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CLEO_2008_I787608

Mass distributions in $\chi_c\to\pi^+\pi^-\pi^0\pi^0$ and $K^\pm\pi^\mp K^0_S\pi^0$
Experiment: CLEO (CESR)
Inspire ID: 787608
Status: VALIDATED NOHEPDATA
Authors:
  • Peter Richardson
References:
  • Phys.Rev.D 78 (2008) 092004
Beams: * *
Beam energies: ANY
Run details:
  • Any process producing chi_c states

Measurement of the mass distributions in the decays $\chi_c\to\pi^+\pi^-\pi^0\pi^0$ and $K^\pm\pi^\mp K^0_S\pi^0$$. The data were read from the plots in the paper and may not be corrected for efficiency.

Source code: CLEO_2008_I787608.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/UnstableParticles.hh"
  4#include "Rivet/Projections/DecayedParticles.hh"
  5
  6namespace Rivet {
  7
  8
  9  /// @briefchi_c -> pi+pi- 2pi0 and K pi K0 pi0
 10  class CLEO_2008_I787608 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2008_I787608);
 15
 16
 17    /// @name Analysis methods
 18    /// @{
 19
 20    /// Book histograms and initialise projections before the run
 21    void init() {
 22      UnstableParticles ufs = UnstableParticles(Cuts::pid==10441 or
 23						Cuts::pid==20443 or
 24						Cuts::pid==445);
 25      declare(ufs, "UFS");
 26      DecayedParticles chi(ufs);
 27      chi.addStable( PID::PI0);
 28      chi.addStable( PID::K0S);
 29      chi.addStable( PID::ETA);
 30      chi.addStable( PID::ETAPRIME);
 31      declare(chi, "chi");
 32      unsigned int iK[3]={4,2,5};
 33      for(unsigned int ix=0;ix<3;++ix) {
 34	for(unsigned int iy=0;iy<iK[ix];++iy) {
 35	  // 4 pion
 36	  if(iy<2) book(_h_pi[ix][iy],1+ix,1,1+iy);
 37	  // 2 K 2 pi
 38	  book(_h_K[ix][iy],4+ix,1,1+iy);
 39	}
 40      }
 41    }
 42
 43
 44    /// Perform the per-event analysis
 45    void analyze(const Event& event) {
 46      static const map<PdgId,unsigned int> & mode1 = { { 211,1}, { -211,1}, {111,2} };
 47      static const map<PdgId,unsigned int> & mode2 = { { 321,1}, { -211,1}, {111,1} , {310,1}};
 48      static const map<PdgId,unsigned int> & mode3 = { {-321,1}, {  211,1}, {111,1} , {310,1}};
 49      DecayedParticles chi = apply<DecayedParticles>(event, "chi");
 50      for(unsigned int ix=0;ix<chi.decaying().size();++ix) {
 51	unsigned int iloc = 0;
 52	int sign=1;
 53	if   (chi.decaying()[ix].pid()==20443) iloc=1;
 54	else if(chi.decaying()[ix].pid()==445) iloc=2;
 55	if(chi.modeMatches(ix,4,mode1)) {
 56	  const Particle & pim  = chi.decayProducts()[ix].at(-211)[0];
 57	  const Particle & pip  = chi.decayProducts()[ix].at( 211)[0];
 58	  const Particles & pi0 = chi.decayProducts()[ix].at( 111);
 59	  for(unsigned int ix=0;ix<2;++ix) {
 60	    _h_pi[iloc][0]->fill((pip.momentum()+pi0[ix].momentum()).mass());
 61	    _h_pi[iloc][1]->fill((pim.momentum()+pi0[ix].momentum()).mass());
 62	  }
 63	  continue;
 64	}
 65	else if(chi.modeMatches(ix,4,mode2)) {
 66	  sign=1;
 67	}
 68	else if(chi.modeMatches(ix,4,mode3)) {
 69	  sign=-1;
 70	}
 71	else
 72	  continue;
 73	const Particle & pim = chi.decayProducts()[ix].at(-sign*211)[0];
 74	const Particle & Kp  = chi.decayProducts()[ix].at( sign*321)[0];
 75	const Particle & pi0 = chi.decayProducts()[ix].at( 111)[0];
 76	const Particle & K0  = chi.decayProducts()[ix].at( 310)[0];
 77	_h_K[iloc][0]->fill((Kp .momentum()+pim.momentum()).mass());
 78	_h_K[iloc][1]->fill((pim.momentum()+pi0.momentum()).mass());
 79	if (_h_K[iloc][2])
 80	  _h_K[iloc][2]->fill((Kp.momentum()+pi0.momentum()).mass());
 81	if (_h_K[iloc][3])
 82	  _h_K[iloc][3]->fill((K0.momentum()+pim.momentum()).mass());
 83	if (_h_K[iloc][4])
 84	  _h_K[iloc][4]->fill((K0.momentum()+pi0.momentum()).mass());
 85      }
 86    }
 87
 88
 89    /// Normalise histograms etc., after the run
 90    void finalize() {
 91      unsigned int iK[3]={4,2,5};
 92      for(unsigned int ix=0;ix<3;++ix) {
 93	for(unsigned int iy=0;iy<iK[ix];++iy) {
 94	  // 4 pion
 95	  if(iy<2) normalize(_h_pi[ix][iy]);
 96	  // 2 K 2 pi
 97	  normalize(_h_K[ix][iy]);
 98	}
 99      }
100    }
101
102    /// @}
103
104
105    /// @name Histograms
106    /// @{
107    Histo1DPtr _h_pi[3][2];
108    Histo1DPtr _h_K [3][5];
109    /// @}
110
111
112  };
113
114
115  RIVET_DECLARE_PLUGIN(CLEO_2008_I787608);
116
117}