Rivet analyses referenceBABAR_2014_I1287632Dalitz plot analysis of $\eta_c\to K^+K^-\eta$ and $\eta_c\to K^+K^-\pi^0$Experiment: BABAR (PEP-II) Inspire ID: 1287632 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decays $\eta_c\to K^+K^-\eta$ and $\eta_c\to K^+K^-\pi^0$ by BaBar. The data were read from the plots in the paper and therefore for some points the error bars are the size of the point. Also the sideband background from the plots has been subtracted. It is also not clear that any resolution effects have been unfolded. Source code: BABAR_2014_I1287632.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 eta_c -> K+K- eta or pi0
10 class BABAR_2014_I1287632 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2014_I1287632);
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::pid== 441);
24 declare(ufs, "UFS");
25 DecayedParticles ETAC(ufs);
26 ETAC.addStable(PID::PI0);
27 ETAC.addStable(PID::ETA);
28 declare(ETAC,"ETAC");
29 // histos
30 book(_h_KK[0],1,1,1);
31 book(_h_KK[1],2,1,1);
32 book(_h_Kpeta,1,1,2);
33 book(_h_Kmeta,1,1,3);
34 book(_h_Kppi ,2,1,2);
35 book(_h_Kmpi ,2,1,3);
36 book(_dalitz[0], "dalitz_1",50,0.5,7.0,50,0.5 ,7.0);
37 book(_dalitz[1], "dalitz_2",50,0.2,6.5,50,0.2,6.5);
38 }
39
40 /// Perform the per-event analysis
41 void analyze(const Event& event) {
42 static const map<PdgId,unsigned int> & mode1 = { { 321,1},{-321,1}, {111,1}};
43 static const map<PdgId,unsigned int> & mode2 = { { 321,1},{-321,1}, {221,1}};
44 DecayedParticles ETAC = apply<DecayedParticles>(event, "ETAC");
45 // loop over particles
46 for(unsigned int ix=0;ix<ETAC.decaying().size();++ix) {
47 int imode=0;
48 if (ETAC.modeMatches(ix,3,mode1)) imode=0;
49 else if(ETAC.modeMatches(ix,3,mode2)) imode=1;
50 else continue;
51 const Particle & Kp = ETAC.decayProducts()[ix].at( 321)[0];
52 const Particle & Km = ETAC.decayProducts()[ix].at(-321)[0];
53 if(imode==0 && ETAC.decaying()[ix].mass()>2.922 && ETAC.decaying()[ix].mass()<3.036) {
54 const Particle & pi0 = ETAC.decayProducts()[ix].at( 111)[0];
55 double mplus = (Kp.momentum()+pi0.momentum()).mass2();
56 double mminus = (Km.momentum()+pi0.momentum()).mass2();
57 double mKK = (Kp.momentum()+Km .momentum()).mass2();
58 _h_KK[1]->fill(mKK);
59 _h_Kppi->fill(mplus);
60 _h_Kmpi->fill(mminus);
61 _dalitz[1]->fill(mplus,mminus);
62 }
63 else if (imode==1 && ETAC.decaying()[ix].mass()>2.910 && ETAC.decaying()[ix].mass()<3.03) {
64 const Particle & eta = ETAC.decayProducts()[ix].at( 221)[0];
65 double mplus = (Kp.momentum()+eta.momentum()).mass2();
66 double mminus = (Km.momentum()+eta.momentum()).mass2();
67 double mKK = (Kp.momentum()+Km .momentum()).mass2();
68 _h_KK[0]->fill(mKK);
69 _h_Kpeta->fill(mplus);
70 _h_Kmeta->fill(mminus);
71 _dalitz[0]->fill(mplus,mminus);
72 }
73 }
74 }
75
76
77 /// Normalise histograms etc., after the run
78 void finalize() {
79 normalize(_h_KK[0]);
80 normalize(_h_KK[1]);
81 normalize(_h_Kmpi);
82 normalize(_h_Kppi);
83 normalize(_h_Kmeta);
84 normalize(_h_Kpeta);
85 normalize(_dalitz[0]);
86 normalize(_dalitz[1]);
87 }
88
89 /// @}
90
91
92 /// @name Histograms
93 /// @{
94 Histo1DPtr _h_KK[2],_h_Kmeta,_h_Kpeta,_h_Kmpi,_h_Kppi;
95 Histo2DPtr _dalitz[2];
96 /// @}
97
98
99 };
100
101
102 RIVET_DECLARE_PLUGIN(BABAR_2014_I1287632);
103
104}
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