Rivet analyses

title: MC_ZINC

Monte Carlo validation observables for $Z[\ell^+ \, \ell^-]$ production

Experiment: ()

Status: VALIDATED

Authors: - Frank Siegert - Christian Gutschow

References: none listed

Beams: * *

Beam energies: ANY

Run details: - $\ell^+ \ell^-$ analysis. Needs mass cut on lepton pair to avoid photon singularity, e.g. a min range of $66 < m_{ll} < 116$ GeV

Monte Carlo validation observables for $Z[\ell^+ \, \ell^-]$ production

Source code:MC_ZINC.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DileptonFinder.hh"

namespace Rivet {

/// @brief MC validation analysis for Z events class MC_ZINC : public Analysis { public:

/// Default constructor
RIVET_DEFAULT_ANALYSIS_CTOR(MC_ZINC);

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

/// Book histograms
void init() {
  _dR = 0.2;
  if (getOption("SCHEME") == "BARE") _dR = 0.0;
  _lepton = PID::ELECTRON;
  if (getOption("LMODE") == "MU") _lepton = PID::MUON;

  // set FS cuts from input options
  const double etacut = getOption<double>("ABSETALMAX", 3.5);
  const double ptcut = getOption<double>("PTLMIN", 25.);

  Cut cut = Cuts::abseta < etacut && Cuts::pT > ptcut * GeV;
  DileptonFinder zfinder(91.2 * GeV, _dR, cut && Cuts::abspid == _lepton,
                         Cuts::massIn(66.0 * GeV, 116.0 * GeV));
  declare(zfinder, "DileptonFinder");

  book(_h_Z_mass, "Z_mass", 50, 66.0, 116.0);
  book(_h_Z_pT, "Z_pT", logspace(100, 1.0, 0.5 * (sqrtS() > 0. ? sqrtS() : 14000.) / GeV));
  book(_h_Z_pT_peak, "Z_pT_peak", 25, 0.0, 25.0);
  book(_h_Z_y, "Z_y", 40, -4.0, 4.0);
  book(_h_Z_phi, "Z_phi", 25, 0.0, TWOPI);
  book(_h_lepton_pT, "lepton_pT", logspace(100, 10.0, 0.25 * (sqrtS() > 0. ? sqrtS() : 14000.) / GeV));
  book(_h_lepton_eta, "lepton_eta", 40, -4.0, 4.0);
}


/// Do the analysis
void analyze(const Event& e) {
  const DileptonFinder& zfinder = apply<DileptonFinder>(e, "DileptonFinder");
  if (zfinder.bosons().size() != 1) vetoEvent;

  FourMomentum zmom(zfinder.bosons()[0].momentum());
  _h_Z_mass->fill(zmom.mass() / GeV);
  _h_Z_pT->fill(zmom.pT() / GeV);
  _h_Z_pT_peak->fill(zmom.pT() / GeV);
  _h_Z_y->fill(zmom.rapidity());
  _h_Z_phi->fill(zmom.phi());
  for (const Particle& l : zfinder.constituents()) {
    _h_lepton_pT->fill(l.pT() / GeV);
    _h_lepton_eta->fill(l.eta());
  }
}


/// Finalize
void finalize() {
  const double s = crossSection() / picobarn / sumOfWeights();
  scale(_h_Z_mass, s);
  scale(_h_Z_pT, s);
  scale(_h_Z_pT_peak, s);
  scale(_h_Z_y, s);
  scale(_h_Z_phi, s);
  scale(_h_lepton_pT, s);
  scale(_h_lepton_eta, s);
}

/// @}

protected:

/// @name Parameters for specialised e/mu and dressed/bare subclassing
/// @{
double _dR;
PdgId _lepton;
/// @}

private:

/// @name Histograms
/// @{
Histo1DPtr _h_Z_mass;
Histo1DPtr _h_Z_pT;
Histo1DPtr _h_Z_pT_peak;
Histo1DPtr _h_Z_y;
Histo1DPtr _h_Z_phi;
Histo1DPtr _h_lepton_pT;
Histo1DPtr _h_lepton_eta;
/// @}

};

RIVET_DECLARE_PLUGIN(MC_ZINC);

} ```