Kemal Ozeren

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

The inclusive Higgs production cross section from gluon fusion is calculated through NNLO QCD, including its top quark mass dependence. This is achieved through a matching of the 1/Mt expansion of the partonic cross sections to the exact large-

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

\hat{s}

Next-to-Leading Order W 5-Jet Production at the LHC

limits which are derived from kT-factorization. The accuracy of this procedure is estimated to be better than 1% for the hadronic cross section. The final result is shown to be within 1% of the commonly used effective theory approach, thus confirming earlier findings.

Four-jet production at the Large Hadron Collider at next-to-leading order in QCD.

Abstract Top quark mass suppressed terms are calculated for the virtual amplitude for Higgs production in gluon fusion at three-loop level, i.e. O ( α s 3 ) . The method of asymptotic expansions in its automated form is used to evaluate the first three non-vanishing orders in terms of M H 2 / M t 2 , where the first order corresponds to the known results of the effective Lagrangian approach.

Driving Missing Data at Next-to-Leading Order

We present next-to-leading order QCD predictions for the total cross section and for a comprehensive set of transverse-momentum distributions in W + 5-jet production at the Large Hadron Collider. We neglect the small contributions from subleading-color virtual terms, top quarks and some terms containing four quark pairs. We also present ratios of total cross sections, and use them to obtain an extrapolation formula to an even larger number of jets. We include the decay of the

Top-mass effects in differential Higgs production through gluon fusion at O\left( {\alpha_s^4} \right)

W

Left-Handed W bosons at the LHC

boson into leptons. This is the first such computation with six final-state vector bosons or jets. We use BlackHat together with SHERPA to carry out the computation.

Colour decompositions of multi-quark one-loop QCD amplitudes

We present the cross sections for production of up to four jets at the Large Hadron Collider, at next-to-leading order in the QCD coupling. We use the BLACKHAT library in conjunction with SHERPA and a recently developed algorithm for assembling primitive amplitudes into color-dressed amplitudes. We adopt the cuts used by ATLAS in their study of multijet events in pp collisions at √s=7 TeV. We include estimates of nonperturbative corrections and compare to ATLAS data. We store intermediate results in a framework that allows the inexpensive computation of additional results for different choices of scale or parton distributions.

Missing Energy and Jets for Supersymmetry Searches

The prediction of backgrounds to new physics signals in topologies with large missing transverse energy and jets is important to new physics searches at the LHC. Following a CMS study, we investigate theoretical issues in using measurements of {gamma} + 2-jet production to predict the irreducible background to searches for missing energy plus two jets that originates from Z + 2-jet production where the Z boson decays to neutrinos. We compute ratios of {gamma} + 2-jet to Z + 2-jet production cross sections and kinematic distributions at next-to-leading order in {alpha}{sub s}, as well as using a parton shower matched to leading-order matrix elements. We find that the ratios obtained in the two approximations are quite similar, making {gamma} + 2-jet production a theoretically reliable estimator for the missing energy plus two jets background. We employ a Frixione-style photon isolation, but we also show that for isolated prompt photon production at high transverse momentum the difference between this criterion and the standard cone isolation used by CMS is small.

Analytic results for Higgs production in bottom fusion

A bstractEffects from a finite top quark mass on differential distributions in the Higgs + jet production cross section through gluon fusion are studied at next-to-leading order in the strong coupling, i.e.