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CLEO_2012_I1086166

Mass distributions in the decay $D^0\to K^+K^-\pi^+\pi^-$
Experiment: CLEO (CESR)
Inspire ID: 1086166
Status: VALIDATED NOHEPDATA
Authors:
  • Peter Richardson
References:
  • Phys.Rev.D 85 (2012) 122002
Beams: * *
Beam energies: ANY
Run details:
  • Any process producing D0 mesons

Measurement of the mass distributions in the decay $D^0\to K^+K^-\pi^+\pi^-$ by CLEO. The data were read from the plots in the paper and therefore for some points the error bars are the size of the point. It is also not clear that any resolution effects have been unfolded.

Source code: CLEO_2012_I1086166.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 -> K+ K- pi+ pi-
10  class CLEO_2012_I1086166 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(CLEO_2012_I1086166);
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::K0S);
28      D0.addStable(PID::ETA);
29      D0.addStable(PID::ETAPRIME);
30      declare(D0, "D0");
31      // histograms
32      for(unsigned int ix=0;ix<6;++ix)
33	book(_h[ix],1,1,1+ix);
34      for(unsigned int ix=0;ix<4;++ix)
35	book(_h[ix+6],2,1,1+ix);
36    }
37
38
39    /// Perform the per-event analysis
40    void analyze(const Event& event) {
41      // define the decay mode
42      static const map<PdgId,unsigned int> & mode   = { { 321,1},{ -321,1}, { 211,1}, { -211,1}};
43      DecayedParticles D0 = apply<DecayedParticles>(event, "D0");
44      // loop over particles
45      for(unsigned int ix=0;ix<D0.decaying().size();++ix) {
46	if ( !D0.modeMatches(ix,4,mode)) continue;
47	int sign = D0.decaying()[ix].pid()/421;
48	const Particles & Kp = D0.decayProducts()[ix].at( sign*321);
49	const Particles & Km = D0.decayProducts()[ix].at(-sign*321);
50	const Particles & pip= D0.decayProducts()[ix].at( sign*211);
51	const Particles & pim= D0.decayProducts()[ix].at(-sign*211);
52	_h[0]->fill((Kp [0].momentum()+Km [0].momentum()).mass2());
53	_h[1]->fill((Kp [0].momentum()+pip[0].momentum()).mass2());
54	_h[2]->fill((Kp [0].momentum()+pim[0].momentum()).mass2());
55	_h[3]->fill((Km [0].momentum()+pip[0].momentum()).mass2());
56	_h[4]->fill((Km [0].momentum()+pim[0].momentum()).mass2());
57	_h[5]->fill((pip[0].momentum()+pim[0].momentum()).mass2());
58	_h[6]->fill((Kp [0].momentum()+Km [0].momentum()+pip[0].momentum()).mass2());
59	_h[7]->fill((Kp [0].momentum()+Km [0].momentum()+pim[0].momentum()).mass2());
60	_h[8]->fill((Kp [0].momentum()+pip[0].momentum()+pim[0].momentum()).mass2());
61	_h[9]->fill((Km [0].momentum()+pip[0].momentum()+pim[0].momentum()).mass2());
62      }
63    }
64
65
66    /// Normalise histograms etc., after the run
67    void finalize() {
68      for(unsigned int ix=0;ix<10;++ix)
69	normalize(_h[ix],1.,false);
70    }
71
72    /// @}
73
74
75    /// @name Histograms
76    /// @{
77    Histo1DPtr _h[10];
78    /// @}
79
80
81  };
82
83
84  RIVET_DECLARE_PLUGIN(CLEO_2012_I1086166);
85
86}