arXiv subjects

N. Merenkov

Publications and source records attributed to N. Merenkov.

5 recordsLinked to original sources

arXiv2022

ESFRAD. FORTRAN code for calculation of QED corrections to polarized ep-scattering by the electron structure function method

The main features of the electron structure function method for calculations of the higher order QED radiative effects to polarized deep-inelastic ep-scattering are presented. A new FORTRAN code ESFRAD based on this method was developed. A detailed quantitative comparison between the results of ESFRAD and other methods implemented in the codes POLRAD and RADGEN for calculation of the higher order radiative corrections is performed.

hep-ph↗

arXiv2004

Final-sate radiation in electron-positron annihilation into a pion pair

The process of $e^+e^-$ annihilation into a $π^+π^-$ pair with radiation of a photon is considered. The amplitude of the reaction $e^+e^-\toπ^+π^-γ$ consists of the model independent initial-state radiation (ISR) and model-dependent final-state radiation (FSR). The general structure of the FSR tensor is constructed from Lorentz covariance, gauge invariance and discrete symmetries in terms of the three invariant functions. To calculate these functions we apply Chiral Perturbation Theory (ChPT) with vector and axial-vector mesons. The contribution of $e^+e^-\toπ^+π^-γ$ process to the muon anomalous magnetic moment is evaluated, and results are compared with the dominant contribution in the framework of a hybrid model, consisting of VMD and point-like scalar eletrodynamics. The developed approach allows us also to calculate the $π^+π^-$ charge asymmetry.

hep-ph↗

arXiv2004

Final-state radiation in electron-positron annihilation into pion pair

The process of $e^+ e^-$ annihilation into $π^+ π^-$ pair with radiation of the photon is considered. The amplitude of the reaction $e^+ e^- \to π^+ π^- γ$ consists of the model independent initial-state radiation (ISR) and model dependent final-state radiation (FSR). The general structure of the FSR tensor is constructed from Lorentz covariance, gauge invariance and discrete symmetries in terms of the three invariant functions. To calculate these functions we apply Chiral Perturbation Theory (ChPT) with vector and axial-vector mesons. The contribution of $e^+ e^- \to π^+ π^- γ$ process to the muon anomalous magnetic moment is evaluated, and results are compared with the dominant contribution in framework of a hybrid model, consisting of VMD and point-like scalar electrodynamics. The developed approach allows us also to calculate the $π^+ π^-$ charge asymmetry.

hep-ph↗

arXiv2001

Model independent radiative corrections in processes of polarized electron-nucleon elastic scattering

The explicit formulae for radiative correction (RC) calculation for elastic $ep$-scattering is presented. Two typical measurements of polarization observables such as beam-target asymmetry or recoil proton polarization, are considered. Possibilities to take into account realistic experimental acceptances are discussed. The Fortran code MASCARAD for providing the RC procedure is presented. Numerical analysis is done for kinematical conditions of TJNAF.

hep-ph↗

arXiv1995

Small Angle Bhabha Scattering for LEP

We present the results of our calculations to a one, two, and three loop approximation of the e$^+$e$^-$$\rightarrow$e$^+$e$^-$ Bhabha scattering cross-section at small angles. All terms contributing to the radiatively corrected cross-section, within an accuracy of $δσ/ σ= 0.1 \% $, are explicitely evaluated and presented in an analytic form. $O(α)$ and $O(α^2)$ contributions are kept up to next-to-leading logarithmic accuracy, and $O(α^3)$ terms are taken into account to the leading logarithmic approximation. We define an experimentally measurable cross-section by integrating the calculated distributions over a given range of final-state energies and angles. The cross-sections for exclusive channels as well as for the totally integrated distributions are also given.

hep-ph↗