A critical appraisal of NLO+PS matching methods

Nov, 2011
33 pages
Published in:
  • JHEP 09 (2012) 049
e-Print:
Report number:
  • SLAC-PUB-14661,
  • IPPP-11-67,
  • DCPT-11-134,
  • LPN11-58,
  • FR-PHENO-2011-019,
  • MCNET-11-24

Citations per year

20112015201920232025020406080100
Abstract: (arXiv)
In this publication, uncertainties in and differences between the MC@NLO and POWHEG methods for matching next-to-leading order QCD calculations with parton showers are discussed. Implementations of both algorithms within the event generator Sherpa and based on Catani-Seymour subtraction are employed to assess the impact on a representative selection of observables. In the case of MC@NLO a substantial simplification is achieved by using dipole subtraction terms to generate the first emission. A phase space restriction is employed, which allows to vary in a transparent way the amount of non-singular radiative corrections that are exponentiated. Effects on various observables are investigated, using the production of a Higgs boson in gluon fusion, with or without an associated jet, as a benchmark process. The case of H+jet production is presented for the first time in an NLO+PS matched simulation. Uncertainties due to scale choices and non-perturbative effects are explored in the production of W and Z bosons in association with a jet. Corresponding results are compared to data from the Tevatron and LHC experiments.
Note:
  • 34 pages, 25 figures/ v2 as accepted for publication in JHEP
  • parton: showers
  • jet: associated production
  • Higgs particle: hadroproduction
  • W: hadroproduction
  • effect: nonperturbative
  • gluon: fusion
  • higher-order: 1
  • quantum chromodynamics
  • Batavia TEVATRON Coll
  • radiative correction