Rivet analyses

Spectra of Σc0 and Σc++ produced in Υ(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 Σc0 and Σc++ produced in Υ(4S) decays measured by the CLEO collaboration.

Source code:CLEOII_1994_I361356.cc

// -*- 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);

}