Rivet analyses

title: CLEOII_1999_I504672

Charged-particle multiplicity in $\Upsilon(4S)$ decays

Experiment: CLEOII (CESR)

Inspire ID: 504672

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D61 (2000) 072002

Beams: * *

Beam energies: ANY

Run details: - Upsilon(4S) decays

Charged particle multiplicity in $\Upsilon(4S)$ decays measured by CLEOII.

Source code:CLEOII_1999_I504672.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Charged particle multplicity in Upsilon 4s decays class CLEOII_1999_I504672 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1999_I504672);


/// @name Analysis methods
/// @{

/// Book histograms and initialise projections before the run
void init() {

  // Initialise and register projections
  declare(UnstableParticles(), "UFS");

  // Book histograms
  book(_n_tot, 1, 1, 1);
  book(_n_lep, 1, 1, 2);
  book(_n_nolep, 1, 1, 3);
  book(_h_n, 2, 1, 1);
  book(_n_Ups_All, "/TMP/n_Ups_All");
  book(_n_Ups_Lep, "/TMP/n_Ups_Lep");
  book(_n_Ups_NoLep, "/TMP/n_Ups_NoLep");
}

void findChildren(const Particle& p, int& nCharged, int& nLep) {
  bool isBottom = PID::isBottomHadron(p.pid());
  for (const Particle& child : p.children()) {
    if (child.children().empty()) {
      if (PID::isCharged(child.pid())) ++nCharged;
      if (isBottom && (child.abspid() == 11 || child.abspid() == 13)) ++nLep;
    }
    else {
      findChildren(child, nCharged, nLep);
    }
  }
}

/// Perform the per-event analysis
void analyze(const Event& event) {
  for (const Particle& p : apply<FinalState>(event, "UFS").particles(Cuts::pid == 300553)) {
    _n_Ups_All->fill();
    int nCharged(0), nLep(0);
    findChildren(p, nCharged, nLep);
    _h_n->fill(nCharged);
    _n_tot->fill(Ecm, nCharged);
    if (nLep == 2) {
      _n_lep->fill(Ecm, nCharged);
      _n_Ups_Lep->fill();
    }
    else {
      _n_nolep->fill(Ecm, nCharged);
      _n_Ups_NoLep->fill();
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_n, 1. / *_n_Ups_All);
  scale(_n_tot, 1. / *_n_Ups_All);
  scale(_n_lep, 1. / *_n_Ups_Lep);
  scale(_n_nolep, 1. / *_n_Ups_NoLep);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_n;
BinnedHistoPtr<string> _n_tot, _n_lep, _n_nolep;
CounterPtr _n_Ups_All, _n_Ups_Lep, _n_Ups_NoLep;
const string Ecm = "10.6";

/// @}

};

RIVET_DECLARE_PLUGIN(CLEOII_1999_I504672);

} ```