Fit to the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules in a renormalon based approach

We study the large order behaviour in perturbation theory of the Bjorken, Ellis-Jaffe and Gross-Llewellyn-Smith sum rules. In particular, we consider their first infrared renormalons, for which we obtain their analytic structure with logarithmic accuracy and also an approximate determination of their normalization constant. Estimates of higher order terms of the perturbative series are given. The Renormalon subtracted scheme is worked out for these observables and compared with experimental data. Overall, good agreement with experiment is found. This allows us to obtain {\hat a}_0 and some higher-twist non-perturbative constants from experiment: {\hat a}_0=0.141\pm 0.089; f_{3,RS}(1 GeV)=-0.124^{+0.137}_{-0.142} GeV^2.Comment: 23 pages, 18 figures, one reference added, journal versio

Di-boson Production beyond NLO QCD and Anomalous Couplings

In these proceedings, we review results for several di-boson production processes beyond NLO QCD at high transverse momenta using the VBFNLO Monte-Carlo program together with the LOOPSIM method. Additionally, we show for the WZ production process how higher order QCD corrections can resemble anomalous coupling effects.Comment: Conference Proceedings:C15-05-25.

Z\gamma\gamma production with leptonic decays and triple photon production at NLO QCD

We present a calculation of the O(alpha_s) QCD corrections to the production of a Z boson in association with two photons and to triple photon production at hadron colliders. All final-state photons are taken as real. For the Z boson, we consider the decays both into charged leptons and into neutrinos including all off-shell effects. Numerical results are obtained via a Monte Carlo program based on the structure of the VBFNLO program package. This allows us to implement general cuts and distributions of the final-state particles. We find that the NLO QCD corrections are sizable and significantly exceed the expectations from a scale variation of the leading-order result. In addition, differential distributions of important observables change considerably. The prediction of two-photon-associated Z production with Z decays into neutrinos from the charged-lepton rate works well, once we use an additional cut on the invariant mass of the charged-lepton pair.Comment: 14 pages, 10 figures, 2 table

Gluon Fusion induced Zg and Zgg Productions in the Standard Model at the LHC

We report calculations of the gluon induced Zg and Zgg productions in the Standard Model at the LHC operating at both 7 TeV and 14 TeV collision energy. We present total cross sections and differential distributions of the processes and compare them with the leading and next-to-leading order QCD pp -> Z+1 jet, Z+2 jets results. Our results show that the gluon induced Zg and Zgg productions contribute to pp -> Z+1 jet, Z+2 jets at 1% level.Comment: 8 pages, 5 figure

NLO QCD corrections to W+W- gamma and Z Z gamma production with leptonic decays

The computation of the NLO QCD corrections to the cross sections for W+W- gamma and ZZgamma production in hadronic collisions is presented. We consider the case of a real photon in the final state, but include full leptonic decays of the W and Z bosons. Numerical results for the LHC and the Tevatron are obtained through a fully flexible parton level Monte Carlo based on the structure of the VBFNLO program, allowing an easy implementation of arbitrary cuts and distributions. We show the dependence on scale variations of the integrated cross sections and provide evidence that NLO QCD corrections strongly modify the LO predictions for observables at the LHC both in magnitude and in shape

W\gamma \gamma production with leptonic decays at NLO QCD

The computation of the NLO-QCD corrections to the cross sections for W \gamma \gamma production in hadronic collisions is presented. We consider the case of real photons in the final state, but include full leptonic decays of the W. Numerical results for the LHC and the Tevatron are obtained through a parton level Monte Carlo based on the structure of the VBFNLO program, allowing an easy implementation of general cuts and distributions. We show the dependence on scale variations of the integrated cross sections and provide evidence of the fact that NLO QCD corrections strongly modify the LO predictions for observables at the LHC both in magnitude and in shape.Comment: 18 pages, 13 figure

Next-to-leading order QCD corrections to Wy production in association with two jets

We present the first calculation of next-to-leading order QCD corrections to QCD-induced ZZ production in association with two jets at hadron colliders. Both Z bosons decay leptonically with all off-shell effects, virtual photon contributions and spin-correlation effects fully taken into account. This process is an important background to weak boson scattering, to the measurement of quartic gauge couplings and to searches for signals of new physics beyond the Standard Model. As expected, the next-to-leading order corrections reduce significantly the scale uncertainty and show a non-trivial phase space dependence in kinematic distributions. Our code will be publicly available as part of the parton level Monte Carlo program VBFNLO.Comment: 12 pages, 4 figures, 2 tables. arXiv admin note: text overlap with arXiv:1402.050

NLO QCD corrections to processes with multiple electroweak bosons

The VBFNLO program package is a collection of Monte Carlo programs for the calculation of NLO QCD corrections to vector boson fusion cross sections, double and triple vector boson production, or the production of two electroweak bosons in association with an additional jet. An overview is given of the processes and features implemented in VBFNLO. WWgamma and Wgamma jet production are discussed as examples.Comment: 6 pages, 3 figures; talk given at RADCOR 2009 - 9th International Symposium on Radiative Corrections (Applications of Quantum Field Theory to Phenomenology), October 25 - 30 2009, Ascona, Switzerlan