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VBF Higgs To Tau Tau

For information on object selection/cuts etc, see the H->TauTau group pages here:


Wednesday 24th June 2009:
Upload talks and put link here....


For information about the analysis code and how to run it, see the VBF Higgs --> Tau Tau CSC group TWiki pages here:

For papers and talks, see the following link:

For details on samples used see the page on AODDataSets.

For the list of things we still have to do, see ThingsToDo.

Getting the Source Code

Make a directory structure AtlasWork/12.0.6/ and then go to that directory.
export CVS_RSH=ssh
export CVS_EDITOR='emacs-nw'

... then either:
cmt co PhysicsAnalysis/HiggsPhys/HiggsToTauTau
for the latest version of the code, or
cmt co -r HiggsToTauTau-00-00-48 PhysicsAnalysis/HiggsPhys/HiggsToTauTau
for a specific version.

(Make sure requirements file in ~/cmthome shows test area = ${HOME}/AtlasWork/ before trying to run!)

Baseline Cuts

The baseline cuts for H → τ τ → lepton+hadron events (see code here: ~/leney/AtlasWork/12.0.6/PhysicsAnalysis/HiggsPhys/HiggsToTauTau/AANanalysis/AnalysisHiggsToTauTau.cxx) are:

  • Lepton Trigger Loops over the tau decay products and asks for either an electron with pT > 25Gev or a muon with pT > 20GeV (ie require either "trig_EF_e25i" or "trig_EF_mu20i").
  • Di-Lepton Veto Requires that the number of decay products from the tau is 2 (TauDau_N==2).
  • Tight Tau The hadronic tau daughter's pT must be greater than the 'tau cut' value (in our case 40 GeV).
  • Two Jets There must be 2 or more jets.
  • Forward Jets The first jet must have a pT > 40 GeV and the second must have pT > 20 GeV.
  • Centrality The tau decay products must lie between the tagged jets in pseduo-rapidity.
  • Jets Separation The difference in pseudo-rapidity of the two leading jets must be ≥ 4.4 and in addition, ηJet1 * ηJet2 must be < 0, ie the jets must be in opposite hemispheres.
  • Collinear Approximation To pass the cut, the hadronic daughter can carry any fraction of it's parent's momentum and the leptonic tau daughter can carry up to 75% of its parents momentum. The angle of separation between the two must not be in the region of 154 to 206 degrees since the approximation breaks down when the decay products are back to back.
  • MT Cut MT must be ≥ 30 GeV
  • Missing ET Cut There must be at least 30 GeV of missing ET.
  • Mjj Cut The mass of the two jets must be at least 700 GeV.
  • Central Jet Veto Requires that there are no jets in the central region with pT > 20 GeV and |η| < 3.2.
  • Mass Window The reconstructed Higgs mass must be within -10 GeV and +15 GeV of the Monte Carlo Higgs mass.

In addition, I also request that the tau decay products have opposite sign charge (for ttbar background events jets can fake taus and there is quite a significant change that the charge on the jet is then reconstructed with the wrong sign) and that the tagged forward jets are not also tagged as b-jets.

-- KatharineLeney - 10 Apr 2007
Topic revision: r18 - 23 Jun 2009, KatharineLeney
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