rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

MC_ZZINC

Monte Carlo validation observables for $Z[e^+ \, e^-]Z[\mu^+ \, \mu^-]$ 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

Monte Carlo validation observables for $Z[e^+ \, e^-]Z[\mu^+ \, \mu^-]$ production

Source code: MC_ZZINC.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/ZFinder.hh"
  4#include "Rivet/Projections/VetoedFinalState.hh"
  5
  6namespace Rivet {
  7
  8
  9  /// @brief MC validation analysis for Z[ee]Z[mumu] events
 10  class MC_ZZINC : public Analysis {
 11  public:
 12
 13    /// Default constructor
 14    MC_ZZINC()
 15      : Analysis("MC_ZZINC")
 16    {    }
 17
 18
 19    /// @name Analysis methods
 20    //@{
 21
 22    /// Book histograms
 23    void init() {
 24      Cut cut = Cuts::abseta < 3.5 && Cuts::pT > 25*GeV;
 25      ZFinder zeefinder(FinalState(), cut, PID::ELECTRON, 65*GeV, 115*GeV,
 26                        0.2, ZFinder::ClusterPhotons::NODECAY, ZFinder::AddPhotons::YES);
 27      declare(zeefinder, "ZeeFinder");
 28
 29      VetoedFinalState zmminput;
 30      zmminput.addVetoOnThisFinalState(zeefinder);
 31      ZFinder zmmfinder(zmminput, cut, PID::MUON, 65*GeV, 115*GeV,
 32                        0.2, ZFinder::ClusterPhotons::NODECAY, ZFinder::AddPhotons::YES);
 33      declare(zmmfinder, "ZmmFinder");
 34
 35      // Properties of the pair momentum
 36      double sqrts = sqrtS()>0. ? sqrtS() : 14000.;
 37      book(_h_ZZ_pT ,"ZZ_pT", logspace(100, 1.0, 0.5*sqrts/GeV));
 38      book(_h_ZZ_pT_peak ,"ZZ_pT_peak", 25, 0.0, 25.0);
 39      book(_h_ZZ_eta ,"ZZ_eta", 40, -7.0, 7.0);
 40      book(_h_ZZ_phi ,"ZZ_phi", 25, 0.0, TWOPI);
 41      book(_h_ZZ_m ,"ZZ_m", logspace(100, 150.0, 180.0 + 0.25*sqrts/GeV));
 42
 43      // Correlations between the ZZ
 44      book(_h_ZZ_dphi ,"ZZ_dphi", 25, 0.0, PI);  /// @todo non-linear?
 45      book(_h_ZZ_deta ,"ZZ_deta", 25, -7.0, 7.0);
 46      book(_h_ZZ_dR ,"ZZ_dR", 25, 0.5, 7.0);
 47      book(_h_ZZ_dpT ,"ZZ_dpT", logspace(100, 1.0, 0.5*sqrts/GeV));
 48      book(_h_ZZ_costheta_planes ,"ZZ_costheta_planes", 25, -1.0, 1.0);
 49
 50      // Properties of the Z bosons
 51      book(_h_Z_pT ,"Z_pT", logspace(100, 10.0, 0.25*sqrts/GeV));
 52      book(_h_Z_eta ,"Z_eta", 70, -7.0, 7.0);
 53
 54      // Properties of the leptons
 55      book(_h_Zl_pT ,"Zl_pT", logspace(100, 30.0, 0.1*sqrts/GeV));
 56      book(_h_Zl_eta ,"Zl_eta", 40, -3.5, 3.5);
 57
 58      // Correlations between the opposite charge leptons
 59      book(_h_ZeZm_dphi ,"ZeZm_dphi", 25, 0.0, PI);
 60      book(_h_ZeZm_deta ,"ZeZm_deta", 25, -5.0, 5.0);
 61      book(_h_ZeZm_dR ,"ZeZm_dR", 25, 0.5, 5.0);
 62      book(_h_ZeZm_m ,"ZeZm_m", 100, 0.0, 300.0);
 63
 64    }
 65
 66
 67
 68    /// Do the analysis
 69    void analyze(const Event& e) {
 70      const ZFinder& zeefinder = apply<ZFinder>(e, "ZeeFinder");
 71      if (zeefinder.bosons().size() != 1) vetoEvent;
 72      const ZFinder& zmmfinder = apply<ZFinder>(e, "ZmmFinder");
 73      if (zmmfinder.bosons().size() != 1) vetoEvent;
 74
 75      // Z momenta
 76      const FourMomentum& zee = zeefinder.bosons()[0].momentum();
 77      const FourMomentum& zmm = zmmfinder.bosons()[0].momentum();
 78      const FourMomentum zz = zee + zmm;
 79      // Lepton momenta
 80      const FourMomentum& ep = zeefinder.constituents()[0].momentum();
