Rivet Analyses Reference

CMS_2014_I1303894

Differential cross-section of $W$ bosons + jets in $pp$ collisions at $\sqrt{s}=7$ TeV
Experiment: CMS (LHC)
Inspire ID: 1303894
Status: VALIDATED
Authors:
  • Darin Baumgartel
  • Emanuela Barberis
References:
  • Phys. Lett. B741 (2014) 12-37
  • https://inspirehep.net/record/1303894
  • http://arxiv.org/abs/1406.7533
Beams: p+ p+
Beam energies: (3500.0, 3500.0) GeV
Run details:
  • Run MC generators with $W$ decaying leptonically at 7 TeV CoM energy. A large number of events are required to populate the high jet multiplicity region. Suitable results can be achieved with 85M events.

A study of jet production in association with $W$ bosons has been performed, in events with the $W$ decaying to a muon. Jets are required to have $pT > 30$ GeV and $|eta| < 2.4$. Muons are required to have $pT > 25$ and $|eta| < 2.1$. Jets are only considered if they are separated from the muon by $\Delta{R} > 0.5$. Muons are dressed with photons in a cone of $0.1$ around the muon.

Source code: CMS_2014_I1303894.cc
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/VetoedFinalState.hh"
#include "Rivet/Projections/PromptFinalState.hh"
#include "Rivet/Projections/InvMassFinalState.hh"
#include "Rivet/Projections/MissingMomentum.hh"
#include "Rivet/Projections/WFinder.hh"
#include "Rivet/Projections/DressedLeptons.hh"

namespace Rivet {


  /// @brief Differential cross-section of W bosons + jets in pp collisions at sqrt(s)=7 TeV
  /// @author Darin Baumgartel (darinb@cern.ch)
  ///
  /// Based on Rivet analysis originally created by Anil Singh (anil@cern.ch), Lovedeep Saini (lovedeep@cern.ch)
  class CMS_2014_I1303894 : public Analysis {
  public:

    /// Constructor
    CMS_2014_I1303894()
      : Analysis("CMS_2014_I1303894")
    {   }


    // Book histograms and initialise projections before the run
    void init() {
      // Prompt leptons only, no test on nu flavour.
      // Projections
      const FinalState fs;
      declare(fs, "FS");

      MissingMomentum missing(fs);
      declare(missing, "MET");

      PromptFinalState pfs(fs);
      IdentifiedFinalState bareMuons(pfs);
      bareMuons.acceptIdPair(PID::MUON);
      DressedLeptons muonClusters(fs, bareMuons, -1); //, Cuts::open(), false, false);
      declare(muonClusters, "muonClusters");

      IdentifiedFinalState neutrinos(pfs);
      neutrinos.acceptIdPair(PID::NU_MU);
      declare(neutrinos, "neutrinos");

      VetoedFinalState jetFS(fs);
      jetFS.addVetoOnThisFinalState(muonClusters);
      jetFS.addVetoOnThisFinalState(neutrinos);
      jetFS.vetoNeutrinos();
      FastJets jetprojection(jetFS, FastJets::ANTIKT, 0.5);
      declare(jetprojection, "Jets");

      // Histograms
      book(_histDPhiMuJet1 ,1,1,1);
      book(_histDPhiMuJet2 ,2,1,1);
      book(_histDPhiMuJet3 ,3,1,1);
      book(_histDPhiMuJet4 ,4,1,1);

      book(_histEtaJet1 ,5,1,1);
      book(_histEtaJet2 ,6,1,1);
      book(_histEtaJet3 ,7,1,1);
      book(_histEtaJet4 ,8,1,1);

      book(_histHT1JetInc ,9,1,1);
      book(_histHT2JetInc ,10,1,1);
      book(_histHT3JetInc ,11,1,1);
      book(_histHT4JetInc ,12,1,1);

      book(_histJet30MultExc  ,13,1,1);
      book(_histJet30MultInc  ,14,1,1);

      book(_histPtJet1 ,15,1,1);
      book(_histPtJet2 ,16,1,1);
      book(_histPtJet3 ,17,1,1);
      book(_histPtJet4 ,18,1,1);

