Rivet analyses

title: BABAR_2012_I1086537

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

Experiment: BABAR (PEP-II)

Inspire ID: 1086537

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 85 (2012) 112010

Beams: * *

Beam energies: ANY

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

Mass distributions in $B^0\to K^+K^-K^0_S$, $B^+\to K^+K^-K^+$ and $B^+\to K^0_SK^0_SK^+$. The data were read from the plots in the paper.

Source code:BABAR_2012_I1086537.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B -> K K K decays class BABAR_2012_I1086537 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2012_I1086537);


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

/// Book histograms and initialise projections before the run
void init() {
  // projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 or Cuts::abspid == 521);
  declare(ufs, "UFS");
  DecayedParticles BB(ufs);
  BB.addStable(310);
  declare(BB, "BB");
  // histograms
  for (unsigned int ix = 0; ix < 3; ++ix)
    for (unsigned int iy = 0; iy < 3; ++iy) book(_h_aver[ix][iy], 1 + 2 * ix, 1, 1 + iy);
  for (unsigned int ix = 0; ix < 2; ++ix) {
    book(_h_charge2[ix], 4, 1, 1 + ix);
    for (unsigned int iy = 0; iy < 2; ++iy) book(_h_charge1[ix][iy], 2, 1 + iy, 1 + ix);
  }
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode1 = {{321, 2}, {-321, 1}};
  static const map<PdgId, unsigned int>& mode1CC = {{321, 1}, {-321, 2}};
  static const map<PdgId, unsigned int>& mode2 = {{310, 2}, {321, 1}};
  static const map<PdgId, unsigned int>& mode2CC = {{310, 2}, {-321, 1}};
  static const map<PdgId, unsigned int>& mode3 = {{310, 1}, {321, 1}, {-321, 1}};
  DecayedParticles BB = apply<DecayedParticles>(event, "BB");
  for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
    int sign = 1, imode = 0;
    if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode1)) {
      imode = 0;
      sign = 1;
    }
    else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode1CC)) {
      imode = 0;
      sign = -1;
    }
    else if (BB.decaying()[ix].pid() > 0 && BB.modeMatches(ix, 3, mode2)) {
      imode = 1;
      sign = 1;
    }
    else if (BB.decaying()[ix].pid() < 0 && BB.modeMatches(ix, 3, mode2CC)) {
      imode = 1;
      sign = -1;
    }
    else if (BB.modeMatches(ix, 3, mode3)) {
      imode = 2;
      if (BB.decaying()[ix].pid() < 0) sign = -1;
    }
    else
      continue;
    // B+ -> K+ K+ K-
    if (imode == 0) {
      const Particles& Kp = BB.decayProducts()[ix].at(sign * 321);
      const Particle& Km = BB.decayProducts()[ix].at(-sign * 321)[0];
      double mKpKm[2];
      for (unsigned int ix = 0; ix < 2; ++ix) mKpKm[ix] = (Kp[ix].momentum() + Km.momentum()).mass();
      if (mKpKm[0] > mKpKm[1]) swap(mKpKm[0], mKpKm[1]);
      _h_aver[0][0]->fill(mKpKm[0]);
      _h_aver[0][1]->fill(mKpKm[1]);
      _h_aver[0][2]->fill((Kp[0].momentum() + Kp[1].momentum()).mass());
      if (BB.decaying()[ix].pid() > 0) {
        for (unsigned int ix = 0; ix < 2; ++ix) _h_charge1[0][ix]->fill(mKpKm[0]);
      }
      else {
        for (unsigned int ix = 0; ix < 2; ++ix) _h_charge1[1][ix]->fill(mKpKm[0]);
      }
    }
    // B+ -> KS0 KS0 K+
    else if (imode == 1) {
      const Particles& K0 = BB.decayProducts()[ix].at(310);
      const Particle& Kp = BB.decayProducts()[ix].at(sign * 321)[0];
      double mK0K0 = (K0[0].momentum() + K0[1].momentum()).mass();
      _h_aver[1][0]->fill(mK0K0);
      double mKpK0[2];
      for (unsigned int ix = 0; ix < 2; ++ix) mKpK0[ix] = (K0[ix].momentum() + Kp.momentum()).mass();
      if (mKpK0[0] > mKpK0[1]) swap(mKpK0[0], mKpK0[1]);
      _h_aver[1][1]->fill(mKpK0[1]);
      _h_aver[1][2]->fill(mKpK0[0]);
      if (BB.decaying()[ix].pid() > 0) {
        _h_charge2[0]->fill(mK0K0);
      }
      else {
        _h_charge2[1]->fill(mK0K0);
      }
    }
    // B0 -> KS0 K+ K-
    else if (imode == 2) {
      const Particle& K0 = BB.decayProducts()[ix].at(310)[0];
      const Particle& Kp = BB.decayProducts()[ix].at(sign * 321)[0];
      const Particle& Km = BB.decayProducts()[ix].at(-sign * 321)[0];
      _h_aver[2][0]->fill((Kp.momentum() + Km.momentum()).mass());
      _h_aver[2][1]->fill((K0.momentum() + Km.momentum()).mass());
      _h_aver[2][2]->fill((K0.momentum() + Kp.momentum()).mass());
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 3; ++ix)
    for (unsigned int iy = 0; iy < 3; ++iy) normalize(_h_aver[ix][iy], 1., false);
  for (unsigned int ix = 0; ix < 2; ++ix) {
    normalize(_h_charge2[ix], 1., false);
    for (unsigned int iy = 0; iy < 2; ++iy) normalize(_h_charge1[ix][iy], 1., false);
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_aver[3][3];
Histo1DPtr _h_charge1[2][2];
Histo1DPtr _h_charge2[2];
/// @}

};

RIVET_DECLARE_PLUGIN(BABAR_2012_I1086537);

} ```