-shell results are reduced to multiple binomial sums which values are presented in analytical form.
We derive an algorithm for computing the total differentials of multi-loop integrals expressed as one-fold integrals of multiple polylogarithms, which can involve square roots of polynomials up to degree four and may evaluate to (elliptic)…
We study predictions for the reaction $e^+e^- \to {\bar \nu} \nu (n \gamma)$. The complete one-loop corrections are taken into account and higher order contributions, in particular those for the observed real photons, are added whenever…
Using the $e^+e^-$ collision data collected with the BESIII detector operating at the BEPCII collider, at center-of-mass energies from the threshold to $4.95$~GeV, we present precise measurements of the cross sections for the process…
The $e^+e^-\to\eta\gamma$ cross section is measured in the center-of-mass energy range from 1.07 to 2.00 GeV in the decay channel $\eta\to 3\pi^0$, $\pi^0\to\gamma\gamma$. The data set with an integrated luminosity of 242 pb$^{-1}$…
A summary of the current understanding of methods of analytical higher order perturbative computations of total cross sections and decay widths in Quantum Chromodynamics is presented. As examples, the total cross section in electron…
The cross sections for the reactions $e^+e^- \to \phi\eta, \quad \phi\eta', \quad \rho\eta, \quad \rho\eta'$ have been measured using a data sample of 516 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$…
In the extended NJL model the total cross sections of the processes $e^+e^- \to (\eta, \eta', \eta(1295), \eta(1405))\gamma$ at energies up to 2 GeV are calculated. The intermediate vector mesons $\rho (770)$, $\omega(782)$, $\phi (1020)$,…
This paper gives high-precision theoretical predictions for cross sections of the process $e^+e^- \to \gamma Z$ for future electron-positron colliders. The calculations are performed using the SANC system. They include complete one-loop…
We use a recent O(alpha_s^2) calculation of the differential cross section for the production of heavy quarks in e+e- annihilation to compute a few moments of the heavy quark single-inclusive production cross section. We verify that,…
We propose a semiclassical approach to calculate multiparticle cross sections in scalar theories, which have been strongly argued to have the exponential form $\exp(\lambda^{-1}F(\lambda n,\epsilon))$ in the regime $\lambda\to0$, $\lambda…
The cross section of the process e^+e^-\to \pi^+\pi^- was measured in the SND experiment at the VEPP-2M collider in the energy region 400<\sqrt[]{s}<1000 MeV. This measurement was based on about 12.4 \times 10^6 selected collinear events,…
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…
Using initial-state radiation events from a total integrated luminosity of 11.957 fb$^{-1}$ of $e^+e^-$ collision data collected at center-of-mass energies between 3.773 and 4.258 GeV with the BESIII detector at BEPCII, the cross section…
We describe a constructive procedure to separate overlapping infrared divergences in multi-loop integrals. Working with a parametric representation in D=4-2*epsilon dimensions, adequate subtractions lead to a Laurent series in epsilon,…
Over the past few years considerable progress has been made on the resummation of double-logarithmically enhanced threshold (large-x) and high-energy (small-x) higher-order contributions to the splitting functions for parton and…
In modern quantum field theory, one of the most important tasks is the calculation of loop integrals. Loop integrals appear when evaluating the Feynman diagrams with one or more loops by integrating over the internal momenta. Even though…
We report first measurements of e+e- -> D(*)+D(*)- processes far above threshold. The cross-sections for e+e- -> DT*+DL*- and e+e- -> D+D*T- at sqrt{s}=10.58 GeV/c2 are measured to be 0.55 +- 0.03 +- 0.05 pb and 0.62 +- 0.03 +- 0.06 pb,…