Rivet analyses

title: MC_ZZINC

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

Experiment: ()

Status: VALIDATED

Authors: - Frank Siegert

References: none listed

Beams: * *

Beam energies: ANY

Run details: - $ZZ$ + jets analysis. Needs mass cut on lepton pairs to avoid photon singularity, e.g. a min range of $66 < m_{ee} < 116$ GeV

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

Source code:MC_ZZINC.cc

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

include "Rivet/Analysis.hh"

include "Rivet/Projections/DileptonFinder.hh"

include "Rivet/Projections/VetoedFinalState.hh"

namespace Rivet {

/// @brief MC validation analysis for Z[ee]Z[mumu] events class MC_ZZINC : public Analysis { public:

/// Default constructor
RIVET_DEFAULT_ANALYSIS_CTOR(MC_ZZINC);


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

/// Book histograms
void init() {
  // set FS cuts from input options
  const double etaecut = getOption<double>("ABSETAEMAX", 3.5);
  const double ptecut = getOption<double>("PTEMIN", 25.);
  Cut cut_e = Cuts::abseta < etaecut && Cuts::pT > ptecut * GeV;
  DileptonFinder zeefinder(91.2 * GeV, 0.2, cut_e && Cuts::abspid == PID::ELECTRON,
                           Cuts::massIn(65 * GeV, 115 * GeV));
  declare(zeefinder, "ZeeFinder");

  VetoedFinalState zmminput;
  zmminput.addVetoOnThisFinalState(zeefinder);

  // set FS cuts from input options
  const double etamucut = getOption<double>("ABSETAMUMAX", 3.5);
  const double ptmucut = getOption<double>("PTMUMIN", 25.);
  Cut cut_mu = Cuts::abseta < etamucut && Cuts::pT > ptmucut * GeV;
  DileptonFinder zmmfinder(PromptFinalState(zmminput), 91.2 * GeV, 0.2,
                           cut_mu && Cuts::abspid == PID::MUON, Cuts::massIn(65 * GeV, 115 * GeV));
  declare(zmmfinder, "ZmmFinder");

  // Properties of the pair momentum
  double sqrts = sqrtS() > 0. ? sqrtS() : 14000.;
  book(_h_ZZ_pT, "ZZ_pT", logspace(100, 1.0, 0.5 * sqrts / GeV));
  book(_h_ZZ_pT_peak, "ZZ_pT_peak", 25, 0.0, 25.0);
  book(_h_ZZ_eta, "ZZ_eta", 40, -7.0, 7.0);
  book(_h_ZZ_phi, "ZZ_phi", 25, 0.0, TWOPI);
  book(_h_ZZ_m, "ZZ_m", logspace(100, 150.0, 180.0 + 0.25 * sqrts / GeV));

  // Correlations between the ZZ
  book(_h_ZZ_dphi, "ZZ_dphi", 25, 0.0, PI); /// @todo non-linear?
  book(_h_ZZ_deta, "ZZ_deta", 25, -7.0, 7.0);
  book(_h_ZZ_dR, "ZZ_dR", 25, 0.5, 7.0);
  book(_h_ZZ_dpT, "ZZ_dpT", logspace(100, 1.0, 0.5 * sqrts / GeV));
  book(_h_ZZ_costheta_planes, "ZZ_costheta_planes", 25, -1.0, 1.0);

  // Properties of the Z bosons
  book(_h_Z_pT, "Z_pT", logspace(100, 10.0, 0.25 * sqrts / GeV));
  book(_h_Z_eta, "Z_eta", 70, -7.0, 7.0);

  // Properties of the leptons
  book(_h_Zl_pT, "Zl_pT", logspace(100, 30.0, 0.1 * sqrts / GeV));
  book(_h_Zl_eta, "Zl_eta", 40, -3.5, 3.5);

  // Correlations between the opposite charge leptons
  book(_h_ZeZm_dphi, "ZeZm_dphi", 25, 0.0, PI);
  book(_h_ZeZm_deta, "ZeZm_deta", 25, -5.0, 5.0);
  book(_h_ZeZm_dR, "ZeZm_dR", 25, 0.5, 5.0);
  book(_h_ZeZm_m, "ZeZm_m", 100, 0.0, 300.0);
}


