Rivet analyses

Spectrum of ϕ mesons in Υ(4S) and Υ(5S) decays

Experiment: CLEO (CESR)

Inspire ID: 728872

Status: VALIDATED

Authors: - Peter Richardson

References: - Phys.Rev. D75 (2007) 012002

Beams: * *

Beam energies: ANY

Run details: - Any process producing Υ(4S) or Υ(5S), original e⁺e⁻

Measurement of the ϕ meson spectrum in Υ(4S) and Υ(5S) decays by CLEO, only the spectra are included not the conclusions on B_s production drawn from them.

Source code:`CLEO_2007_I728872.cc`

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {


  /// @brief phi spectrum at Upsilon 4 and 5s
  class CLEO_2007_I728872 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2007_I728872);


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

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

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

      // Book histograms
      book(_h_4S, 1, 1, 5);
      book(_h_5S, 2, 1, 5);
      book(_c_4S, "/TMP/N4S");
      book(_c_5S, "/TMP/N5S");
    }

    void findDecayProducts(const Particle & p, Particles & phi) {
      for(const Particle & child : p.children()) {
    if(child.pid()==333)
      phi.push_back(child);
    else if(!child.children().empty())
      findDecayProducts(child,phi);
      }
    }

    /// Perform the per-event analysis
    void analyze(const Event& event) {
      // Find the Upsilons among the unstables
      const UnstableParticles& ufs = apply<UnstableParticles>(event, "UFS");
      Particles upsilons = ufs.particles(Cuts::pid==300553 || Cuts::pid==400553|| Cuts::pid==9000553);
      for (const Particle& ups : upsilons) {
        LorentzTransform cms_boost;
        if (ups.p3().mod() > 1*MeV)
          cms_boost = LorentzTransform::mkFrameTransformFromBeta(ups.momentum().betaVec());
    Particles phis;
        findDecayProducts(ups, phis);

    if(ups.pid()==300553)
      _c_4S->fill();
    else
      _c_5S->fill();

    for(const Particle & phi : phis) {
          FourMomentum p2 = cms_boost.transform(phi.momentum());
      double x = 2.*p2.p3().mod()/ups.mass();
    if(ups.pid()==300553)
      _h_4S->fill(x);
    else
      _h_5S->fill(x);
    }
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      if(_h_4S->effNumEntries()!=0)
    scale(_h_4S   ,100./ *_c_4S);
      if(_h_5S->effNumEntries()!=0)
    scale(_h_5S   ,100./ *_c_5S);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h_4S,_h_5S;
    CounterPtr _c_4S,_c_5S;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(CLEO_2007_I728872);


}

Rivet analyses

Spectrum of ϕ mesons in Υ(4S) and Υ(5S) decays

Source code:CLEO_2007_I728872.cc

Source code:`CLEO_2007_I728872.cc`