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## Rivet analyses reference

### SLD_1996_S3398250

Charged particle multiplicities in heavy and light quark initiated events on the $Z^0$ peak
Experiment: SLD (SLC)
Inspire ID: 422172
Status: VALIDATED
Authors:
• Peter Richardson
References:
• Phys.Lett.B386:475-485,1996
• hep-ex/9608008
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)

Measurements of the mean charged multiplicities separately for $b\bar b$, $c\bar c$ and light quark ($uds$) initiated events in $e^+e^-$ interactions at the $Z^0$ mass.

Source code: SLD_1996_S3398250.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 // -*- C++ -*- #include "Rivet/Analysis.hh" #include "Rivet/Projections/Beam.hh" #include "Rivet/Projections/FinalState.hh" #include "Rivet/Projections/ChargedFinalState.hh" #include "Rivet/Projections/Sphericity.hh" #include "Rivet/Projections/Thrust.hh" #include "Rivet/Projections/FastJets.hh" #include "Rivet/Projections/ParisiTensor.hh" #include "Rivet/Projections/Hemispheres.hh" #include "Rivet/Projections/InitialQuarks.hh" #include namespace Rivet { /// @brief SLD multiplicities at mZ /// @author Peter Richardson class SLD_1996_S3398250 : public Analysis { public: /// Constructor SLD_1996_S3398250() : Analysis("SLD_1996_S3398250"), _weightLight(0.),_weightCharm(0.),_weightBottom(0.) {} /// @name Analysis methods //@{ void init() { // Projections declare(Beam(), "Beams"); declare(ChargedFinalState(), "CFS"); declare(InitialQuarks(), "IQF"); _h_bottom = bookHisto1D(1, 1, 1); _h_charm = bookHisto1D(2, 1, 1); _h_light = bookHisto1D(3, 1, 1); } void analyze(const Event& event) { const double weight = event.weight(); // Even if we only generate hadronic events, we still need a cut on numCharged >= 2. const FinalState& cfs = apply(event, "CFS"); if (cfs.size() < 2) vetoEvent; int flavour = 0; const InitialQuarks& iqf = apply(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 quarkmap; foreach (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 += weight; _h_light->fillBin(0, numParticles*weight); break; case 4: _weightCharm += weight; _h_charm->fillBin(0, numParticles*weight); break; case 5: _weightBottom += weight; _h_bottom->fillBin(0, numParticles*weight); break; } } void multiplicity_subtract(const Histo1DPtr first, const Histo1DPtr second, int a, int b, int c) { const double x = first->bin(0).xMid(); const double ex = first->bin(0).xWidth()/2.; const double y = first->bin(0).area() - second->bin(0).area(); const double ey = sqrt(sqr(first->bin(0).areaErr()) + sqr(second->bin(0).areaErr())); Scatter2DPtr scatter = bookScatter2D(a, b, c); scatter->addPoint(x, y, ex, ey); } void finalize() { if (_weightBottom != 0) scale(_h_bottom, 1./_weightBottom); if (_weightCharm != 0) scale(_h_charm, 1./_weightCharm ); if (_weightLight != 0) scale(_h_light, 1./_weightLight ); multiplicity_subtract(_h_charm, _h_light, 4, 1, 1); multiplicity_subtract(_h_bottom, _h_light, 5, 1, 1); } //@} private: /// @name Weights //@{ double _weightLight; double _weightCharm; double _weightBottom; //@} Histo1DPtr _h_bottom; Histo1DPtr _h_charm; Histo1DPtr _h_light; }; // The hook for the plugin system DECLARE_RIVET_PLUGIN(SLD_1996_S3398250); }