ATLAS_2011_S9019561.cc

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// -*- C++ -*- 
#include "Rivet/Analysis.hh"
#include "Rivet/Tools/BinnedHistogram.hh"
#include "Rivet/RivetAIDA.hh"
#include "Rivet/Tools/Logging.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/ChargedFinalState.hh"
#include "Rivet/Projections/VisibleFinalState.hh"
#include "Rivet/Projections/IdentifiedFinalState.hh"
#include "Rivet/Projections/FastJets.hh"

namespace Rivet {


  class ATLAS_2011_S9019561 : public Analysis {
  public:

    /// @name Constructors etc.
    //@{

    /// Constructor

    ATLAS_2011_S9019561()
      : Analysis("ATLAS_2011_S9019561")

    {
      /// Set whether your finalize method needs the generator cross section
      setNeedsCrossSection(false);
    }

    //@}


  public:

    /// @name Analysis methods
    //@{

    /// Book histograms and initialise projections before the run
    void init() {

      // projection to find the electrons
      std::vector<std::pair<double, double> > eta_e;
      eta_e.push_back(make_pair(-2.47,2.47));
      IdentifiedFinalState elecs(eta_e, 20.0*GeV);
      elecs.acceptIdPair(ELECTRON);
      addProjection(elecs, "elecs");


      // veto region electrons
      std::vector<std::pair<double, double> > eta_v_e;
      eta_v_e.push_back(make_pair(-1.52,-1.37));
      eta_v_e.push_back(make_pair( 1.37, 1.52));
      IdentifiedFinalState veto_elecs(eta_v_e, 10.0*GeV);
      veto_elecs.acceptIdPair(ELECTRON);
      addProjection(veto_elecs, "veto_elecs");


      // projection to find the muons
      std::vector<std::pair<double, double> > eta_m;
      eta_m.push_back(make_pair(-2.4,2.4));
      IdentifiedFinalState muons(eta_m, 20.0*GeV);
      muons.acceptIdPair(MUON);
      addProjection(muons, "muons");


      // jet finder
      VetoedFinalState vfs;
      vfs.addVetoPairDetail(MUON,20*GeV,7000*GeV);
      vfs.addVetoPairDetail(ELECTRON,20*GeV,7000*GeV);
      addProjection(FastJets(vfs, FastJets::ANTIKT, 0.4),
                   "AntiKtJets04");


      // all tracks (to do deltaR with leptons)
      addProjection(ChargedFinalState(-3.0,3.0,0.5*GeV),"cfs");


      // for pTmiss
      addProjection(VisibleFinalState(-4.9,4.9),"vfs");


      /// book histograms
      _count_OS_e_mu = bookHistogram1D("count_OS_e+-mu-+", 1, 0., 1.);
      _count_OS_e_e = bookHistogram1D("count_OS_e+e-", 1, 0., 1.);
      _count_OS_mu_mu = bookHistogram1D("count_OS_mu+mu-", 1, 0., 1.);
      _count_SS_e_mu = bookHistogram1D("count_SS_e+-mu+-", 1, 0., 1.);
      _count_SS_e_e = bookHistogram1D("count_SS_e+-e+-", 1, 0., 1.);
      _count_SS_mu_mu = bookHistogram1D("count_SS_mu+-mu+-", 1, 0., 1.);

      _hist_eTmiss_OS  = bookHistogram1D("Et_miss_OS", 20, 0., 400.);
      _hist_eTmiss_SS  = bookHistogram1D("Et_miss_SS", 20, 0., 400.);   


    }




    /// Perform the per-event analysis
    void analyze(const Event& event) {

      const double weight = event.weight();      

      ParticleVector veto_e 
    = applyProjection<IdentifiedFinalState>(event, "veto_elecs").particles();
      if ( ! veto_e.empty() ) {
        MSG_DEBUG("electrons in veto region");
        vetoEvent;
      }

      Jets cand_jets;
      foreach (const Jet& jet, 
        applyProjection<FastJets>(event, "AntiKtJets04").jetsByPt(20.0*GeV) ) {
        if ( fabs( jet.momentum().eta() ) < 2.5 ) {
          cand_jets.push_back(jet);
        }
      } 

      ParticleVector cand_e = 
    applyProjection<IdentifiedFinalState>(event, "elecs").particlesByPt();      
      ParticleVector candtemp_mu = 
    applyProjection<IdentifiedFinalState>(event,"muons").particlesByPt();
      ParticleVector chg_tracks = 
    applyProjection<ChargedFinalState>(event, "cfs").particles();
      ParticleVector cand_mu;


      // pTcone around muon track 
      foreach ( const Particle & mu, candtemp_mu ) {
    double pTinCone = -mu.momentum().pT();
    foreach ( const Particle & track, chg_tracks ) {
      if ( deltaR(mu.momentum(),track.momentum()) < 0.2 )
        pTinCone += track.momentum().pT();
    }
    if ( pTinCone < 1.8*GeV ) 
      cand_mu.push_back(mu);
      }


      // Discard jets that overlap with electrons
      Jets cand_jets_2;
      foreach ( const Jet& jet, cand_jets ) {
    if ( fabs( jet.momentum().eta() ) < 1.5 )
      cand_jets_2.push_back( jet );
    else {
      bool away_from_e = true;
      foreach ( const Particle & e, cand_e ) {
        if ( deltaR(e.momentum(),jet.momentum()) <= 0.2 ) {
          away_from_e = false;
          break;
        }
      }
      if ( away_from_e ) 
        cand_jets_2.push_back( jet );
    }
      }

