Rivet analyses referenceBABAR_2012_I1125567Mass distributions in the decay $\tau^-\to\pi^-K^0_SK^0_S$Experiment: BABAR (PEP-II) Inspire ID: 1125567 Status: VALIDATED NOHEPDATA Authors:
Beam energies: ANY Run details:
Measurements of mass distributions in $\tau^-\to\pi^-K^0_SK^0_S$ decays. The data were read from the plots in the paper and are not corrected, although the backgrounds given in the paper have been subtracted. The plots should therefore only be used for qualitative comparisons however the data is useful as there are not corrected distributions for this decay mode. Source code: BABAR_2012_I1125567.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 tau -> pi- KS0 KS0 nu
10 class BABAR_2012_I1125567 : public Analysis {
11 public:
12
13 /// Constructor
14 RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2012_I1125567);
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==15);
24 declare(ufs, "UFS");
25 DecayedParticles TAU(ufs);
26 TAU.addStable(310);
27 TAU.addStable(111);
28 declare(TAU, "TAU");
29 // histograms
30 for(unsigned int ix=0;ix<3;++ix) {
31 book(_h[ix],1,1,1+ix);
32 }
33 }
34
35
36 /// Perform the per-event analysis
37 void analyze(const Event& event) {
38 static const map<PdgId,unsigned int> & mode = { { 310,2}, {-211,1},{ 16,1}};
39 static const map<PdgId,unsigned int> & modeCC = { { 310,2}, { 211,1},{-16,1}};
40 DecayedParticles TAU = apply<DecayedParticles>(event, "TAU");
41 // loop over particles
42 for(unsigned int ix=0;ix<TAU.decaying().size();++ix) {
43 int sign = 1;
44 if(TAU.decaying()[ix].pid()>0 &&
45 TAU.modeMatches(ix,4,mode)) sign=1;
46 else if (TAU.decaying()[ix].pid()<0 &&
47 TAU.modeMatches(ix,4,modeCC)) sign=-1;
48 else
49 continue;
50 const Particle & pim = TAU.decayProducts()[ix].at(-211*sign)[0];
51 const Particles & K0 = TAU.decayProducts()[ix].at( 310);
52 _h[0]->fill((pim.momentum()+K0[0].momentum()+K0[1].momentum()).mass());
53 _h[2]->fill((K0[0].momentum()+K0[1].momentum()).mass());
54 for(unsigned int ix=0;ix<2;++ix) {
55 _h[1]->fill((pim.momentum()+K0[ix].momentum()).mass());
56 }
57 }
58 }
59
60
61 /// Normalise histograms etc., after the run
62 void finalize() {
63 for(unsigned int ix=0;ix<3;++ix) {
64 normalize(_h[ix],1.,false);
65 }
66 }
67
68 /// @}
69
70
71 /// @name Histograms
72 /// @{
73 Histo1DPtr _h[3];
74 /// @}
75
76
77 };
78
79
80 RIVET_DECLARE_PLUGIN(BABAR_2012_I1125567);
81
82}
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