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Rivet analyses reference

ATLAS_2012_I1083318

$W$+jets production at 7 TeV
Experiment: ATLAS (LHC)
Inspire ID: 1083318
Status: VALIDATED
Authors:
  • Frank Siegert
References: Beams: p+ p+
Beam energies: (3500.0, 3500.0) GeV
Run details:
  • W+jet events in either the electron or the muon decay channel (but not both).

Differential cross-sections of properties of the four leading jets in $W$+jets production, using the full 2010 dataset of 36 pb$^-1$. Observables include jet multiplicities, $pT$, $H_T$, angular distances, and others. All observables are available using jets with $pT>30$ and $pT>20$ GeV.

Source code: ATLAS_2012_I1083318.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/IdentifiedFinalState.hh"
  4#include "Rivet/Projections/VetoedFinalState.hh"
  5#include "Rivet/Projections/MissingMomentum.hh"
  6#include "Rivet/Projections/FastJets.hh"
  7#include "Rivet/Projections/LeptonFinder.hh"
  8#include "Rivet/Projections/LeadingParticlesFinalState.hh"
  9
 10namespace Rivet {
 11
 12
 13  /// ATLAS W + jets production at 7 TeV
 14  class ATLAS_2012_I1083318 : public Analysis {
 15  public:
 16
 17    /// Constructor
 18    RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2012_I1083318);
 19
 20
 21    /// @name Analysis methods
 22    /// @{
 23
 24    /// Book histograms and initialise projections before the run
 25    void init() {
 26
 27      FinalState fs;
 28      Cut cuts = Cuts::abseta < 2.5 && Cuts::pT > 20*GeV;
 29      LeptonFinder leptons(0.1, cuts && (Cuts::abspid == PID::ELECTRON || Cuts::abspid == PID::MUON));
 30      declare(leptons, "leptons");
 31
 32      // Leading neutrinos for Etmiss
 33      LeadingParticlesFinalState neutrinos(fs);
 34      neutrinos.addParticleIdPair(PID::NU_E);
 35      neutrinos.addParticleIdPair(PID::NU_MU);
 36      neutrinos.setLeadingOnly(true);
 37      declare(neutrinos, "neutrinos");
 38
 39      // Input for the jets: "Neutrinos, electrons, and muons from decays of the
 40      // massive W boson were not used"
 41      VetoedFinalState veto;
 42      veto.addVetoOnThisFinalState(leptons);
 43      veto.addVetoOnThisFinalState(neutrinos);
 44      FastJets jets(veto, JetAlg::ANTIKT, 0.4, JetMuons::ALL, JetInvisibles::DECAY);
 45      declare(jets, "jets");
 46
 47      for (size_t i = 0; i < 2; ++i) {
 48        book(_h_NjetIncl[i] ,1, 1, i+1);
 49        book(_h_RatioNjetIncl[i], 2, 1, i+1);
 50        book(_h_FirstJetPt_1jet[i] ,3, 1, i+1);
 51        book(_h_FirstJetPt_2jet[i] ,4, 1, i+1);
 52        book(_h_FirstJetPt_3jet[i] ,5, 1, i+1);
 53        book(_h_FirstJetPt_4jet[i] ,6, 1, i+1);
 54        book(_h_SecondJetPt_2jet[i] ,7, 1, i+1);
 55        book(_h_SecondJetPt_3jet[i] ,8, 1, i+1);
 56        book(_h_SecondJetPt_4jet[i] ,9, 1, i+1);
 57        book(_h_ThirdJetPt_3jet[i] ,10, 1, i+1);
 58        book(_h_ThirdJetPt_4jet[i] ,11, 1, i+1);
 59        book(_h_FourthJetPt_4jet[i] ,12, 1, i+1);
 60        book(_h_Ht_1jet[i] ,13, 1, i+1);
 61        book(_h_Ht_2jet[i] ,14, 1, i+1);
 62        book(_h_Ht_3jet[i] ,15, 1, i+1);
 63        book(_h_Ht_4jet[i] ,16, 1, i+1);
 64        book(_h_Minv_2jet[i] ,17, 1, i+1);
 65        book(_h_Minv_3jet[i] ,18, 1, i+1);
 66        book(_h_Minv_4jet[i] ,19, 1, i+1);
