1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/FinalState.hh"
  4#include "Rivet/Projections/FastJets.hh"
  5#include "Rivet/Projections/DISKinematics.hh"
  6#include "Rivet/Projections/UnstableParticles.hh"
  7namespace Rivet {
  8
  9
 10  /// @brief Inclusive D0 and D*+- production in deep inelastic e p scattering at HERA (H1)
 11  class H1_1996_I421105 : public Analysis {
 12  public:
 13
 14    /// Constructor
 15    RIVET_DEFAULT_ANALYSIS_CTOR(H1_1996_I421105);
 16
 17
 18    /// @name Analysis methods
 19    ///@{
 20
 21    /// Book histograms and initialise projections before the run
 22    void init() {
 23
 24      // Declare projections
 25      declare(DISKinematics(), "Kinematics");
 26      declare(UnstableParticles(), "UFS");
 27      declare(FinalState(Cuts::abseta < 4.9), "FS");
 28
 29      // Book histograms from reference data using HEPData ID (digits in "d01-x01-y01")
 30      book(_h["p_tD*_norm"], 4, 1, 1);
 31      book(_h["p_tD*"], 4, 1, 2);
 32      book(_h["p_tD0_norm"], 5, 1, 1);
 33      book(_h["p_tD0"], 5, 1, 2);
 34      book(_h["xD_D*_norm"], 6, 1, 1);
 35      book(_h["xD_D*"], 6, 1, 2);
 36      book(_h["xD_D0_norm"], 7, 1, 1);
 37      book(_h["xD_D0"], 7, 1, 2);
 38    }
 39
 40
 41    /// Perform the per-event analysis
 42    void analyze(const Event& event) {
 43
 44      /// @todo Do the event by event analysis here
 45      const DISKinematics& dk = apply<DISKinematics>(event, "Kinematics");
 46      const LorentzTransform hcmboost = dk.boostHCM();
 47
 48      // Get the DIS kinematics
 49      double y = dk.y();
 50      double W2 = dk.W2()/GeV2;
 51      double Q2 = dk.Q2()/GeV;
 52
 53     bool cut ;
 54     cut = Q2 > 10 && Q2 < 100 && y > 0.01 && y < 0.7 ;
 55     
 56     if (! cut ) vetoEvent ;
 57     bool etacut ;
 58     for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles()) {
 59        etacut = abs(p.momentum().eta()) < 1.5 ;
 60        const FourMomentum hcmMom = hcmboost.transform(p.momentum());
 61        double p_D ;
 62        double x_D = 0 ;
 63        p_D = std::sqrt( hcmMom.px()*hcmMom.px() + hcmMom.py()*hcmMom.py() + hcmMom.pz()*hcmMom.pz() );
 64        x_D = 2.*p_D/sqrt(W2);
 65        if (p.abspid() == 421) {
 66           _h["p_tD0"]->fill(p.momentum().pT()/GeV);
 67           _h["p_tD0_norm"]->fill(p.momentum().pT()/GeV);
 68           if (etacut ) _h["xD_D0"]->fill(x_D);
 69           if (etacut ) _h["xD_D0_norm"]->fill(x_D);
 70        }
 71          
 72        if (p.abspid() == 413) {
 73          _h["p_tD*"]->fill(p.momentum().pT()/GeV);
 74          _h["p_tD*_norm"]->fill(p.momentum().pT()/GeV);
 75          // x_D is defined for the D0
 76          if (etacut ) _h["xD_D*"]->fill(x_D);
 77          if (etacut ) _h["xD_D*_norm"]->fill(x_D);
 78        } 
 79    }
 80
 81  }
 82    /// Normalise histograms etc., after the run
 83    void finalize() {
 84        
 85    
 86     scale(_h["p_tD*"], crossSection()/nanobarn/sumW()); 
 87     scale(_h["p_tD0"], crossSection()/nanobarn/sumW()); 
 88     normalize(_h["p_tD*_norm"]);
 89     normalize(_h["p_tD0_norm"]);
 90     
 91     scale(_h["xD_D*"], crossSection()/nanobarn/sumW()); 
 92     scale(_h["xD_D0"], crossSection()/nanobarn/sumW()); 
 93     normalize(_h["xD_D*_norm"]);
 94     normalize(_h["xD_D0_norm"]);
 95
 96
 97    }
 98
 99    ///@}
100
101
102    /// @name Histograms
103    ///@{
104    map<string, Histo1DPtr> _h;
105    ///@}
106
107  };
108
109
110  RIVET_DECLARE_PLUGIN(H1_1996_I421105);
111
112}