1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/UnstableParticles.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Add a short analysis description here
10  class FENICE_1998_I471263 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(FENICE_1998_I471263);
15
16
17    /// @name Analysis methods
18    /// @{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22      // Initialise and register projections
23      declare(FinalState(), "FS");
24      declare(UnstableParticles(), "UFS");
25      book(_nNeutron,  "/TMP/nNeutron" );
26    }
27
28
29    /// Perform the per-event analysis
30    void analyze(const Event& event) {
31      const FinalState& fs = apply<FinalState>(event, "FS");
32      // total hadronic and muonic cross sections
33      map<long,int> nCount;
34      int ntotal(0);
35      for (const Particle& p : fs.particles()) {
36	nCount[p.pid()] += 1;
37	++ntotal;
38      }
39      if(ntotal==2 && nCount[2112]==1 && nCount[-2112]==1)
40	_nNeutron->fill();
41    }
42
43
44    /// Normalise histograms etc., after the run
45    void finalize() {
46      double fact = crossSection()/ sumOfWeights() /nanobarn;
47      double sigma = _nNeutron->val()*fact;
48      double error = _nNeutron->err()*fact;
49      Estimate1DPtr mult;
50      book(mult, 1, 1, 1);
51      for (auto& b : mult->bins()) {
52        if (inRange(sqrtS()/GeV, b.xMin(), b.xMax())) {
53          b.set(sigma, error);
54        }
55      }
56    }
57
58    /// @}
59
60
61    /// @name Histograms
62    /// @{
63    CounterPtr _nNeutron;
64    /// @}
65
66
67  };
68
69
70  RIVET_DECLARE_PLUGIN(FENICE_1998_I471263);
71
72
73}