1// -*- C++ -*-
 2#include "Rivet/Projections/ImpactParameterProjection.hh"
 3#include "Rivet/Analysis.hh"
 4#include "Rivet/Analyses/AliceCommon.hh"
 5
 6namespace Rivet {
 7
 8
 9/// Generic analysis looking at various distributions of final state particles
10class ALICE_2015_CENT_PPB : public Analysis {
11
12public:
13
14  RIVET_DEFAULT_ANALYSIS_CTOR(ALICE_2015_CENT_PPB);
15
16  /// Book histograms and initialise projections before the run
17  void init() {
18
19    // One projection for the actual observable, and one for the
20    // generated impact parameter.
21    declare(ALICE::V0AMultiplicity(), "V0A");
22    declare(ImpactParameterProjection(), "IMP");
23    declare(ALICE::V0AndTrigger(), "Trigger");
24
25    // The calibration histogram:
26    book(_calib, "V0A", 100, 0.0, 500.0);
27
28
29    // The alternative histogram based on impact parameter. Note that
30    // it MUST be named the same as the histogram for the experimental
31    // observable with an added _IMP suffix.
32    book(_impcalib, "V0A_IMP", 400, 0.0, 20.0);
33
34  }
35
36  /// Perform the per-event analysis
37  void analyze(const Event& event) {
38
39    // The alternative centrality based on generated impact
40    // parameter, assumes that the generator does not describe the
41    // full final state, and should therefore be filled even if the
42    // event is not triggered.
43    _impcalib->fill(apply<SingleValueProjection>(event, "IMP")());
44
45    if ( !apply<ALICE::V0AndTrigger>(event, "Trigger")() ) vetoEvent;
46
47    _calib->fill(apply<ALICE::V0AMultiplicity>(event, "V0A")());
48
49  }
50
51
52  /// Finalize
53  void finalize() {
54
55    _calib->normalize();
56    _impcalib->normalize();
57
58  }
59
60private:
61
62  /// The calibration histograms.
63  Histo1DPtr _calib;
64  Histo1DPtr _impcalib;
65
66};
67
68
69RIVET_DECLARE_PLUGIN(ALICE_2015_CENT_PPB);
70
71}