Rivet analyses

title: BABAR_2007_I755548

Mass distributions in $B\to p\bar{p} K^{(*)}$

Experiment: BABAR (PEP-II)

Inspire ID: 755548

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 76 (2007) 092004

Beams: * *

Beam energies: ANY

Run details: none listed

Measurement of mass distributions in $B^0\to p \bar{p} K^0_S$, $B^0\to p \bar{p} K^{0}$, $B^+\to p \bar{p} K^+$ and $B^+\to p \bar{p} K^{+}$. The corrected data were read from the plots in the paper.

Source code:BABAR_2007_I755548.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B -> p pbar meson class BABAR_2007_I755548 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2007_I755548);


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

/// Book histograms and initialise projections before the run
void init() {
  // projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 511 || Cuts::abspid == 521);
  declare(ufs, "UFS");
  DecayedParticles BB(ufs);
  BB.addStable(310);
  BB.addStable(313);
  BB.addStable(323);
  BB.addStable(-313);
  BB.addStable(-323);
  BB.addStable(441);
  BB.addStable(443);
  BB.addStable(100443);
  BB.addStable(10441);
  BB.addStable(20443);
  BB.addStable(445);
  declare(BB, "BB");
  // histograms
  for (unsigned int ix = 0; ix < 4; ++ix) {
    book(_h_mass[ix], 1, 1, 1 + ix);
    book(_c[ix], "TMP/c_" + toString(ix + 1));
    for (unsigned int iy = 0; iy < 2; ++iy)
      if (!(ix == 0 && iy == 1)) book(_h_mass2[iy][ix], 2, 1 + iy, 1 + ix);
  }
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode1 = {{2212, 1}, {-2212, 1}, {310, 1}};
  static const map<PdgId, unsigned int>& mode1CC = {{2212, 1}, {-2212, 1}, {310, 1}};
  static const map<PdgId, unsigned int>& mode2 = {{2212, 1}, {-2212, 1}, {321, 1}};
  static const map<PdgId, unsigned int>& mode2CC = {{2212, 1}, {-2212, 1}, {-321, 1}};
  static const map<PdgId, unsigned int>& mode3 = {{2212, 1}, {-2212, 1}, {313, 1}};
  static const map<PdgId, unsigned int>& mode3CC = {{2212, 1}, {-2212, 1}, {-313, 1}};
  static const map<PdgId, unsigned int>& mode4 = {{2212, 1}, {-2212, 1}, {323, 1}};
  static const map<PdgId, unsigned int>& mode4CC = {{2212, 1}, {-2212, 1}, {-323, 1}};
  DecayedParticles BB = apply<DecayedParticles>(event, "BB");
  // loop over particles
  for (unsigned int ix = 0; ix < BB.decaying().size(); ++ix) {
    int sign = BB.decaying()[ix].pid() / BB.decaying()[ix].abspid();
    int imode = -1, iK;
    if ((sign > 0 && BB.modeMatches(ix, 3, mode1)) || (sign < 0 && BB.modeMatches(ix, 3, mode1CC))) {
      imode = 0;
      iK = 310;
    }
    else if ((sign > 0 && BB.modeMatches(ix, 3, mode2)) || (sign < 0 && BB.modeMatches(ix, 3, mode2CC))) {
      imode = 1;
      iK = sign * 321;
    }
    else if ((sign > 0 && BB.modeMatches(ix, 3, mode3)) || (sign < 0 && BB.modeMatches(ix, 3, mode3CC))) {
      imode = 2;
      iK = sign * 313;
    }
    else if ((sign > 0 && BB.modeMatches(ix, 3, mode4)) || (sign < 0 && BB.modeMatches(ix, 3, mode4CC))) {
      imode = 3;
      iK = sign * 323;
    }
    else
      continue;
    _c[imode]->fill();
    const Particle& pp = BB.decayProducts()[ix].at(sign * 2212)[0];
    const Particle& pbar = BB.decayProducts()[ix].at(-sign * 2212)[0];
    const Particle& meson = BB.decayProducts()[ix].at(iK)[0];
    FourMomentum pbaryon = pp.momentum() + pbar.momentum();
    double mass = pbaryon.mass();
    _h_mass[imode]->fill(mass);
    double mph[2] = {(pp.momentum() + meson.momentum()).mass(),
                     (pbar.momentum() + meson.momentum()).mass()};
    if (imode == 0) {
      _h_mass2[0][imode]->fill(max(mph[0], mph[1]));
    }
    else {
      if (mph[0] > mph[1])
        _h_mass2[0][imode]->fill(mph[0]);
      else
        _h_mass2[1][imode]->fill(mph[1]);
    }
  }
}

/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 4; ++ix) {
    normalize(_h_mass[ix], 1., false);
    for (unsigned int iy = 0; iy < 2; ++iy)
      if (_h_mass2[iy][ix]) scale(_h_mass2[iy][ix], 1. / *_c[ix]);
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h_mass[4], _h_mass2[2][4];
CounterPtr _c[4];
/// @}

};

RIVET_DECLARE_PLUGIN(BABAR_2007_I755548);

} ```