Rivet analyses

title: PDG_UPSILON4S_HADRON_MULTIPLICITIES

Hadron multiplicities in $\Upsilon(4S)$ decays

Experiment: PDG (Various)

Inspire ID: 1688995

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D98 (2018) no.3, 030001

Beams: * *

Beam energies: ANY

Run details: - Any process producing Upsilon(4S) mesons

Hadron multiplicities in $\Upsilon(4S)$ decays. In the PDG these are quoted as the $B^\pm/B^0$ admixture, however in fact the quoted numbers are half the multplicity in $\Upsilon(4S)$ decays.

Source code:PDG_UPSILON4S_HADRON_MULTIPLICITIES.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

include "Rivet/Tools/Cuts.hh"

namespace Rivet {

class PDG_UPSILON4S_HADRON_MULTIPLICITIES : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(PDG_UPSILON4S_HADRON_MULTIPLICITIES);


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

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

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

  for (int ix : _ihistos) book(_histos[ix], ix, 1, 1);
  book(_wSum, "/TMP/SumWeights");
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  for (const Particle& meson : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid == 300553)) {
    _wSum->fill();
    map<int, unsigned int> ncount;
    findDecayProducts(meson, ncount);
    _histos[29]->fill(10.579, double(ncount[411] + ncount[-411]));
    _histos[30]->fill(10.579, double(ncount[421] + ncount[-421]));
    _histos[31]->fill(10.579, double(ncount[413] + ncount[-413]));
    _histos[32]->fill(10.579, double(ncount[423] + ncount[-423]));
    _histos[33]->fill(10.579, double(ncount[431] + ncount[-431]));
    _histos[34]->fill(10.579, double(ncount[433] + ncount[-433]));
    _histos[48]->fill(10.579, double(ncount[443]));
    _histos[50]->fill(10.579, double(ncount[100443]));
    _histos[51]->fill(10.579, double(ncount[20443]));
    _histos[53]->fill(10.579, double(ncount[445]));
    _histos[60]->fill(10.579, double(ncount[321] + ncount[-321]));
    _histos[61]->fill(10.579, double(ncount[321]));
    _histos[62]->fill(10.579, double(ncount[-321]));
    _histos[63]->fill(10.579, double(ncount[130] + ncount[310]));
    _histos[64]->fill(10.579, double(ncount[323] + ncount[-323]));
    _histos[65]->fill(10.579, double(ncount[313] + ncount[-313]));
    _histos[87]->fill(10.579, double(ncount[211] + ncount[-211]));
    _histos[88]->fill(10.579, double(ncount[111]));
    _histos[89]->fill(10.579, double(ncount[221]));
    _histos[90]->fill(10.579, double(ncount[113]));
    _histos[92]->fill(10.579, double(ncount[333]));
    _histos[96]->fill(10.579, double(ncount[4122] + ncount[-4122]));
    _histos[104]->fill(10.579, double(ncount[-4222]));
    _histos[106]->fill(10.579, double(ncount[-4112]));
    _histos[110]->fill(10.579, double(ncount[2212] + ncount[-2212]));
    _histos[113]->fill(10.579, double(ncount[3122] + ncount[-3122]));
    _histos[116]->fill(10.579, double(ncount[3312] + ncount[-3312]));
  }
}

void findDecayProducts(const Particle& mother, map<int, unsigned int>& ncount) {
  for (const Particle& p : mother.children()) {
    int id = p.pid();
    if (p.children().empty()) {
      ncount[id] += 1;
    }
    else {
      // check particle is not a child or itself, eg copy or from photon radiation
      bool isChild(false);
      for (const Particle& p2 : p.children()) {
        if (p2.pid() == id) {
          isChild = true;
          break;
        }
      }
      if (!isChild) ncount[id] += 1;
      findDecayProducts(p, ncount);
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {

  for (auto hist : _histos) {
    scale(hist.second, 1. / _wSum->sumW());
  }
}

/// @}


/// @name Histograms
/// @{
vector<int> _ihistos = {29, 30, 31, 32, 33, 34, 48, 50, 51,  53,  60,  61,  62, 63,
                        64, 65, 87, 88, 89, 90, 92, 96, 104, 106, 110, 113, 116};
map<int, Histo1DPtr> _histos;
CounterPtr _wSum;
/// @}

};

RIVET_DECLARE_PLUGIN(PDG_UPSILON4S_HADRON_MULTIPLICITIES);

} ```