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BESIII_2022_I1945692

Dalitz decay of $D^+_s\to K^0_SK^0_S\pi^+$
Experiment: BESIII (BEPC)
Inspire ID: 1945692
Status: VALIDATED NOHEPDATA
Authors:
  • Peter Richardson
References:
  • Phys.Rev.D 105 (2022) 5, L051103
Beams: * *
Beam energies: ANY
Run details:
  • Any process producing D_s+ mesons

Measurement of the mass distributions in the decay $D^+_s\to K^0_SK^0_S\pi^+$ 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_2022_I1945692.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+ -> KS0 KS0 pi+
10  class BESIII_2022_I1945692 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I1945692);
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      // histograms
30      book(_h_KK ,1,1,1);
31      book(_h_Kpi,1,1,2);
32      book(_dalitz,"dalitz",50,0.3,2.3,50,0.3,2.3);
33    }
34
35    /// Perform the per-event analysis
36    void analyze(const Event& event) {
37      static const map<PdgId,unsigned int> & mode   = { { 211,1}, {310,2}};
38      static const map<PdgId,unsigned int> & modeCC = { {-211,1}, {310,2}};
39      DecayedParticles DS = apply<DecayedParticles>(event, "DS");
40      // loop over particles
41      for(unsigned int ix=0;ix<DS.decaying().size();++ix) {
42	int sign = 1;
43	if (DS.decaying()[ix].pid()>0 && DS.modeMatches(ix,3,mode)) {
44	  sign=1;
45	}
46	else if  (DS.decaying()[ix].pid()<0 && DS.modeMatches(ix,3,modeCC)) {
47	  sign=-1;
48	}
49	else
50	  continue;
51	const Particles & K0  = DS.decayProducts()[ix].at(      310);
52	const Particle  & pip = DS.decayProducts()[ix].at( sign*211)[0];
53	double m1  = (K0[0].momentum()+pip.momentum()).mass2();
54	double m2  = (K0[1].momentum()+pip.momentum()).mass2();
55	double mKK = (K0[0].momentum()+K0[1].momentum()).mass2();
56	_dalitz->fill(m1,m2);
57	_dalitz->fill(m2,m1);
58	_h_KK->fill(sqrt(mKK));
59	_h_Kpi->fill(sqrt(m1));
60	_h_Kpi->fill(sqrt(m2));
61      }
62    }
63
64
65    /// Normalise histograms etc., after the run
66    void finalize() {
67      normalize(_h_Kpi);
68      normalize(_h_KK );
69      normalize(_dalitz);
70    }
71
72    /// @}
73
74
75    /// @name Histograms
76    /// @{
77    Histo1DPtr _h_Kpi,_h_KK;
78    Histo2DPtr _dalitz;
79    /// @}
80
81
82  };
83
84
85  RIVET_DECLARE_PLUGIN(BESIII_2022_I1945692);
86
87}