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

  // Z momenta
  const FourMomentum& zee = zeefinder.bosons()[0].momentum();
  const FourMomentum& zmm = zmmfinder.bosons()[0].momentum();
  const FourMomentum zz = zee + zmm;
  // Lepton momenta
  const FourMomentum& ep = zeefinder.constituents()[0].momentum();
  const FourMomentum& em = zeefinder.constituents()[1].momentum();
  const FourMomentum& mp = zmmfinder.constituents()[0].momentum();
  const FourMomentum& mm = zmmfinder.constituents()[1].momentum();

  _h_ZZ_pT->fill(zz.pT() / GeV);
  _h_ZZ_pT_peak->fill(zz.pT() / GeV);
  _h_ZZ_eta->fill(zz.eta());
  _h_ZZ_phi->fill(zz.phi());
  if (zz.mass2() > 0.0) ///< @todo Protection still needed?
    _h_ZZ_m->fill(zz.mass() / GeV);

  _h_ZZ_dphi->fill(deltaPhi(zee, zmm));
  _h_ZZ_deta->fill(zee.eta() - zmm.eta());
  _h_ZZ_dR->fill(deltaR(zee, zmm));
  _h_ZZ_dpT->fill(fabs(zee.pT() - zmm.pT()));

  const Vector3 crossZee = ep.p3().cross(em.p3());
  const Vector3 crossZmm = mp.p3().cross(mm.p3());
  const double costheta = crossZee.dot(crossZmm) / crossZee.mod() / crossZmm.mod();
  _h_ZZ_costheta_planes->fill(costheta);

  _h_Z_pT->fill(zee.pT() / GeV);
  _h_Z_pT->fill(zmm.pT() / GeV);
  _h_Z_eta->fill(zee.eta());
  _h_Z_eta->fill(zmm.eta());

  _h_Zl_pT->fill(ep.pT() / GeV);
  _h_Zl_pT->fill(em.pT() / GeV);
  _h_Zl_pT->fill(mp.pT() / GeV);
  _h_Zl_pT->fill(mm.pT() / GeV);
  _h_Zl_eta->fill(ep.eta());
  _h_Zl_eta->fill(em.eta());
  _h_Zl_eta->fill(mp.eta());
  _h_Zl_eta->fill(mm.eta());

  _h_ZeZm_dphi->fill(deltaPhi(ep, mm));
  _h_ZeZm_deta->fill(ep.eta() - mm.eta());
  _h_ZeZm_dR->fill(deltaR(ep, mm));
  const FourMomentum epmm = ep + mm;
  const double m_epmm = (epmm.mass2() > 0) ? epmm.mass() : 0; ///< @todo Protection still needed?
  _h_ZeZm_m->fill(m_epmm / GeV);
}


/// Finalize
void finalize() {
  const double s = crossSection() / picobarn / sumOfWeights();
  scale(_h_ZZ_pT, s);
  scale(_h_ZZ_pT_peak, s);
  scale(_h_ZZ_eta, s);
  scale(_h_ZZ_phi, s);
  scale(_h_ZZ_m, s);
  scale(_h_ZZ_dphi, s);
  scale(_h_ZZ_deta, s);
  scale(_h_ZZ_dR, s);
  scale(_h_ZZ_dpT, s);
  scale(_h_ZZ_costheta_planes, s);
  scale(_h_Z_pT, s);
  scale(_h_Z_eta, s);
  scale(_h_Zl_pT, s);
  scale(_h_Zl_eta, s);
  scale(_h_ZeZm_dphi, s);
  scale(_h_ZeZm_deta, s);
  scale(_h_ZeZm_dR, s);
  scale(_h_ZeZm_m, s);
}

/// @}

private:

/// @name Histograms
/// @{
Histo1DPtr _h_ZZ_pT;
Histo1DPtr _h_ZZ_pT_peak;
Histo1DPtr _h_ZZ_eta;
Histo1DPtr _h_ZZ_phi;
Histo1DPtr _h_ZZ_m;
Histo1DPtr _h_ZZ_dphi;
Histo1DPtr _h_ZZ_deta;
Histo1DPtr _h_ZZ_dR;
Histo1DPtr _h_ZZ_dpT;
Histo1DPtr _h_ZZ_costheta_planes;
Histo1DPtr _h_Z_pT;
Histo1DPtr _h_Z_eta;
Histo1DPtr _h_Zl_pT;
Histo1DPtr _h_Zl_eta;
Histo1DPtr _h_ZeZm_dphi;
Histo1DPtr _h_ZeZm_deta;
Histo1DPtr _h_ZeZm_dR;
Histo1DPtr _h_ZeZm_m;
/// @}

};

RIVET_DECLARE_PLUGIN(MC_ZZINC);

} ```