1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/FastJets.hh"
  5#include "Rivet/Projections/LeptonFinder.hh"
  6#include "Rivet/Projections/MissingMomentum.hh"
  7#include "Rivet/Projections/PromptFinalState.hh"
  8
  9namespace Rivet {
 10
 11
 12  /// @brief Measurements of W+W- boson pair production in pp collisions at 13 TeV
 13  class CMS_2020_I1814328 : public Analysis {
 14  public:
 15
 16    /// Constructor
 17    RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2020_I1814328);
 18
 19
 20    /// @name Analysis methods
 21    /// @{
 22
 23    /// Book histograms and initialise projections before the run
 24    void init() {
 25
 26      // Initialise and register projections
 27
 28      // The basic final-state projection:
 29      // all final-state particles within
 30      // the given eta acceptance
 31      const FinalState fs(Cuts::abseta < 4.9);
 32      const FinalState fsjet4p5(Cuts::abseta < 4.5);
 33      const FinalState fsjet2p5(Cuts::abseta < 2.5);
 34
 35      // The final-state particles declared above are clustered using FastJet with
 36      // the anti-kT algorithm and a jet-radius parameter 0.4
 37      // muons and neutrinos are excluded from the clustering
 38      FastJets jet4p5fs(fsjet4p5, JetAlg::ANTIKT, 0.4);
 39      declare(jet4p5fs, "jets4p5");
 40      FastJets jet2p5fs(fsjet2p5, JetAlg::ANTIKT, 0.4);
 41      declare(jet2p5fs, "jets2p5");
 42
 43      // FinalState of prompt photons and bare muons and electrons in the event
 44      PromptFinalState photons(Cuts::abspid == PID::PHOTON);
 45      PromptFinalState bare_leps(Cuts::abspid == PID::MUON || Cuts::abspid == PID::ELECTRON);
 46      bare_leps.acceptTauDecays(false);
 47
 48      // Dress the prompt bare leptons with prompt photons within dR < 0.1,
 49      // and apply some fiducial cuts on the dressed leptons
 50      Cut lepton_cuts = Cuts::abseta < 2.5 && Cuts::pT > 25*GeV;
 51      LeptonFinder dressed_leps(bare_leps, photons, 0.1, lepton_cuts);
 52      declare(dressed_leps, "leptons");
 53
 54      // Missing momentum
 55      declare(MissingMomentum(fs), "MET");
 56
 57      // Book histograms
 58      book(_h_WW_njets_norm, 2, 1, 1);
 59      book(_h["mll"], 4, 1, 1);
 60      book(_h["ptlmax"], 5, 1, 1);
 61      book(_h["ptlmin"], 6, 1, 1);
 62      book(_h["dphill"], 7, 1, 1);
 63      book(_h_WW_njet0, 8, 1, 1);
 64
 65    }
 66
 67    /// Perform the per-event analysis
 68    void analyze(const Event& event) {
 69
 70      if (_edges.empty()) {
 71        _edges = _h_WW_njets_norm->xEdges();
 72        _edges0 = _h_WW_njet0->xEdges();
 73      }
 74
 75      // Apply a missing-momentum cut
 76      if (apply<MissingMomentum>(event, "MET").missingPt() < 20*GeV) return;
 77
 78      // Retrieve dressed leptons, sorted by pT
 79      DressedLeptons leptons = apply<LeptonFinder>(event, "leptons").dressedLeptons();
 80
 81      // Retrieve clustered jets, sorted by pT, with a minimum pT cut
 82      Jets jets25 = apply<FastJets>(event, "jets4p5").jetsByPt(Cuts::pT > 25*GeV);
 83      Jets jets30 = apply<FastJets>(event, "jets4p5").jetsByPt(Cuts::pT > 30*GeV);
 84      Jets jets35 = apply<FastJets>(event, "jets4p5").jetsByPt(Cuts::pT > 35*GeV);
 85      Jets jets45 = apply<FastJets>(event, "jets4p5").jetsByPt(Cuts::pT > 45*GeV);
 86      Jets jets60 = apply<FastJets>(event, "jets4p5").jetsByPt(Cuts::pT > 60*GeV);
 87      Jets jetsNj = apply<FastJets>(event, "jets2p5").jetsByPt(Cuts::pT > 30*GeV);
 88
 89      // Remove all jets within dR < 0.4 of a dressed lepton
 90      idiscardIfAnyDeltaRLess(jets25, leptons, 0.4);
 91      idiscardIfAnyDeltaRLess(jets30, leptons, 0.4);
 92      idiscardIfAnyDeltaRLess(jets35, leptons, 0.4);
 93      idiscardIfAnyDeltaRLess(jets45, leptons, 0.4);
 94      idiscardIfAnyDeltaRLess(jets60, leptons, 0.4);
 95      idiscardIfAnyDeltaRLess(jetsNj, leptons, 0.4);
 96
 97      if (leptons.size() == 2 && leptons[0].pid() * leptons[1].pid() < 0) {
 98        FourMomentum dilCand = leptons[0].momentum() + leptons[1].momentum();
 99        if (dilCand.mass() > 20*GeV && dilCand.pT() > 30*GeV){
100          double ptlmax = leptons[0].pT(); double ptlmin = leptons[1].pT();
101          if (ptlmax < ptlmin) {
102            ptlmax = leptons[1].pT(); ptlmin = leptons[0].pT();
103          }
104
105          if (leptons[0].abspid() != leptons[1].abspid()) {
106            _h_WW_njets_norm ->fill(_edges[ min((int)jetsNj.size(), 2) ]);
107            _h["mll"]->fill(min(dilCand.mass()/GeV, 1499.999));
108            _h["ptlmax"]->fill(min(ptlmax/GeV, 399.999));
109            _h["ptlmin"]->fill(min(ptlmin/GeV, 149.999));
110            _h["dphill"]->fill(deltaPhi(leptons[0], leptons[1]));
111          }
112
113          if (jets25.size() == 0) _h_WW_njet0->fill(_edges0[0]);
114          if (jets30.size() == 0) _h_WW_njet0->fill(_edges0[1]);
115          if (jets35.size() == 0) _h_WW_njet0->fill(_edges0[2]);
116          if (jets45.size() == 0) _h_WW_njet0->fill(_edges0[3]);
117          if (jets60.size() == 0) _h_WW_njet0->fill(_edges0[4]);
118
119        }
120      }
121
122    }
123
124
125    /// Normalise histograms etc., after the run
126    void finalize() {
127
128      double norm = (sumOfWeights() != 0) ? crossSection()/picobarn/sumOfWeights() : 1.0;
129
130      normalize(_h_WW_njets_norm );
131      for (auto& item : _h) {
132        const double rho = item.second->densitySum();
133        if (rho)  scale(item.second, 1.0/rho);
134      }
135      scale(_h_WW_njet0, norm);
136
137    }
138
139    /// @}
140
141
142    /// @name Histograms
143    /// @{
144    BinnedHistoPtr<string> _h_WW_njets_norm, _h_WW_njet0;
145    map<string, Histo1DPtr> _h;
146    vector<string> _edges, _edges0;
147    /// @}
148
149  };
150
151
152
153  RIVET_DECLARE_PLUGIN(CMS_2020_I1814328);
154
155}