N. P. Merenkov

Hadronic cross sections in electron-positron annihilation with tagged photon

Events with tagged photons in the process of electron-positron annihilation into hadrons are considered. The initial state radiation is suggested to scan the hadronic cross section with the energy. QED radiative corrections are taken into account. The results for the total and exclusive cross sections are given in an analytic form. Some numerical estimates are presented.

Large angle QED processes at e+e− colliders at energies below 3 GeV

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%.

Radiative corrections for pion and kaon production at e+e? colliders of energies below 2 GeV

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%.

Scanning of hadra]on cross section at DAΦNE by analysis of the initial-state radiative events

The initial-state radiative events in electron-positron annihilation into hadrons at DAΦNE are considered. The corresponding cross section with the full first-order radiative corrections is calculated. The analytical calculations take into account the actual angular acceptance and energy cutoff of the DAΦNE photon detector.The initial-state radiative events in electron-positron annihilation into hadrons at DAFNE have been considered. The coresponding cross-section with the full first order radiative correction has been calculated. The analytical calculations take into account the realistic angular acceptance and energy cut of DAFNE photon detector.

Single-spin asymmetries in the bethe-heitler process e- + p → e- + γ + p induced by loop corrections

The single-spin beam and target asymmetries in the hard electroproduction process e− + p → e− + γ + p induced by the loop radiative corrections to the vertex part of lepton interaction are considered. The physical reason for the appearance of such asymmetries is the nonzero imaginary part of the amplitude (on the level of radiative corrections) caused by diagrams with photon radiation from the outgoing electron. We calculate the single-spin beam and target asymmetries at a longitudinally polarized electron beam or at arbitrary polarizations of the target proton for the CLAS and HERMES experimental conditions.

QED corrections in deep-inelastic scattering from tensor-polarized deuteron target

The leading-log model-independent radiative corrections to deep-inelastic scattering of an unpolarized electron beam from the tensor-polarized deuteron target have been considered. The calculation is based on the covariant parameterization of the deuteron quadrupole polarization tensor and the use of the Drell-Yan-like representation in electrodynamics to describe the radiation of real and virtual particles by the initial and scattered electron.

Vector Meson dominance pion electromagnetic form factor with σ-model loop corrections

A model is developed for the electromagnetic form factor of the pion. One-loop corrections are included in the linear σ-model. The ρ-meson contribution is added in an extended VMD model. The form factor, calculated without fitting parameters, is in a good agreement with experiment for spacelike and timelike photon momenta. Loop corrections to the two-pion hadronic contribution aμ(had,π) to the muon anomalous magnetic moment are calculated. The optimal value of the σ-meson mass appears to be very close to the ρ-meson mass.

Current tensor with heavy photon for double hard photon emission by a longitudinally polarized electron

The electron current tensor for the scattering of a heavy photon on a longitudinally polarized electron with the emission of two hard real photons is considered. The contributions of collinear and semicollinear kinematics are computed. The result allows one to calculate the corresponding contribution to the second-order radiative correction to the deep inelastic scattering or electron-positron annihilation cross sections with next-to-leading-order accuracy.The electron current tensor for the scattering of heavy photon on longitudinally polarized electron accompanied with two hard real photonsis considered. The contribution of collinear and semicollinear kinematics is computed. The obtained result allows to calculate the corresponding contribution into second order radiative correction to DIS or electron-positron annihilation cross-sections with the next-to-leading accuracy.

Tagged-photon events in polarized deep inelastic scattering

Deep-inelastic events for the scattering of the longitudinally polarized electron by polarized proton with tagged collinear photon radiated from initial-state electron are considered. The corresponding cross-section is derived in the Born approximation. The model-independent radiative corrections to the Born cross-section are also calculated. Obtained result is applied to the case of elastic scattering.Deep inelastic scattering events of a longitudinally polarized electron by a polarized proton with a tagged collinear photon radiated from the initial-state electron are considered. The corresponding cross section is derived in the Born approximation. The model-independent radiative corrections to the Born cross section are also calculated. The obtained result is applied to the elastic scattering.

QED corrections to DIS cross section with tagged photon

We calculate the QED corrections to the deep inelastic scattering cross section with tagged photon at HERA, taking into account the leading and next-to-leading contributions. Different types of event selection are investigated.