QCD corrections to the parton-model sum rules for structure functions of deep inelastic scattering

The results of two-loop calculations of the O(α_s²) corrections to the first nonsinglet moments of the deep inelastic scattering structure functions for polarized and unpolarized targets are presented.     

Electromagnetic corrections to deep inelastic scattering at HERA

The dominant electromagnetic radiative corrections to neutral current deep inelastic scattering at HERA energies have been calculated analytically in collinear approximation for unpolarized beams. The results may be used for the construction of an event generator and are applied to discuss the influence of cuts on the magnitude of the correction. For final state collinear photon emission the measurement of the resulting electromagnetic jet (electron plus collinear photon) reducesx-andy-dependence of the correction factor. Electromagnetic corrections to charged current interactions are discussed in leading logarithmic approximation.     

Unitarity corrections to the Lipatov Pomeron and the four-gluon operator in deep inelastic scattering in QCD

Starting from a four-gluon partial-wave amplitude which provides the first unitarity corrections to the Lipatov Pomeron we study the deep inelastic limit. We find mixing between the four-gluon operator and a twistfour piece of the two-gluon operator. We calculate the diagonal elements of the matrix of the anomalous dimensions and the coefficient function of the singular part (nearn=1) of the four-gluon operator. Several disagreements between our results and the Gribov-Levin-Ryskin evolution equation are found.     

QCD cascade model in deep inelastic scattering

We develop a new QCD cascade model for jets in deep inelastic scattering. We use the light-like axial gauge whose gauge vector is parallel to momentum of the initial parton so that only final partons cascade. Due to this feature we can generate events for any given virtualityQ ² andx _B =Q ²/2Pq.     

Electroweak radiative corrections to deep inelastic scattering at HERA

Analytic results are presented on electroweak radiative corrections for neutral-current deepinelastic electron proton scattering at HERA energies. Single photon bremsstrahlung is included without cuts.     

Electroweak radiative corrections to deep inelastic scattering at HERA. Charged current scattering

Analytic results are presented on electroweak radiative corrections for charged-current deep-inelastic electron proton scattering at HERA energies. Single photon bremsstrahlung is included without cuts.     

Evidence for higher order asymptotic freedom corrections to deep inelastic scattering

We find new evidence for higher order asymptotic freedom corrections to the moments of the proton structure function in electron, muon scattering for spins n ? 4. We show that it is unlikely that this effect can be associated in any simple way with higher-twist effects.     

QCD asymptotics and kinematic thresholds in deep inelastic scattering

The Nachtmann moments of deep inelastic scattering structure functions are required by kinematics to contain a so far neglected threshold factor which is dependent on both n and q². Its presence significantly affects the “moment analysis” in the usual QCD phenomenology and it resolves the difficulties connected with improper threshold behavior of the “ξ-scaling” analysis of structure functions.     

QCD power corrections to deep-inelastic scattering

Q^?2 corrections due to next-to-leading twist operators are calculated for the first and the second moments of deep-in-elastic structure functions.     

NLO QCD corrections to Drell-Yan processes in the SANC framework

NLO QCD corrections to charged and neutral current Drell-Yan processes are computed with help of the computer system SANC. At the partonic level both quark-antiquark and quark-gluon scattering channels are taken into account. Subtraction of collinear singularities in the massive quark scheme is compared with the one in the $ \overline {MS} $ \overline {MS} scheme. Numerical results at the hadronic level are received for the LHC conditions with help of Monte-Carlo integrators and event generator programs based on the standard SANC modules. Comparison with analogous results of the MCFM package is shown.     

On the electromagnetic corrections in deep inelastic νN scattering

The electromagnetic (EM) radiative corrections to the inclusive νN deep inelastic charged and neutral-current (CC and NC) scattering are studied in the on-shell renormalization scheme of the standard electroweak (EW) model.     

Radiative corrections to deep inelastic electron-deuteron scattering: The case of tensor-polarized deuteron

Model-independent radiative corrections to deep inelastic scattering of an unpolarized electron beam off the tensor-polarized deuteron target are considered. The contribution to the radiative corrections due to the hard photon emission from the elastic electron-deuteron scattering (the so-called elastic radiative tail) is also investigated. The calculation is based on the covariant parametrization of the deuteron quadrupole polarization tensor. Radiative corrections to the polarization observables are estimated numerically for the kinematical conditions of the current experiment at HERA.     

QCD effects in semi-inclusive deep inelastic scattering from a polarized target

The next-to-leading logarithmic corrections to cross-sections for semi-inclusive deep inelastic scattering from a polarized target are worked out. Predictions for pion asymmetries and pion charge ratios are given.     

Higher order QCD effects in inclusive annihilation and deep inelastic scattering

We present a parton model interpretation of the predictions of quantum chromodynamics in the process e⁺e^?→hadron + anything. We give thecomplete list of parameters needed for the study of the scaling violations of fragmentation functions up to the next-to-leading logarithmic approximation. This includes flavour non-singlet and flavour singlet anomalous dimensions up to order α² and coefficient functions up to order α. We also present results for the deep inelastic scattering e^?h→e^? + anything. We find that in e⁺e^? annihilation the ratio of scaling violations of second order to first order is in general bigger than the corresponding ratio for deep inelastic scattering. The Gribov-Lipatov relation is thus violated in second order. We also find that a modified Drell-Yan analytic continuation relation holds between the deep inelastic and annihilation structure functions for quarks and gluons. In x space we give detailed numerical evaluation of the QCD effects for non-singlet and singlet densities, in the space-like and time-like regions.     

On the problem of large radiative corrections in deep inelastic scattering

A serious problem caused by large radiative corrections in deep inelastic scattering is indicated. A simple way how to avoid a principal difficulty related to it is suggested.An abreviated version of this article was presented as a contribution to Hadron Structure '90 conference at Smolenice castle, Czechoslovakia, 25 October, 1990.     

Two-loop QCD corrections to the coefficient functions of the deep inelastic structure functionsF 2 andF L

We present the analytic two-loop perturbative QCD corrections in the leading twist approximation to the coefficient functions of the operator product expansion for the second to tenth moments of the nonsinglet and singlet deep inelastic structure functionsF ₂ andF _L .