Standard Model Theory

The field of precision calculations for Standard Model processes at the LHC has experienced enormous progress in recent years. This talk highlights some examples from the physics of parton distribution functions, jets, electroweak gauge bosons and Higgs bosons.Comment: 10 pages, 8 figures, latex, to appear in the Proceedings of the EPS Conference on High Energy Physics (EPS-HEP), Venice, July 2017, reference adde

Radiative corrections to W-pair production in e+e- annihilation

The status of precision calculations for the processes e+e- --> WW --> 4 fermions is reviewed, paying particular attention to questions of gauge invariance and recent progress concerning photonic radiative corrections.Comment: 16 pages, latex, 4 postscript figures, contribution to the proceedings of "IVth International Symposium on Radiative Corrections, RADCOR 98", September 1998, Barcelona, Spai

Electroweak corrections to e+ e- -> f anti-f H

Some of the most interesting Higgs-production processes at future e+ e- colliders are of the type e+ e- -> f anti-f H. We present a calculation of the complete O(alpha) corrections to these processes in the Standard Model for final-state neutrinos and top quarks. Initial-state radiation beyond O(alpha) at the leading-logarithmic level as well as QCD corrections are also included. The electroweak corrections turn out to be sizable and reach the order of +/-10% and will thus be an important part of precise theoretical predictions for future e+ e- colliders.Comment: 4 pages, LaTeX, 4 postscript figures, talk given at Loops and Legs 2004, 7th DESY Workshop on Elementary Particle Theory, Zinnowitz, German

Approximations for W-Pair Production at Linear-Collider Energies

We determine the accuracy of various approximations to the O(alpha) corrections for on-shell W-pair production. While an approximation based on the universal corrections arising from initial-state radiation, from the running of alpha, and from corrections proportional to m_t^2 fails in the Linear-Collider energy range, a high-energy approximation improved by the exact universal corrections is sufficiently good above about 500GeV. These results indicate that in Monte Carlo event generators for off-shell W-pair production the incorporation of the universal corrections is not sufficient and more corrections should be included.Comment: 7 pages, late

Gauge-Boson Production in Electron-Photon Collisions

We summarize results for the processes $e^-\gamma \to \nu W^-, e^-Z, e^-\gamma$ within the electroweak Standard Model. We discuss the essential features of the corresponding lowest-order cross-sections and present numerical results for the unpolarized cross-sections including the complete $O(\alpha)$ virtual, soft-photonic, and hard-photonic corrections. While at low energies the weak corrections are dominated by the leading universal corrections, at high energies we find large, non-universal corrections, which arise from vertex and box diagrams involving non-Abelian gauge couplings.Comment: 7 pages + 5 figures appended as ps-files (uuencoded), latex, CERN-TH. 6980/9

Radiative corrections to the neutral-current Drell-Yan process in the Standard Model and its minimal supersymmetric extension

An adequate description of the neutral-current Drell-Yan process at the Tevatron and the LHC, in particular, requires the inclusion of electroweak radiative corrections. We extend earlier work in this direction in various ways. First, we define and numerically compare different methods to describe the Z-boson resonance including next-to-leading order electroweak corrections; moreover, we provide explicit analytical expressions for those. Second, we pay particular attention to contributions from photon-photon and photon-quark collisions, which involve photons in the initial state, and work out how their impact can be enhanced by selection cuts. Third, we supplement the O(\alpha) corrections by universal electroweak effects of higher order, such as universal two-loop contributions from \Delta\alpha and \Delta\rho, and the leading two-loop corrections in the high-energy Sudakov regime as well as multi-photon radiation off muons in the structure-function approach. Finally, we present results on the complete next-to-leading order electroweak and QCD corrections within the minimal supersymmetric extension of the Standard Model.Comment: 57 pages, latex, 19 figures, 7 tables; photon PDF factorization changed; minor corrections; version to appear in JHE