1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4
 5namespace Rivet {
 6
 7
 8  /// @brief e+e- > 2pi+2pi-
 9  class GAMMAGAMMA_1980_I153382 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(GAMMAGAMMA_1980_I153382);
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      // Book histograms
24      book(_npion, "TMP/pion", refData(1, 1, 1));
25    }
26
27
28    /// Perform the per-event analysis
29    void analyze(const Event& event) {
30      const FinalState& fs = apply<FinalState>(event, "FS");
31      if(fs.particles().size()!=4) vetoEvent;
32      for (const Particle& p : fs.particles()) {
33	if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
34      }
35      _npion->fill(sqrtS()/GeV);
36    }
37
38
39    /// Normalise histograms etc., after the run
40    void finalize() {
41      scale(_npion, crossSection()/ sumOfWeights() /nanobarn);
42      Estimate1DPtr mult;
43      book(mult, 1, 1, 1);
44      barchart(_npion,mult);
45    }
46
47    /// @}
48
49
50    /// @name Histograms
51    /// @{
52    Histo1DPtr _npion;
53    /// @}
54
55
56  };
57
58
59  RIVET_DECLARE_PLUGIN(GAMMAGAMMA_1980_I153382);
60
61
62}