Rivet analyses referenceBESIII_2014_I1277070Dalitz plot analysis of $D^+\to K^0_S\pi^+\pi^0$Experiment: BESIII (BEPC) Inspire ID: 1277070 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decay $D^+\to K^0_S\pi^+\pi^0$. The data were read from the plots in the paper. Resolution/acceptance effects have been not unfolded and given the agreement with the model in the paper this analysis should only be used for qualitative studies. Source code: BESIII_2014_I1277070.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 D+ -> K_0S pi+ pi0
10 class BESIII_2014_I1277070 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BESIII_2014_I1277070);
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==411);
24 declare(ufs, "UFS");
25 DecayedParticles DP(ufs);
26 DP.addStable(PID::PI0);
27 DP.addStable(PID::K0S);
28 declare(DP,"DP");
29 // histos
30 book(_h_pipi ,1,1,1);
31 book(_h_KS0pi0,1,1,2);
32 book(_h_KS0pip,1,1,3);
33 book(_dalitz, "dalitz",50,0.3,3.1,50,0.,2.0);
34 }
35
36 /// Perform the per-event analysis
37 void analyze(const Event& event) {
38 static const map<PdgId,unsigned int> & mode = { { 211,1},{ 111,1}, {310,1}};
39 static const map<PdgId,unsigned int> & modeCC = { {-211,1},{ 111,1}, {310,1}};
40 DecayedParticles DP = apply<DecayedParticles>(event, "DP");
41 // loop over particles
42 for(unsigned int ix=0;ix<DP.decaying().size();++ix) {
43 int sign = 1;
44 if (DP.decaying()[ix].pid()>0 && DP.modeMatches(ix,3,mode)) {
45 sign=1;
46 }
47 else if (DP.decaying()[ix].pid()<0 && DP.modeMatches(ix,3,modeCC)) {
48 sign=-1;
49 }
50 else
51 continue;
52 const Particle & K0 = DP.decayProducts()[ix].at( 310)[0];
53 const Particle & pi0 = DP.decayProducts()[ix].at( 111)[0];
54 const Particle & pip = DP.decayProducts()[ix].at( sign*211)[0];
55 double mpipi = (pi0.momentum()+pip.momentum()).mass2();
56 double mKS0pip = (K0 .momentum()+pip.momentum()).mass2();
57 double mKS0pi0 = (K0 .momentum()+pi0.momentum()).mass2();
58 _h_pipi ->fill(mpipi);
59 _h_KS0pip->fill(mKS0pip);
60 _h_KS0pi0->fill(mKS0pi0);
61 _dalitz->fill(mKS0pi0,mpipi);
62 }
63 }
64
65
66 /// Normalise histograms etc., after the run
67 void finalize() {
68 normalize(_h_pipi);
69 normalize(_h_KS0pi0);
70 normalize(_h_KS0pip);
71 normalize(_dalitz);
72 }
73
74 /// @}
75
76
77 /// @name Histograms
78 /// @{
79 Histo1DPtr _h_pipi,_h_KS0pi0, _h_KS0pip;
80 Histo2DPtr _dalitz;
81 /// @}
82
83
84 };
85
86
87 RIVET_DECLARE_PLUGIN(BESIII_2014_I1277070);
88
89}
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