1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/DileptonFinder.hh"
  4#include "Rivet/Projections/FastJets.hh"
  5
  6namespace Rivet {
  7
  8
  9  /// @brief D0 differential Z/\f$ \gamma^* \f$ + jet + \f$ X \f$ cross sections
 10  ///
 11  /// @author Gavin Hesketh, Andy Buckley, Frank Siegert
 12  class D0_2008_I792812 : public Analysis {
 13  public:
 14
 15    RIVET_DEFAULT_ANALYSIS_CTOR(D0_2008_I792812);
 16
 17
 18    /// @name Analysis methods
 19    /// @{
 20
 21    /// Book histograms
 22    void init() {
 23
 24      Cut cut = Cuts::abseta < 1.7 && Cuts::pT > 15*GeV;
 25      DileptonFinder zfinder(91.2*GeV, 0.2, cut && Cuts::abspid == PID::MUON, Cuts::massIn(65*GeV, 115*GeV));
 26      declare(zfinder, "DileptonFinder");
 27
 28      FastJets conefinder(zfinder.remainingFinalState(), JetAlg::D0ILCONE, 0.5);
 29      declare(conefinder, "ConeFinder");
 30
 31      book(_sum_of_weights_inclusive, "sum_of_weights_inclusive");
 32
 33      book(_h_jet_pT_cross_section ,1, 1, 1);
 34      book(_h_jet_pT_normalised ,1, 1, 2);
 35      book(_h_jet_y_cross_section ,2, 1, 1);
 36      book(_h_jet_y_normalised ,2, 1, 2);
 37      book(_h_Z_pT_cross_section ,3, 1, 1);
 38      book(_h_Z_pT_normalised ,3, 1, 2);
 39      book(_h_Z_y_cross_section ,4, 1, 1);
 40      book(_h_Z_y_normalised ,4, 1, 2);
 41      book(_h_total_cross_section ,5, 1, 1);
 42    }
 43
 44
 45    // Do the analysis
 46    void analyze(const Event& e) {
 47      const DileptonFinder& zfinder = apply<DileptonFinder>(e, "DileptonFinder");
 48      if (zfinder.bosons().size()==1) {
 49        _sum_of_weights_inclusive->fill();
 50        const JetFinder& jetpro = apply<JetFinder>(e, "ConeFinder");
 51        const Jets& jets = jetpro.jetsByPt(Cuts::pT > 20*GeV && Cuts::abseta < 2.8);
 52
 53        // Return if there are no jets:
 54        if (jets.size() < 1) {
 55          MSG_DEBUG("Skipping event " << numEvents() << " because no jets pass cuts ");
 56          vetoEvent;
 57        }
 58
 59        const FourMomentum Zmom = zfinder.bosons()[0].momentum();
 60
 61        // In jet pT
 62        _h_jet_pT_cross_section->fill( jets[0].pT());
 63        _h_jet_pT_normalised->fill( jets[0].pT());
 64        _h_jet_y_cross_section->fill( fabs(jets[0].rapidity()));
 65        _h_jet_y_normalised->fill( fabs(jets[0].rapidity()));
 66
 67        // In Z pT
 68        _h_Z_pT_cross_section->fill(Zmom.pT());
 69        _h_Z_pT_normalised->fill(Zmom.pT());
 70        _h_Z_y_cross_section->fill(Zmom.absrap());
 71        _h_Z_y_normalised->fill(Zmom.absrap());
 72
 73        _h_total_cross_section->fill(1960);
 74      }
 75    }
 76
 77
 78    /// Finalize
 79    void finalize() {
 80      const double invlumi = crossSection()/picobarn/sumOfWeights();
 81      scale(_h_total_cross_section, invlumi);
 82      scale(_h_jet_pT_cross_section, invlumi);
 83      scale(_h_jet_y_cross_section, invlumi);
 84      scale(_h_Z_pT_cross_section, invlumi);
 85      scale(_h_Z_y_cross_section, invlumi);
 86
 87      double factor=1/dbl(*_sum_of_weights_inclusive);
 88      if (_sum_of_weights_inclusive->val() == 0) factor = 0;
 89      scale(_h_jet_pT_normalised, factor);
 90      scale(_h_jet_y_normalised, factor);
 91      scale(_h_Z_pT_normalised, factor);
 92      scale(_h_Z_y_normalised, factor);
 93    }
 94
 95    /// @}
 96
 97
 98  private:
 99
100    /// @name Histograms
101    /// @{
102    Histo1DPtr _h_jet_pT_cross_section;
103    Histo1DPtr _h_jet_y_cross_section;
104    Histo1DPtr _h_Z_pT_cross_section;
105    Histo1DPtr _h_Z_y_cross_section;
106    Histo1DPtr _h_total_cross_section;
107    Histo1DPtr _h_jet_pT_normalised;
108    Histo1DPtr _h_jet_y_normalised;
109    Histo1DPtr _h_Z_pT_normalised;
110    Histo1DPtr _h_Z_y_normalised;
111    /// @}
112
113    CounterPtr _sum_of_weights_inclusive;
114
115  };
116
117
118  RIVET_DECLARE_ALIASED_PLUGIN(D0_2008_I792812, D0_2008_S7863608);
119
120}