Rivet analyses

Dalitz plot analysis of D+ → K+K−π+

Experiment: CLEO (CESR)

Inspire ID: 791716

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 78 (2008) 072003

Beams: * *

Beam energies: ANY

Run details: - Any process producing D0

Kinematic distributions in the decay D+ →  → K+K−π+. Resolution/acceptance effects have been not unfolded. Given the agreement with the model in the paper this analysis should only be used for qualitative studies.

Source code:CLEO_2008_I791716.cc

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

namespace Rivet {


  /// @brief D+ -> K+K-pi+
  class CLEO_2008_I791716 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2008_I791716);


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

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid==411);
      declare(ufs, "UFS");
      DecayedParticles DP(ufs);
      DP.addStable(PID::PI0);
      DP.addStable(PID::K0S);
      DP.addStable(PID::ETA);
      DP.addStable(PID::ETAPRIME);
      declare(DP, "DP");
      // histos
      book(_h_Kppi,1,1,1);
      book(_h_Kmpi,1,1,2);
      book(_h_KK  ,1,1,3);
      book(_dalitz, "dalitz",50,0.,2.,50,0.9,3.1);
    }

    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId,unsigned int> & mode   = { { 321,1},{-321,1}, { 211,1}};
      static const map<PdgId,unsigned int> & modeCC = { { 321,1},{-321,1}, {-211,1}};
      DecayedParticles DP = apply<DecayedParticles>(event, "DP");
      // loop over particles
      for(unsigned int ix=0;ix<DP.decaying().size();++ix) {
    int sign = 1;
    if (DP.decaying()[ix].pid()>0 && DP.modeMatches(ix,3,mode)) {
      sign=1;
    }
    else if  (DP.decaying()[ix].pid()<0 && DP.modeMatches(ix,3,modeCC)) {
      sign=-1;
    }
    else
      continue;
    const Particles & Kp = DP.decayProducts()[ix].at( sign*321);
    const Particles & Km = DP.decayProducts()[ix].at(-sign*321);
    const Particles & pip= DP.decayProducts()[ix].at( sign*211);
    double mminus = (Km[0].momentum()+pip[0].momentum() ).mass2();
    double mplus  = (Kp[0].momentum()+pip[0].momentum() ).mass2();
    double mKK    = (Kp[0].momentum()+Km[0].momentum()).mass2();
    _h_Kppi->fill(mplus);
    _h_Kmpi->fill(mminus);
    _h_KK  ->fill(mKK);
    _dalitz->fill(mminus,mKK); 
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      normalize(_h_Kppi);
      normalize(_h_Kmpi);
      normalize(_h_KK  );
      normalize(_dalitz);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h_Kppi,_h_Kmpi,_h_KK;
    Histo2DPtr _dalitz;
    /// @}


  };


  RIVET_DECLARE_PLUGIN(CLEO_2008_I791716);

}