 81      const FourMomentum& em = zeefinder.constituents()[1].momentum();
 82      const FourMomentum& mp = zmmfinder.constituents()[0].momentum();
 83      const FourMomentum& mm = zmmfinder.constituents()[1].momentum();
 84
 85      const double weight = 1.0;
 86      _h_ZZ_pT->fill(zz.pT()/GeV, weight);
 87      _h_ZZ_pT_peak->fill(zz.pT()/GeV, weight);
 88      _h_ZZ_eta->fill(zz.eta(), weight);
 89      _h_ZZ_phi->fill(zz.phi(), weight);
 90      if (zz.mass2() > 0.0) ///< @todo Protection still needed?
 91        _h_ZZ_m->fill(zz.mass()/GeV, weight);
 92
 93      _h_ZZ_dphi->fill(deltaPhi(zee, zmm), weight);
 94      _h_ZZ_deta->fill(zee.eta()-zmm.eta(), weight);
 95      _h_ZZ_dR->fill(deltaR(zee,zmm), weight);
 96      _h_ZZ_dpT->fill(fabs(zee.pT()-zmm.pT()), weight);
 97
 98      const Vector3 crossZee = ep.p3().cross(em.p3());
 99      const Vector3 crossZmm = mp.p3().cross(mm.p3());
100      const double costheta = crossZee.dot(crossZmm)/crossZee.mod()/crossZmm.mod();
101      _h_ZZ_costheta_planes->fill(costheta, weight);
102
103      _h_Z_pT->fill(zee.pT()/GeV, weight);
104      _h_Z_pT->fill(zmm.pT()/GeV, weight);
105      _h_Z_eta->fill(zee.eta(), weight);
106      _h_Z_eta->fill(zmm.eta(), weight);
107
108      _h_Zl_pT->fill(ep.pT()/GeV, weight);
109      _h_Zl_pT->fill(em.pT()/GeV, weight);
110      _h_Zl_pT->fill(mp.pT()/GeV, weight);
111      _h_Zl_pT->fill(mm.pT()/GeV, weight);
112      _h_Zl_eta->fill(ep.eta(), weight);
113      _h_Zl_eta->fill(em.eta(), weight);
114      _h_Zl_eta->fill(mp.eta(), weight);
115      _h_Zl_eta->fill(mm.eta(), weight);
116
117      _h_ZeZm_dphi->fill(deltaPhi(ep, mm), weight);
118      _h_ZeZm_deta->fill(ep.eta()-mm.eta(), weight);
119      _h_ZeZm_dR->fill(deltaR(ep, mm), weight);
120      const FourMomentum epmm = ep + mm;
121      const double m_epmm = (epmm.mass2() > 0) ? epmm.mass() : 0; ///< @todo Protection still needed?
122      _h_ZeZm_m->fill(m_epmm/GeV, weight);
123    }
124
125
126    /// Finalize
127    void finalize() {
128      const double s = crossSection()/picobarn/sumOfWeights();
129      scale(_h_ZZ_pT, s);
130      scale(_h_ZZ_pT_peak, s);
131      scale(_h_ZZ_eta, s);
132      scale(_h_ZZ_phi, s);
133      scale(_h_ZZ_m, s);
134      scale(_h_ZZ_dphi, s);
135      scale(_h_ZZ_deta, s);
136      scale(_h_ZZ_dR, s);
137      scale(_h_ZZ_dpT, s);
138      scale(_h_ZZ_costheta_planes, s);
139      scale(_h_Z_pT, s);
140      scale(_h_Z_eta, s);
141      scale(_h_Zl_pT, s);
142      scale(_h_Zl_eta, s);
143      scale(_h_ZeZm_dphi, s);
144      scale(_h_ZeZm_deta, s);
145      scale(_h_ZeZm_dR, s);
146      scale(_h_ZeZm_m, s);
147    }
148
149    //@}
150
151
152  private:
153
154    /// @name Histograms
155    //@{
156    Histo1DPtr _h_ZZ_pT;
157    Histo1DPtr _h_ZZ_pT_peak;
158    Histo1DPtr _h_ZZ_eta;
159    Histo1DPtr _h_ZZ_phi;
160    Histo1DPtr _h_ZZ_m;
161    Histo1DPtr _h_ZZ_dphi;
162    Histo1DPtr _h_ZZ_deta;
163    Histo1DPtr _h_ZZ_dR;
164    Histo1DPtr _h_ZZ_dpT;
165    Histo1DPtr _h_ZZ_costheta_planes;
166    Histo1DPtr _h_Z_pT;
167    Histo1DPtr _h_Z_eta;
168    Histo1DPtr _h_Zl_pT;
169    Histo1DPtr _h_Zl_eta;
170    Histo1DPtr _h_ZeZm_dphi;
171    Histo1DPtr _h_ZeZm_deta;
172    Histo1DPtr _h_ZeZm_dR;
173    Histo1DPtr _h_ZeZm_m;
174    //@}
175
176  };
177
178
179
180  // The hook for the plugin system
181  RIVET_DECLARE_PLUGIN(MC_ZZINC);
182
183}