Rivet analyses

title: BABAR_2008_I766290

Mass distribution in $B^-\to\Lambda_c^+\bar{\Lambda}_c^-K^-$

Experiment: BABAR (PEP-II)

Inspire ID: 766290

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 77 (2008) 031101

Beams: * *

Beam energies: ANY

Run details: - Any process producing B+/-, orignally Upsilon(4S) decays

Measurement of mass distributions in $B^-\to\Lambda_c^+\bar{\Lambda}_c^-K^-$ decays. The data was read from plots in the paper, the data is not corrected for efficiency/acceptance although the sideband backgrounds given in the paper have been subtracted.

Source code:BABAR_2008_I766290.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B- -> Lambda_c+ Lambdabar_c- K- class BABAR_2008_I766290 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2008_I766290);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == PID::BPLUS);
  declare(ufs, "UFS");
  DecayedParticles BP(ufs);
  BP.addStable(4122);
  BP.addStable(-4122);
  declare(BP, "BP");
  // histos
  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) {
  static const map<PdgId, unsigned int>& mode = {{4122, 1}, {-4122, 1}, {321, 1}};
  static const map<PdgId, unsigned int>& modeCC = {{4122, 1}, {-4122, 1}, {-321, 1}};
  DecayedParticles BP = apply<DecayedParticles>(event, "BP");
  for (unsigned int ix = 0; ix < BP.decaying().size(); ++ix) {
    // select right decay mode
    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 Particle& lam = BP.decayProducts()[ix].at(4122 * sign)[0];
    const Particle& lbar = BP.decayProducts()[ix].at(-4122 * sign)[0];
    const Particle& Kp = BP.decayProducts()[ix].at(321 * sign)[0];
    _h[0]->fill((lbar.momentum() + Kp.momentum()).mass());
    _h[1]->fill((lam.momentum() + lbar.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(BABAR_2008_I766290);

} ```