Rivet analyses

title: BELLE_2011_I924618

$B^-\to\bar{p}\Lambda^0D^0$ Differential branching ratio

Experiment: BELLE (KEKB)

Inspire ID: 924618

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 84 (2011) 071501

Beams: * *

Beam energies: ANY

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

Differential branching ratio for $B^-\to\bar{p}\Lambda^0D^0$ as a function of the $\bar{p}\Lambda^0$ mass measured by BELLE.

Source code:BELLE_2011_I924618.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B- -> pbar Lambda D0 class BELLE_2011_I924618 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2011_I924618);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 521);
  declare(ufs, "UFS");
  DecayedParticles BP(ufs);
  BP.addStable(3122);
  BP.addStable(-3122);
  BP.addStable(421);
  BP.addStable(-421);
  declare(BP, "BP");
  // histos
  book(_h, 1, 1, 1);
  book(_c, "TMP/nB");
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode = {{-2212, 1}, {3122, 1}, {421, 1}};
  static const map<PdgId, unsigned int>& modeCC = {{2212, 1}, {-3122, 1}, {-421, 1}};
  DecayedParticles BP = apply<DecayedParticles>(event, "BP");
  // loop over particles
  for (unsigned int ix = 0; ix < BP.decaying().size(); ++ix) {
    _c->fill();
    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& pbar = BP.decayProducts()[ix].at(-sign * 2212)[0];
    const Particle& Lam = BP.decayProducts()[ix].at(sign * 3122)[0];
    _h->fill((pbar.momentum() + Lam.momentum()).mass());
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  scale(_h, 1e6 / *_c);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h;
CounterPtr _c;
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2011_I924618);

} ```