Rivet Analyses Reference

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// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/DISKinematics.hh"
#include "Rivet/Projections/FastJets.hh"
#include "fastjet/SISConePlugin.hh"

namespace Rivet {


  /// @brief ZEUS inclusive jet photoproduction study used to measure alpha_s
  ///
  /// @author Jon Butterworth
  class ZEUS_2012_I1116258 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(ZEUS_2012_I1116258);

    /// @name Analysis methods
    //@{

    // Book projections and histograms
    void init() {

      // Projections

      // Jet schemes checked with original code, M.Wing, A.Geiser
      FinalState fs;
      double jet_radius = 1.0;
      declare(FastJets(fs, fastjet::JetAlgorithm::kt_algorithm, fastjet::RecombinationScheme::Et_scheme, jet_radius), "Jets");
      declare(FastJets(fs, fastjet::JetAlgorithm::antikt_algorithm, fastjet::RecombinationScheme::Et_scheme, jet_radius), "Jets_akt");

      // bit of messing about to use the correct recombnation scheme for SISCone.
      double overlap_threshold = 0.75;
      fastjet::SISConePlugin * plugin = new fastjet::SISConePlugin(jet_radius, overlap_threshold);
      plugin->set_use_jet_def_recombiner(true);
      JetDefinition siscone(plugin);
      siscone.set_recombination_scheme(fastjet::RecombinationScheme::Et_scheme);
      declare(FastJets(fs, siscone), "Jets_sis");


      declare(DISKinematics(), "Kinematics");

      // all eta
      book(_h_etjet[0], 1, 1, 1);

      // two ET cuts.
      book(_h_etajet[0], 2, 1, 1);
      book(_h_etajet[1], 3, 1, 1);

      // in eta regions
      book(_h_etjet[1], 4, 1, 1);
      book(_h_etjet[2], 5, 1, 1);
      book(_h_etjet[3], 6, 1, 1);
      book(_h_etjet[4], 7, 1, 1);
      book(_h_etjet[5], 8, 1, 1);

      // antiKT
      book(_h_etjet[6], 9, 1, 1);
      book(_h_etajet[2], 11, 1, 1);

      // SiSCone
      book(_h_etjet[7], 10, 1, 1);
      book(_h_etajet[3], 12, 1, 1);

    }


    // Do the analysis
    void analyze(const Event& event) {

      // Determine kinematics, including event orientation since ZEUS coord system is for +z = proton direction
      const DISKinematics& kin = apply<DISKinematics>(event, "Kinematics");
      const int orientation = kin.orientation();

      // Q2 and inelasticity cuts
      if (kin.Q2() > 1*GeV2) vetoEvent;
      if (!inRange(sqrt(kin.W2()), 142.0, 293.0)) vetoEvent;

      // Jet selection
      // @TODO check the recombination scheme
      const Jets jets = apply<FastJets>(event, "Jets")          \
        .jets(Cuts::Et > 17*GeV && Cuts::etaIn(-1*orientation, 2.5*orientation), cmpMomByEt);
      MSG_DEBUG("kT Jet multiplicity = " << jets.size());

      const Jets jets_akt = apply<FastJets>(event, "Jets_akt")      \
        .jets(Cuts::Et > 17*GeV && Cuts::etaIn(-1*orientation, 2.5*orientation), cmpMomByEt);

      const Jets jets_sis = apply<FastJets>(event, "Jets_sis")  \
        .jets(Cuts::Et > 17*GeV && Cuts::etaIn(-1*orientation, 2.5*orientation), cmpMomByEt);


      // Fill histograms
      for (const Jet& jet : jets ){
        _h_etjet[0]->fill(jet.pt());
        _h_etajet[0]->fill(orientation*jet.eta());
        if (jet.pt()>21*GeV) {
          _h_etajet[1]->fill(orientation*jet.eta());
        }
        if (orientation*jet.eta() < 0) {
          _h_etjet[1]->fill(jet.pt());
        } else if (orientation*jet.eta() < 1) {
          _h_etjet[2]->fill(jet.pt());
        } else if (orientation*jet.eta() < 1.5) {
          _h_etjet[3]->fill(jet.pt());
        } else if (orientation*jet.eta() < 2) {
          _h_etjet[4]->fill(jet.pt());
        } else {
          _h_etjet[5]->fill(jet.pt());
        }
      }

      for (const Jet& jet : jets_akt ){
        _h_etjet[6]->fill(jet.pt());
        _h_etajet[2]->fill(orientation*jet.eta());
      }
      for (const Jet& jet : jets_sis ){
        _h_etjet[7]->fill(jet.pt());
        _h_etajet[3]->fill(orientation*jet.eta());
      }

    }


    // Finalize
    void finalize() {
      const double sf = crossSection()/picobarn/sumOfWeights();
      for( int i = 0; i < 8; i++ ) {
        scale(_h_etjet[i], sf);
      }
      for( int i = 0; i < 4; i++ ) {
        scale(_h_etajet[i], sf);
      }
    }

    //@}


  private:

    /// @name Histograms
    //@{
    Histo1DPtr _h_etjet[8], _h_etajet[4];
    //@}

  };


  RIVET_DECLARE_PLUGIN(ZEUS_2012_I1116258);

}