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Simplified Template Cross Sections (STXS) and EFT constraints

People interested (add your name): Francesco Riva, Ken Mimasu, Fabio Maltoni, Benjamin Fuks, Kristin Lohwasser, Jorge de Blas, Pasquale Musella, Alexandra Carvalho, Caterina Vernieri, Benjamin Freund, Adam Falkowski

Perform a case study of the constraining power on EFT Wilson coefficients from Higgs data through STXS. Compare the sensitivity of performing a fit to the Wilson coefficients of interest via the STXS with a direct fit from LHC data and quantify any loss of information incurred.

Github repository

Processes of interest:

  • Associated production (VH→bb)
  • Vector Boson Fusion (VBF→gamma gamma, tau tau, …)




  1. Generate signal and background processes (Ken, Jorge)
  2. Modify madanalysis to smear jets and output csv file (Benjamin)
  3. Define selection cuts (Caterina and Kristin)
  4. Develop RooFit-based stat analysis (Kristin)
  5. Prepare skeleton for BDT training (Pasquale)

Samples to generate

  • Baseline:
    • 500k events / process
    • 4-5 EFT points (start with 1-2)
  • VH(bb): SM Z(ll)H, EFT Z(ll)H, SM Z(ll)bb (100<mbb<150)
  • VBF(tau tau): SM VBF, EFT VBF, SM Z(tau tau)
  • EFT operators to probe: OHW (SILH), more?

Selection cuts and smearing




  • leptons > 25 GeV ,|eta|<2.5
  • bjets, |eta| < 2.5, pT>20
  • Z mass window –> 75 - 105
  • ptV>0 GeV
VBS Htautau



  • Exactly 2 jets > 30 gev
  • mjj>300 GeV
  • detajj>2.5
  • [1) - Note: would probably leave it out?]
  • pT (tau) >30 GeV coming from
    • tau_had: >50 / >40
    • lep-had: >20 (26e) / > 30 (had)
    • lep-lep: 13(e)/24(m) / 24(e) / 15(m)

Available UFO models:

  • HEL at LO (extensive set of SILH basis operators) (link)
  • HEL at NLO (small subset of SILH basis operators relevant for EW production) (link)


  • Session 1 STXS page. (link)
  • Rivet tool implementing stage 1 and 0 selections maintained by LHCHXSWG (link)
vectorial sum pT taus+met > 50 GeV (lep) / > 100 GeV (had)
2017/groups/np/stxsveeft.txt · Last modified: 2017/10/24 10:30 by jorge.de_blas