Rivet analyses

title: BABAR_2011_I924163

Mass distributions in $\bar{B}^0\to\Lambda^+_c\bar{\Lambda}^0K^-$

Experiment: BABAR (PEP-II)

Inspire ID: 924163

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 84 (2011) 071102

Beams: * *

Beam energies: ANY

Run details: - Any process producing B0, originally e+e- at Upsilon(4S)

Mass distributions in $\bar{B}^0\to\Lambda^+_c\bar{\Lambda}^0K^-$, data read from plots in papers but is background subtracted.

Source code:BABAR_2011_I924163.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Bbar0 -> Lambda_c+ Lambdabar K- class BABAR_2011_I924163 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2011_I924163);


/// @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(3122);
  B0.addStable(-3122);
  B0.addStable(4122);
  B0.addStable(-4122);
  declare(B0, "B0");
  // histos
  for (unsigned int ix = 0; ix < 3; ++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 = {{4122, 1}, {-3122, 1}, {-321, 1}};
  static const map<PdgId, unsigned int>& modeCC = {{-4122, 1}, {3122, 1}, {321, 1}};
  DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
  // loop over particles
  for (unsigned int ix = 0; ix < B0.decaying().size(); ++ix) {
    int sign = 1;
    if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 3, mode)) {
      sign = 1;
    }
    else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 3, modeCC)) {
      sign = -1;
    }
    else
      continue;
    const Particle& LamC = B0.decayProducts()[ix].at(sign * 4122)[0];
    const Particle& Lam = B0.decayProducts()[ix].at(-sign * 3122)[0];
    const Particle& Km = B0.decayProducts()[ix].at(-sign * 321)[0];
    _h[0]->fill((LamC.momentum() + Lam.momentum()).mass());
    _h[1]->fill((Lam.momentum() + Km.momentum()).mass());
    _h[2]->fill((LamC.momentum() + Km.momentum()).mass());
  }
}


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

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[3];
/// @}

};

RIVET_DECLARE_PLUGIN(BABAR_2011_I924163);

} ```