Related papers: $R_{e^+ e^-}$ and an effective QCD charge
Infrared finite solutions for the gluon propagator of pure QCD are obtained from the gauge-invariant non-linear Schwinger-Dyson equation formulated in the Feynman gauge of the background field method. These solutions may be fitted using a…
Electromagnetic dipole polarizabilities are fundamental properties of a hadron that represent its resistance to deformation under external fields. For a charged hadron, the presence of acceleration and Landau levels complicates the…
We use a boost-invariant one-dimensional (cylindrically symmetric) fluid dynamics code to calculate $e^+e^-$ production from $\rho^0$ and $\omega$ decay in the central rapidity region of a central S+Au collision at $\sqrt{s}=20$…
New integral representations for the Adler D-function and the R-ratio of the electron-positron annihilation into hadrons are derived in the general framework of the analytic approach to QCD. These representations capture the nonperturbative…
We report the first double differential cross sections of two charged pions and kaons ($e^+e^- \rightarrow hhX$) in electron-positron annihilation as a function of the fractional energies of the two hadrons for any charge and hadron…
We present the first genuine QCD five-loop calculation of the vacuum polarization functions: analytical terms of order alpha_s^4 n_f^2 to the absorptive parts of vector and scalar correlators. These corrections form an important…
We compute the inclusive spectrum of produced particles in e+e- annihilation in confining gauge theories that have a gravity dual and show that the momentum distribution exhibits the thermal behavior.
The effective charge of an element is a parameter characterizing the electromgration effect, which can determine the reliability of interconnection in electronic technologies. In this work, machine learning approaches were employed to model…
Hadronization corrections to the predictions of perturbative QCD are reviewed. The existing models for the conversion of quarks and gluons into hadrons are summarized. The most successful models give a good description of the data on…
The precise determination of the cross section for electron-positron annihilation into hadrons is one of the central tasks of ongoing experiments at low energy colliders. These measurements have to be complemented by Monte Carlo generators…
We estimate the non-perturbative power-suppressed corrections to heavy flavour fragmentation and correlation functions in e^+e^- annihilation, using a model based on the analysis of one-loop Feynman graphs containing a massive gluon. This…
We consider the $\pi^+\pi^-\pi_0\gamma$ final state in electron-positron annihilation at cms energies not far from the threshold. Both initial and final state radiations of the hard photon is considered but without interference between…
We compute the electrical conductivity of the strongly interacting medium in the presence of strong magnetic background fields, $eB=4,9~GeV^2$, and for different values of the temperature, both in the confined and in the deconfined…
The experimental data from VENUS, TOPAS, OPAL, DELPHI, ALEPH and L3 collaborations, collected from 1989 to 2003, are applied to study the QED framework through direct contact interaction terms approach, using the annihilation reaction $\rm…
The lowest order radiative correction to the differential cross-section of process of muon pair production with emission of hard photon at high energy electron-positron annihilation are calculated. Taking into account the emission of…
The process $e^{+}e^{-} \to q\bar{q}$ plays an important role in electroweak precision measurements. We are studying this process with ILD full simulation. The key for the reconstruction of the quark pair final states is quark charge…
The experimental data collected by KEDR and BESIII collaborations at the energies below charm quark thresholds are compared with the QCD expressions for the $e^+e^-$ annihilation R-ratio truncated at different orders of perturbation theory.…
We evaluate the next-to-leading order radiative corrections to a process in the massless Schwinger model that is the analogue of the $e^+e^-$ inclusive annihilation into hadrons process in QCD. We then carry out an asymptotic expansion of…
The complete calculation of the 2-loop electroweak corrections to the renormalization of the electric charge in the Standard Model allows to discuss in detail the value of the MSbar effective coupling $\hat e(m_Z)$. We discuss the…
The experimental charged particles multiplicity distributions in $e^+e^-$ annihilation to hadrons are compared with the distributions obtained by PYTHIA. The ratio $\chi^2$/degrees of freedom is calculated for 6 energies at $\sqrt{s}$ 14 --…