1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/Beam.hh"
 4#include "Rivet/Projections/ChargedFinalState.hh"
 5#include "Rivet/Projections/UnstableParticles.hh"
 6
 7namespace Rivet {
 8
 9
10  /// @brief Add a short analysis description here
11  class DELPHI_2006_I719387 : public Analysis {
12  public:
13
14    /// Constructor
15    RIVET_DEFAULT_ANALYSIS_CTOR(DELPHI_2006_I719387);
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(ChargedFinalState(), "FS");
25      declare(UnstableParticles(), "UFS");
26
27      // Book histograms
28      book(_histXi, 1, 3, 1);
29
30    }
31
32
33    /// Perform the per-event analysis
34    void analyze(const Event& event) {
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 of unstable particles to get particle spectra
53      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
54
55      for (const Particle& p : ufs.particles(Cuts::abspid==3312)) {
56	const double xi = -log(p.p3().mod()/meanBeamMom);
57	_histXi->fill(xi);
58      }
59    }
60
61
62    /// Normalise histograms etc., after the run
63    void finalize() {
64      // mult by bin width
65      scale(_histXi, 1./sumOfWeights()*.2);
66    }
67
68    /// @}
69
70
71    /// @name Histograms
72    /// @{
73    Histo1DPtr _histXi;
74    /// @}
75
76  };
77
78
79  RIVET_DECLARE_PLUGIN(DELPHI_2006_I719387);
80
81
82}