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 SND_2014_I1321689 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(SND_2014_I1321689);
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(_nneutron, "TMP/neutron");
28
29    }
30
31
32    /// Perform the per-event analysis
33    void analyze(const Event& event) {
34      const FinalState& fs = apply<FinalState>(event, "FS");
35      if(fs.particles().size()!=2) vetoEvent;
36      for (const Particle& p : fs.particles()) {
37	if(abs(p.pid())!=PID::NEUTRON) vetoEvent;
38      }
39      _nneutron->fill();
40    }
41
42
43    /// Normalise histograms etc., after the run
44    void finalize() {
45
46      double sigma = _nneutron->val();
47      double error = _nneutron->err();
48      sigma *= crossSection()/ sumOfWeights() /nanobarn;
49      error *= crossSection()/ sumOfWeights() /nanobarn;
50      for (unsigned int ix=1;ix<3;++ix) {
51        Estimate1DPtr mult;
52        book(mult, ix, 1, 1);
53        for (auto& b : mult->bins()) {
54          if (inRange(sqrtS()/MeV, b.xMin(), b.xMax())) {
55            b.set(sigma, error);
56          }
57        }
58      }
59    }
60
61    /// @}
62
63
64    /// @name Histograms
65    /// @{
66    CounterPtr _nneutron;
67    /// @}
68
69
70  };
71
72
73  RIVET_DECLARE_PLUGIN(SND_2014_I1321689);
74
75
76}