Rivet analyses

Mass distributions in B⁺ → ϕϕK⁺

Experiment: BELLE (KEKB)

Inspire ID: 1841899

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 103 (2021) 5, 052013

Beams: * *

Beam energies: ANY

Run details: - Any process producing B+, originally e+e-

Mass distributions in B⁺ → ϕϕK⁺ measured by BELLE, the data were read from the plots in the paper.

Source code:`BELLE_2021_I1841899.cc`

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

namespace Rivet {


  /// @brief B+ -> phi phi K+
  class BELLE_2021_I1841899 : public Analysis {
  public:

    /// Constructor
    RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2021_I1841899);


    /// @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);
      BP.addStable(PID::PI0);
      BP.addStable(PID::K0S);
      BP.addStable(PID::ETA);
      BP.addStable(PID::ETAPRIME);
      BP.addStable(PID::PHI);
      declare(BP, "BP");
      // histograms
      for (unsigned int ix = 0; ix < 2; ++ix) book(_h[ix], 1, 1, 1 + ix);
    }


    /// Perform the per-event analysis
    void analyze(const Event& event) {
      // define the decay mode
      static const map<PdgId, unsigned int>& mode = {{321, 1}, {333, 2}};
      static const map<PdgId, unsigned int>& modeCC = {{-321, 1}, {333, 2}};
      DecayedParticles BP = apply<DecayedParticles>(event, "BP");
      // loop over particles
      for (unsigned int ix = 0; ix < BP.decaying().size(); ++ix) {
        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 Particles& Kp = BP.decayProducts()[ix].at(sign * 321);
        const Particles& phi = BP.decayProducts()[ix].at(333);
        _h[0]->fill((phi[0].momentum() + phi[1].momentum()).mass());
        _h[1]->fill((Kp[0].momentum() + phi[0].momentum()).mass());
        _h[1]->fill((Kp[0].momentum() + phi[1].momentum()).mass());
      }
    }


    /// Normalise histograms etc., after the run
    void finalize() {
      for (unsigned int ix = 0; ix < 2; ++ix) normalize(_h[ix], 1., false);
    }

    /// @}


    /// @name Histograms
    /// @{
    Histo1DPtr _h[2];
    /// @}
  };


  RIVET_DECLARE_PLUGIN(BELLE_2021_I1841899);

}

Rivet analyses

Mass distributions in B+ → ϕϕK+

Source code:BELLE_2021_I1841899.cc

Mass distributions in B⁺ → ϕϕK⁺

Source code:`BELLE_2021_I1841899.cc`