Rivet analyses referenceBELLE_2014_I1289224Dalitz plot analysis of D0→K0Sπ+π−Experiment: BELLE (KEKB) Inspire ID: 1289224 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of Kinematic distributions in the decay D0→K0Sπ+π− by BELLE. The data were read from the plots in the paper and for many points the errors are given by the size of the point. Resolution/acceptance effects have been not unfolded. Source code: BELLE_2014_I1289224.cc 1#// -*- C++ -*-
2#include "Rivet/Analysis.hh"
3#include "Rivet/Projections/UnstableParticles.hh"
4#include "Rivet/Projections/DecayedParticles.hh"
5namespace Rivet {
6
7
8 /// @brief D0 -> KS0 pi+ pi-
9 class BELLE_2014_I1289224 : public Analysis {
10 public:
11
12 /// Constructor
13 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2014_I1289224);
14
15
16 /// @name Analysis methods
17 /// @{
18
19 /// Book histograms and initialise projections before the run
20 void init() {
21 // Initialise and register projections
22 UnstableParticles ufs = UnstableParticles(Cuts::abspid==421);
23 declare(ufs, "UFS");
24 DecayedParticles D0(ufs);
25 D0.addStable(PID::PI0);
26 D0.addStable(PID::K0S);
27 D0.addStable(PID::ETA);
28 D0.addStable(PID::ETAPRIME);
29 declare(D0, "D0");
30 // Histograms
31 for(unsigned int ix=0;ix<3;++ix)
32 book(_h[ix],1,1,1+ix);
33 book(_dalitz, "dalitz",50,0.3,3.2,50,0.3,3.2);
34 }
35
36
37 /// Perform the per-event analysis
38 void analyze(const Event& event) {
39
40 // define the decay mode
41 static const map<PdgId,unsigned int> & mode = { { 310,1}, { 211,1},{-211,1}};
42 DecayedParticles D0 = apply<DecayedParticles>(event, "D0");
43 // loop over particles
44 for(unsigned int ix=0;ix<D0.decaying().size();++ix) {
45 int sign = D0.decaying()[ix].pid()/421;
46 // KS0 pi+pi-
47 if (!D0.modeMatches(ix,3,mode) ) continue;
48 const Particle & pip= D0.decayProducts()[ix].at( sign*211)[0];
49 const Particle & pim= D0.decayProducts()[ix].at(-sign*211)[0];
50 const Particle & K0 = D0.decayProducts()[ix].at( 310)[0];
51 double mminus = (pim.momentum()+K0.momentum() ).mass2();
52 double mplus = (pip.momentum()+K0.momentum() ).mass2();
53 double mpipi = (pip.momentum()+pim.momentum()).mass2();
54 _h[1]->fill(mplus);
55 _h[2]->fill(mminus);
56 _h[0]->fill(mpipi);
57 _dalitz->fill(mminus,mplus);
58 }
59 }
60
61
62 /// Normalise histograms etc., after the run
63 void finalize() {
64 for(unsigned int ix=0;ix<3;++ix)
65 normalize(_h[ix],1.,false);
66 normalize(_dalitz);
67 }
68
69 /// @}
70
71
72 /// @name Histograms
73 /// @{
74 Histo1DPtr _h[3];
75 Histo2DPtr _dalitz;
76 /// @}
77
78
79 };
80
81
82 RIVET_DECLARE_PLUGIN(BELLE_2014_I1289224);
83
84}
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