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| // -*- C++ -*
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/FinalState.hh"
#include "Rivet/Projections/VetoedFinalState.hh"
#include "Rivet/Projections/IdentifiedFinalState.hh"
#include "Rivet/Projections/PromptFinalState.hh"
#include "Rivet/Projections/DressedLeptons.hh"
#include "Rivet/Projections/FastJets.hh"
#include "Rivet/Projections/MissingMomentum.hh"
#include "fastjet/contrib/Njettiness.hh"
#include "fastjet/contrib/Nsubjettiness.hh"
#include "fastjet/contrib/NjettinessPlugin.hh"
namespace Rivet {
class ATLAS_2017_I1614149 : public Analysis {
public:
/// Constructor
///@brief: Resolved and boosted ttbar l+jets cross sections at 13 TeV
RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2017_I1614149);
void init() {
// Eta ranges
Cut eta_full = (Cuts::abseta < 5.0);
Cut lep_cuts = (Cuts::abseta < 2.5) && (Cuts::pT > 25*GeV);
// All final state particles
FinalState fs(eta_full);
IdentifiedFinalState all_photons(fs);
all_photons.acceptIdPair(PID::PHOTON);
// Get photons to dress leptons
IdentifiedFinalState ph_id(fs);
ph_id.acceptIdPair(PID::PHOTON);
// Projection to find the electrons
IdentifiedFinalState el_id(fs);
el_id.acceptIdPair(PID::ELECTRON);
PromptFinalState photons(ph_id);
photons.acceptTauDecays(true);
declare(photons, "photons");
PromptFinalState electrons(el_id);
electrons.acceptTauDecays(true);
DressedLeptons dressedelectrons(photons, electrons, 0.1, lep_cuts);
declare(dressedelectrons, "elecs");
DressedLeptons ewdressedelectrons(all_photons, electrons, 0.1, eta_full);
// Projection to find the muons
IdentifiedFinalState mu_id(fs);
mu_id.acceptIdPair(PID::MUON);
PromptFinalState muons(mu_id);
muons.acceptTauDecays(true);
DressedLeptons dressedmuons(photons, muons, 0.1, lep_cuts);
declare(dressedmuons, "muons");
DressedLeptons ewdressedmuons(all_photons, muons, 0.1, eta_full);
// Projection to find MET
declare(MissingMomentum(fs), "MET");
// remove prompt neutrinos from jet clustering
IdentifiedFinalState nu_id(fs);
nu_id.acceptNeutrinos();
PromptFinalState neutrinos(nu_id);
neutrinos.acceptTauDecays(true);
// Jet clustering.
VetoedFinalState vfs(fs);
vfs.addVetoOnThisFinalState(ewdressedelectrons);
vfs.addVetoOnThisFinalState(ewdressedmuons);
vfs.addVetoOnThisFinalState(neutrinos);
FastJets jets(vfs, FastJets::ANTIKT, 0.4, JetAlg::Muons::ALL, JetAlg::Invisibles::ALL);
declare(jets, "jets");
// Addition of the large-R jets
VetoedFinalState vfs1(fs);
vfs1.addVetoOnThisFinalState(neutrinos);
FastJets fjets(vfs1, FastJets::ANTIKT, 1.);
fjets.useInvisibles(JetAlg::Invisibles::NONE);
fjets.useMuons(JetAlg::Muons::NONE);
declare(fjets, "fjets");
bookHists("top_pt_res", 15);
bookHists("top_absrap_res", 17);
bookHists("ttbar_pt_res", 19);
bookHists("ttbar_absrap_res", 21);
bookHists("ttbar_m_res", 23);
bookHists("top_pt_boost", 25);
bookHists("top_absrap_boost", 27);
}
void analyze(const Event& event) {
// Get the selected objects, using the projections.
vector<DressedLepton> electrons = apply<DressedLeptons>(event, "elecs").dressedLeptons();
vector<DressedLepton> muons = apply<DressedLeptons>(event, "muons").dressedLeptons();
const Jets& jets = apply<FastJets>(event, "jets").jetsByPt(Cuts::pT > 25*GeV && Cuts::abseta < 2.5);
const PseudoJets& all_fjets = apply<FastJets>(event, "fjets").pseudoJetsByPt();
// get MET
const Vector3 met = apply<MissingMomentum>(event, "MET").vectorMPT();
Jets bjets, lightjets;
for (const Jet& jet : jets) {
bool b_tagged = jet.bTags(Cuts::pT > 5*GeV).size();
if ( b_tagged && bjets.size() < 2) bjets +=jet;
else lightjets += jet;
}
// Implementing large-R jets definition
// trim the jets
PseudoJets trimmed_fatJets;
float Rfilt = 0.2;
float pt_fraction_min = 0.05;
fastjet::Filter trimmer(fastjet::JetDefinition(fastjet::kt_algorithm, Rfilt), fastjet::SelectorPtFractionMin(pt_fraction_min));
for (PseudoJet pjet : all_fjets) trimmed_fatJets += trimmer(pjet);
trimmed_fatJets = fastjet::sorted_by_pt(trimmed_fatJets);
PseudoJets trimmed_jets;
for (unsigned int i = 0; i < trimmed_fatJets.size(); ++i) {