 67        book(_h_JetRapidity[i] ,20, 1, i+1);
 68        book(_h_DeltaYElecJet[i] ,21, 1, i+1);
 69        book(_h_SumYElecJet[i] ,22, 1, i+1);
 70        book(_h_DeltaR_2jet[i] ,23, 1, i+1);
 71        book(_h_DeltaY_2jet[i] ,24, 1, i+1);
 72        book(_h_DeltaPhi_2jet[i] ,25, 1, i+1);
 73      }
 74    }
 75
 76
 77    /// Perform the per-event analysis
 78    void analyze(const Event& event) {
 79      const DressedLeptons& leptons = apply<LeptonFinder>(event, "leptons").dressedLeptons();
 80      Particles neutrinos = apply<FinalState>(event, "neutrinos").particlesByPt();
 81
 82      if (leptons.size() != 1 || (neutrinos.size() == 0)) vetoEvent;
 83
 84      FourMomentum lepton = leptons[0].momentum();
 85      FourMomentum p_miss = neutrinos[0].momentum();
 86      if (p_miss.Et() < 25.0*GeV) vetoEvent;
 87
 88      double mT = sqrt(2.0 * lepton.pT() * p_miss.Et() * (1.0 - cos( lepton.phi()-p_miss.phi()) ) );
 89      if (mT < 40.0*GeV) vetoEvent;
 90
 91      double jetcuts[] = { 30.0*GeV, 20.0*GeV };
 92      for (size_t i = 0; i < 2; ++i) {
 93        Jets jets = apply<FastJets>(event, "jets").jetsByPt(Cuts::absrap < 4.4 && Cuts::pT > jetcuts[i]);
 94        idiscard(jets, deltaRLess(lepton, 0.5));
 95
 96        const double HT = sum(jets, Kin::pT, lepton.pT() + p_miss.pT());
 97
 98        _h_NjetIncl[i]->fill(0.0);
 99
100        // Njet>=1 observables
101        if (jets.size() < 1) continue;
102        _h_NjetIncl[i]->fill(1.0);
103        _h_FirstJetPt_1jet[i]->fill(jets[0].pT());
104        _h_JetRapidity[i]->fill(jets[0].rapidity());
105        _h_Ht_1jet[i]->fill(HT);
106        _h_DeltaYElecJet[i]->fill(lepton.rapidity()-jets[0].rapidity());
107        _h_SumYElecJet[i]->fill(lepton.rapidity()+jets[0].rapidity());
108
109        // Njet>=2 observables
110        if (jets.size() < 2) continue;
111        _h_NjetIncl[i]->fill(2.0);
112        _h_FirstJetPt_2jet[i]->fill(jets[0].pT());
113        _h_SecondJetPt_2jet[i]->fill(jets[1].pT());
114        _h_Ht_2jet[i]->fill(HT);
115        double m2_2jet = (jets[0].mom()+jets[1].mom()).mass2();
116        _h_Minv_2jet[i]->fill(m2_2jet>0.0 ? sqrt(m2_2jet) : 0.0);
117        _h_DeltaR_2jet[i]->fill(deltaR(jets[0], jets[1]));
118        _h_DeltaY_2jet[i]->fill(jets[0].rapidity()-jets[1].rapidity());
119        _h_DeltaPhi_2jet[i]->fill(deltaPhi(jets[0], jets[1]));
120
121        // Njet>=3 observables
122        if (jets.size() < 3) continue;
123        _h_NjetIncl[i]->fill(3.0);
124        _h_FirstJetPt_3jet[i]->fill(jets[0].pT());
125        _h_SecondJetPt_3jet[i]->fill(jets[1].pT());
126        _h_ThirdJetPt_3jet[i]->fill(jets[2].pT());
127        _h_Ht_3jet[i]->fill(HT);
128        double m2_3jet = (jets[0].mom()+jets[1].mom()+jets[2].mom()).mass2();
129        _h_Minv_3jet[i]->fill(m2_3jet>0.0 ? sqrt(m2_3jet) : 0.0);
130
131        // Njet>=4 observables
132        if (jets.size() < 4) continue;
133        _h_NjetIncl[i]->fill(4.0);
134        _h_FirstJetPt_4jet[i]->fill(jets[0].pT());
135        _h_SecondJetPt_4jet[i]->fill(jets[1].pT());
136        _h_ThirdJetPt_4jet[i]->fill(jets[2].pT());
137        _h_FourthJetPt_4jet[i]->fill(jets[3].pT());
138        _h_Ht_4jet[i]->fill(HT);
139        double m2_4jet = (jets[0].mom()+jets[1].mom()+jets[2].mom()+jets[3].mom()).mass2();
