Rivet analyses

title: MC_ZZJETS

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

In addition to the typical jet observables this analysis contains observables related to properties of the ZZ-pair momentum, correlations between the ZZ, properties of the Z bosons, properties of the leptons, correlations between the opposite charge leptons and correlations with jets.

Source code:MC_ZZJETS.cc

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

include "Rivet/Analyses/MC_JETS_BASE.hh"

include "Rivet/Projections/DileptonFinder.hh"

include "Rivet/Projections/FastJets.hh"

include "Rivet/Projections/VetoedFinalState.hh"

namespace Rivet {

/// @brief MC validation analysis for Z[ee]Z[mumu] + jets events class MC_ZZJETS : public MC_JETS_BASE { public:

/// Default constructor
MC_ZZJETS()
    : MC_JETS_BASE("MC_ZZJETS", 4, "Jets") { }


/// @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 cute = Cuts::abseta < etaecut && Cuts::pT > ptecut * GeV;
  DileptonFinder zeefinder(91.2 * GeV, 0.2, cute && 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 cutmu = Cuts::abseta < etamucut && Cuts::pT > ptmucut * GeV;
  DileptonFinder zmmfinder(zmminput, 91.2 * GeV, 0.2, cutmu && Cuts::abspid == PID::MUON,
                           Cuts::massIn(65 * GeV, 115 * GeV));
  declare(zmmfinder, "ZmmFinder");

  VetoedFinalState jetinput;
  jetinput.addVetoOnThisFinalState(zeefinder).addVetoOnThisFinalState(zmmfinder);

  // set ptcut from input option
  const double jetptcut = getOption<double>("PTJMIN", 20.0);
  _jetptcut = jetptcut * GeV;

  // set clustering radius from input option
  const double R = getOption<double>("R", 0.4);

  // set clustering algorithm from input option
  JetAlg clusterAlgo;
  const string algoopt = getOption("ALGO", "ANTIKT");
  if (algoopt == "KT") {
    clusterAlgo = JetAlg::KT;
  }
  else if (algoopt == "CA") {
    clusterAlgo = JetAlg::CA;
  }
  else if (algoopt == "ANTIKT") {
    clusterAlgo = JetAlg::ANTIKT;
  }
  else {
    MSG_WARNING("Unknown jet clustering algorithm option " + algoopt + ". Defaulting to anti-kT");
    clusterAlgo = JetAlg::ANTIKT;
  }

  FastJets jetpro(jetinput, clusterAlgo, R);
  declare(jetpro, "Jets");

  // Correlations with jets
  book(_h_ZZ_jet1_deta, "ZZ_jet1_deta", 70, -7.0, 7.0);
  book(_h_ZZ_jet1_dR, "ZZ_jet1_dR", 25, 1.5, 7.0);
  book(_h_Ze_jet1_dR, "Ze_jet1_dR", 25, 0.0, 7.0);

  // Global stuff
  book(_h_HT, "HT", logspace(100, 100.0, 0.5 * (sqrtS() > 0. ? sqrtS() : 14000.) / GeV));

  MC_JETS_BASE::init();
}


/// 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();

  const Jets& jets = apply<FastJets>(e, "Jets").jetsByPt(Cuts::pT > _jetptcut);
  if (jets.size() > 0) {
    const FourMomentum j0 = jets[0].momentum();
    _h_ZZ_jet1_deta->fill(zz.eta() - j0.eta());
    _h_ZZ_jet1_dR->fill(deltaR(zz, j0));
    _h_Ze_jet1_dR->fill(deltaR(ep, j0));
  }

  const double HT = sum(jets, Kin::pT, ep.pT() + em.pT() + mp.pT() + mm.pT());
  if (HT > 0.0) _h_HT->fill(HT / GeV);

  MC_JETS_BASE::analyze(e);
}


/// Finalize
void finalize() {
  const double s = crossSection() / picobarn / sumOfWeights();
  scale(_h_ZZ_jet1_deta, s);
  scale(_h_ZZ_jet1_dR, s);
  scale(_h_Ze_jet1_dR, s);
  scale(_h_HT, s);
  MC_JETS_BASE::finalize();
}

/// @}

private:

/// @name Histograms
/// @{
Histo1DPtr _h_ZZ_jet1_deta;
Histo1DPtr _h_ZZ_jet1_dR;
Histo1DPtr _h_Ze_jet1_dR;
Histo1DPtr _h_HT;
/// @}

};

RIVET_DECLARE_PLUGIN(MC_ZZJETS);

} ```