Rivet analyses

title: MC_FSPARTICLES

Final-state particle distributions

Experiment: ()

Status: VALIDATED

Authors: - Ian Bruce - Andy Buckley

References: none listed

Beams: * *

Beam energies: ANY

Run details: - Any!

Generic analysis of typical per-particle distributions such as $\eta$, $y$, $p_\perp$, $\phi$, etc.

Source code:MC_FSPARTICLES.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/ChargedFinalState.hh"

namespace Rivet {

/// Analysis looking at various distributions of final-state particles class MC_FSPARTICLES : public Analysis { public:

/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(MC_FSPARTICLES);


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

/// Book histograms and initialise projections before the run
void init() {

  // Get cut variables from the analysis options
  const double PTMIN = getOption<double>("PTMIN", 0.0) * GeV;
  const double PTMAX = getOption<double>("PTMAX", max(30.0 * GeV, 2 * PTMIN)) * GeV;
  const double NMIN = getOption<double>("NMIN", -0.5);
  const double NMAX = getOption<double>("NMAX", 499.5);

  // Projections
  FinalState fs(Cuts::abseta < 5 && Cuts::pT > PTMIN);
  declare(fs, "FS");
  declare(ChargedFinalState(fs), "CFS");

  // Histograms
  book(_histMult, "Mult", 50, NMIN, NMAX);
  book(_histMultCh, "MultCh", 50, NMIN, NMAX);

  book(_histPt, "Pt", 300, PTMIN / GeV, PTMAX / GeV);
  book(_histPtCh, "PtCh", 300, PTMIN / GeV, PTMAX / GeV);

  book(_histE, "E", logspace(100, max(PTMIN / GeV, 0.1), 10 * PTMAX));
  book(_histECh, "ECh", logspace(100, max(PTMIN / GeV, 0.1), 10 * PTMAX));

  book(_histEtaSumEt, "EtaSumEt", 25, 0, 5);

  book(_histEta, "Eta", 50, -5, 5);
  book(_histEtaCh, "EtaCh", 50, -5, 5);
  book(_tmphistEtaPlus, "TMP/EtaPlus", 25, 0, 5);
  book(_tmphistEtaMinus, "TMP/EtaMinus", 25, 0, 5);
  book(_tmphistEtaChPlus, "TMP/EtaChPlus", 25, 0, 5);
  book(_tmphistEtaChMinus, "TMP/EtaChMinus", 25, 0, 5);

  book(_histRapidity, "Rapidity", 50, -5, 5);
  book(_histRapidityCh, "RapidityCh", 50, -5, 5);
  book(_tmphistRapPlus, "TMP/RapPlus", 25, 0, 5);
  book(_tmphistRapMinus, "TMP/RapMinus", 25, 0, 5);
  book(_tmphistRapChPlus, "TMP/RapChPlus", 25, 0, 5);
  book(_tmphistRapChMinus, "TMP/RapChMinus", 25, 0, 5);

  book(_histPhi, "Phi", 50, 0, TWOPI);
  book(_histPhiCh, "PhiCh", 50, 0, TWOPI);

  book(_histEtaPMRatio, "EtaPMRatio");
  book(_histEtaChPMRatio, "EtaChPMRatio");
  book(_histRapidityPMRatio, "RapidityPMRatio");
  book(_histRapidityChPMRatio, "RapidityChPMRatio");
}


/// Perform the per-event analysis
void analyze(const Event& event) {
  // Charged + neutral final state
  const FinalState& fs = apply<FinalState>(event, "FS");
  MSG_DEBUG("Total multiplicity = " << fs.size());
  _histMult->fill(fs.size());
  for (const Particle& p : fs.particles()) {
    _histEta->fill(p.eta());
    _histEtaSumEt->fill(p.abseta(), p.Et());
    (p.eta() > 0 ? _tmphistEtaPlus : _tmphistEtaMinus)->fill(p.abseta());
    //
    _histRapidity->fill(p.rap());
    (p.rap() > 0 ? _tmphistRapPlus : _tmphistRapMinus)->fill(p.absrap());
    //
    _histPt->fill(p.pT() / GeV);
    _histE->fill(p.E() / GeV);
    _histPhi->fill(p.phi());
  }

  // Same for the charged FS particles only
  const FinalState& cfs = apply<FinalState>(event, "CFS");
  MSG_DEBUG("Total charged multiplicity = " << cfs.size());
  _histMultCh->fill(cfs.size());
  for (const Particle& p : cfs.particles()) {
    _histEtaCh->fill(p.eta());
    (p.eta() > 0 ? _tmphistEtaChPlus : _tmphistEtaChMinus)->fill(p.abseta());
    //
    _histRapidityCh->fill(p.rap());
    (p.rap() > 0 ? _tmphistRapChPlus : _tmphistRapChMinus)->fill(p.absrap());
    //
    _histPtCh->fill(p.pT() / GeV);
    _histECh->fill(p.E() / GeV);
    _histPhiCh->fill(p.phi());
  }
}


/// Finalize
void finalize() {
  normalize(_histMult);
  normalize(_histEta);
  normalize(_histRapidity);
  normalize(_histPt);
  normalize(_histE);
  normalize(_histPhi);
  normalize(_histMultCh);
  normalize(_histEtaCh);
  normalize(_histRapidityCh);
  normalize(_histPtCh);
  normalize(_histECh);
  normalize(_histPhiCh);
  divide(_tmphistEtaPlus, _tmphistEtaMinus, _histEtaPMRatio);
  divide(_tmphistEtaChPlus, _tmphistEtaChMinus, _histEtaChPMRatio);
  divide(_tmphistRapPlus, _tmphistRapMinus, _histRapidityPMRatio);
  divide(_tmphistRapChPlus, _tmphistRapChMinus, _histRapidityChPMRatio);
}

/// @}

private:

/// @name Histograms
/// @{
Histo1DPtr _histMult, _histEta, _histRapidity, _histPt, _histE, _histPhi;
Histo1DPtr _histMultCh, _histEtaCh, _histRapidityCh, _histPtCh, _histECh, _histPhiCh;
Profile1DPtr _histEtaSumEt;
Estimate1DPtr _histEtaPMRatio, _histEtaChPMRatio, _histRapidityPMRatio, _histRapidityChPMRatio;
/// @}

/// @name Temporary histos used to calculate +/- rapidity ratio plots
/// @{
Histo1DPtr _tmphistEtaPlus, _tmphistEtaMinus, _tmphistEtaChPlus, _tmphistEtaChMinus;
Histo1DPtr _tmphistRapPlus, _tmphistRapMinus, _tmphistRapChPlus, _tmphistRapChMinus;
/// @}

};

RIVET_DECLARE_PLUGIN(MC_FSPARTICLES);

} ```