Rivet analyses referenceBESIII_2022_I2122392$\psi(2S)\to \Lambda \bar{\Lambda}\omega$Experiment: BESIII (BEPC) Inspire ID: 2122392 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decay $\psi(2S)\to \Lambda \bar{\Lambda}\omega$. 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_2022_I2122392.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 omega
10 class BESIII_2022_I2122392 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2022_I2122392);
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 book(_h[ix],1,1,1+ix);
35 book(_dalitz, "dalitz",50,3.,7.,50,3.,7.);
36 }
37
38
39 /// Perform the per-event analysis
40 void analyze(const Event& event) {
41 static const map<PdgId,unsigned int> & mode = { { 3122,1}, {-3122,1}, { 223,1} };
42 DecayedParticles psi = apply<DecayedParticles>(event, "psi");
43 // loop over particles
44 for(unsigned int ix=0;ix<psi.decaying().size();++ix) {
45 if(!psi.modeMatches(ix,3,mode)) continue;
46 const Particles & omega = psi.decayProducts()[ix].at( 223);
47 double mOmega=omega[0].mass();
48 if(mOmega>.873 || mOmega<.753) continue;
49 const Particles & lam = psi.decayProducts()[ix].at( 3122);
50 const Particles & lbar = psi.decayProducts()[ix].at(-3122);
51 double mminus = (lbar[0].momentum()+omega[0].momentum()).mass2();
52 double mplus = (lam [0].momentum()+omega[0].momentum()).mass2();
53 _h[0]->fill(mplus );
54 _h[1]->fill(mminus);
55 _dalitz->fill(mplus,mminus);
56 }
57 }
58
59
60 /// Normalise histograms etc., after the run
61 void finalize() {
62 for(unsigned int ix=0;ix<2;++ix)
63 normalize(_h[ix]);
64 normalize(_dalitz);
65 }
66
67 /// @}
68
69
70 /// @name Histograms
71 /// @{
72 Histo1DPtr _h[2];
73 Histo2DPtr _dalitz;
74 /// @}
75
76
77 };
78
79
80 RIVET_DECLARE_PLUGIN(BESIII_2022_I2122392);
81
82}
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