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DELPHI_1992_I334948

Charge multiplicity for different jet multiplicities in hadronic $Z^0$ decays
Experiment: DELPHI (LEP)
Inspire ID: 334948
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Z.Phys. C56 (1992) 63-76, 1992
Beams: e+ e-
Beam energies: (45.6, 45.6) GeV
Run details:
  • $\sqrt{s} = 91.2$ GeV, $e^+ e^- -> Z^0$ production with hadronic decays only

The charged multiplicity distribution in hadron $Z^0$ decays for different numbers of final state jets.

Source code: DELPHI_1992_I334948.cc
 1// -*- C++ -*-
 2#include "Rivet/Analysis.hh"
 3#include "Rivet/Projections/ChargedFinalState.hh"
 4#include "Rivet/Projections/FastJets.hh"
 5
 6namespace Rivet {
 7
 8
 9  /// @brief Charged multiplicity for different numbers of final state jets
10  class DELPHI_1992_I334948 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(DELPHI_1992_I334948);
15
16
17    /// @name Analysis methods
18    //@{
19
20    /// Book histograms and initialise projections before the run
21    void init() {
22
23      // Initialise and register projections
24      const ChargedFinalState cfs;
25      declare(cfs, "FS");
26      declare(FastJets(cfs, FastJets::JADE, 0.7), "Jets");
27
28      // Book histograms
29      for(unsigned int ih=0;ih<3;++ih) {
30	for(unsigned int iy=0;iy<3;++iy) {
31	  book(_h_mult[ih][iy],ih+1,1,iy+1);
32	}
33      }
34    }
35
36
37    /// Perform the per-event analysis
38    void analyze(const Event& event) {
39      const FinalState& fs = apply<FinalState>(event, "FS");
40      const size_t numParticles = fs.particles().size();
41      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
42      if (numParticles < 2) {
43        MSG_DEBUG("Failed leptonic event cut");
44        vetoEvent;
45      }
46      MSG_DEBUG("Passed leptonic event cut");
47      const FastJets& jets = apply<FastJets>(event, "Jets");
48      if (jets.clusterSeq()) {
49	vector<double> ycut = {0.01,0.02,0.04};
50	for (unsigned int ih=0;ih<3;++ih) {
51	  int nbin = jets.clusterSeq()->n_exclusive_jets_ycut(ycut[ih])-2;
52	  if(nbin<0 || nbin>2) continue;
53	  _h_mult[ih][nbin]->fill(numParticles);
54	}
55      }
56    }
57
58
59    /// Normalise histograms etc., after the run
60    void finalize() {
61
62      for(unsigned int ih=0;ih<3;++ih) {
63	for(unsigned int iy=0;iy<3;++iy) {
64	  normalize(_h_mult[ih][iy],2000.);
65	}
66      }
67    }
68
69    //@}
70
71
72    /// @name Histograms
73    //@{
74    Histo1DPtr _h_mult[3][3];
75    //@}
76
77
78  };
79
80
81  // The hook for the plugin system
82  RIVET_DECLARE_PLUGIN(DELPHI_1992_I334948);
83
84
85}