Rivet analyses

title: BELLE_2021_I1841899

Mass distributions in $B^+\to \phi\phi K^+$

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 $B^+\to \phi\phi K^+$ measured by BELLE, the data were read from the plots in the paper.

Source code:BELLE_2021_I1841899.cc

```c++ // -- 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);

} ```