arXiv subjects
Publications and source records attributed to F. Campanario.
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.
We calculate the $W^\pmγj + X$-production cross sections at next-to-leading order QCD for Tevatron and LHC collisions. We include leptonic decays of the $W$ to light leptons, with all off-shell effects taken into account. The corrections are sizable and have significant impact on the differential distributions.
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.
VBFNLO is a fully flexible parton level Monte Carlo program for the simulation of vector boson fusion, double and triple vector boson production in hadronic collisions at next-to-leading order in the strong coupling constant. VBFNLO includes Higgs and vector boson decays with full spin correlations and all off-shell effects. In addition, VBFNLO implements CP-even and CP-odd Higgs boson via gluon fusion, associated with two jets, at the leading-order one-loop level with the full top- and bottom-quark mass dependence in a generic two-Higgs-doublet model. A variety of effects arising from beyond the Standard Model physics are implemented for selected processes. This includes anomalous couplings of Higgs and vector bosons and a Warped Higgsless extra dimension model. The program offers the possibility to generate Les Houches Accord event files for all processes available at leading order.
We compute the O(alpha_s) QCD corrections to charged triple vector boson production at a hadron collider, i.e. the processes pp -> ZZW + X and pp -> WWW + X. Intermediate Higgs boson exchange effects, spin correlations from leptonic vector boson decays, and off-shell contributions are all taken into account. Results are implemented in a fully flexible Monte Carlo program that allows for an easy customization of kinematical cuts and variation of the factorization and renormalization scales. We analyze the dependence of the differential cross sections under scale variations and present distributions where the QCD corrections strongly modify the leading-order results.
Using soft-collinear effective theory (SCET), we examine the 1/m_b corrections to the factorization formulas for inclusive semi-leptonic B decays in the endpoint region, where the hadronic final state consists of a single jet. At tree level, we find a new contribution from four-quark operators that was previously assumed absent. Beyond tree level many sub-leading shape-functions are needed to correctly describe the decay process.
We investigate the structure of the leading IR renormalon singularity in the QCD/HQET matching coefficients for heavy-light quark currents beyond the large-β_0 limit. From this result, we derive the large-order behaviour of the perturbative series for these coefficients, and for ratios of meson matrix elements, such as f_{B^*}/f_B.