1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/Beam.hh"
 4#include "Rivet/Projections/FinalState.hh"
 5#include "Rivet/Projections/ChargedFinalState.hh"
 6#include "Rivet/Projections/UnstableParticles.hh"
 7
 8
 9
10namespace Rivet {
11
12
13  class DELPHI_2011_I890503 : public Analysis {
14  public:
15
16    /// Constructor
17    DELPHI_2011_I890503()
18      : Analysis("DELPHI_2011_I890503")
19    {
20    }
21
22
23    /// Book projections and histograms
24    void init() {
25      declare(Beam(), "Beams");
26      declare(ChargedFinalState(), "FS");
27      declare(UnstableParticles(), "UFS");
28
29      book(_histXbweak     ,1, 1, 1);
30      book(_histMeanXbweak ,2, 1, 1);
31    }
32
33
34    void analyze(const Event& e) {
35
36      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
37      if (apply<FinalState>(e, "FS").particles().size() < 2) {
38        MSG_DEBUG("Failed ncharged cut");
39        vetoEvent;
40      }
41      MSG_DEBUG("Passed ncharged cut");
42
43      // Get beams and average beam momentum
44      const ParticlePair& beams = apply<Beam>(e, "Beams").beams();
45      const double meanBeamMom = ( beams.first.p3().mod() +
46                                   beams.second.p3().mod() ) / 2.0;
47      MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
48
49      const UnstableParticles& ufs = apply<UnstableParticles>(e, "UFS");
50      // Get Bottom hadrons
51      const Particles bhads = filter_select(ufs.particles(), isBottomHadron);
52
53      for (const Particle& bhad : bhads) {
54        // Check for weak decay, i.e. no more bottom present in children
55        if (bhad.children(lastParticleWith(hasBottom)).empty()) {
56          const double xp = bhad.E()/meanBeamMom;
57          _histXbweak->fill(xp);
58          _histMeanXbweak->fill(_histMeanXbweak->bin(0).xMid(), xp);
59        }
60      }
61    }
62
63
64    // Finalize
65    void finalize() {
66      normalize(_histXbweak);
67    }
68
69
70  private:
71
72    Histo1DPtr _histXbweak;
73    Profile1DPtr _histMeanXbweak;
74
75  };
76
77
78
79  // The hook for the plugin system
80  RIVET_DECLARE_PLUGIN(DELPHI_2011_I890503);
81
82}