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Robert Harlander

Publications and source records attributed to Robert Harlander.

25 records · Page 2Linked to original sources
arXiv2003

Effects of SUSY-QCD in hadronic Higgs production at next-to-next-to-leading order

An estimate of the NNLO supersymmetric QCD effects for Higgs production at hadron colliders is given. Assuming an effective gluon-Higgs interaction, these corrections enter only in terms of process-independent, factorizable terms. We argue that the current knowledge of these terms up to NLO is sufficient to derive the NNLO hadronic cross section within the limitations of the standard theoretical uncertainties arising mainly from renormalization and factorization scale variations. The SUSY contributions are small with respect to the QCD effects, which means that the NNLO corrections to Higgs production are very similar in the Standard Model and the MSSM.

hep-ph↗
arXiv2003

NNLO QCD corrections to the Higgs-strahlung processes at hadron colliders

We implement, at next-to-next-to-leading order, the QCD corrections to Standard Model Higgs boson production in association with vector bosons at hadron colliders, $q\bar{q} \to HV$ with $V=W,Z$. They consist of the two--loop corrections to the Drell--Yan process for the production of off-shell vector bosons, $q\bar{q} \to V^*$, and in the case of $Z$ final states, of the additional contribution from heavy-quark loop mediated processes, in particular $gg \to HZ$. For the Higgs boson masses relevant at the Tevatron and the LHC, $M_H \lsim 200$--300 GeV, the two-loop corrections are small, increasing the production cross sections by less than 5% and 10%, respectively; the scale dependence is reduced to a level of less than a few per cent. This places these processes among the most theoretically clean Higgs boson production channels at hadron colliders.

hep-ph↗
arXiv2000

Higgs production in gluon fusion to order α_s^4

The calculation of the NNLO QCD corrections to the partonic process gg -> H is outlined. For the coupling of the Higgs boson to the gluons we use an effective Lagrangian in the limit of a heavy top quark. The focus is on the evaluation of the virtual two-loop corrections. It is shown that the leading pole terms are in agreement with the general formula by Catani.

hep-ph↗
arXiv1999

Asymptotic Expansions - Methods and Applications

Different viewpoints on the asymptotic expansion of Feynman diagrams are reviewed. The relations between the field theoretic and diagrammatic approaches are sketched. The focus is on problems with large masses or large external momenta. Several recent applications also for other limiting cases are touched upon. Finally, the pros and cons of the different approaches are briefly discussed.

hep-ph↗
arXiv1998

Higher order corrections to Z decay

Recent developments in the field of automatic computation of Feynman diagrams using asymptotic expansions are reviewed. The hadronic decay rate of the Z-boson is taken as an example for their physical application.

hep-ph↗