Rivet analyses referenceBESIII_2019_I1725265Mass distributions in the decay $D^0\to K^-\pi^+\pi^0\pi^0$Experiment: BESIII (BEPC) Inspire ID: 1725265 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decay $D^0\to K^-\pi^+\pi^0\pi^0$ 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_2019_I1725265.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 D0 -> K- pi+ pi0 pi0
10 class BESIII_2019_I1725265 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2019_I1725265);
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==421);
24 declare(ufs, "UFS");
25 DecayedParticles D0(ufs);
26 D0.addStable(PID::PI0);
27 D0.addStable(PID::K0S);
28 D0.addStable(PID::ETA);
29 D0.addStable(PID::ETAPRIME);
30 declare(D0, "D0");
31 // histograms
32 for(unsigned int ix=0;ix<4;++ix)
33 book(_h[ix],1,1,1+ix);
34 }
35
36 /// Perform the per-event analysis
37 void analyze(const Event& event) {
38 // define the decay mode
39 static const map<PdgId,unsigned int> & mode = { {-321,1},{ 211,1}, { 111,2}};
40 static const map<PdgId,unsigned int> & modeCC = { { 321,1},{-211,1}, { 111,2}};
41 DecayedParticles D0 = apply<DecayedParticles>(event, "D0");
42 // loop over particles
43 for(unsigned int ix=0;ix<D0.decaying().size();++ix) {
44 int sign = 1;
45 if (D0.decaying()[ix].pid()>0 && D0.modeMatches(ix,4,mode)) {
46 sign=1;
47 }
48 else if (D0.decaying()[ix].pid()<0 && D0.modeMatches(ix,4,modeCC)) {
49 sign=-1;
50 }
51 else
52 continue;
53 const Particles & pi0= D0.decayProducts()[ix].at(111);
54 double mpipi = (pi0[0].momentum()+pi0[1].momentum()).mass();
55 if (mpipi>.458 && mpipi<.52) continue;
56 const Particles & Km = D0.decayProducts()[ix].at(-sign*321);
57 const Particles & pip= D0.decayProducts()[ix].at( sign*211);
58 _h[0]->fill((Km [0].momentum()+pip[0].momentum()).mass2());
59 _h[1]->fill((Km [0].momentum()+pi0[0].momentum()).mass2());
60 _h[1]->fill((Km [0].momentum()+pi0[1].momentum()).mass2());
61 _h[2]->fill((pip[0].momentum()+pi0[0].momentum()).mass2());
62 _h[2]->fill((pip[0].momentum()+pi0[1].momentum()).mass2());
63 _h[3]->fill(sqr(mpipi));
64 }
65 }
66
67
68 /// Normalise histograms etc., after the run
69 void finalize() {
70 for(unsigned int ix=0;ix<4;++ix)
71 normalize(_h[ix],1.,false);
72 }
73
74 /// @}
75
76
77 /// @name Histograms
78 /// @{
79 Histo1DPtr _h[4];
80 /// @}
81
82
83 };
84
85
86 RIVET_DECLARE_PLUGIN(BESIII_2019_I1725265);
87
88}
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