Rivet analyses referenceBELLE_2021_I1835729Mass distributions in $\Xi^0_c\to\Xi^0K^+K^-$Experiment: BELLE (KEKB) Inspire ID: 1835729 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decay $\Xi^0_c\to\Xi^0K^+K^-$ by BELLE. The data were read from the plots in the paper, and for many points the error bars are the size of the point. It is also not clear that any resolution effects have been unfolded. Source code: BELLE_2021_I1835729.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 Xi_c0 -> Xi0 K+K-
10 class BELLE_2021_I1835729 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2021_I1835729);
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==4132);
24 declare(ufs, "UFS");
25 DecayedParticles XIC0(ufs);
26 XIC0.addStable(PID::PI0);
27 XIC0.addStable(PID::K0S);
28 XIC0.addStable(PID::ETA);
29 XIC0.addStable(PID::ETAPRIME);
30 XIC0.addStable(PID::XI0);
31 declare(XIC0, "XIC0");
32 // histograms
33 for(unsigned int ix=0;ix<3;++ix)
34 book(_h[ix],1,1,1+ix);
35 book(_dalitz, "dalitz",50,0.9,1.4,50,3.2,4.);
36 }
37
38
39 /// Perform the per-event analysis
40 void analyze(const Event& event) {
41 static const map<PdgId,unsigned int> & mode = { {-321,1},{ 321,1}, { PID::XI0,1}};
42 static const map<PdgId,unsigned int> & modeCC = { { 321,1},{-321,1}, {-PID::XI0,1}};
43 DecayedParticles XIC0 = apply<DecayedParticles>(event, "XIC0");
44 // loop over particles
45 for(unsigned int ix=0;ix<XIC0.decaying().size();++ix) {
46 int sign = 1;
47 if (XIC0.decaying()[ix].pid()>0 && XIC0.modeMatches(ix,3,mode)) {
48 sign=1;
49 }
50 else if (XIC0.decaying()[ix].pid()<0 && XIC0.modeMatches(ix,3,modeCC)) {
51 sign=-1;
52 }
53 else
54 continue;
55 const Particles & xi0 = XIC0.decayProducts()[ix].at( sign*PID::XI0);
56 const Particles & Kp = XIC0.decayProducts()[ix].at( sign*PID::KPLUS);
57 const Particles & Km = XIC0.decayProducts()[ix].at( sign*PID::KMINUS);
58 double mXiKp = (xi0[0].momentum()+Kp[0].momentum()).mass2();
59 double mXiKm = (xi0[0].momentum()+Km[0].momentum()).mass2();
60 double mKK = (Kp [0].momentum()+Km[0].momentum()).mass2();
61 _dalitz ->fill(mKK,mXiKm);
62 _h[0]->fill(sqrt(mKK ));
63 _h[1]->fill(sqrt(mXiKm));
64 _h[2]->fill(sqrt(mXiKp));
65 }
66 }
67
68
69 /// Normalise histograms etc., after the run
70 void finalize() {
71 for(unsigned int ix=0;ix<3;++ix)
72 normalize(_h[ix]);
73 normalize(_dalitz );
74 }
75
76 /// @}
77
78
79 /// @name Histograms
80 /// @{
81 Histo1DPtr _h[3];
82 Histo2DPtr _dalitz;
83 /// @}
84
85
86 };
87
88
89 RIVET_DECLARE_PLUGIN(BELLE_2021_I1835729);
90
91}
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