1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief Add a short analysis description here
 9  class SND_2001_I579319 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(SND_2001_I579319);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24
25      // Book histograms
26      for(unsigned int ix=0;ix<2;++ix) {
27        book(_npion[ix], 1+ix, 1, 1);
28        for (const string& en : _npion[ix].binning().edges<0>()) {
29          const double end = std::stod(en)*GeV;
30          if (isCompatibleWithSqrtS(end)) {
31            _ecms[ix] = en;
32            break;
33          }
34        }
35      }
36      if (_ecms[0].empty() && _ecms[1].empty())
37        MSG_ERROR("Beam energy incompatible with analysis.");
38    }
39
40
41    /// Perform the per-event analysis
42    void analyze(const Event& event) {
43      const FinalState& fs = apply<FinalState>(event, "FS");
44
45      map<long,int> nCount;
46      int ntotal(0);
47      for (const Particle& p : fs.particles()) {
48	nCount[p.pid()] += 1;
49	++ntotal;
50      }
51      if(ntotal!=4) vetoEvent;
52      if(nCount[-211]==2&&nCount[211]==2)
53	_npion[0]->fill(_ecms[0]);
54      else if(nCount[-211]==1&&nCount[211]==1&&nCount[111]==2)
55	_npion[1]->fill(_ecms[1]);
56    }
57
58
59    /// Normalise histograms etc., after the run
60    void finalize() {
61      for (unsigned int ix=0;ix<2;++ix)
62        scale(_npion[ix], crossSection()/ sumOfWeights() /nanobarn);
63    }
64
65    /// @}
66
67
68    /// @name Histograms
69    /// @{
70    BinnedHistoPtr<string> _npion[2];
71    string _ecms[2];
72    /// @}
73
74
75  };
76
77
78  RIVET_DECLARE_PLUGIN(SND_2001_I579319);
79
80
81}