Rivet analyses

Spectra of Ξc0 and Ξc+ produced in Υ(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 Ξc0 and Ξc+ produced in Υ(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++ -*-
#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);

}