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      book(_npion1, "TMP/pion1");
27      book(_npion2, "TMP/pion2");
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
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      if(ntotal!=4) vetoEvent;
42      if(nCount[-211]==2&&nCount[211]==2)
43	_npion1->fill();
44      else if(nCount[-211]==1&&nCount[211]==1&&nCount[111]==2)
45	_npion2->fill();
46    }
47
48
49    /// Normalise histograms etc., after the run
50    void finalize() {
51      for (unsigned int ix=1;ix<3;++ix) {
52        double sigma,error;
53        if(ix==1) {
54          sigma = _npion1->val();
55          error = _npion1->err();
56        }
57        else {
58          sigma = _npion2->val();
59          error = _npion2->err();
60        }
61        sigma *= crossSection()/ sumOfWeights() /nanobarn;
62        error *= crossSection()/ sumOfWeights() /nanobarn;
63        Estimate1DPtr mult;
64        book(mult, ix, 1, 1);
65        for (auto& b : mult->bins()) {
66          if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
67            b.set(sigma, error);
68          }
69        }
70      }
71    }
72
73    /// @}
74
75
76    /// @name Histograms
77    /// @{
78    CounterPtr _npion1,_npion2;
79    /// @}
80
81
82  };
83
84
85  RIVET_DECLARE_PLUGIN(SND_2001_I579319);
86
87
88}