NLO QCD corrections to the jet activity in Higgs boson production via vector-boson fusion

Higgs production plus two jets via vector-boson fusion is expected to provide crucial information on the Higgs boson couplings at the CERN Large Hadron Collider. The achievable statistical accuracy demands comparison with next-to-leading order QCD calculations, which are presented here in the form of a fully flexible partonic Monte Carlo program. QCD corrections are determined for jet distributions and are shown to be modest, of the order of 5%--10% in most cases, but reaching 30% occasionally. Remaining scale uncertainties range from the order of 5% or less for distributions to below +/-2% for the Higgs boson cross section in typical vector-boson fusion search regions.; Higgs boson production plus two jets via vector-fusion is sensitive to the tensor of the HVV (V = W, Z ) couplings, which distinguishes loop induced vertices from SM expectations. At the CERN Large Hadron Collider this information shows up in the azimuthal angle correlations of the two forward and backward quark jets which are typical for weak boson fusion. The next-to-leading order QCD corrections to this process, in the presence of anomalous HVV couplings are computed. It is shown that gluon emission does not significantly change the azimuthal jet correlations.; For Higgs production via vector boson fusion (VBF), there is suppressed jet activity in the central region of rapidity. Higgs production via VBF in the association of three jets (Hjjj) is computed to NLO accuracy in QCD. K factors for Hjjj are modest, typically, 1.03 to 1.06. Scale uncertainties for the total cross section at NLO are less than 5%. 3-jet ratios for Higgs production via VBF are computed at LO and NLO. The scale dependence of 3-jet ratios is shown to be reduced at NLO.