      // Counters
      book(_n_1jet, "n_1jet");
      book(_n_2jet, "n_2jet");
      book(_n_3jet, "n_3jet");
      book(_n_4jet, "n_4jet");
      book(_n_inclusivebinsummation, "n_inclusivebinsummation");
    }


    void analyze(const Event& event) {
      // Get the dressed muon
      const DressedLeptons& muonClusters = apply<DressedLeptons>(event, "muonClusters");
      int nmu = muonClusters.dressedLeptons().size();
      if (nmu < 1) vetoEvent;
      DressedLepton dressedmuon = muonClusters.dressedLeptons()[0];
      if (dressedmuon.momentum().abseta() > 2.1) vetoEvent;
      if (dressedmuon.momentum().pT() < 25.0*GeV) vetoEvent;

      // Get the muon neutrino
      //const Particles& neutrinos = apply<FinalState>(event, "neutrinos").particlesByPt();

      // Check that the muon and neutrino are not decay products of tau
      if (dressedmuon.constituentLepton().hasAncestor( PID::TAU)) vetoEvent;
      if (dressedmuon.constituentLepton().hasAncestor(-PID::TAU)) vetoEvent;

      // Get the missing momentum
      const MissingMomentum& met = apply<MissingMomentum>(event, "MET");
      const double ptmet = met.visibleMomentum().pT();
      const double phimet = (-met.visibleMomentum()).phi();

      // Calculate MET and MT(mu,MET), and remove events with MT < 50 GeV
      const double ptmuon = dressedmuon.pT();
      const double phimuon = dressedmuon.phi();
      const double mt_mumet = sqrt(2*ptmuon*ptmet*(1.0 - cos(phimet-phimuon)));

      // Remove events in MT < 50 region
      if (mt_mumet < 50*GeV) vetoEvent;

      // Loop over jets and fill pt/eta/phi quantities in vectors
      const Jets& jets_filtered = apply<FastJets>(event, "Jets").jetsByPt(0.0*GeV);
      vector<float> finaljet_pT_list, finaljet_eta_list, finaljet_phi_list;
      double htjets = 0.0;
      for (size_t ii = 0; ii < jets_filtered.size(); ++ii) {
        // Jet pT/eta/phi
        double jet_pt = jets_filtered[ii].pT();
        double jet_eta = jets_filtered[ii].eta();
        double jet_phi = jets_filtered[ii].phi();

        // Kinemetic cuts for jet acceptance
        if (fabs(jet_eta) > 2.4) continue;
        if (jet_pt < 30.0*GeV) continue;
        if (deltaR(dressedmuon, jets_filtered[ii]) < 0.5) continue;

        // Add jet to jet list and increases the HT variable
        finaljet_pT_list.push_back(jet_pt);
        finaljet_eta_list.push_back(jet_eta);
        finaljet_phi_list.push_back(jet_phi);
        htjets += fabs(jet_pt);
      }


      // Filling of histograms:
      // Fill as many jets as there are into the exclusive jet multiplicity
      if (!finaljet_pT_list.empty())
        _histJet30MultExc->fill(finaljet_pT_list.size());

      for (size_t ij = 0; ij < finaljet_pT_list.size(); ++ij) {
        _histJet30MultInc->fill(ij+1);
        _n_inclusivebinsummation->fill();
      }

      if (finaljet_pT_list.size() >= 1) {
        _histPtJet1->fill(finaljet_pT_list[0]);
        _histEtaJet1->fill(fabs(finaljet_eta_list[0]));
        _histDPhiMuJet1->fill(deltaPhi(finaljet_phi_list[0], phimuon));
        _histHT1JetInc->fill(htjets);
        _n_1jet->fill();
      }

