arXiv subjects
Publications and source records attributed to N. P. Merenkov.
The leading and next-to-leading radiative corrections to deep inelastic events with tagged photons are calculated analytically. Comparisons with previous results and numerical estimations are presented for the experimental conditions at HERA.
QED processes at electron-positron colliders are considerd. We present differential cross-sections for large-angle Bhabha scattering, annihilation into muons and photons. Radiative corrections in the first order are taken into account exactly. Leading logarithmic contributions are calculated in all orders by means of the structure-function method. An accuracy of the calculation can be estimated about 0.2%.
Processes of electron-positron annihilation into charged pions and kaons are considered. Radiative corrections are taken into account exactly in the first order and within the leading logarithmic approximation in higher orders. A combined approach for accounting exact calculations and electron structure functions is used. An accuracy of the calculation can be estimated about 0.2%.
Analytical formulae for small-angle Bhabha scattering cross-section at LEP1 are given for the case of wide-narrow angular acceptance. Inclusive and calorimeter event selections are considered. Numerical results are presented.
Analytical method is applied for description of the small angle Bhabha scattering at LEP1. Inclusive event selection for asymmetrical wide-narrow circular detectors is considered. The QED correction to the Born cross-section is calculated with leading and next-to-leading accuracy in the second order of perturbation theory and with leading one --- in the third order. All contributions in the second order due to photonic radiative corrections and pair production are calculated starting from essential Feynman diagrams. The third order correction is computed by means of electron structure function. Numerical results illustrate the analytical calculsations.
A closed expression for the differential cross section of the large-angle Bhabha $e^+ e^-$ scattering which explicitly takes into account the leading and next-to-leading contributions due to the emission of two hard photons is presented. Both collinear and semi-collinear kinematical regions are considered. The results are illustrated by numerical calculations.
We present the calculation of the elastic and inelastic high--energy small--angle electron--positron scattering with a {\it per mille} accuracy. PACS numbers 12.15.Lk, 12.20.--m, 12.20.Ds, 13.40.--f
We consider small--angle electron--positron scattering in Quantum Electrodynamics. Leading logarithmic contributions to the cross--section are explicitly calculated to three loop. Next--to--leading terms are exactly computed to two loop. All the radiative corrections due to photons as well as pair production are taken into account. The impact of newly evaluated next-to-leading and higher order leading corrections is discussed and numerical results are explicitly given. The results obtained are generally valid for high and low energy $e^+e^-$ colliders. At LEP and SLC these results can be used to reduce the uncertainty on the cross--section below the per mille level. PACS numbers 12.15.Lk, 12.20.--m, 12.20.Ds, 13.40.--f
The elastic and inelastic high--energy small--angle electron--positron scattering is considered. All radiative corrections to the cross--section with the relative accuracy $δσ/ σ= 0.1 \% $ are explicitly taken into account. According to the generalized eikonal representation for the elastic amplitude, in higher orders only diagrams with one exchanged photon may be considered. Single photon emission with radiative corrections and next--to--leading two--photon and pair production diagrams are evaluated, together with leading three--loop corrections. All contributions have been calculated analytically. We integrate the calculated distributions over typical for LEP~1 experiments intervals of angles and energies. To the leading approximation, the results are shown to be described in terms of kernels of electron structure functions. Some numerical results are presented. PACS numbers 12.15.Lk, 12.20.--m, 12.20.Ds, 13.40.--f
Radiative corrections due to the production of virtual as well as real soft and hard pairs in small-angle Bhabha scattering are calculated analytically. Both the collinear and the semi-collinear kinematical regions of hard pair production are considered. The calculation, within the leading and next-to-leading logarithmic approximation, provides an accuracy of O(0.1%). Numerical results show that the effects of pair production have to be taken into account for a luminosity determination accurate to O(0.1%) at LEP.