1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class SND_2002_I587084 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(SND_2002_I587084);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22
23      // Initialise and register projections
24      declare(FinalState(), "FS");
25      book(_numPiPiGamma, "TMP/PiPiGamma");
26
27    }
28
29
30    /// Perform the per-event analysis
31    void analyze(const Event& event) {
32
33      const FinalState& fs = apply<FinalState>(event, "FS");
34
35      map<long,int> nCount;
36      int ntotal(0);
37      for (const Particle& p : fs.particles()) {
38        nCount[p.pid()] += 1;
39        ++ntotal;
40      }
41      // three particles (pi0 pi0 gamma)
42      if(ntotal!=3) vetoEvent;
43      if(nCount[111]==2 && nCount[22]==1)
44        _numPiPiGamma->fill();
45    }
46
47
48    /// Normalise histograms etc., after the run
49    void finalize() {
50
51      double sigma = _numPiPiGamma->val();
52      double error = _numPiPiGamma->err();
53      sigma *= crossSection()/ sumOfWeights() /nanobarn;
54      error *= crossSection()/ sumOfWeights() /nanobarn;
55      Estimate1DPtr mult;
56      book(mult, 1, 1, 1);
57      for (auto& b : mult->bins()) {
58        if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
59          b.set(sigma, error);
60        }
61      }
62    }
63
64    /// @}
65
66
67    /// @name Histograms
68    /// @{
69    CounterPtr _numPiPiGamma;
70    /// @}
71
72
73  };
74
75
76  RIVET_DECLARE_PLUGIN(SND_2002_I587084);
77
78
79}