Rivet analyses

title: CLEOII_1997_I442910

Spectra of $\Xi_c^0$ and $\Xi_c^+$ produced in $\Upsilon(4S)$ decays

Experiment: CLEOII (CESR)

Inspire ID: 442910

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 79 (1997) 3599-3603

Beams: * *

Beam energies: ANY

Run details: - Any process producing Upsilon(4S), originally e+e-

Spectra of $\Xi_c^0$ and $\Xi_c^+$ produced in $\Upsilon(4S)$ decays measured by the CLEO collaboration. The simluation is normalised to the integrated result in the paper.

Source code:CLEOII_1997_I442910.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Xi_c0 Xi_c+ spectrum in upsilon(4s) decays class CLEOII_1997_I442910 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1997_I442910);


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

/// Book histograms and initialise projections before the run
void init() {
  // projections
  declare(UnstableParticles(), "UFS");
  // book histos
  book(_h_Xi_c0, 1, 1, 1);
  book(_h_Xi_cPlus, 2, 1, 1);
}

void findDecayProducts(Particle parent, Particles& Xic) {
  for (const Particle& p : parent.children()) {
    int id = abs(p.pid());
    if (id == 4132 || id == 4232) {
      Xic.push_back(p);
    }
    else if (!p.children().empty()) {
      findDecayProducts(p, Xic);
    }
  }
}

/// Perform the per-event analysis
void analyze(const Event& event) {
  // Find the upsilons
  for (const Particle& p : apply<UnstableParticles>(event, "UFS").particles(Cuts::pid == 300553)) {
    // Find the decay products we want
    Particles Xic;
    findDecayProducts(p, Xic);
    if (Xic.empty()) continue;
    LorentzTransform boost;
    if (p.p3().mod() > 1 * MeV)
      boost = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());

    for (const Particle& xi : Xic) {
      double Emax = sqrt(0.25 * sqr(p.mass()) - sqr(xi.mass()));
      double xp = boost.transform(xi.momentum()).vector3().mod() / Emax;
      if (xi.abspid() == 4132)
        _h_Xi_c0->fill(xp);
      else
        _h_Xi_cPlus->fill(xp);
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  // normalize to the data as norm in hepdata is weird
  normalize(_h_Xi_c0, 0.144);
  normalize(_h_Xi_cPlus, 0.453);
}

/// @}

/// @name Histograms
/// @{
Histo1DPtr _h_Xi_c0, _h_Xi_cPlus;
/// @}

};

RIVET_DECLARE_PLUGIN(CLEOII_1997_I442910);

} ```