Rivet analyses

title: CLEOII_1994_I361356

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

Experiment: CLEOII (CESR)

Inspire ID: 361356

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev.Lett. 73 (1994) 1472-1476

Beams: * *

Beam energies: ANY

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

Spectra of $\Sigma_c^0$ and $\Sigma_c^{++}$ produced in $\Upsilon(4S)$ decays measured by the CLEO collaboration.

Source code:CLEOII_1994_I361356.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Sigma_c 0,++ spectra class CLEOII_1994_I361356 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CLEOII_1994_I361356);


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

/// Book histograms and initialise projections before the run
void init() {
  // projections
  declare(UnstableParticles(), "UFS");
  // book histos
  book(_b_Sigma_pp, 1, 1, 1);
  book(_b_Sigma_0, 1, 1, 2);
  book(_h_Sigma_pp, 2, 1, 1);
  book(_h_Sigma_0, 2, 1, 2);
  book(_c_ups, "TMP/c_ups");
}

void findDecayProducts(Particle parent, Particles& Sigma) {
  for (const Particle& p : parent.children()) {
    int id = abs(p.pid());
    if (id == 4112 || id == 4222) {
      Sigma.push_back(p);
    }
    else if (!p.children().empty()) {
      findDecayProducts(p, Sigma);
    }
  }
}

/// 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)) {
    _c_ups->fill();
    // Find the decay products we want
    Particles Sigma;
    findDecayProducts(p, Sigma);
    if (Sigma.empty()) continue;
    LorentzTransform boost;
    if (p.p3().mod() > 1 * MeV)
      boost = LorentzTransform::mkFrameTransformFromBeta(p.momentum().betaVec());
    for (const Particle& sig : Sigma) {
      double mom = boost.transform(sig.momentum()).vector3().mod();
      if (sig.abspid() == 4222) {
        _h_Sigma_pp->fill(mom);
        _b_Sigma_pp->fill();
      }
      else {
        _h_Sigma_0->fill(mom);
        _b_Sigma_0->fill();
      }
    }
  }
}

/// Normalise histograms etc., after the run
void finalize() {
  scale(_h_Sigma_0, 0.5 / *_c_ups);
  scale(_h_Sigma_pp, 0.5 / *_c_ups);
  scale(_b_Sigma_0, 0.5 / *_c_ups);
  scale(_b_Sigma_pp, 0.5 / *_c_ups);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_Sigma_0, _h_Sigma_pp;
CounterPtr _b_Sigma_0, _b_Sigma_pp;
CounterPtr _c_ups;
/// @}

};

RIVET_DECLARE_PLUGIN(CLEOII_1994_I361356);

} ```