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 CMD_1985_I221309 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CMD_1985_I221309);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22
23      // Initialise and register projections
24      declare(FinalState(), "FS");
25
26      // Book histograms
27      book(_npion, "TMP/pion");
28    }
29
30
31    /// Perform the per-event analysis
32    void analyze(const Event& event) {
33      const FinalState& fs = apply<FinalState>(event, "FS");
34      if(fs.particles().size()!=2) vetoEvent;
35      for (const Particle& p : fs.particles()) {
36	if(abs(p.pid())!=PID::PIPLUS) vetoEvent;
37      }
38      _npion->fill();
39    }
40
41
42    /// Normalise histograms etc., after the run
43    void finalize() {
44      double sigma = _npion->val();
45      double error = _npion->err();
46      sigma *= crossSection()/ sumOfWeights() /nanobarn;
47      error *= crossSection()/ sumOfWeights() /nanobarn;
48      for (unsigned int ix=1;ix<3;++ix) {
49        Estimate1DPtr mult;
50        book(mult, ix, 1, 1);
51        for (auto& b : mult->bins()) {
52          if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
53            b.set(sigma, error);
54          }
55        }
56      }
57    }
58
59    /// @}
60
61
62    /// @name Histograms
63    /// @{
64    CounterPtr _npion;
65    /// @}
66
67
68  };
69
70
71  RIVET_DECLARE_PLUGIN(CMD_1985_I221309);
72
73
74}