Jet vetoes versus giant K-factors in the exclusive Z+1-jet cross section

We perform a detailed study of the exclusive Z+1-jet cross section at the 13 TeV LHC, motivated by the importance of similar exclusive cross sections in understanding the production of the Higgs boson in the W^+W^- final state. We point out a feature of the ATLAS analysis that has significant impact on the theoretical predictions: the jet-isolation criterion implemented by ATLAS effectively allows dijet events where an energetic jet is collinear to a final-state lepton. This process contains a giant $K$-factor arising from the collinear emission of a Z-boson from the dijet configuration. This overwhelms the effect of the jet-veto logarithms, making it difficult to test their resummation in this process. We provide numerical results that demonstrate the interplay between the jet-veto logarithms and the giant K-factor in the theoretical prediction. We study several observables, including the transverse momentum distributions of the leading jet and the Z-boson, in the exclusive Z+1-jet process, and discuss their sensitivity to both the giant K-factor and the jet-veto logarithms. We suggest a modified isolation criterion that removes the giant K-factor and allows for a direct test of the jet-veto resummation framework in the exclusive Z+1-jet process.Comment: 24 pages, 7 figures, 5 tables. Analysis and discussion extended to 13 TeV. Version published in PR

Mixed QCD-electroweak corrections to Higgs boson production in gluon fusion

We compute the 3-loop O(\alpha \alpha_s) correction to the Higgs boson production cross section arising from light quarks using an effective theory approach. Our calculation probes the factorization of QCD and electroweak perturbative corrections to this process. We combine our results with the best current estimates for contributions from top and bottom quarks to derive an updated theoretical prediction for the Higgs boson production cross section in gluon fusion. With the use of the MSTW 2008 parton distribution functions that include the newest experimental data, our study results in cross sections approximately 4-6% lower for intermediate Higgs boson masses than those used in recent Tevatron analyses that imposed a 95% confidence level exclusion limit of a Standard Model Higgs boson with M_H=170 GeV.Comment: 16 pgs., 5 figs. References and discussion added. Numerical results updated to use recent MSTW 2008 PDFs, which decrease the predicted Tevatron cross sectio