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V. A. Zykunov

Publications and source records attributed to V. A. Zykunov.

10 recordsLinked to original sources
arXiv2025

Exact calculation of photon polarization observables in Bethe-Heitler process

The effects of polarization transfer from the initial electron to the bremsstrahlung photon in electron-nucleus scattering (Bethe-Heitler process) are considered. The calculation is carried out without the assumption of smallness of the electron mass. A detailed comparison with previous well-known works is made. Some issues related to neglecting the electron mass are shown and commented on. The results are applicable to the modelling of polarized cross sections at low energies (even at a few electron mass scale).

hep-ph↗
arXiv2019

Radiative corrections in proton--antiproton annihilation to electron-positron and their application to the PANDA experiment

Radiative corrections to the annihilation of proton--antiproton into electron--positron are revisited, including virtual and real (soft and hard) photon emission. This issue is relevant for the time-like form factors measurements planned at the PANDA experiment at the FAIR facility, in next future. The relevant formulas are given. A stand-alone Monte-Carlo integrator is developed on the basis of the calculated radiative cross section and its application to the PANDA experiment is illustrated.

hep-ph↗
arXiv2017

Low and High Energy Asymptotic Behavior of Electroweak Corrections in Polarized $e^+ e^- \to μ^+ μ^-$ Process

Electroweak radiative corrections will play a major role in the analysis of several upcoming ultra-precision experiments such as Belle-II, so is crucial to make sure that they are fully under control. The article outlines the recent developments in the theoretical and computational approaches to one-loop (NLO) electroweak radiative corrections to the parity-violating asymmetry in $e^- e^+ \to μ^- μ^+ (γ)$ process with longitudinally polarized electrons. We derive asymptotic expressions for low and high energy regions (well below or above $Z$-resonance, correspondingly) and analyze the leading contributions. For most of energy regions, our results are in good agreement with precise computer-algebra based calculation and can used as a quicker alternative.

hep-ph↗
arXiv2015

Two-loop electroweak vertex corrections for polarized Møller scattering

The contributions to the electron-electron-photon vertex of two-loop electroweak corrections are calculated. The relative correction to the parity-violating asymmetry of Møller scattering for the case of 11 GeV electron scattered off the electron at rest is found to be about -0.0034 and should be taken into account at future experiment MOLLER at JLab.

hep-ph↗
arXiv2015

NNLO electroweak corrections for polarized Moller scattering: one-loop insertions to boxes

The paper discusses the two-loop (NNLO) electroweak radiative corrections to the parity-violating Moller scattering asymmetry induced by insertions to boxes of electron and neutrino mass operators (fermion self-energies), vertex functions and boson self-energies. The results will be relevant to the ultra-precise 11 GeV MOLLER experiment planned at the Jefferson Laboratory, which will measure the weak charge of the electron and search for new physics. The numerical estimations for the NNLO contribution to the cross section asymmetry are presented.

hep-ph↗
arXiv2012

Parity violating Moller scattering asymmetry up to the two-loop level

The paper investigates contributions of $Z$, $W$ and $γ$ intermediate states to the parity-violating Moller scattering asymmetry up to two-loop level. Using the Yennie--Frautschi--Suura factorization form for amplitudes, we demonstrate that QED corrections, with an exception of vacuum-polarization effects, cancel at the asymmetry level. We obtain chiral amplitudes at Born, one-loop and partially at two-loop level: boxes with lepton self-energies, ladder boxes and decorated boxes. Our calculations are relevant for the ultra-precise 11 GeV MOLLER experiment planned at Jefferson Laboratory and future ILC experiments. The numerical comparision of the two-loop contributions with the experimental accuracy of MOLLER is provided.

hep-ph↗
arXiv2012

One-loop chiral amplitudes of Moller scattering process

The high energy amplitudes of the large angles Moller scattering are calculated in frame of chiral basis in Born and 1-loop QED level. Taking into account as well the contribution from emission of soft real photons the compact relations free from infrared divergences are obtained. The expressions for separate chiral amplitudes contribution to the cross section are in agreement with renormalization group predictions.

hep-ph↗
arXiv2007

Weak radiative corrections to the Drell-Yan process for large invariant mass of a dilepton pair

The weak radiative corrections to the Drell-Yan process above the Z-peak have been studied. The compact asymptotic expression for the two heavy boson exchange - one of the significant contributions to the investigated process - has been obtained, the results expand in the powers of the Sudakov electroweak logarithms. At the quark level we compare the weak radiative corrections to the total cross section and forward-backward asymmetry with the existing results and achieve a rather good coincidence at \sqrt{s}>= 0.5 TeV. The numerical analysis has been performed in the high energy region corresponding to the future experiments at the CERN Large Hadron Collider (LHC). To simulate the detector acceptance we used the standard CMS detector cuts. It was shown that double Sudakov logarithms of the WW boxes are the dominant contributions in hadronic cross section. The considered radiative corrections are significant at high dilepton mass M and change the dilepton mass distribution up to ~+3(-12)% at the LHC energies and M=1(5) TeV.

hep-ph↗
arXiv2001

Electroweak corrections to the observables of W-boson production at RHIC

The processes of the single W-production in hadron-hadron collisions are suggested for investigation of the nucleon spin. An approach is proposed for the determination of quark spin densities at low x. The lowest order electroweak radiative corrections to the observable quantities are calculated. The numerical calculations of the cross sections and the single spin asymmetries taking into consideration the electroweak corrections at RHIC energies have been made.

hep-ph↗