Robert V. Harlander

Next-to-next-to-leading order Higgs production at hadron colliders

The Higgs-boson production cross section at pp and pp colliders is calculated in QCD at next-to-next-to-leading order (NNLO). We find that the perturbative expansion of the production cross section is well behaved and that scale dependence is reduced relative to the NLO result. These findings give us confidence in the reliability of the prediction. We also report an error in the NNLO correction to Drell-Yan production.

Higgs boson production in bottom quark fusion at next-to-next-to leading order

The total cross section for Higgs boson production in bottom-quark annihilation is evaluated at next-to-next-to-leading order in QCD. This is the first time that all terms at order

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

{\ensuremath{\alpha}}_{s}^{2}

Corrections of to the decay of the Z boson into bottom quarks

are taken into account. We find a greatly reduced scale dependence with respect to lower order results, for both the factorization and the renormalization scales. The behavior of the result is consistent with earlier determinations of the appropriate factorization scale for this process of

Higgs production and decay: Analytic results at next-to-leading order QCD

{\ensuremath{\mu}}_{F}\ensuremath{\approx}{M}_{H}/4,

Finite top mass effects for hadronic Higgs production at next-to-next-to-leading order

and supports the validity of the bottom parton density approach for computing the total inclusive rate. We present precise predictions for the cross section at the Fermilab Tevatron and the CERN Large Hadron Collider.

Higgs production in gluon fusion at next-to-next-to-leading order QCD for finite top mass

Abstract 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 q →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 q →V ∗ , and in the case of Z final states, of the additional contribution from heavy-quark loop mediated processes, in particular gg→HZ. For the Higgs boson masses relevant at the Tevatron and the LHC, MH≲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.

Light MSSM Higgs boson mass to three-loop accuracy

Abstract For the vertex corrections to the partial decay rate Γ(Z→b b ) involving the top quark only the leading terms of order αα s in the 1/ M t expansion are known. In this work we compute the missing next-to-leading corrections. They turn out to be equally important as the leading term and therefore have to be included into an O (αα s ) analysis to arrive at reliable predictions.

Production of a pseudo-scalar Higgs boson at hadron colliders at next-to-next-to-leading order

The virtual two-loop corrections for Higgs production in gluon fusion are calculated analytically in QCD for arbitrary Higgs and quark masses. Both scalar and pseudo-scalar Higgs bosons are considered. The results are obtained by expanding the known one-dimensional integral representation in terms of mH/mq, and matching it with a suitably chosen ansatz of Harmonic Polylogarithms. This ansatz is motivated by the known analytic result for the Higgs decay rate into two photons. The method also allows us to check this result and to extend it to the pseudo-scalar decay rate.

Top mass effects in Higgs production at next-to-next-to-leading order QCD: Virtual corrections

The first four terms of an expansion in MH2/Mt2 of the total inclusive cross section for Higgs production in gluon fusion are evaluated through next-to-next-to-leading order QCD. A reliable and precise approximation of the full top mass dependence at NNLO is derived and compared to the frequently used heavy-top limit. It is found that both results agree numerically to better than 0.5% in the Higgs mass range of 100–300 GeV. This validates the higher order results for the inclusive Higgs cross section and justifies the heavy-top limit as a powerful tool for Higgs phenomenology at the LHC and the Tevatron.