1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/ChargedFinalState.hh"
  5#include "Rivet/Projections/Sphericity.hh"
  6#include "Rivet/Projections/FastJets.hh"
  7
  8namespace Rivet {
  9
 10
 11  /// @brief 3 jet events at 29 GeV
 12  class MARKII_1985_I216850 : public Analysis {
 13  public:
 14
 15    /// Constructor
 16    RIVET_DEFAULT_ANALYSIS_CTOR(MARKII_1985_I216850);
 17
 18
 19    /// @name Analysis methods
 20    /// @{
 21
 22    /// Book histograms and initialise projections before the run
 23    void init() {
 24      // projections
 25      const FinalState fs;
 26      declare(fs, "FS");
 27      const ChargedFinalState cfs;
 28      declare(cfs, "CFS");
 29      Sphericity sphere(fs);
 30      declare(sphere, "Sphericity");
 31      FastJets jadeJets = FastJets(fs, JetAlg::JADE, 0.7, JetMuons::ALL, JetInvisibles::DECAY);
 32      declare(jadeJets, "JadeJets");
 33      // histos
 34      book(_h,1,1,1);
 35      book(_njet,"TMP/njet");
 36    }
 37
 38
 39    /// Perform the per-event analysis
 40    void analyze(const Event& event) {
 41      // at least 5 charged particles
 42      const FinalState& cfs = apply<FinalState>(event, "CFS");
 43      if (cfs.particles().size()<5) vetoEvent;
 44      // sphericity cuts
 45      const Sphericity& sphericity = apply<Sphericity>(event, "Sphericity");
 46      if (sphericity.lambda3()<0.06 || sphericity.lambda2()-sphericity.lambda3()<0.05) vetoEvent;
 47      // cluster particles using jet
 48      const FastJets& jadejet = apply<FastJets>(event, "JadeJets");
 49      Particles fs = apply<FinalState>(event, "FS").particles();
 50      PseudoJets pjets = jadejet.clusterSeq()->exclusive_jets(3);
 51      Jets jets = jadejet.mkJets(pjets,fs);
 52      Vector3 n[3];
 53      // loop over the jets
 54      for (unsigned int ix=0; ix<jets.size(); ++ix) {
 55        if (jets[ix].constituents().size()<3) vetoEvent;
 56        double energy=0.;
 57        for (const Particle & p : jets[ix].constituents()) energy+=p.E();
 58        if (energy<2.*GeV) vetoEvent;
 59        n[ix] = jets[ix].mom().p3().unit();
 60      }
 61      vector<double> dot; dot.reserve(3);
 62      for (unsigned int ix=0; ix<jets.size(); ++ix) {
 63        for(unsigned int iy=ix+1; iy<jets.size(); ++iy) {
 64          dot.push_back(n[ix].dot(n[iy]));
 65          const double angle = acos(dot.back())*180./M_PI;
 66          if (angle<100 || angle>140) vetoEvent;
 67        }
 68      }
 69      double Ejet[3];
 70      Ejet[0] = (sqrtS()*(dot[1] - dot[0]*dot[2]))/((-1 + dot[0])*(1 + dot[0] - dot[1] - dot[2]));
 71      Ejet[1] = (sqrtS()*(-(dot[0]*dot[1]) + dot[2]))/((-1 + dot[0])*(1 + dot[0] - dot[1] - dot[2]));
 72      Ejet[2] = (sqrtS()*(1 + dot[0]))/(1 + dot[0] - dot[1] - dot[2]);
 73      // now loop over jets
 74      for (unsigned int ix=0;ix<3;++ix) {
 75        _njet->fill();
 76        for(const Particle & p : jets[ix].constituents()) {
 77          if (p.isCharged()) {
 78            _h->fill(p.momentum().p3().mod()/Ejet[ix]);
 79          }
 80        }
 81      }
 82    }
 83
 84
 85    /// Normalise histograms etc., after the run
 86    void finalize() {
 87      scale(_h, 1./ *_njet);
 88    }
 89
 90    /// @}
 91
 92
 93    /// @name Histograms
 94    /// @{
 95    Histo1DPtr _h;
 96    CounterPtr _njet;
 97    /// @}
 98
 99
100  };
101
102
103  RIVET_DECLARE_PLUGIN(MARKII_1985_I216850);
104
105}