Rivet analyses referenceBABAR_2015_I1403544Dalitz plot analysis of $\eta_c\to K^0_SK^\pm\pi^\mp$ and $\eta_c\to K^+K^-\pi^0$Experiment: BABAR (PEP-II) Inspire ID: 1403544 Status: VALIDATED Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decays $\eta_c\to K^0_SK^\pm\pi^\mp$ 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_2015_I1403544.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-pi0 KS0 K+-pi-+
10 class BABAR_2015_I1403544 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2015_I1403544);
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::K0S);
28 ETAC.addStable(PID::ETA);
29 ETAC.addStable(PID::ETAPRIME);
30 declare(ETAC,"ETAC");
31 // histograms
32 book(_h_Kppip,3,1,1);
33 book(_h_K0pip,3,1,2);
34 book(_h_K0Kp ,3,1,3);
35 book(_dalitz[0], "dalitz_1",50,0.,8.,50,0.,8.);
36 book(_h_Kppi0,4,1,1);
37 book(_h_Kmpi0,4,1,2);
38 book(_h_KpKm ,4,1,3);
39 book(_dalitz[1], "dalitz_2",50,0.,8.,50,0.,8.);
40 }
41
42 /// Perform the per-event analysis
43 void analyze(const Event& event) {
44 static const map<PdgId,unsigned int> & mode1 = { { 321,1}, {-321,1}, { 111,1}};
45 static const map<PdgId,unsigned int> & mode2 = { { 321,1}, {-211,1}, { 310,1}};
46 static const map<PdgId,unsigned int> & mode2CC = { {-321,1}, { 211,1}, { 310,1}};
47 DecayedParticles ETAC = apply<DecayedParticles>(event, "ETAC");
48 // loop over particles
49 for(unsigned int ix=0;ix<ETAC.decaying().size();++ix) {
50 // K+ K- pi0
51 if (ETAC.modeMatches(ix,3,mode1)&&
52 ETAC.decaying()[ix].mass()>2.922 && ETAC.decaying()[ix].mass()<3.036) {
53 const Particle & Kp = ETAC.decayProducts()[ix].at( 321)[0];
54 const Particle & Km = ETAC.decayProducts()[ix].at(-321)[0];
55 const Particle & pi0 = ETAC.decayProducts()[ix].at( 111)[0];
56 double mplus = (Kp.momentum()+pi0.momentum()).mass2();
57 double mminus = (Km.momentum()+pi0.momentum()).mass2();
58 double mKK = (Kp.momentum()+Km .momentum()).mass2();
59 _h_KpKm->fill(mKK);
60 _h_Kppi0->fill(mplus);
61 _h_Kmpi0->fill(mminus);
62 _dalitz[1]->fill(mplus,mminus);
63 continue;
64 }
65 else if(ETAC.decaying()[ix].mass()>2.922 && ETAC.decaying()[ix].mass()<3.039) {
66 int sign=1;
67 if (ETAC.modeMatches(ix,3,mode2 )) sign= 1;
68 else if(ETAC.modeMatches(ix,3,mode2CC)) sign=-1;
69 else continue;
70 const Particle & KS0 = ETAC.decayProducts()[ix].at( 310)[0];
71 const Particle & Kp = ETAC.decayProducts()[ix].at( sign*321)[0];
72 const Particle & pim = ETAC.decayProducts()[ix].at(-sign*211)[0];
73 double mplus = (Kp.momentum() + pim.momentum()).mass2();
74 double mminus = (KS0.momentum() + pim.momentum()).mass2();
75 double mKK = (Kp.momentum() + KS0.momentum()).mass2();
76 _h_K0Kp ->fill(mKK);
77 _h_Kppip->fill(mplus);
78 _h_K0pip->fill(mminus);
79 _dalitz[0]->fill(mplus,mminus);
80 }
81 }
82 }
83
84
85 /// Normalise histograms etc., after the run
86 void finalize() {
87 normalize(_h_Kppip);
88 normalize(_h_K0pip);
89 normalize(_h_K0Kp );
90 normalize(_dalitz[0]);
91 normalize(_h_Kppi0);
92 normalize(_h_Kmpi0);
93 normalize(_h_KpKm );
94 normalize(_dalitz[1]);
95 }
96
97 /// @}
98
99
100 /// @name Histograms
101 /// @{
102 Histo1DPtr _h_Kppip,_h_K0pip,_h_K0Kp;
103 Histo1DPtr _h_Kppi0,_h_Kmpi0,_h_KpKm;
104 Histo2DPtr _dalitz[2];
105 /// @}
106
107
108 };
109
110
111 RIVET_DECLARE_PLUGIN(BABAR_2015_I1403544);
112
113}
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