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BABAR_2010_I878120

Dalitz plot analysis of $D^+_s\to K^+K^-\pi^+$
Experiment: BABAR (PEP-II)
Inspire ID: 878120
Status: VALIDATED NOHEPDATA
Authors:
  • Peter Richardson
References:
  • Phys.Rev.D 83 (2011) 052001
Beams: * *
Beam energies: ANY
Run details:
  • Any process producing D_s+->K+K-pi+, original e+e->Upsilon(4S)

Measurement of the mass distributions in the decay $D^+_s\to K^+K^-\pi^+$ by BaBar. The data were read from the plots in the paper and therefore for some points the error bars are the size of the point. It is also not clear that any resolution effects have been unfolded.

Source code: BABAR_2010_I878120.cc
  1// -*- C++ -*-
  2#include "Rivet/Analysis.hh"
  3#include "Rivet/Projections/DecayedParticles.hh"
  4#include "Rivet/Projections/UnstableParticles.hh"
  5
  6namespace Rivet {
  7
  8
  9  /// @brief D_s -> K+K-pi+ /K+K+pi-
 10  class BABAR_2010_I878120 : public Analysis {
 11  public:
 12
 13    /// Constructor
 14    RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2010_I878120);
 15
 16
 17    /// @name Analysis methods
 18    /// @{
 19
 20    /// Book histograms and initialise projections before the run
 21    void init() {
 22      // Initialise and register projections
 23      UnstableParticles ufs = UnstableParticles(Cuts::abspid==431);
 24      declare(ufs, "UFS");
 25      DecayedParticles DS(ufs);
 26      DS.addStable(PID::PI0);
 27      declare(DS, "DS");
 28      // histos
 29      book(_h_KK[0],1,1,1);
 30      book(_h_KK[1],1,1,2);
 31      book(_h_Kmpi ,1,1,3);
 32      book(_h_Kppi ,1,1,4);
 33      book(_h_Kppi2,1,1,5);
 34      book(_dalitz, "dalitz",50,0.3,3.5,50,0.07,2.5);
 35      book(_dalitz2, "dalitz2",50,0.3,2.3,50,0.03,2.3);
 36    }
 37
 38    /// Perform the per-event analysis
 39    void analyze(const Event& event) {
 40      static const map<PdgId,unsigned int> & mode1   = { { 211,1}, { 321,1}, {-321,1} };
 41      static const map<PdgId,unsigned int> & mode1CC = { {-211,1}, { 321,1}, {-321,1} };
 42      static const map<PdgId,unsigned int> & mode2   = { {-211,1}, { 321,2} };
 43      static const map<PdgId,unsigned int> & mode2CC = { { 211,1}, {-321,2} };
 44      // Loop over D+ mesons
 45      DecayedParticles DS = apply<DecayedParticles>(event, "DS");
 46      for(unsigned int ix=0;ix<DS.decaying().size();++ix) {
 47	int sign = DS.decaying()[ix].pid()/DS.decaying()[ix].abspid();
 48       	if     ( DS.modeMatches(ix,3,mode1  ) ||
 49		 DS.modeMatches(ix,3,mode1CC)) {
 50          const Particle & pip = DS.decayProducts()[ix].at( sign*211)[0];
 51          const Particle & Km  = DS.decayProducts()[ix].at(-sign*321)[0];
 52          const Particle & Kp  = DS.decayProducts()[ix].at( sign*321)[0];
 53          double mplus  = (Kp.momentum()+pip.momentum()).mass2();
 54          double mminus = (Km.momentum()+pip.momentum()).mass2();
 55          double mKK    = (Kp.momentum()+Km .momentum()).mass2();
 56          _h_KK[0]->fill(mKK);
 57          _h_KK[1]->fill(mKK);
 58          _h_Kppi->fill(mplus);
 59          _h_Kmpi->fill(mminus);
 60          _dalitz->fill(mKK,mminus);
 61	}
 62	else if( DS.modeMatches(ix,3,mode2  ) ||
 63		 DS.modeMatches(ix,3,mode2CC)) {
 64	  const Particle  & pim = DS.decayProducts()[ix].at(-sign*211)[0];
 65	  const Particles & Kp  = DS.decayProducts()[ix].at( sign*321);
 66	  double mKpi[2];
 67	  for(unsigned int ix=0;ix<2;++ix){
 68	    mKpi[ix] = (Kp[ix].momentum()+pim.momentum()).mass2();
 69	    _h_Kppi2->fill(sqrt(mKpi[ix]));
 70	  }
 71	  _dalitz2->fill(mKpi[0],mKpi[1]);
 72	  _dalitz2->fill(mKpi[1],mKpi[0]);
 73	}
 74      }
 75    }
 76
 77
 78    /// Normalise histograms etc., after the run
 79    void finalize() {
 80      normalize(_h_KK[0]);
 81      normalize(_h_KK[1],1.,false);
 82      normalize(_h_Kmpi);
 83      normalize(_h_Kppi);
 84      normalize(_h_Kppi2);
 85      normalize(_dalitz);
 86      normalize(_dalitz2);
 87    }
 88
 89    /// @}
 90
 91
 92    /// @name Histograms
 93    /// @{
 94    Histo1DPtr _h_KK[2],_h_Kmpi,_h_Kppi,_h_Kppi2;
 95    Histo2DPtr _dalitz,_dalitz2;
 96    /// @}
 97
 98
 99  };
100
101
102  RIVET_DECLARE_PLUGIN(BABAR_2010_I878120);
103
104}