Rivet analyses

title: BABAR_2012_I1127599

Mass distributions in $B^-\to\Sigma_c^{++}\bar{p}\pi^-\pi^-$

Experiment: BABAR (PEP-II)

Inspire ID: 1127599

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 86 (2012) 091102

Beams: * *

Beam energies: ANY

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

Measurements of mass distributions in $B^-\to\Sigma_c^{++}\bar{p}\pi^-\pi^-$. The data were read from the plots in the paper but are background subtracted and efficiency corrected.

Source code:BABAR_2012_I1127599.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief B- -> Sigma_c++ pbar pi- pi- class BABAR_2012_I1127599 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2012_I1127599);


/// @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(4222);
  BP.addStable(-4222);
  declare(BP, "BP");
  // histos
  for (unsigned int ix = 0; ix < 3; ++ix) book(_h[ix], 1 + ix, 1, 1);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode = {{4222, 1}, {-2212, 1}, {-211, 2}};
  static const map<PdgId, unsigned int>& modeCC = {{-4222, 1}, {2212, 1}, {211, 2}};
  DecayedParticles BP = apply<DecayedParticles>(event, "BP");
  // loop over particles
  for (unsigned int ix = 0; ix < BP.decaying().size(); ++ix) {
    int sign = 1;
    if (BP.decaying()[ix].pid() < 0 && BP.modeMatches(ix, 4, mode)) {
      sign = 1;
    }
    else if (BP.decaying()[ix].pid() > 0 && BP.modeMatches(ix, 4, modeCC)) {
      sign = -1;
    }
    else
      continue;
    const Particle& SigC = BP.decayProducts()[ix].at(sign * 4222)[0];
    const Particle& pbar = BP.decayProducts()[ix].at(-sign * 2212)[0];
    const Particles& pim = BP.decayProducts()[ix].at(-sign * 211);
    for (unsigned int ix = 0; ix < 2; ++ix) {
      _h[0]->fill((pbar.momentum() + pim[ix].momentum()).mass());
      _h[1]->fill((SigC.momentum() + pim[ix].momentum()).mass());
    }
    _h[2]->fill((SigC.momentum() + pim[0].momentum() + pim[1].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_2012_I1127599);

} ```