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    RIVET_DEFAULT_ANALYSIS_CTOR(DELPHI_2011_I890503);
18
19
20    /// Book projections and histograms
21    void init() {
22      declare(Beam(), "Beams");
23      declare(ChargedFinalState(), "FS");
24      declare(UnstableParticles(), "UFS");
25
26      book(_histXbweak,     1, 1, 1);
27      book(_histMeanXbweak, 2, 1, 1);
28    }
29
30
31    void analyze(const Event& e) {
32
33      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
34      if (apply<FinalState>(e, "FS").particles().size() < 2) {
35        MSG_DEBUG("Failed ncharged cut");
36        vetoEvent;
37      }
38      MSG_DEBUG("Passed ncharged cut");
39
40      // Get beams and average beam momentum
41      const ParticlePair& beams = apply<Beam>(e, "Beams").beams();
42      const double meanBeamMom = ( beams.first.p3().mod() +
43                                   beams.second.p3().mod() ) / 2.0;
44      MSG_DEBUG("Avg beam momentum = " << meanBeamMom);
45
46      const UnstableParticles& ufs = apply<UnstableParticles>(e, "UFS");
47      // Get Bottom hadrons
48      const Particles bhads = select(ufs.particles(), isBottomHadron);
49
50      for (const Particle& bhad : bhads) {
51        // Check for weak decay, i.e. no more bottom present in children
52        if (bhad.isLastWith(hasBottom)) {
53          const double xp = bhad.E()/meanBeamMom;
54          _histXbweak->fill(xp);
55          _histMeanXbweak->fill(Ecm, xp);
56        }
57      }
58    }
59
60
61    // Finalize
62    void finalize() {
63      normalize(_histXbweak);
64    }
65
66
67  private:
68
69    Histo1DPtr _histXbweak;
70    BinnedProfilePtr<string> _histMeanXbweak;
71    const string Ecm = "91.2";
72
73  };
74
75
76
77  RIVET_DECLARE_PLUGIN(DELPHI_2011_I890503);
78
79}