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## Rivet analyses reference

### OPAL_1994_S2927284

Measurement of the production rates of charged hadrons in $e^+e^-$ annihilation at the $Z^0$
Experiment: OPAL (LEP 1)
Inspire ID: 372772
Status: VALIDATED
Authors:
• Peter Richardson
References:
• Z.Phys.C63:181-196,1994
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 inclusive production rates of $\pi^\pm$, $K^\pm$ and $p\bar{p}$ in $Z^0$ decays measured using the OPAL detector at LEP. Only the differential cross sections are currently implemented.

Source code: OPAL_1994_S2927284.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 // -*- C++ -*- #include "Rivet/Analysis.hh" #include "Rivet/Projections/Beam.hh" #include "Rivet/Projections/ChargedFinalState.hh" namespace Rivet { /// @brief OPAL charged particle fragmentation functions /// @author Peter Richardson class OPAL_1994_S2927284 : public Analysis { public: /// Constructor OPAL_1994_S2927284() : Analysis("OPAL_1994_S2927284") { } /// @name Analysis methods //@{ void analyze(const Event& e) { // Even if we only generate hadronic events, we still need a cut on numCharged >= 2. const FinalState& fs = apply(e, "FS"); if (fs.particles().size() < 2) { MSG_DEBUG("Failed ncharged cut"); vetoEvent; } MSG_DEBUG("Passed ncharged cut"); // Get beams and average beam momentum const ParticlePair& beams = apply(e, "Beams").beams(); const double meanBeamMom = ( beams.first.p3().mod() + beams.second.p3().mod() ) / 2.0; MSG_DEBUG("Avg beam momentum = " << meanBeamMom); for (const Particle& p : fs.particles()) { int id = p.abspid(); // charged pions if (id == PID::PIPLUS) { _histXpPiPlus->fill(p.p3().mod()); } else if(id == PID::KPLUS) { _histXpKPlus->fill(p.p3().mod()); } else if(id == PID::PROTON) { _histXpProton->fill(p.p3().mod()); } } } void init() { // Projections declare(Beam(), "Beams"); declare(ChargedFinalState(), "FS"); book(_histXpPiPlus , 1, 1, 1); book(_histXpKPlus , 2, 1, 1); book(_histXpProton , 3, 1, 1); } /// Finalize void finalize() { scale(_histXpPiPlus,1./sumOfWeights()); scale(_histXpKPlus ,1./sumOfWeights()); scale(_histXpProton,1./sumOfWeights()); } //@} private: Histo1DPtr _histXpPiPlus; Histo1DPtr _histXpKPlus; Histo1DPtr _histXpProton; //@} }; // The hook for the plugin system DECLARE_RIVET_PLUGIN(OPAL_1994_S2927284); }