Rivet Analyses Reference

OPAL_1992_I321190

Hadronic Z decay charged multiplicity measurement
Experiment: OPAL (LEP 1)
Inspire ID: 321190
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Z.Phys. C53 (1992) 539-554
Beams: e+ e-
Beam energies: (45.6, 45.6) GeV
Run details:
  • Hadronic Z decay events generated on the Z pole ($\sqrt{s} = 91.2$ GeV)

The charged particle multiplicity distribution of hadronic Z decays, as measured on the peak of the Z resonance using the OPAL detector at LEP.

Source code: OPAL_1992_I321190.cc
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// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/ChargedFinalState.hh"

namespace Rivet {


  /// @brief OPAL LEP1 charged multiplicity, code basically a copy of the ALEPH one
  /// @author Peter Richardson
  class OPAL_1992_I321190 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(OPAL_1992_I321190);


    /// @name Analysis methods
    //@{

    /// Book histograms and initialise projections before the run
    void init() {
      const ChargedFinalState cfs;
      declare(cfs, "CFS");

      book(_histChTot, 1, 1, 1);
      book(_histAver , 5, 1, 1);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      const FinalState& cfs = apply<FinalState>(event, "CFS");
      MSG_DEBUG("Total charged multiplicity = " << cfs.size());
      _histChTot->fill(cfs.size(), 1.0);
      _histAver->fill(sqrtS(),cfs.size(),1.0);
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      scale(_histChTot, 200.0/sumOfWeights()); // bin width (2) and %age (100)
    }

    //@}


  private:

    /// @name Histograms
    //@{
    Histo1DPtr _histChTot;
    Profile1DPtr _histAver;
    //@}

  };


  // The hook for the plugin system
  RIVET_DECLARE_PLUGIN(OPAL_1992_I321190);


}