      if (finaljet_pT_list.size() >= 2) {
        _histPtJet2->fill(finaljet_pT_list[1]);
        _histEtaJet2->fill(fabs(finaljet_eta_list[1]));
        _histDPhiMuJet2->fill(deltaPhi(finaljet_phi_list[1], phimuon));
        _histHT2JetInc->fill(htjets);
        _n_2jet->fill();
      }

      if (finaljet_pT_list.size() >= 3) {
        _histPtJet3->fill(finaljet_pT_list[2]);
        _histEtaJet3->fill(fabs(finaljet_eta_list[2]));
        _histDPhiMuJet3->fill(deltaPhi(finaljet_phi_list[2], phimuon));
        _histHT3JetInc->fill(htjets);
        _n_3jet->fill();
      }

      if (finaljet_pT_list.size() >=4 ) {
        _histPtJet4->fill(finaljet_pT_list[3]);
        _histEtaJet4->fill(fabs(finaljet_eta_list[3]));
        _histDPhiMuJet4->fill(deltaPhi(finaljet_phi_list[3], phimuon));
        _histHT4JetInc-> fill(htjets);
        _n_4jet->fill();
      }

    }


    // Finalize the histograms.
    void finalize() {

      const double inclusive_cross_section = crossSection();
      const double norm_1jet_histo = inclusive_cross_section*dbl(*_n_1jet)/sumOfWeights();
      const double norm_2jet_histo = inclusive_cross_section*dbl(*_n_2jet)/sumOfWeights();
      const double norm_3jet_histo = inclusive_cross_section*dbl(*_n_3jet)/sumOfWeights();
      const double norm_4jet_histo = inclusive_cross_section*dbl(*_n_4jet)/sumOfWeights();
      const double norm_incmultiplicity = inclusive_cross_section*dbl(*_n_inclusivebinsummation)/sumOfWeights();

      normalize(_histJet30MultExc, norm_1jet_histo);
      normalize(_histJet30MultInc, norm_incmultiplicity);

      normalize(_histPtJet1, norm_1jet_histo);
      normalize(_histHT1JetInc, norm_1jet_histo);
      normalize(_histEtaJet1, norm_1jet_histo);
      normalize(_histDPhiMuJet1, norm_1jet_histo);

      normalize(_histPtJet2, norm_2jet_histo);
      normalize(_histHT2JetInc, norm_2jet_histo);
      normalize(_histEtaJet2, norm_2jet_histo);
      normalize(_histDPhiMuJet2, norm_2jet_histo);

      normalize(_histPtJet3, norm_3jet_histo);
      normalize(_histHT3JetInc, norm_3jet_histo);
      normalize(_histEtaJet3, norm_3jet_histo);
      normalize(_histDPhiMuJet3, norm_3jet_histo);

      normalize(_histPtJet4, norm_4jet_histo);
      normalize(_histHT4JetInc, norm_4jet_histo);
      normalize(_histEtaJet4, norm_4jet_histo);
      normalize(_histDPhiMuJet4, norm_4jet_histo);
    }


  private:

    Histo1DPtr  _histJet30MultExc, _histJet30MultInc;
    Histo1DPtr  _histPtJet1, _histPtJet2, _histPtJet3, _histPtJet4;
    Histo1DPtr  _histEtaJet1, _histEtaJet2, _histEtaJet3, _histEtaJet4;
    Histo1DPtr  _histDPhiMuJet1, _histDPhiMuJet2, _histDPhiMuJet3, _histDPhiMuJet4;
    Histo1DPtr  _histHT1JetInc, _histHT2JetInc, _histHT3JetInc, _histHT4JetInc;

    CounterPtr _n_1jet, _n_2jet, _n_3jet, _n_4jet, _n_inclusivebinsummation;

  };


  RIVET_DECLARE_PLUGIN(CMS_2014_I1303894);

}