On the reduction of negative weights in MC@NLO-type matching procedures

Feb 28, 2020
44 pages
Published in:
  • JHEP 07 (2020) 238
  • Published: Jul 31, 2020
e-Print:
Report number:
  • LU-TP 20-09,
  • MCNET-20-08
Experiments:

Citations per year

202020212022202320240246810
Abstract: (Springer)
We show how a careful analysis of the behaviour of a parton shower Monte Carlo in the vicinity of the soft and collinear regions allows one to formulate a modified MC@NLO-matching prescription that reduces the number of negative-weight events with respect to that stemming from the standard MC@NLO procedure. As a first practical application of such a prescription, that we dub MC@NLO-∆, we have implemented it in the MadGraph5_aMC@NLO framework, by employing the Pythia8 Monte Carlo. We present selected MC@NLO-∆ results at the 13 TeV LHC, and compare them with MC@NLO ones. We find that the former predictions are consistent with the latter ones within the typical matching systematics, and that the reduction of negative-weight events is significant.
Note:
  • 44 pages, 13 figures; several minor text amendments and one figure added
  • NLO Computations
  • QCD Phenomenology
  • parton: showers
  • Monte Carlo
  • PYTHIA
  • higher-order: 1
  • CERN LHC Coll
  • collinear