Rivet analyses referenceBESIII_2010_I878544Mass distributions in χcJ→4π0Experiment: BESIII (BEPC) Inspire ID: 878544 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
easurement of the mass distributions in the decays χcJ→4π0. The data were read from the plots in the paper and may not be corrected for backgrounds and efficiency. Source code: BESIII_2010_I878544.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 chi_cJ -> 4 pi0
10 class BESIII_2010_I878544 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2010_I878544);
15
16
17 /// @name Analysis methods
18 /// @{
19
20 /// Book histograms and initialise projections before the run
21 void init() {
22 // projections
23 UnstableParticles ufs = UnstableParticles(Cuts::pid==10441 ||
24 Cuts::pid==445 ||
25 Cuts::pid==20443);
26 declare(ufs, "UFS");
27 DecayedParticles chi(ufs);
28 chi.addStable( PID::PI0);
29 declare(chi, "chi");
30 // histograms
31 for(unsigned int ix=0;ix<3;++ix)
32 book(_h[ix],1,1,1+ix);
33 }
34
35
36 /// Perform the per-event analysis
37 void analyze(const Event& event) {
38 static const map<PdgId,unsigned int> & mode = { { 111,4} };
39 DecayedParticles chi = apply<DecayedParticles>(event, "chi");
40 // loop over particles
41 for(unsigned int ix=0;ix<chi.decaying().size();++ix) {
42 if(!chi.modeMatches(ix,4,mode)) continue;
43 const Particles & pi0 = chi.decayProducts()[ix].at(111);
44 unsigned int imode = 0;
45 if(chi.decaying()[ix].pid()==20443) imode=1;
46 else if(chi.decaying()[ix].pid()==445) imode=2;
47 for(unsigned int ix=0;ix<pi0.size();++ix) {
48 for(unsigned int iy=ix+1;iy<pi0.size();++iy) {
49 _h[imode]->fill((pi0[ix].momentum()+pi0[iy].momentum()).mass());
50 }
51 }
52 }
53 }
54
55
56 /// Normalise histograms etc., after the run
57 void finalize() {
58 for(unsigned int ix=0;ix<3;++ix)
59 normalize(_h[ix]);
60 }
61
62 /// @}
63
64
65 /// @name Histograms
66 /// @{
67 Histo1DPtr _h[3];
68 /// @}
69
70
71 };
72
73
74 RIVET_DECLARE_PLUGIN(BESIII_2010_I878544);
75
76}
|
