1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/FinalState.hh"
 4#include "Rivet/Projections/UnstableParticles.hh"
 5#include "Rivet/Projections/Beam.hh"
 6
 7namespace Rivet {
 8
 9
10  /// @brief Add a short analysis description here
11  class HRS_1988_I250824 : public Analysis {
12  public:
13
14    /// Constructor
15    RIVET_DEFAULT_ANALYSIS_CTOR(HRS_1988_I250824);
16
17
18    /// @name Analysis methods
19    /// @{
20
21    /// Book histograms and initialise projections before the run
22    void init() {
23      declare(Beam(), "Beams");
24      declare(FinalState(), "FS");
25      declare(UnstableParticles(), "UFS");
26
27      // Book histograms
28      book(_h_eta, 1 , 1, 1);
29    }
30
31
32    /// Perform the per-event analysis
33    void analyze(const Event& event) {
34      if (_edges.empty())  _edges = _h_eta->xEdges();
35      // First, veto on leptonic events by requiring at least 4 charged FS particles
36      const FinalState& fs = apply<FinalState>(event, "FS");
37      const size_t numParticles = fs.particles().size();
38
39      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
40      if (numParticles < 2) {
41        MSG_DEBUG("Failed leptonic event cut");
42        vetoEvent;
43      }
44      MSG_DEBUG("Passed leptonic event cut");
45
46      // Get beams and average beam momentum
47      const ParticlePair& beams = apply<Beam>(event, "Beams").beams();
48      const double meanBeamMom = ( beams.first.p3().mod() +
49                                   beams.second.p3().mod() ) / 2.0;
50      MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
51
52      // Final state to get particle spectra
53      for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid==221)) {
54        const double xE = p.E()/meanBeamMom;
55        _h_eta->fill(map2string(xE));
56      }
57    }
58
59    string map2string(const double val) const {
60      const size_t idx = _axis.index(val);
61      if (idx && idx <= _edges.size())  return _edges[idx-1];
62      return "OTHER";
63    }
64
65
66    /// Normalise histograms etc., after the run
67    void finalize() {
68
69      const double fact = sqr(sqrtS())/GeV2*crossSection()/microbarn/sumOfWeights();
70      scale(_h_eta, fact);
71    }
72
73    /// @}
74
75
76    /// @name Histograms
77    /// @{
78    BinnedHistoPtr<string> _h_eta;
79    YODA::Axis<double> _axis{0.1435, 0.1765, 0.210, 0.244, 0.2785, 0.313, 0.347,
80                             0.381, 0.4155, 0.45, 0.4925, 0.5525, 0.6215, 0.6905};
81    vector<string> _edges;
82    /// @}
83
84
85  };
86
87
88  RIVET_DECLARE_PLUGIN(HRS_1988_I250824);
89
90
91}