Rivet analyses referenceBELLE_2010_I862241Mass distributions in $B^0\to K^+K^-K^0_S$Experiment: BELLE (KEKB) Inspire ID: 862241 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of Mass distributions in $B^0\to K^+K^-K^0_S$ decays. The data were read from the plots in the paper and may not be corrected for efficiency/acceptable, however the backgrounds given in the paper have been subtracted. Source code: BELLE_2010_I862241.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 B0 -> K+ K- KS0
10 class BELLE_2010_I862241 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2010_I862241);
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==511);
24 declare(ufs, "UFS");
25 DecayedParticles B0(ufs);
26 B0.addStable(PID::K0S);
27 declare(B0, "B0");
28 // histograms
29 for(unsigned int ix=0;ix<4;++ix)
30 book(_h[ix],1,1,1+ix);
31 }
32
33
34 /// Perform the per-event analysis
35 void analyze(const Event& event) {
36 static const map<PdgId,unsigned int> & mode = { { 321,1}, {-321,1}, { 310,1}};
37 DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
38 // loop over particles
39 for(unsigned int ix=0;ix<B0.decaying().size();++ix) {
40 if (!B0.modeMatches(ix,3,mode)) continue;
41 int sign = B0.decaying()[ix].pid()>0 ? 1 : -1;
42 const Particle & Kp = B0.decayProducts()[ix].at( 321*sign)[0];
43 const Particle & Km = B0.decayProducts()[ix].at(-321*sign)[0];
44 const Particle & K0 = B0.decayProducts()[ix].at( 310 )[0];
45 _h[0]->fill((K0.momentum()+Kp.momentum()).mass());
46 _h[1]->fill((K0.momentum()+Km.momentum()).mass());
47 _h[2]->fill((Km.momentum()+Kp.momentum()).mass());
48 _h[3]->fill((Km.momentum()+Kp.momentum()).mass());
49 }
50 }
51
52
53 /// Normalise histograms etc., after the run
54 void finalize() {
55 for(unsigned int ix=0;ix<4;++ix)
56 normalize(_h[ix],1.);
57 }
58
59 /// @}
60
61
62 /// @name Histograms
63 /// @{
64 Histo1DPtr _h[4];
65 /// @}
66
67
68 };
69
70
71 RIVET_DECLARE_PLUGIN(BELLE_2010_I862241);
72
73}
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