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/DecayedParticles.hh"
#include "Rivet/Projections/UnstableParticles.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`