140        _h_Minv_4jet[i]->fill(m2_4jet>0.0 ? sqrt(m2_4jet) : 0.0);
141
142        // Njet>=5 observables
143        if (jets.size() < 5) continue;
144        _h_NjetIncl[i]->fill(5.0);
145      }
146    }
147
148
149    /// Normalise histograms etc., after the run
150    void finalize() {
151      for (size_t i = 0; i < 2; ++i) {
152
153        // Construct jet multiplicity ratio
154        for (size_t n = 1; n < _h_NjetIncl[i]->numBins(); ++n) {
155          const auto& b0 = _h_NjetIncl[i]->bin(n);
156          const auto& b1 = _h_NjetIncl[i]->bin(n+1);
157          double val = 0.0, err= 0.0;
158          if (b0.sumW() && b1.sumW()) {
159            val = b1.sumW() / b0.sumW();
160            err = b1.sumW() / b0.sumW() * (b0.relErrW() + b1.relErrW());
161          }
162          _h_RatioNjetIncl[i]->bin(n).set(val, err);
163        }
164
165        // Scale all histos to the cross section
166        const double factor = crossSection()/picobarn/sumOfWeights();
167        scale(_h_DeltaPhi_2jet[i], factor);
168        scale(_h_DeltaR_2jet[i], factor);
169        scale(_h_DeltaY_2jet[i], factor);
170        scale(_h_DeltaYElecJet[i], factor);
171        scale(_h_FirstJetPt_1jet[i], factor);
172        scale(_h_FirstJetPt_2jet[i], factor);
173        scale(_h_FirstJetPt_3jet[i], factor);
174        scale(_h_FirstJetPt_4jet[i], factor);
175        scale(_h_FourthJetPt_4jet[i], factor);
176        scale(_h_Ht_1jet[i], factor);
177        scale(_h_Ht_2jet[i], factor);
178        scale(_h_Ht_3jet[i], factor);
179        scale(_h_Ht_4jet[i], factor);
180        scale(_h_JetRapidity[i], factor);
181        scale(_h_Minv_2jet[i], factor);
182        scale(_h_Minv_3jet[i], factor);
183        scale(_h_Minv_4jet[i], factor);
184        scale(_h_NjetIncl[i], factor);
185        scale(_h_SecondJetPt_2jet[i], factor);
186        scale(_h_SecondJetPt_3jet[i], factor);
187        scale(_h_SecondJetPt_4jet[i], factor);
188        scale(_h_SumYElecJet[i], factor);
189        scale(_h_ThirdJetPt_3jet[i], factor);
190        scale(_h_ThirdJetPt_4jet[i], factor);
191      }
192    }
193
194    /// @}
195
196
197  private:
198
199    /// @name Histograms
200    /// @{
201    Histo1DPtr _h_DeltaPhi_2jet[2];
202    Histo1DPtr _h_DeltaR_2jet[2];
203    Histo1DPtr _h_DeltaY_2jet[2];
204    Histo1DPtr _h_DeltaYElecJet[2];
205    Histo1DPtr _h_FirstJetPt_1jet[2];
206    Histo1DPtr _h_FirstJetPt_2jet[2];
207    Histo1DPtr _h_FirstJetPt_3jet[2];
208    Histo1DPtr _h_FirstJetPt_4jet[2];
209    Histo1DPtr _h_FourthJetPt_4jet[2];
210    Histo1DPtr _h_Ht_1jet[2];
211    Histo1DPtr _h_Ht_2jet[2];
212    Histo1DPtr _h_Ht_3jet[2];
213    Histo1DPtr _h_Ht_4jet[2];
214    Histo1DPtr _h_JetRapidity[2];
215    Histo1DPtr _h_Minv_2jet[2];
216    Histo1DPtr _h_Minv_3jet[2];
217    Histo1DPtr _h_Minv_4jet[2];
218    Histo1DPtr _h_NjetIncl[2];
219    Estimate1DPtr _h_RatioNjetIncl[2];
220    Histo1DPtr _h_SecondJetPt_2jet[2];
221    Histo1DPtr _h_SecondJetPt_3jet[2];
222    Histo1DPtr _h_SecondJetPt_4jet[2];
223    Histo1DPtr _h_SumYElecJet[2];
224    Histo1DPtr _h_ThirdJetPt_3jet[2];
225    Histo1DPtr _h_ThirdJetPt_4jet[2];
226    /// @}
227
228
229  };
230
231
232
233  RIVET_DECLARE_PLUGIN(ATLAS_2012_I1083318);
234
235}