User Tools

Site Tools


Sidebar

Les Houches

2019 Session

Wikis of Previous sessions

Les Houches Themes

Help

2017:groups:np:stxsveeft

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, …)

Workflow

{{:2017:groups:higgs:stxeftworkflow.png?400|

Tasks

  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

ZH->bbar

References https://cds.cern.ch/record/2206813/files/ATLAS-CONF-2016-091.pdf?version=1 https://journals.aps.org/prd/abstract/10.1103/PhysRevD.89.012003

Selections:

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

References: https://cds.cern.ch/record/2264522/files/HIG-16-043-pas.pdf

Selections:

  • 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)
Smearings

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)

References:

  • Session 1 STXS page. (link)
  • Rivet tool implementing stage 1 and 0 selections maintained by LHCHXSWG (link)
1)
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