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| // -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/DressedLeptons.hh"
#include "Rivet/Projections/IdentifiedFinalState.hh"
#include "Rivet/Projections/VetoedFinalState.hh"
namespace Rivet {
/// Jet multiplicity in lepton+jets ttbar at 8 TeV
class CMS_2016_PAS_TOP_15_006 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(CMS_2016_PAS_TOP_15_006);
/// @name Analysis methods
//@{
/// Set up projections and book histograms
void init() {
// Complete final state
FinalState fs;
Cut superLooseLeptonCuts = Cuts::pt > 5*GeV;
SpecialDressedLeptons dressedleptons(fs, superLooseLeptonCuts);
declare(dressedleptons, "DressedLeptons");
// Projection for jets
VetoedFinalState fsForJets(fs);
fsForJets.addVetoOnThisFinalState(dressedleptons);
declare(FastJets(fsForJets, FastJets::ANTIKT, 0.5), "Jets");
// Booking of histograms
book(_normedElectronMuonHisto, "normedElectronMuonHisto", 7, 3.5, 10.5);
book(_absXSElectronMuonHisto , "absXSElectronMuonHisto", 7, 3.5, 10.5);
}
/// Per-event analysis
void analyze(const Event& event) {
// Select ttbar -> lepton+jets
const SpecialDressedLeptons& dressedleptons = applyProjection<SpecialDressedLeptons>(event, "DressedLeptons");
vector<FourMomentum> selleptons;
for (const DressedLepton& dressedlepton : dressedleptons.dressedLeptons()) {
// Select good leptons
if (dressedlepton.pT() > 30*GeV && dressedlepton.abseta() < 2.4) selleptons += dressedlepton.mom();
// Veto loose leptons
else if (dressedlepton.pT() > 15*GeV && dressedlepton.abseta() < 2.5) vetoEvent;
}
if (selleptons.size() != 1) vetoEvent;
// Identify hardest tight lepton
const FourMomentum lepton = selleptons[0];
// Jets
const FastJets& jets = applyProjection<FastJets>(event, "Jets");
const Jets jets30 = jets.jetsByPt(30*GeV);
int nJets = 0, nBJets = 0;
for (const Jet& jet : jets30) {
if (jet.abseta() > 2.5) continue;
if (deltaR(jet.momentum(), lepton) < 0.5) continue;
nJets += 1;
if (jet.bTagged(Cuts::pT > 5*GeV)) nBJets += 1;
}
// Require >= 4 resolved jets, of which two must be b-tagged
if (nJets < 4 || nBJets < 2) vetoEvent;
// Fill histograms
_normedElectronMuonHisto->fill(min(nJets, 10));
_absXSElectronMuonHisto ->fill(min(nJets, 10));
}
void finalize() {
const double ttbarXS = !std::isnan(crossSectionPerEvent()) ? crossSection() : 252.89*picobarn;
if (std::isnan(crossSectionPerEvent()))
MSG_INFO("No valid cross-section given, using NNLO (arXiv:1303.6254; sqrt(s)=8 TeV, m_t=172.5 GeV): " <<
ttbarXS/picobarn << " pb");
const double xsPerWeight = ttbarXS/picobarn / sumOfWeights();
scale(_absXSElectronMuonHisto, xsPerWeight);
normalize(_normedElectronMuonHisto);
}
//@}
/// @brief Special dressed lepton finder
///
/// Find dressed leptons by clustering all leptons and photons
class SpecialDressedLeptons : public FinalState {
public:
/// Constructor
SpecialDressedLeptons(const FinalState& fs, const Cut& cut)
: FinalState(cut)
{
setName("SpecialDressedLeptons");
IdentifiedFinalState ifs(fs);
ifs.acceptIdPair(PID::PHOTON);
ifs.acceptIdPair(PID::ELECTRON);
ifs.acceptIdPair(PID::MUON);
declare(ifs, "IFS");
declare(FastJets(ifs, FastJets::ANTIKT, 0.1), "LeptonJets");
}
/// Clone on the heap
virtual unique_ptr<Projection> clone() const {
return unique_ptr<Projection>(new SpecialDressedLeptons(*this));
}
/// Retrieve the dressed leptons
const vector<DressedLepton>& dressedLeptons() const { return _clusteredLeptons; }
/// Perform the calculation
void project(const Event& e) {
_theParticles.clear();
_clusteredLeptons.clear();
vector<DressedLepton> allClusteredLeptons;
const Jets jets = applyProjection<FastJets>(e, "LeptonJets").jetsByPt(5*GeV);
for (const Jet& jet : jets) {
Particle lepCand;
for (const Particle& cand : jet.particles()) {
const int absPdgId = cand.abspid();
if (absPdgId == PID::ELECTRON || absPdgId == PID::MUON) {
if (cand.pt() > lepCand.pt()) lepCand = cand;
}
}
// Central lepton must be the major component
if ((lepCand.pt() < jet.pt()/2.) || (!lepCand.isChargedLepton())) continue;
DressedLepton lepton = DressedLepton(lepCand);
for (const Particle& cand : jet.particles()) {
if (isSame(cand, lepCand)) continue;
lepton.addConstituent(cand, true);
}
allClusteredLeptons.push_back(lepton);
}
for (const DressedLepton& lepton : allClusteredLeptons) {
if (accept(lepton)) {
_clusteredLeptons.push_back(lepton);
_theParticles.push_back(lepton.constituentLepton());
_theParticles += lepton.constituentPhotons();
}
}
}
private:
/// Container which stores the clustered lepton objects
vector<DressedLepton> _clusteredLeptons;
};
private:
/// Histograms
Histo1DPtr _normedElectronMuonHisto, _absXSElectronMuonHisto;
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(CMS_2016_PAS_TOP_15_006);
}
|