Rivet Analyses Reference

VENUS_1998_I453613

Charged particle multiplicities in heavy and light quark initiated events at 58 GeV
Experiment: VENUS (Tristan)
Inspire ID: 453613
Status: VALIDATED
No authors listed References:
  • Phys.Lett. B423 (1998) 407-418
Beams: e+ e-
Beam energies: (29.0, 29.0) GeV
Run details:
  • e+e- > hadrons

Measurement of the mean charged multiplicities separately for $b\bar b$, and light quark ($uds$) initiated events in $e^+e^-$ interactions at 58 GeV.

Source code: VENUS_1998_I453613.cc
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/Beam.hh"
#include "Rivet/Projections/ChargedFinalState.hh"

#define I_KNOW_THE_INITIAL_QUARKS_PROJECTION_IS_DODGY_BUT_NEED_TO_USE_IT
#include "Rivet/Projections/InitialQuarks.hh"

namespace Rivet {


  /// @brief charged multiplicity at 58 GeV
  class VENUS_1998_I453613 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(VENUS_1998_I453613);


    /// @name Analysis methods
    //@{

    /// Book histograms and initialise projections before the run
    void init() {
      declare(Beam(), "Beams");
      declare(ChargedFinalState(), "CFS");
      declare(InitialQuarks(), "IQF");
      book(_cLight , "/TMP/CLIGHT" );
      book(_cBottom, "/TMP/CBOTTOM");
      book(_weightLight , "/TMP/WLIGHT" );
      book(_weightBottom, "/TMP/WBOTTOM");
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      // Even if we only generate hadronic events, we still need a cut on numCharged >= 2.
      const FinalState& cfs = apply<FinalState>(event, "CFS");
      if (cfs.size() < 2) vetoEvent;


      int flavour = 0;
      const InitialQuarks& iqf = apply<InitialQuarks>(event, "IQF");

      // If we only have two quarks (qqbar), just take the flavour.
      // If we have more than two quarks, look for the highest energetic q-qbar pair.
      if (iqf.particles().size() == 2) {
        flavour = iqf.particles().front().abspid();
      }
      else {
        map<int, double> quarkmap;
        for ( const Particle& p : iqf.particles()) {
          if (quarkmap[p.pid()] < p.E()) {
            quarkmap[p.pid()] = p.E();
          }
        }
        double maxenergy = 0.;
        for (int i = 1; i <= 5; ++i) {
          if (quarkmap[i]+quarkmap[-i] > maxenergy) {
            flavour = i;
          }
        }
      }
      const size_t numParticles = cfs.particles().size();
      switch (flavour) {
      case 1: case 2: case 3:
	_weightLight->fill();  ;
        _cLight->fill(numParticles);
        break;
      case 5:
        _weightBottom->fill();
        _cBottom->fill(numParticles);
        break;
      }

    }


    /// Normalise histograms etc., after the run
    void finalize() {
      // calculate the averages and diffs
      if(_weightLight ->effNumEntries()!=0) scale( _cLight, 1./ *_weightLight);
      if(_weightBottom->effNumEntries()!=0) scale(_cBottom, 1./ *_weightBottom);
      Counter _cDiff = *_cBottom - *_cLight;
      // fill the histograms
      for(unsigned int ix=1;ix<4;++ix) {
	double val(0.), err(0.0);
	if(ix==1) {
	  val = _cBottom->val();
	  err = _cBottom->err();
	}
	else if(ix==2) {
	  val = _cLight->val();
	  err = _cLight->err();
	}
	else if(ix==3) {
	  val = _cDiff.val();
	  err = _cDiff.err();
	}
	Scatter2D temphisto(refData(1, 1, ix));
	Scatter2DPtr mult;
	book(mult,1, 1, ix);
	for (size_t b = 0; b < temphisto.numPoints(); b++) {
	  const double x  = temphisto.point(b).x();
	  pair<double,double> ex = temphisto.point(b).xErrs();
	  pair<double,double> ex2 = ex;
	  if(ex2.first ==0.) ex2. first=0.0001;
	  if(ex2.second==0.) ex2.second=0.0001;
	  if (inRange(sqrtS()/GeV, x-ex2.first, x+ex2.second)) {
	    mult->addPoint(x, val, ex, make_pair(err,err));
	  }
	  else {
	    mult->addPoint(x, 0., ex, make_pair(0.,.0));
	  }
	}
      }

    }

    //@}

    /// @name Multiplicities
    //@{
    CounterPtr _cLight;
    CounterPtr _cCharm;
    CounterPtr _cBottom;
    //@}

    /// @name Weights
    //@{
    CounterPtr _weightLight;
    CounterPtr _weightBottom;
    //@}

  };


  // The hook for the plugin system
  RIVET_DECLARE_PLUGIN(VENUS_1998_I453613);


}