Rivet analyses referenceBESIII_2013_I1223625$J/\psi\to p \bar{p}\omega$Experiment: BESIII (BEPC) Inspire ID: 1223625 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decay $J/\psi\to p \bar{p}\omega$. The data were read from the plots in the paper. It is also not clear that any resolution effects have been unfolded. Source code: BESIII_2013_I1223625.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 J/psi -> p pbar omega
10 class BESIII_2013_I1223625 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2013_I1223625);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 UnstableParticles ufs = UnstableParticles(Cuts::pid==443);
23 declare(ufs, "UFS");
24 DecayedParticles psi(ufs);
25 psi.addStable(PID::PI0);
26 psi.addStable(PID::K0S);
27 psi.addStable(PID::ETA);
28 psi.addStable(PID::ETAPRIME);
29 psi.addStable(PID::OMEGA);
30 declare(psi, "psi");
31 for(unsigned int ix=0;ix<3;++ix)
32 book(_h[ix],1,1,1+ix);
33 book(_dalitz, "dalitz",50,2.5,5.,50,2.5,5.);
34 }
35
36
37 /// Perform the per-event analysis
38 void analyze(const Event& event) {
39 static const map<PdgId,unsigned int> & mode = { { 2212,1}, {-2212,1}, { 223,1} };
40 DecayedParticles psi = apply<DecayedParticles>(event, "psi");
41 // loop over particles
42 for(unsigned int ix=0;ix<psi.decaying().size();++ix) {
43 if(!psi.modeMatches(ix,3,mode)) continue;
44 const Particles & omega = psi.decayProducts()[ix].at( 223);
45 const Particles & pp = psi.decayProducts()[ix].at( 2212);
46 const Particles & pbar = psi.decayProducts()[ix].at(-2212);
47 double mminus = (pbar[0].momentum()+omega[0].momentum()).mass2();
48 double mplus = (pp [0].momentum()+omega[0].momentum()).mass2();
49 double mneut = (pp [0].momentum()+pbar [0].momentum()).mass2();
50 _h[0]->fill(sqrt(mplus ));
51 _h[1]->fill(sqrt(mneut ));
52 _h[2]->fill(sqrt(mminus));
53 _dalitz->fill(mplus,mminus);
54 }
55 }
56
57
58 /// Normalise histograms etc., after the run
59 void finalize() {
60 for(unsigned int ix=0;ix<3;++ix)
61 normalize(_h[ix]);
62 normalize(_dalitz);
63 }
64
65 /// @}
66
67
68 /// @name Histograms
69 /// @{
70 Histo1DPtr _h[3];
71 Histo2DPtr _dalitz;
72 /// @}
73
74
75 };
76
77
78 RIVET_DECLARE_PLUGIN(BESIII_2013_I1223625);
79
80}
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