rivet is hosted by Hepforge, IPPP Durham

Rivet analyses reference

ARGUS_1993_S2653028

Inclusive production of charged pions, kaons and protons in $\Upsilon(4S)$ decays.
Experiment: ()
Inspire ID: 340894
Status: VALIDATED
Authors:
  • Peter Richardson
References:
  • Z.Phys. C58 (1993) 191-198
Beams: e+ e-
Beam energies: (5.3, 5.3) GeV
Run details:
  • $e^+ e^-$ analysis on the $\Upsilon(4S)$ resonance.

Measurement of inclusive production of charged pions, kaons and protons from $\Upsilon(4S)$ decays. Kaon spectra are determined in two different ways using particle identification and detecting decays in-flight. Results are background continuum subtracted. This analysis is useful for tuning $B$ meson decay modes.

Source code: ARGUS_1993_S2653028.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
143
144
145
146
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief ARGUS pi+/-, K+/- and proton/antiproton spectrum at Upsilon(4S)
  /// @author Peter Richardson
  class ARGUS_1993_S2653028 : public Analysis {
  public:

    ARGUS_1993_S2653028()
      : Analysis("ARGUS_1993_S2653028"){ }


    void analyze(const Event& e) {
      // Find the upsilons
      const UnstableParticles& ufs = apply<UnstableParticles>(e, "UFS");
      for (const Particle& p : ufs.particles(Cuts::pid==300553)) {
	_weightSum->fill();
        Particles pionsA,pionsB,protonsA,protonsB,kaons;
        // Find the decay products we want
        findDecayProducts(p, pionsA, pionsB, protonsA, protonsB, kaons);
        LorentzTransform cms_boost;
        if (p.p3().mod() > 1*MeV)
          cms_boost = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());
        for (size_t ix = 0; ix < pionsA.size(); ++ix) {
          FourMomentum ptemp(pionsA[ix].momentum());
          FourMomentum p2 = cms_boost.transform(ptemp);
          double pcm = cms_boost.transform(ptemp).vector3().mod();
          _histPiA->fill(pcm);
        }
        _multPiA->fill(10.58,double(pionsA.size()));
        for (size_t ix = 0; ix < pionsB.size(); ++ix) {
          double pcm = cms_boost.transform(pionsB[ix].momentum()).vector3().mod();
          _histPiB->fill(pcm);
        }
        _multPiB->fill(10.58,double(pionsB.size()));
        for (size_t ix = 0; ix < protonsA.size(); ++ix) {
          double pcm = cms_boost.transform(protonsA[ix].momentum()).vector3().mod();
          _histpA->fill(pcm);
        }
        _multpA->fill(10.58,double(protonsA.size()));
        for (size_t ix = 0; ix < protonsB.size(); ++ix) {
          double pcm = cms_boost.transform(protonsB[ix].momentum()).vector3().mod();
          _histpB->fill(pcm);
        }
        _multpB->fill(10.58,double(protonsB.size()));
        for (size_t ix = 0 ;ix < kaons.size(); ++ix) {
          double pcm = cms_boost.transform(kaons[ix].momentum()).vector3().mod();
          _histKA->fill(pcm);
          _histKB->fill(pcm);
        }
        _multK->fill(10.58,double(kaons.size()));
      }
    }


    void finalize() {
      if (_weightSum->val() > 0.) {
        scale(_histPiA, 1. / *_weightSum);
        scale(_histPiB, 1. / *_weightSum);
        scale(_histKA , 1. / *_weightSum);
        scale(_histKB , 1. / *_weightSum);
        scale(_histpA , 1. / *_weightSum);
        scale(_histpB , 1. / *_weightSum);
        scale(_multPiA, 1. / *_weightSum);
        scale(_multPiB, 1. / *_weightSum);
        scale(_multK  , 1. / *_weightSum);
        scale(_multpA , 1. / *_weightSum);
        scale(_multpB , 1. / *_weightSum);
      }
    }


    void init() {
      declare(UnstableParticles(), "UFS");

      // spectra
      book(_histPiA ,1, 1, 1);
      book(_histPiB ,2, 1, 1);
      book(_histKA  ,3, 1, 1);
      book(_histKB  ,6, 1, 1);
      book(_histpA  ,4, 1, 1);
      book(_histpB  ,5, 1, 1);
      // multiplicities
      book(_multPiA , 7, 1, 1);
      book(_multPiB , 8, 1, 1);
      book(_multK   , 9, 1, 1);
      book(_multpA  ,10, 1, 1);
      book(_multpB  ,11, 1, 1);

      book(_weightSum, "TMP/weightSum");
    } // init


  private:

    //@{
    /// Count of weights
    CounterPtr _weightSum;
    /// Spectra
    Histo1DPtr _histPiA, _histPiB, _histKA, _histKB, _histpA, _histpB;
    /// Multiplicities
    Histo1DPtr _multPiA, _multPiB, _multK, _multpA, _multpB;
    //@}


    void findDecayProducts(Particle parent, Particles & pionsA, Particles & pionsB,
                           Particles & protonsA, Particles & protonsB, Particles & kaons) {
      int parentId = parent.pid();
      for(const Particle & p : parent.children()) {
        int id = abs(p.pid());
        if (id == PID::PIPLUS) {
          if (parentId != PID::LAMBDA && parentId != PID::K0S) {
            pionsA.push_back(p);
            pionsB.push_back(p);
          }
          else
            pionsB.push_back(p);
        }
        else if (id == PID::PROTON) {
          if (parentId != PID::LAMBDA && parentId != PID::K0S) {
            protonsA.push_back(p);
            protonsB.push_back(p);
          }
          else
            protonsB.push_back(p);
        }
        else if (id == PID::KPLUS) {
          kaons.push_back(p);
        }
        else if (!p.children().empty())
          findDecayProducts(p, pionsA, pionsB, protonsA, protonsB, kaons);
      }
    }


  };


  // The hook for the plugin system
  DECLARE_RIVET_PLUGIN(ARGUS_1993_S2653028);

}