      
      // Leptons far from jet
      ParticleVector recon_e, recon_mu;  
      foreach ( const Particle & e, cand_e ) {
        bool e_near_jet = false;
    foreach ( const Jet& jet, cand_jets_2 ) {  
          if ( deltaR(e.momentum(),jet.momentum()) < 0.4 ) 
        e_near_jet = true;
    }
        if ( e_near_jet == false )
          recon_e.push_back( e );  
      }

      foreach ( const Particle & mu, cand_mu ) {
         bool mu_near_jet = false;
         foreach ( const Jet& jet, cand_jets_2 ) {  
           if ( deltaR(mu.momentum(),jet.momentum()) < 0.4 ) 
         mu_near_jet = true;       
     }
     if ( mu_near_jet == false) 
      recon_mu.push_back( mu );
       } 


      // pTmiss
      ParticleVector vfs_particles 
    = applyProjection<VisibleFinalState>(event, "vfs").particles();
      FourMomentum pTmiss;
      foreach ( const Particle & p, vfs_particles ) {
    pTmiss -= p.momentum();
      }
      double eTmiss = pTmiss.pT();


      // Final jet filter
      Jets recon_jets;
      foreach ( const Jet& jet, cand_jets_2 ) {
      recon_jets.push_back( jet );
      }


      // Electron isolation criterion
      foreach ( Particle e, recon_e ) {
    double EtinCone = -e.momentum().Et();
    foreach ( const Particle & track, chg_tracks) {
      if ( deltaR(e.momentum(),track.momentum()) <= 0.2 )  
        EtinCone += track.momentum().Et();
    }
    if ( EtinCone/e.momentum().pT() >= 0.15 )
      vetoEvent;
      }


      // Exactly two leptons for each event
      int num_leptons = recon_mu.size() + recon_e.size();
      if ( num_leptons != 2) 
    vetoEvent;
            
    

      // Lepton pair mass
      double mass_leptons = 0;
      foreach ( Particle e, recon_e ) {
        mass_leptons += e.momentum().E();
      }
      foreach ( Particle mu, recon_mu) { 
        mass_leptons += mu.momentum().E();
      }
    
      if ( mass_leptons <= 5.0 * GeV) {
    MSG_DEBUG("Not enough m_ll: " << mass_leptons << " < 5");   
        vetoEvent;              
      }      
      
   

    // ==================== FILL ====================

    
      // electron, electron
      if (recon_e.size() == 2 ) {

    // SS ee    
    if ( recon_e[0].pdgId() * recon_e[1].pdgId() > 0 ) {
      _hist_eTmiss_SS->fill(eTmiss, weight);
      if ( eTmiss > 100 ) {
        MSG_DEBUG("Hits SS e+/-e+/-");
        _count_SS_e_e->fill(0.5, weight);
      }
    }   

    // OS ee
    else if ( recon_e[0].pdgId() * recon_e[1].pdgId() < 0) { 
      _hist_eTmiss_OS->fill(eTmiss, weight);
      if ( eTmiss > 150 ) {
        MSG_DEBUG("Hits OS e+e-");
        _count_OS_e_e->fill(0.5, weight);
      }
    }
      }


      // muon, electron 
      else if ( recon_e.size() == 1 ) {

    // SS mu_e
    if ( recon_e[0].pdgId() * recon_mu[0].pdgId() > 0 ) {
      _hist_eTmiss_SS->fill(eTmiss, weight);
      if ( eTmiss > 100 ) {
        MSG_DEBUG("Hits SS e+/-mu+/-");
        _count_SS_e_mu->fill(0.5, weight);
      }
    }

    // OS mu_e
    else if ( recon_e[0].pdgId() * recon_mu[0].pdgId() < 0) { 
      _hist_eTmiss_OS->fill(eTmiss, weight);
      if ( eTmiss > 150 ) {
        MSG_DEBUG("Hits OS e+mu-");
        _count_OS_e_mu->fill(0.5, weight);
      }
    }
      }


      // muon, muon
      else if ( recon_mu.size() == 2 ) {

    // SS mu_mu
    if ( recon_mu[0].pdgId() * recon_mu[1].pdgId() > 0 ) {
      _hist_eTmiss_SS->fill(eTmiss, weight);
      if ( eTmiss > 100 ) {
        MSG_DEBUG("Hits SS mu+/-mu+/-");
        _count_SS_mu_mu->fill(0.5, weight);
      } 
    }

    // OS mu_mu
    else if ( recon_mu[0].pdgId() * recon_mu[1].pdgId() < 0) { 
      _hist_eTmiss_OS->fill(eTmiss, weight);
      if ( eTmiss > 150 ) {
        MSG_DEBUG("Hits OS mu+mu-");
        _count_OS_mu_mu->fill(0.5, weight);
      }
    }
      }


    }

    //@}

    
    void finalize() { }


  private:

    /// @name Histograms
    //@{
    AIDA::IHistogram1D* _count_OS_e_mu;
    AIDA::IHistogram1D* _count_OS_e_e;
    AIDA::IHistogram1D* _count_OS_mu_mu;
    AIDA::IHistogram1D* _count_SS_e_mu;
    AIDA::IHistogram1D* _count_SS_e_e;
    AIDA::IHistogram1D* _count_SS_mu_mu;
    AIDA::IHistogram1D* _hist_eTmiss_OS;
    AIDA::IHistogram1D* _hist_eTmiss_SS;

    //@}


  };



  // This global object acts as a hook for the plugin system
  AnalysisBuilder<ATLAS_2011_S9019561> plugin_ATLAS_2011_S9019561;


}