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 CMD2_1999_I498859 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CMD2_1999_I498859);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24
25      // Book histograms
26      book(_npion, "TMP/pion");
27    }
28
29
30    /// Perform the per-event analysis
31    void analyze(const Event& event) {
32      const FinalState& fs = apply<FinalState>(event, "FS");
33      if(fs.particles().size()!=2) vetoEvent;
34      for (const Particle& p : fs.particles()) {
35        if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
36      }
37      _npion->fill();
38    }
39
40
41    /// Normalise histograms etc., after the run
42    void finalize() {
43      double sigma = _npion->val();
44      double error = _npion->err();
45      sigma *= crossSection()/ sumOfWeights() /nanobarn;
46      error *= crossSection()/ sumOfWeights() /nanobarn;
47      Estimate1DPtr mult;
48      book(mult, 1, 1, 1);
49      for (auto& b : mult->bins()) {
50        if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
51          b.set(sigma, error);
52        }
53      }
54    }
55
56    /// @}
57
58
59    /// @name Histograms
60    /// @{
61    CounterPtr _npion;
62    /// @}
63
64
65  };
66
67
68  RIVET_DECLARE_PLUGIN(CMD2_1999_I498859);
69
70
71}