Rivet analyses

title: BELLE_2010_I862241

Mass distributions in $B^0\to K^+K^-K^0_S$

Experiment: BELLE (KEKB)

Inspire ID: 862241

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 82 (2010) 073011

Beams: * *

Beam energies: ANY

Run details: - Any process producing B0 mesons, originally Upsilon(4S) decays

Measurement of Mass distributions in $B^0\to K^+K^-K^0_S$ decays. The data were read from the plots in the paper and may not be corrected for efficiency/acceptable, however the backgrounds given in the paper have been subtracted.

Source code:BELLE_2010_I862241.cc

```c++ // -- C++ --

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B0 -> K+ K- KS0 class BELLE_2010_I862241 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2010_I862241);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511);
  declare(ufs, "UFS");
  DecayedParticles B0(ufs);
  B0.addStable(PID::K0S);
  declare(B0, "B0");
  // histograms
  for (unsigned int ix = 0; ix < 4; ++ix) book(_h[ix], 1, 1, 1 + ix);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode = {{321, 1}, {-321, 1}, {310, 1}};
  DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
  // loop over particles
  for (unsigned int ix = 0; ix < B0.decaying().size(); ++ix) {
    if (!B0.modeMatches(ix, 3, mode)) continue;
    int sign = B0.decaying()[ix].pid() > 0 ? 1 : -1;
    const Particle& Kp = B0.decayProducts()[ix].at(321 * sign)[0];
    const Particle& Km = B0.decayProducts()[ix].at(-321 * sign)[0];
    const Particle& K0 = B0.decayProducts()[ix].at(310)[0];
    _h[0]->fill((K0.momentum() + Kp.momentum()).mass());
    _h[1]->fill((K0.momentum() + Km.momentum()).mass());
    _h[2]->fill((Km.momentum() + Kp.momentum()).mass());
    _h[3]->fill((Km.momentum() + Kp.momentum()).mass());
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 4; ++ix) normalize(_h[ix], 1.);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[4];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2010_I862241);

} ```