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Rivet analyses reference

MC_ZZJETS

Monte Carlo validation observables for $Z[e^+ \, e^-]Z[\mu^+ \, \mu^-]$ + jets production
Experiment: ()
Status: VALIDATED
Authors:
  • Frank Siegert
No references listed
Beams: * *
Beam energies: ANY
Run details:
  • $ZZ$ + jets analysis. Needs mass cut on lepton pairs to avoid photon singularity, e.g. a min range of $66 < m_{ee} < 116$ GeV

In addition to the typical jet observables this analysis contains observables related to properties of the ZZ-pair momentum, correlations between the ZZ, properties of the Z bosons, properties of the leptons, correlations between the opposite charge leptons and correlations with jets.

Source code: MC_ZZJETS.cc
  1// -*- C++ -*-
  2#include "Rivet/Analyses/MC_JETS_BASE.hh"
  3#include "Rivet/Projections/DileptonFinder.hh"
  4#include "Rivet/Projections/FastJets.hh"
  5#include "Rivet/Projections/VetoedFinalState.hh"
  6
  7namespace Rivet {
  8
  9
 10  /// @brief MC validation analysis for Z[ee]Z[mumu] + jets events
 11  class MC_ZZJETS : public MC_JETS_BASE {
 12  public:
 13
 14    /// Default constructor
 15    MC_ZZJETS()
 16      : MC_JETS_BASE("MC_ZZJETS", 4, "Jets")
 17    {    }
 18
 19
 20    /// @name Analysis methods
 21    /// @{
 22
 23    /// Book histograms
 24    void init() {
 25      // set FS cuts from input options
 26      const double etaecut = getOption<double>("ABSETAEMAX", 3.5);
 27      const double ptecut = getOption<double>("PTEMIN", 25.);
 28      Cut cute = Cuts::abseta < etaecut && Cuts::pT > ptecut*GeV;
 29      DileptonFinder zeefinder(91.2*GeV, 0.2, cute && Cuts::abspid == PID::ELECTRON, Cuts::massIn(65*GeV, 115*GeV));
 30      declare(zeefinder, "ZeeFinder");
 31      VetoedFinalState zmminput;
 32      zmminput.addVetoOnThisFinalState(zeefinder);
 33
 34      // set FS cuts from input options
 35      const double etamucut = getOption<double>("ABSETAMUMAX", 3.5);
 36      const double ptmucut = getOption<double>("PTMUMIN", 25.);
 37      Cut cutmu = Cuts::abseta < etamucut && Cuts::pT > ptmucut*GeV;
 38      DileptonFinder zmmfinder(zmminput, 91.2*GeV, 0.2, cutmu && Cuts::abspid == PID::MUON,
 39                               Cuts::massIn(65*GeV, 115*GeV));
 40      declare(zmmfinder, "ZmmFinder");
 41
 42      VetoedFinalState jetinput;
 43      jetinput
 44          .addVetoOnThisFinalState(zeefinder)
 45          .addVetoOnThisFinalState(zmmfinder);
 46
 47      // set ptcut from input option
 48      const double jetptcut = getOption<double>("PTJMIN", 20.0);
 49      _jetptcut = jetptcut * GeV;
 50
 51      // set clustering radius from input option
 52      const double R = getOption<double>("R", 0.4);
 53
 54      // set clustering algorithm from input option
 55      JetAlg clusterAlgo;
 56      const string algoopt = getOption("ALGO", "ANTIKT");
 57      if ( algoopt == "KT" ) {
 58        clusterAlgo = JetAlg::KT;
 59      } else if ( algoopt == "CA" ) {
 60        clusterAlgo = JetAlg::CA;
 61      } else if ( algoopt == "ANTIKT" ) {
 62        clusterAlgo = JetAlg::ANTIKT;
 63      } else {
 64        MSG_WARNING("Unknown jet clustering algorithm option " + algoopt + ". Defaulting to anti-kT");
 65        clusterAlgo = JetAlg::ANTIKT;
 66      }
 67
 68      FastJets jetpro(jetinput, clusterAlgo, R);
 69      declare(jetpro, "Jets");
 70
 71      // Correlations with jets
 72      book(_h_ZZ_jet1_deta ,"ZZ_jet1_deta", 70, -7.0, 7.0);
 73      book(_h_ZZ_jet1_dR ,"ZZ_jet1_dR", 25, 1.5, 7.0);
 74      book(_h_Ze_jet1_dR ,"Ze_jet1_dR", 25, 0.0, 7.0);
 75
 76      // Global stuff
 77      book(_h_HT ,"HT", logspace(100, 100.0, 0.5*(sqrtS()>0.?sqrtS():14000.)/GeV));
 78
 79      MC_JETS_BASE::init();
 80    }
 81
 82
 83
 84    /// Do the analysis
 85    void analyze(const Event& e) {
 86
 87      const DileptonFinder& zeefinder = apply<DileptonFinder>(e, "ZeeFinder");
 88      if (zeefinder.bosons().size() != 1) vetoEvent;
 89
 90      const DileptonFinder& zmmfinder = apply<DileptonFinder>(e, "ZmmFinder");
 91      if (zmmfinder.bosons().size() != 1) vetoEvent;
 92
 93      // Z momenta
 94      const FourMomentum& zee = zeefinder.bosons()[0].momentum();
 95      const FourMomentum& zmm = zmmfinder.bosons()[0].momentum();
 96      const FourMomentum zz = zee + zmm;
 97      // Lepton momenta
 98      const FourMomentum& ep = zeefinder.constituents()[0].momentum();
 99      const FourMomentum& em = zeefinder.constituents()[1].momentum();
100      const FourMomentum& mp = zmmfinder.constituents()[0].momentum();
101      const FourMomentum& mm = zmmfinder.constituents()[1].momentum();
102
103      const Jets& jets = apply<FastJets>(e, "Jets").jetsByPt(Cuts::pT > _jetptcut);
104      if (jets.size() > 0) {
105        const FourMomentum j0 = jets[0].momentum();
106        _h_ZZ_jet1_deta->fill(zz.eta()-j0.eta());
107        _h_ZZ_jet1_dR->fill(deltaR(zz, j0));
108        _h_Ze_jet1_dR->fill(deltaR(ep, j0));
109      }
110
111      const double HT = sum(jets, Kin::pT, ep.pT() + em.pT() + mp.pT() + mm.pT());
112      if (HT > 0.0) _h_HT->fill(HT/GeV);
113
114      MC_JETS_BASE::analyze(e);
115    }
116
117
118    /// Finalize
119    void finalize() {
120      const double s = crossSection()/picobarn/sumOfWeights();
121      scale(_h_ZZ_jet1_deta, s);
122      scale(_h_ZZ_jet1_dR, s);
123      scale(_h_Ze_jet1_dR, s);
124      scale(_h_HT, s);
125      MC_JETS_BASE::finalize();
126    }
127
128    /// @}
129
130
131  private:
132
133    /// @name Histograms
134    /// @{
135    Histo1DPtr _h_ZZ_jet1_deta;
136    Histo1DPtr _h_ZZ_jet1_dR;
137    Histo1DPtr _h_Ze_jet1_dR;
138    Histo1DPtr _h_HT;
139    /// @}
140
141  };
142
143
144
145  RIVET_DECLARE_PLUGIN(MC_ZZJETS);
146
147}