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Precise Higgs-background predictions: merging NLO QCD and squared quark-loop corrections to four-lepton + 0,1 jet production

  • F. Cascioli
  • S. Höche
  • F. Krauss
  • P. Maierhöfer
  • S. Pozzorini
  • F. Siegert
Open Access
Article

Abstract

We present precise predictions for four-lepton plus jets production at the LHC obtained within the fully automated Sherpa + OpenLoops framework. Off-shell intermediate vector bosons and related interferences are consistently included using the complex-mass scheme. Four-lepton plus 0- and 1-jet final states are described at NLO accuracy, and the precision of the simulation is further increased by squared quark-loop NNLO contributions in the gg → 4, gg → 4 + g, gq → 4 + q, and \( q\overline{q} \) → 4 + g channels. These NLO and NNLO contributions are matched to the Sherpa parton shower, and the 0- and 1-jet final states are consistently merged using the Meps@Nlo technique. Thanks to Sudakov resummation, the parton shower provides improved predictions and uncertainty estimates for exclusive observables. This is important when jet vetoes or jet bins are used to separate four-lepton final states arising from Higgs decays, diboson production, and top-pair production. Detailed predictions are presented for the Atlas and Cms H → WW* analyses at 8 TeV in the 0- and 1-jet bins. Assessing renormalisation-, factorisation- and resummationscale uncertainties, which reflect also unknown subleading Sudakov logarithms in jet bins, we find that residual perturbative uncertainties are as small as a few percent.

Keywords

NLO Computations Monte Carlo Simulations 

Notes

Open Access

This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

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Copyright information

© The Author(s) 2014

Authors and Affiliations

  • F. Cascioli
    • 1
  • S. Höche
    • 2
  • F. Krauss
    • 3
  • P. Maierhöfer
    • 1
  • S. Pozzorini
    • 1
  • F. Siegert
    • 4
  1. 1.Institut für Theoretische PhysikUniversität ZürichZürichSwitzerland
  2. 2.SLAC National Accelerator LaboratoryMenlo ParkU.S.A.
  3. 3.Institute for Particle Physics PhenomenologyDurham UniversityDurhamU.K.
  4. 4.Physikalisches InstitutAlbert-Ludwigs-Universität FreiburgFreiburgGermany

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