1//-*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/CentralityProjection.hh"
  4#include "Rivet/Analyses/AliceCommon.hh"
  5
  6namespace Rivet {
  7
  8
  9  /// Pion, Kaon, and Proton Production in 0-5%
 10  ///  central Pb--Pb Collisions at 2.76 TeV
 11  class ALICE_2012_I1126966 : public Analysis {
 12  public:
 13
 14    /// Constructor
 15    RIVET_DEFAULT_ANALYSIS_CTOR(ALICE_2012_I1126966);
 16
 17    /// Book histograms and initialise projections before the run
 18    void init() {
 19      // Particles of interest.
 20      declare(ALICE::PrimaryParticles(Cuts::absrap < 0.5),"CFS");
 21
 22      // The event trigger.
 23      declare(ALICE::V0AndTrigger(), "V0-AND");
 24      // The centrality projection.
 25      declareCentrality(ALICE::V0MMultiplicity(),
 26           "ALICE_2015_PBPBCentrality", "V0M", "V0M");
 27
 28      // Invariant pT distributions.
 29      book(_histPtPi, "d01-x01-y01"); //pi+
 30      book(_histPtPibar, "d01-x01-y02");// pi-
 31      book(_histPtKaon, "d02-x01-y01"); //K+
 32      book(_histPtKaonbar, "d02-x01-y02"); //K-
 33      book(_histPtProton, "d03-x01-y01"); //P+
 34      book(_histPtProtonbar, "d03-x01-y02"); //P-
 35      // Yield histograms.
 36      book(_histNpi, "d04-x01-y01");
 37      book(_histNpibar, "d04-x01-y02");
 38      book(_histNKaon, "d04-x01-y03");
 39      book(_histNKaonbar, "d04-x01-y04");
 40      book(_histNproton, "d04-x01-y05");
 41      book(_histNprotonbar, "d04-x01-y06");
 42      // Sum of weights of triggered events.
 43      book(sow, "sow");
 44    }
 45
 46
 47    /// Perform the per-event analysis
 48    void analyze(const Event& event) {
 49      // Analysis only considers 0-5% central events
 50      if (apply<CentralityProjection>(event,"V0M")() > 5.0)
 51        vetoEvent;
 52      // Event trigger.
 53      if (!apply<ALICE::V0AndTrigger>(event, "V0-AND")() ) vetoEvent;
 54
 55      sow->fill();
 56      // ID particles counters for this event.
 57      int Npi=0;
 58      int Npibar=0;
 59      int NKaon=0;
 60      int NKaonbar=0;
 61      int Nproton=0;
 62      int Nprotonbar=0;
 63
 64      for (const Particle& p : apply<ALICE::PrimaryParticles>(event,"CFS").particles()) {
 65          const double pWeight = 1.0 / p.pT() / 2. / M_PI;
 66          switch (p.pid()) {
 67            case 211: // pi+
 68	      Npi++;
 69              _histPtPi->fill(p.pT()/GeV,  pWeight);
 70              break;
 71	    case -211: //pi-
 72	      Npibar++;
 73	      _histPtPibar->fill(p.pT()/GeV, pWeight);
 74              break;
 75            case 2212: // proton
 76	      Nproton++;
 77              _histPtProton->fill(p.pT()/GeV, pWeight);
 78	      break;
 79	    case -2212: // p-bar
 80	      Nprotonbar++;
 81              _histPtProtonbar->fill(p.pT()/GeV, pWeight);
 82              break;
 83            case 321: // K+
 84	      NKaon++;
 85              _histPtKaon->fill(p.pT()/GeV,  pWeight);
 86	      break;
 87	    case -321: // K-
 88	      NKaonbar++;
 89              _histPtKaonbar->fill(p.pT()/GeV,  pWeight);
 90             break;
 91        }
 92      } // Particle loop ends.
 93
 94      // Fill yield histograms.
 95      _histNpi->fill(0.0, Npi);
 96      _histNpibar->fill(0.0, Npibar);
 97      _histNKaon->fill(0.0, NKaon);
 98      _histNKaonbar->fill(0.0, NKaonbar);
 99      _histNproton->fill(0.0, Nproton);
100      _histNprotonbar->fill(0.0, Nprotonbar);
101    }
102
103
104    void finalize() {
105       const double s = 1./sow->sumW();
106       _histPtPi->scaleW(s);
107       _histPtPibar->scaleW(s);
108       _histPtKaon->scaleW(s);
109       _histPtKaonbar->scaleW(s);
110       _histPtProton->scaleW(s);
111       _histPtProtonbar->scaleW(s);
112       _histNpi->scaleW(s);
113       _histNpibar->scaleW(s);
114       _histNKaon->scaleW(s);
115       _histNKaonbar->scaleW(s);
116       _histNproton->scaleW(s);
117       _histNprotonbar->scaleW(s);
118
119}
120
121  private:
122
123      // pT histograms
124    Histo1DPtr _histPtPi;
125    Histo1DPtr _histPtKaon;
126    Histo1DPtr _histPtProton;
127    Histo1DPtr _histPtPibar;
128    Histo1DPtr _histPtKaonbar;
129    Histo1DPtr _histPtProtonbar;
130    Histo1DPtr _histNpi;
131    Histo1DPtr _histNpibar;
132    Histo1DPtr _histNKaon;
133    Histo1DPtr _histNKaonbar;
134    Histo1DPtr _histNproton;
135    Histo1DPtr _histNprotonbar;
136    CounterPtr sow;
137
138  };
139
140
141  RIVET_DECLARE_PLUGIN(ALICE_2012_I1126966);
142
143
144}