Rivet analyses referenceBESIII_2023_I2702517ψ(2S)→ΛˉΛη′Experiment: BESIII (BEPC) Inspire ID: 2702517 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decay ψ(2S)→ΛˉΛη′. 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_2023_I2702517.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 psi(2S) -> Lambda Lambdabar eta'
10 class BESIII_2023_I2702517 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2023_I2702517);
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==100443);
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 psi.addStable( 3122);
31 psi.addStable(-3122);
32 declare(psi, "psi");
33 for (unsigned int ix=0; ix<2; ++ix) {
34 for (unsigned int iy=0; iy<2; ++iy) {
35 book(_h[ix][iy], 1+ix, 1, 1+iy);
36 }
37 }
38 }
39
40
41 /// Perform the per-event analysis
42 void analyze(const Event& event) {
43 DecayedParticles psi = apply<DecayedParticles>(event, "psi");
44 // loop over particles
45 for (unsigned int ix=0;ix<psi.decaying().size();++ix) {
46 if (!psi.modeMatches(ix,3,mode)) continue;
47 const Particle& eta = psi.decayProducts()[ix].at( 331)[0];
48 const Particle& lam = psi.decayProducts()[ix].at( 3122)[0];
49 const Particle& lbar = psi.decayProducts()[ix].at(-3122)[0];
50 for (unsigned int iy=0; iy<2; ++iy) {
51 _h[0][iy]->fill((lbar.mom()+eta .mom()).mass());
52 _h[0][iy]->fill((lam .mom()+eta .mom()).mass());
53 _h[1][iy]->fill((lam .mom()+lbar.mom()).mass());
54 }
55 }
56 }
57
58
59 /// Normalise histograms etc., after the run
60 void finalize() {
61 for (unsigned int ix=0;ix<2;++ix) {
62 normalize(_h[ix],1.,false);
63 }
64 }
65
66 /// @}
67
68
69 /// @name Histograms
70 /// @{
71 Histo1DPtr _h[2][2];
72 const map<PdgId,unsigned int> mode = { { 3122,1}, {-3122,1}, { 331,1} };
73 /// @}
74
75
76 };
77
78
79 RIVET_DECLARE_PLUGIN(BESIII_2023_I2702517);
80
81}
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