Rivet analyses

title: BELLE_2002_I566127

Mass distributions in $\Lambda_c^+\to \Sigma^+ K^+K^-$ and $\Lambda_c^+\to \Lambda^0K^0_SK^+$

Experiment: BELLE (KEKB)

Inspire ID: 566127

Status: VALIDATED NOHEPDATA

Authors: - Peter Richardson

References: - Phys.Lett.B 524 (2002) 33-43

Beams: * *

Beam energies: ANY

Run details: none listed

Mass distributions in $\Lambda_c^+\to \Sigma^+ K^+K^-$ and $\Lambda_c^+\to \Lambda^0K^0_SK^+$. The data were read from the plots in the paper and are not corrected. The background given was subtracted. The statistics are fairly low, however these are the only distributions available for these modes.

Source code:BELLE_2002_I566127.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DecayedParticles.hh"

include "Rivet/Projections/UnstableParticles.hh"

namespace Rivet {

/// @brief Lambda_c decays class BELLE_2002_I566127 : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2002_I566127);


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

/// Book histograms and initialise projections before the run
void init() {
  // Initialise and register projections
  UnstableParticles ufs = UnstableParticles(Cuts::abspid == 4122);
  declare(ufs, "UFS");
  DecayedParticles LAMBDAC(ufs);
  LAMBDAC.addStable(PID::PI0);
  LAMBDAC.addStable(PID::K0S);
  LAMBDAC.addStable(3122);
  LAMBDAC.addStable(-3122);
  LAMBDAC.addStable(3222);
  LAMBDAC.addStable(-3222);
  declare(LAMBDAC, "LAMBDAC");
  // 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) {
  DecayedParticles LAMBDAC = apply<DecayedParticles>(event, "LAMBDAC");
  // loop over particles
  for (unsigned int ix = 0; ix < LAMBDAC.decaying().size(); ++ix) {
    int sign = LAMBDAC.decaying()[ix].pid() / LAMBDAC.decaying()[ix].abspid();
    if ((LAMBDAC.decaying()[ix].pid() > 0 && LAMBDAC.modeMatches(ix, 3, mode1))
        || (LAMBDAC.decaying()[ix].pid() < 0 && LAMBDAC.modeMatches(ix, 3, mode1CC))) {
      const Particle& sig = LAMBDAC.decayProducts()[ix].at(sign * 3222)[0];
      const Particle& Kp = LAMBDAC.decayProducts()[ix].at(sign * 321)[0];
      const Particle& Km = LAMBDAC.decayProducts()[ix].at(-sign * 321)[0];
      _h[0]->fill((Kp.mom() + Km.mom()).mass());
      _h[1]->fill((sig.mom() + Km.mom()).mass());
    }
    else if ((LAMBDAC.decaying()[ix].pid() > 0 && LAMBDAC.modeMatches(ix, 3, mode2))
             || (LAMBDAC.decaying()[ix].pid() < 0 && LAMBDAC.modeMatches(ix, 3, mode2CC))) {
      const Particle& lam = LAMBDAC.decayProducts()[ix].at(sign * 3122)[0];
      const Particle& K0 = LAMBDAC.decayProducts()[ix].at(310)[0];
      _h[2]->fill((lam.mom() + K0.mom()).mass());
    }
  }
}


/// Normalise histograms etc., after the run
void finalize() {
  normalize(_h, 1.0, false);
}

/// @}


/// @name Histograms
/// @{
Histo1DPtr _h[3];
const map<PdgId, unsigned int> mode1 = {{3222, 1}, {321, 1}, {-321, 1}};
const map<PdgId, unsigned int> mode1CC = {{-3222, 1}, {321, 1}, {-321, 1}};
const map<PdgId, unsigned int> mode2 = {{3122, 1}, {310, 1}, {321, 1}};
const map<PdgId, unsigned int> mode2CC = {{-3122, 1}, {310, 1}, {-321, 1}};
/// @}

};

RIVET_DECLARE_PLUGIN(BELLE_2002_I566127);

} ```