Rivet analyses

title: BELLE_2018_I1641071

Mass distributions in $\Omega_c^0$ decays

Experiment: BELLE (KEKB)

Inspire ID: 1641071

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Rev.D 97 (2018) 3, 032001

Beams: * *

Beam energies: ANY

Run details: - Any process producing Omega_c

Measurement of the mass distributions in the decays $\Omega_c^0\to\Omega^-\pi^+\pi^0$, $\Xi^-K^+\pi^+\pi^+$ and $\Xi^0K^-\pi^+$ . The data were read from the plots in the paper and are not corrected.

Source code:BELLE_2018_I1641071.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Omega_c decays class BELLE_2018_I1641071 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2018_I1641071);


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

/// Book histograms and initialise projections before the run
void init() {
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 4332);
  declare(ufs, "UFS");
  DecayedParticles OMEGAC(ufs);
  OMEGAC.addStable(PID::PI0);
  OMEGAC.addStable(PID::K0S);
  OMEGAC.addStable(PID::XIMINUS);
  OMEGAC.addStable(-PID::XIMINUS);
  OMEGAC.addStable(PID::XI0);
  OMEGAC.addStable(-PID::XI0);
  OMEGAC.addStable(PID::OMEGAMINUS);
  OMEGAC.addStable(-PID::OMEGAMINUS);
  declare(OMEGAC, "OMEGAC");
  for (unsigned int ix = 0; ix < 4; ++ix) book(_h[ix], 1, 1, 1 + ix);
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  static const map<PdgId, unsigned int>& mode1 = {{3334, 1}, {211, 1}, {111, 1}};
  static const map<PdgId, unsigned int>& mode1CC = {{-3334, 1}, {-211, 1}, {111, 1}};
  static const map<PdgId, unsigned int>& mode2 = {{3312, 1}, {-321, 1}, {211, 2}};
  static const map<PdgId, unsigned int>& mode2CC = {{-3312, 1}, {321, 1}, {-211, 2}};
  static const map<PdgId, unsigned int>& mode3 = {{3322, 1}, {-321, 1}, {211, 1}};
  static const map<PdgId, unsigned int>& mode3CC = {{-3322, 1}, {321, 1}, {-211, 1}};
  DecayedParticles OMEGAC = apply<DecayedParticles>(event, "OMEGAC");
  // loop over particles
  for (unsigned int ix = 0; ix < OMEGAC.decaying().size(); ++ix) {
    int sign = OMEGAC.decaying()[ix].pid() / OMEGAC.decaying()[ix].abspid();
    // omega pi+ pi0
    if ((sign == 1 && OMEGAC.modeMatches(ix, 3, mode1))
        || (sign == -1 && OMEGAC.modeMatches(ix, 3, mode1CC))) {
      const Particle& pi0 = OMEGAC.decayProducts()[ix].at(111)[0];
      const Particle& pip = OMEGAC.decayProducts()[ix].at(sign * 211)[0];
      _h[0]->fill((pi0.momentum() + pip.momentum()).mass());
    }
    // Xi- K- pi+pi+
    else if ((sign == 1 && OMEGAC.modeMatches(ix, 4, mode2))
             || (sign == -1 && OMEGAC.modeMatches(ix, 4, mode2CC))) {
      const Particles& pip = OMEGAC.decayProducts()[ix].at(sign * 211);
      const Particle& Km = OMEGAC.decayProducts()[ix].at(-sign * 321)[0];
      const Particle& xim = OMEGAC.decayProducts()[ix].at(sign * 3312)[0];
      _h[1]->fill((xim.momentum() + pip[0].momentum()).mass());
      _h[1]->fill((xim.momentum() + pip[1].momentum()).mass());
      _h[2]->fill((Km.momentum() + pip[0].momentum()).mass());
      _h[2]->fill((Km.momentum() + pip[1].momentum()).mass());
    }
    // Xi0 K- pi+
    else if ((sign == 1 && OMEGAC.modeMatches(ix, 3, mode3))
             || (sign == -1 && OMEGAC.modeMatches(ix, 3, mode3CC))) {
      const Particle& pip = OMEGAC.decayProducts()[ix].at(sign * 211)[0];
      const Particle& Km = OMEGAC.decayProducts()[ix].at(-sign * 321)[0];
      _h[3]->fill((Km.momentum() + pip.momentum()).mass());
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  for (unsigned int ix = 0; ix < 4; ++ix) normalize(_h[ix]);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[4];
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2018_I1641071);

} ```