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BESIII_2021_I1830524

Dalitz plot analysis of $D^+_s\to K^+K^-\pi^+$
Experiment: BESIII (BEPC)
Inspire ID: 1830524
Status: VALIDATED NOHEPDATA
Authors:
  • Peter Richardson
References:
  • Phys.Rev.D 104 (2021) 1, 012016
Beams: * *
Beam energies: ANY
Run details:
  • Any process producing D_s+->K+K-pi+

Measurement of the mass distributions in the decay $D^+_s\to K^+K^-\pi^+$ by BES. 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: BESIII_2021_I1830524.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  /// @brief  D_s -> K+K-pi+
10  class BESIII_2021_I1830524 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2021_I1830524);
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      DS.addStable(PID::K0S);
28      declare(DS,"DS");
29      // histos
30      book(_h_KK[0],1,1,1);
31      book(_h_KK[1],1,1,2);
32      book(_h_Kmpi ,1,1,3);
33      book(_h_Kppi ,1,1,4);
34      book(_dalitz, "dalitz",50,0.3,3.5,50,0.07,2.5);
35    }
36
37    /// Perform the per-event analysis
38    void analyze(const Event& event) {
39      static const map<PdgId,unsigned int> & mode   = { { 211,1},{ 321,1}, {-321,1}};
40      static const map<PdgId,unsigned int> & modeCC = { {-211,1},{ 321,1}, {-321,1}};
41      DecayedParticles DS = apply<DecayedParticles>(event, "DS");
42      // loop over particles
43      for(unsigned int ix=0;ix<DS.decaying().size();++ix) {
44	int sign = 1;
45	if (DS.decaying()[ix].pid()>0 && DS.modeMatches(ix,3,mode)) {
46	  sign=1;
47	}
48	else if  (DS.decaying()[ix].pid()<0 && DS.modeMatches(ix,3,modeCC)) {
49	  sign=-1;
50	}
51	else
52	  continue;
53	const Particle & pip = DS.decayProducts()[ix].at( sign*211)[0];
54	const Particle & Kp  = DS.decayProducts()[ix].at( sign*321)[0];
55	const Particle & Km  = DS.decayProducts()[ix].at(-sign*321)[0];
56	double mplus  = (Kp.momentum()+pip.momentum()).mass2();
57	double mminus = (Km.momentum()+pip.momentum()).mass2();
58	double mKK    = (Kp.momentum()+Km .momentum()).mass2();
59	_h_KK[0]->fill(mKK);
60	_h_KK[1]->fill(mKK);
61	_h_Kppi->fill(mplus);
62	_h_Kmpi->fill(mminus);
63	_dalitz->fill(mKK,mminus);
64      }
65    }
66
67
68    /// Normalise histograms etc., after the run
69    void finalize() {
70      normalize(_h_KK[0]);
71      normalize(_h_KK[1],1.,false);
72      normalize(_h_Kmpi);
73      normalize(_h_Kppi);
74      normalize(_dalitz);
75    }
76
77    /// @}
78
79
80    /// @name Histograms
81    /// @{
82    Histo1DPtr _h_KK[2],_h_Kmpi,_h_Kppi;
83    Histo2DPtr _dalitz;
84    /// @}
85
86
87  };
88
89
90  RIVET_DECLARE_PLUGIN(BESIII_2021_I1830524);
91
92}