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 DM1_1982_I168552 : public Analysis {
10  public:
11
12    /// Constructor
13    RIVET_DEFAULT_ANALYSIS_CTOR(DM1_1982_I168552);
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");
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();
36    }
37
38
39    /// Normalise histograms etc., after the run
40    void finalize() {
41      double sigma = _npion->val();
42      double error = _npion->err();
43      sigma *= crossSection()/ sumOfWeights() /nanobarn;
44      error *= crossSection()/ sumOfWeights() /nanobarn;
45      Estimate1DPtr mult;
46      book(mult, 1, 1, 1);
47      for (auto& b : mult->bins()) {
48        if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
49          b.set(sigma, error);
50        }
51      }
52    }
53
54    /// @}
55
56
57    /// @name Histograms
58    /// @{
59    CounterPtr _npion;
60    /// @}
61
62
63  };
64
65
66  RIVET_DECLARE_PLUGIN(DM1_1982_I168552);
67
68
69}