Rivet analyses referenceCLEO_2005_I679349Dalitz plot analysis of $D^0\to \pi^+\pi^-\pi^0$Experiment: CLEO (CESR) Inspire ID: 679349 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurement of the mass distributions in the decay $D^0\to \pi^+\pi^-\pi^0$. 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: CLEO_2005_I679349.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 D0 -> pi+pi-pi0
10 class CLEO_2005_I679349 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2005_I679349);
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==421);
24 declare(ufs, "UFS");
25 DecayedParticles D0(ufs);
26 D0.addStable(PID::PI0);
27 D0.addStable(PID::ETA);
28 D0.addStable(PID::ETAPRIME);
29 declare(D0, "D0");
30 // histograms
31 book(_h_pi[0],1,1,1);
32 book(_h_pi[1],1,1,2);
33 book(_h_pi[2],1,1,3);
34 book(_dalitz, "dalitz",50,0.,3.2,50,0.0,3.2);
35 }
36
37 /// Perform the per-event analysis
38 void analyze(const Event& event) {
39 // define the decay mode
40 static const map<PdgId,unsigned int> & mode = { {211,1},{-211,1}, { 111,1}};
41 DecayedParticles D0 = apply<DecayedParticles>(event, "D0");
42 // loop over particles
43 for(unsigned int ix=0;ix<D0.decaying().size();++ix) {
44 if ( !D0.modeMatches(ix,3,mode) ) continue;
45 int sign = D0.decaying()[ix].pid()/421;
46 const Particles & pi0= D0.decayProducts()[ix].at( 111);
47 const Particles & pip= D0.decayProducts()[ix].at( sign*211);
48 const Particles & pim= D0.decayProducts()[ix].at(-sign*211);
49 double mneut = (pim[0].momentum()+pip[0].momentum()).mass2();
50 double mplus = (pip[0].momentum()+pi0[0].momentum()).mass2();
51 double mminus = (pim[0].momentum()+pi0[0].momentum()).mass2();
52 _h_pi[0]->fill(mplus);
53 _h_pi[1]->fill(mneut);
54 _h_pi[2]->fill(mminus);
55 _dalitz->fill(mneut,mplus);
56 }
57 }
58
59
60 /// Normalise histograms etc., after the run
61 void finalize() {
62 for(unsigned int ix=0;ix<3;++ix)
63 normalize(_h_pi[ix]);
64 normalize(_dalitz);
65
66 }
67
68 /// @}
69
70
71 /// @name Histograms
72 /// @{
73 Histo1DPtr _h_pi[3];
74 Histo2DPtr _dalitz;
75 /// @}
76
77
78 };
79
80
81 RIVET_DECLARE_PLUGIN(CLEO_2005_I679349);
82
83}
|