1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FastJets.hh"
  4#include "Rivet/Projections/VetoedFinalState.hh"
  5#include "Rivet/Projections/VisibleFinalState.hh"
  6#include "Rivet/Projections/MissingMomentum.hh"
  7
  8namespace Rivet {
  9
 10
 11  /// @brief D0 Run II angular correlations in di-jet events
 12  /// @author Lars Sonnenschein
 13  ///
 14  /// Measurement of angular correlations in di-jet events.
 15  ///
 16  /// @par Run conditions
 17  /// @arg \f$ \sqrt{s} = \f$ 1960 GeV
 18  /// @arg Run with generic QCD events.
 19  /// @arg Several \f$ p_\perp^\text{min} \f$ cutoffs are probably required to fill the histograms:
 20  /// @arg \f$ p_\perp^\text{min} = \f$ 50, 75, 100, 150 GeV for the four pT ranges respecively
 21  ///
 22  class D0_2004_I659398 : public Analysis {
 23  public:
 24
 25    RIVET_DEFAULT_ANALYSIS_CTOR(D0_2004_I659398);
 26
 27
 28    /// @name Analysis methods
 29    /// @{
 30
 31    void init() {
 32      // Final state for jets, mET etc.
 33      const FinalState fs(Cuts::abseta < 3.0);
 34      declare(fs, "FS");
 35      // Veto neutrinos, and muons with pT above 1.0 GeV
 36      VetoedFinalState vfs(fs);
 37      vfs.vetoNeutrinos();
 38      vfs.addVetoPairDetail(PID::MUON, 1.0*GeV, DBL_MAX);
 39      declare(vfs, "VFS");
 40      declare(FastJets(vfs, JetAlg::D0ILCONE, 0.7), "Jets");
 41      declare(MissingMomentum(vfs), "CalMET");
 42
 43      // Book histograms
 44      book(_histJetAzimuth_pTmax75_100  ,1, 2, 1);
 45      book(_histJetAzimuth_pTmax100_130 ,2, 2, 1);
 46      book(_histJetAzimuth_pTmax130_180 ,3, 2, 1);
 47      book(_histJetAzimuth_pTmax180_    ,4, 2, 1);
 48    }
 49
 50
 51    /// Do the analysis
 52    void analyze(const Event& event) {
 53
 54      // Analyse and print some info
 55      const JetFinder& jetpro = apply<JetFinder>(event, "Jets");
 56      MSG_DEBUG("Jet multiplicity before any pT cut = " << jetpro.size());
 57
 58      const Jets jets  = jetpro.jetsByPt(Cuts::pT > 40.0*GeV);
 59      if (jets.size() >= 2) {
 60        MSG_DEBUG("Jet multiplicity after pT > 40 GeV cut = " << jets.size());
 61      }
 62      else  vetoEvent;
 63
 64      const double rap1 = jets[0].absrap();
 65      const double rap2 = jets[1].absrap();
 66      if (rap1 > 0.5 || rap2 > 0.5) {
 67        vetoEvent;
 68      }
 69      MSG_DEBUG("Jet eta and pT requirements fulfilled");
 70      const double pT1 = jets[0].pT();
 71
 72      const MissingMomentum& caloMissEt = apply<MissingMomentum>(event, "CalMET");
 73      MSG_DEBUG("Missing vector Et = " << caloMissEt.vectorEt()/GeV << " GeV");
 74      if (caloMissEt.vectorEt().mod() > 0.7*pT1) {
 75        MSG_DEBUG("Vetoing event with too much missing ET: "
 76                  << caloMissEt.vectorEt()/GeV << " GeV > "
 77                  << 0.7*pT1/GeV << " GeV");
 78        vetoEvent;
 79      }
 80
 81      if (pT1/GeV >= 75.0) {
 82        const double dphi = deltaPhi(jets[0].phi(), jets[1].phi());
 83        if (inRange(pT1/GeV, 75.0, 100.0)) {
 84          _histJetAzimuth_pTmax75_100->fill(dphi);
 85        } else if (inRange(pT1/GeV, 100.0, 130.0)) {
 86          _histJetAzimuth_pTmax100_130->fill(dphi);
 87        } else if (inRange(pT1/GeV, 130.0, 180.0)) {
 88          _histJetAzimuth_pTmax130_180->fill(dphi);
 89        } else if (pT1/GeV > 180.0) {
 90          _histJetAzimuth_pTmax180_->fill(dphi);
 91        }
 92      }
 93
 94    }
 95
 96
 97    // Finalize
 98    void finalize() {
 99      // Normalize histograms to unit area
100      normalize(_histJetAzimuth_pTmax75_100);
101      normalize(_histJetAzimuth_pTmax100_130);
102      normalize(_histJetAzimuth_pTmax130_180);
103      normalize(_histJetAzimuth_pTmax180_);
104    }
105
106    /// @}
107
108
109  private:
110
111    /// @name Histograms
112    /// @{
113    Histo1DPtr _histJetAzimuth_pTmax75_100;
114    Histo1DPtr _histJetAzimuth_pTmax100_130;
115    Histo1DPtr _histJetAzimuth_pTmax130_180;
116    Histo1DPtr _histJetAzimuth_pTmax180_;
117    /// @}
118
119  };
120
121
122
123  RIVET_DECLARE_ALIASED_PLUGIN(D0_2004_I659398, D0_2004_S5992206);
124
125}