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 OLYA_1984_I208231 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(OLYA_1984_I208231);
14
15
16    /// @name Analysis methods
17    /// @{
18
19    /// Book histograms and initialise projections before the run
20    void init() {
21      // Initialise and register projections
22      declare(FinalState(), "FS");
23
24      // Book histograms
25      book(_npion, "TMP/pion");
26    }
27
28
29    /// Perform the per-event analysis
30    void analyze(const Event& event) {
31      const FinalState& fs = apply<FinalState>(event, "FS");
32      if(fs.particles().size()!=2) vetoEvent;
33      for (const Particle& p : fs.particles()) {
34	if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
35      }
36      _npion->fill();
37    }
38
39
40    /// Normalise histograms etc., after the run
41    void finalize() {
42      double sigma = _npion->val();
43      double error = _npion->err();
44      sigma *= crossSection()/ sumOfWeights() /nanobarn;
45      error *= crossSection()/ sumOfWeights() /nanobarn;
46      Estimate1DPtr mult;
47      book(mult, 1, 1, 1);
48      for (auto& b : mult->bins()) {
49        if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
50          b.set(sigma, error);
51        }
52      }
53    }
54
55    /// @}
56
57
58    /// @name Histograms
59    /// @{
60    CounterPtr _npion;
61    /// @}
62
63
64  };
65
66
67  RIVET_DECLARE_PLUGIN(OLYA_1984_I208231);
68
69
70}