Rivet analyses

Mass distributions in B⁺ → K⁺K⁻π⁺

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⁺ → K⁺K⁻π⁺.

Source code:`BELLE_2017_I1598461.cc`

// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"

namespace Rivet {


  /// @brief B+ -> K+ K- pi+
  class BELLE_2017_I1598461 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2017_I1598461);


    /// @name Analysis methods
    /// @{

    /// Book histograms and initialise projections before the run
    void init() {
      // Initialise and register projections
      UnstableParticles ufs = UnstableParticles(Cuts::abspid==521);
      declare(ufs, "UFS");
      DecayedParticles BP(ufs);
      declare(BP, "BP");
      // book histograms
      for(unsigned int ix=0;ix<3;++ix) {
    if(ix==0) book(_h[ix],1,1,1);
    else      book(_h[ix],"TMP/h_"+toString(ix+1),refData(1,1,1));
    book(_c[ix],"TMP/c_"+toString(ix+1));
      }
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      static const map<PdgId,unsigned int> & mode   = { { 321,1},{-321,1}, { 211,1}};
      static const map<PdgId,unsigned int> & modeCC = { { 321,1},{ 321,1}, {-211,1}};
      DecayedParticles BP = apply<DecayedParticles>(event, "BP");
      // loop over particles
      for(unsigned int ix=0;ix<BP.decaying().size();++ix) {
    _c[0]->fill();
    if(BP.decaying()[ix].pid()>0) _c[1]->fill();
    else                          _c[2]->fill();
        int sign = 1;
        if (BP.decaying()[ix].pid()>0 && BP.modeMatches(ix,3,mode)) {
          sign=1;
        }
        else if  (BP.decaying()[ix].pid()<0 && BP.modeMatches(ix,3,modeCC)) {
          sign=-1;
        }
        else
          continue;
        const Particle & Kp  = BP.decayProducts()[ix].at( 321)[0];
        const Particle & Km  = BP.decayProducts()[ix].at(-321)[0];
    double mKK = (Kp.momentum()+Km.momentum()).mass();
    _h[0]->fill(mKK);
    if(sign==1) _h[1]->fill(mKK);
    else        _h[2]->fill(mKK);
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for(unsigned int ix=0;ix<3;++ix)
    scale(_h[ix],1e7/ *_c[ix]);
      Estimate1DPtr as;
      book(as,1,1,2);
      asymm(_h[2],_h[1],as);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[3];
    CounterPtr _c[3];
    /// @}


  };


  RIVET_DECLARE_PLUGIN(BELLE_2017_I1598461);

}

Rivet analyses

Mass distributions in B+ → K+K−π+

Source code:BELLE_2017_I1598461.cc

Mass distributions in B⁺ → K⁺K⁻π⁺

Source code:`BELLE_2017_I1598461.cc`