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BELLE_2017_I1598461

Mass distributions in $B^+\to K^+K^-\pi^+$
Experiment: BELLE (KEKB)
Inspire ID: 1598461
Status: VALIDATED NOHEPDATA
Authors:
  • Peter Richardson
References:
  • Phys.Rev.D 96 (2017) 3, 031101
Beams: * *
Beam energies: ANY
Run details:
  • Any process producing B+ mesons, originally e+e- at Upsilon(4S)

Differential branching ratio and CP-asymmetry in the mass of the kaon pair for the decay $B^+\to K^+K^-\pi^+$.

Source code: BELLE_2017_I1598461.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 B+ -> K+ K- pi+
10  class BELLE_2017_I1598461 : public Analysis {
11  public:
12
13    /// Constructor
14    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2017_I1598461);
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==521);
24      declare(ufs, "UFS");
25      DecayedParticles BP(ufs);
26      declare(BP, "BP");
27      // book histograms
28      for(unsigned int ix=0;ix<3;++ix) {
29	if(ix==0) book(_h[ix],1,1,1);
30	else      book(_h[ix],"TMP/h_"+toString(ix+1),refData(1,1,1));
31	book(_c[ix],"TMP/c_"+toString(ix+1));
32      }
33    }
34
35
36    /// Perform the per-event analysis
37    void analyze(const Event& event) {
38      static const map<PdgId,unsigned int> & mode   = { { 321,1},{-321,1}, { 211,1}};
39      static const map<PdgId,unsigned int> & modeCC = { { 321,1},{ 321,1}, {-211,1}};
40      DecayedParticles BP = apply<DecayedParticles>(event, "BP");
41      // loop over particles
42      for(unsigned int ix=0;ix<BP.decaying().size();++ix) {
43	_c[0]->fill();
44	if(BP.decaying()[ix].pid()>0) _c[1]->fill();
45	else                          _c[2]->fill();
46      	int sign = 1;
47      	if (BP.decaying()[ix].pid()>0 && BP.modeMatches(ix,3,mode)) {
48      	  sign=1;
49      	}
50      	else if  (BP.decaying()[ix].pid()<0 && BP.modeMatches(ix,3,modeCC)) {
51      	  sign=-1;
52      	}
53      	else
54      	  continue;
55      	const Particle & Kp  = BP.decayProducts()[ix].at( 321)[0];
56      	const Particle & Km  = BP.decayProducts()[ix].at(-321)[0];
57	double mKK = (Kp.momentum()+Km.momentum()).mass();
58	_h[0]->fill(mKK);
59	if(sign==1) _h[1]->fill(mKK);
60	else        _h[2]->fill(mKK);
61      }
62    }
63
64
65    /// Normalise histograms etc., after the run
66    void finalize() {
67      for(unsigned int ix=0;ix<3;++ix)
68	scale(_h[ix],1e7/ *_c[ix]);
69      Estimate1DPtr as;
70      book(as,1,1,2);
71      asymm(_h[2],_h[1],as);
72    }
73
74    /// @}
75
76
77    /// @name Histograms
78    /// @{
79    Histo1DPtr _h[3];
80    CounterPtr _c[3];
81    /// @}
82
83
84  };
85
86
87  RIVET_DECLARE_PLUGIN(BELLE_2017_I1598461);
88
89}