Rivet analyses

title: BABAR_2013_I1217425

Mass distributions in the decay $\bar{B}^0\to\Lambda_c^+\bar{p}\pi^+\pi^-$

Experiment: BABAR (PEP-II)

Inspire ID: 1217425

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 87 (2013) 9, 092004

Beams: * *

Beam energies: ANY

Run details: - Any process producing B0/Bbar0, original e+e- at Upsilon(4S)

Measurements of mass distributions in $\bar{B}^0\to\Lambda_c^+\bar{p}\pi^+\pi^-$ and modes with intermediate states. The data were read from the plots in the paper but are background subtracted and efficiency corrected.

Source code:BABAR_2013_I1217425.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Bbar0 -> Lambda_c+ pbar pi+ pi- class BABAR_2013_I1217425 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BABAR_2013_I1217425);


/// @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);
  // treat Lambda_c, Sigma_c and sigma_c* as stable
  B0.addStable(4122);
  B0.addStable(-4122);
  B0.addStable(4112);
  B0.addStable(-4112);
  B0.addStable(4212);
  B0.addStable(-4212);
  B0.addStable(4222);
  B0.addStable(-4222);
  B0.addStable(4114);
  B0.addStable(-4114);
  B0.addStable(4214);
  B0.addStable(-4214);
  B0.addStable(4224);
  B0.addStable(-4224);
  declare(B0, "B0");
  // histograms
  for (unsigned int ix = 0; ix < 5; ++ix) {
    for (unsigned int iy = 0; iy < 6; ++iy) {
      if ((ix < 3 && iy >= 3) or (ix == 4 && iy >= 4)) continue;
      book(_h[ix][iy], 1 + ix, 1, 1 + iy);
    }
  }
}


void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode1 = {{4112, 1}, {-2212, 1}, {211, 1}};
  static const map<PdgId, unsigned int>& mode1CC = {{-4112, 1}, {2212, 1}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode2 = {{4222, 1}, {-2212, 1}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode2CC = {{-4222, 1}, {2212, 1}, {211, 1}};
  static const map<PdgId, unsigned int>& mode3 = {{4224, 1}, {-2212, 1}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode3CC = {{-4224, 1}, {2212, 1}, {211, 1}};
  static const map<PdgId, unsigned int>& mode4 = {{4122, 1}, {-2212, 1}, {211, 1}, {-211, 1}};
  static const map<PdgId, unsigned int>& mode4CC = {{-4122, 1}, {2212, 1}, {211, 1}, {-211, 1}};
  DecayedParticles B0 = apply<DecayedParticles>(event, "B0");
  // loop over particles
  for (unsigned int ix = 0; ix < B0.decaying().size(); ++ix) {
    int sign = 1, imode = -1, ibaryon, ipi = -211;
    if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 3, mode1)) {
      sign = 1;
      imode = 0;
      ibaryon = 4112;
      ipi = 211;
    }
    else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 3, mode1CC)) {
      sign = -1;
      imode = 0;
      ibaryon = 4112;
      ipi = 211;
    }
    else if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 3, mode2)) {
      sign = 1;
      imode = 1;
      ibaryon = 4222;
    }
    else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 3, mode2CC)) {
      sign = -1;
      imode = 1;
      ibaryon = 4222;
    }
    else if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 3, mode3)) {
      sign = 1;
      imode = 2;
      ibaryon = 4224;
    }
    else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 3, mode3CC)) {
      sign = -1;
      imode = 2;
      ibaryon = 4224;
    }
    else if (B0.decaying()[ix].pid() < 0 && B0.modeMatches(ix, 4, mode4)) {
      sign = 1;
      imode = 3;
      ibaryon = 4122;
    }
    else if (B0.decaying()[ix].pid() > 0 && B0.modeMatches(ix, 4, mode4CC)) {
      sign = -1;
      imode = 3;
      ibaryon = 4122;
    }
    else
      continue;
    const Particle& SigC = B0.decayProducts()[ix].at(sign * ibaryon)[0];
    const Particle& pbar = B0.decayProducts()[ix].at(-sign * 2212)[0];
    const Particle& pim = B0.decayProducts()[ix].at(sign * ipi)[0];
    if (imode <= 2) {
      _h[imode][0]->fill((SigC.momentum() + pim.momentum()).mass());
      _h[imode][1]->fill((SigC.momentum() + pbar.momentum()).mass());
      _h[imode][2]->fill((pbar.momentum() + pim.momentum()).mass());
    }
    else {
      const Particle& pip = B0.decayProducts()[ix].at(-sign * ipi)[0];
      _h[imode][0]->fill((SigC.momentum() + pip.momentum()).mass());
      _h[imode][1]->fill((SigC.momentum() + pim.momentum()).mass());
      _h[imode][2]->fill((pbar.momentum() + pip.momentum()).mass());
      _h[imode][3]->fill((pbar.momentum() + pim.momentum()).mass());
      FourMomentum ppipi = pip.momentum() + pim.momentum();
      _h[imode][4]->fill(ppipi.mass());
      FourMomentum plam = SigC.momentum() + pbar.momentum();
      _h[imode][5]->fill(plam.mass());
      _h[4][0]->fill((ppipi + pbar.momentum()).mass());
      _h[4][1]->fill((ppipi + SigC.momentum()).mass());
      _h[4][2]->fill((plam + pim.momentum()).mass());
      _h[4][3]->fill((plam + pip.momentum()).mass());
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 5; ++ix) {
    for (unsigned int iy = 0; iy < 6; ++iy) {
      if ((ix < 3 && iy >= 3) or (ix == 4 && iy >= 5)) continue;
      normalize(_h[ix][iy], 1., false);
    }
  }
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[5][6];
/// @}

};

RIVET_DECLARE_PLUGIN(BABAR_2013_I1217425);

} ```