FourMomentum tj_mom = momentum(trimmed_fatJets[i]);
if (tj_mom.pt() <= 300*GeV) continue;
if (tj_mom.abseta() >= 2.0) continue;
trimmed_jets.push_back(trimmed_fatJets[i]);
}
bool single_electron = (electrons.size() == 1) && (muons.empty());
bool single_muon = (muons.size() == 1) && (electrons.empty());
DressedLepton *lepton = NULL;
if (single_electron) lepton = &electrons[0];
else if (single_muon) lepton = &muons[0];
if (!single_electron && !single_muon) vetoEvent;
bool pass_resolved = true;
bool num_b_tagged_jets = (bjets.size() == 2);
if (!num_b_tagged_jets) pass_resolved = false;
if (jets.size() < 4) pass_resolved = false;
bool pass_boosted = true;
int fatJetIndex = -1;
bool passTopTag = false;
bool passDphi = false;
bool passAddJet = false;
bool goodLepJet = false;
bool lepbtag = false;
bool hadbtag=false;
vector<int> lepJetIndex;
vector<int> jet_farFromHadTopJetCandidate;
if (met.mod() < 20*GeV) pass_boosted = false;
if (pass_boosted) {
double transmass = _mT(lepton->momentum(), met);
if (transmass + met.mod() < 60*GeV) pass_boosted = false;
}
if (pass_boosted) {
if (trimmed_jets.size() >= 1) {
for (unsigned int j = 0; j<trimmed_jets.size(); ++j) {
if (tau32( trimmed_jets.at(j), 1. ) < 0.75 &&
momentum(trimmed_jets.at(j)).mass() > 100*GeV &&
momentum(trimmed_jets.at(j)).pt() > 300*GeV &&
momentum(trimmed_jets.at(j)).pt() < 1500*GeV &&
fabs(momentum(trimmed_jets.at(j)).eta()) < 2.) {
passTopTag = true;
fatJetIndex = j;
break;
}
}
}
}
if(!passTopTag && fatJetIndex == -1) pass_boosted = false;
if (pass_boosted) {
double dPhi_fatjet = deltaPhi(lepton->phi(), momentum(trimmed_jets.at(fatJetIndex)).phi());
double dPhi_fatjet_lep_cut = 1.0; //2.3
if (dPhi_fatjet > dPhi_fatjet_lep_cut ) {
passDphi = true;
}
}
if (!passDphi) pass_boosted = false;
if (bjets.empty()) pass_boosted = false;
if (pass_boosted) {
for (unsigned int sj = 0; sj < jets.size(); ++sj) {
double dR = deltaR(jets.at(sj).momentum(), momentum(trimmed_jets.at(fatJetIndex)));
if(dR > 1.5) {
passAddJet = true;
jet_farFromHadTopJetCandidate.push_back(sj);
}
}
}
if (!passAddJet) pass_boosted = false;
if (pass_boosted) {
for (int ltj : jet_farFromHadTopJetCandidate) {
double dR_jet_lep = deltaR(jets.at(ltj).momentum(), lepton->momentum());
double dR_jet_lep_cut = 2.0;//1.5
if (dR_jet_lep < dR_jet_lep_cut) {
lepJetIndex.push_back(ltj);
goodLepJet = true;
}
}
}
if(!goodLepJet) pass_boosted = false;
if (pass_boosted) {
for (int lepj : lepJetIndex) {
lepbtag = jets.at(lepj).bTags(Cuts::pT > 5*GeV).size();
if (lepbtag) break;
}
}
double dR_fatBjet_cut = 1.0;
if (pass_boosted) {
for (const Jet& bjet : bjets) {
hadbtag |= deltaR(momentum(trimmed_jets.at(fatJetIndex)), bjet) < dR_fatBjet_cut;
}
}
if (!(lepbtag || hadbtag)) pass_boosted = false;
FourMomentum pbjet1; //Momentum of bjet1
FourMomentum pbjet2; //Momentum of bjet
int Wj1index = -1, Wj2index = -1;
if (pass_resolved) {
if ( deltaR(bjets[0], *lepton) <= deltaR(bjets[1], *lepton) ) {
pbjet1 = bjets[0].momentum();
pbjet2 = bjets[1].momentum();
} else {
pbjet1 = bjets[1].momentum();
pbjet2 = bjets[0].momentum();
}
double bestWmass = 1000.0*TeV;
double mWPDG = 80.399*GeV;
for (unsigned int i = 0; i < (lightjets.size() - 1); ++i) {
for (unsigned int j = i + 1; j < lightjets.size(); ++j) {
double wmass = (lightjets[i].momentum() + lightjets[j].momentum()).mass();
if (fabs(wmass - mWPDG) < fabs(bestWmass - mWPDG)) {
bestWmass = wmass;
Wj1index = i;
Wj2index = j;
}
}
}
FourMomentum pjet1 = lightjets[Wj1index].momentum();
FourMomentum pjet2 = lightjets[Wj2index].momentum();
// compute hadronic W boson
FourMomentum pWhadron = pjet1 + pjet2;
double pz = computeneutrinoz(lepton->momentum(), met);
FourMomentum ppseudoneutrino( sqrt(sqr(met.x()) + sqr(met.y()) + sqr(pz)), met.x(), met.y(), pz);
//compute leptonic, hadronic, combined pseudo-top
FourMomentum ppseudotoplepton = lepton->momentum() + ppseudoneutrino + pbjet1;
FourMomentum ppseudotophadron = pbjet2 + pWhadron;
FourMomentum pttbar = ppseudotoplepton + ppseudotophadron;
fillHists("top_pt_res", ppseudotophadron.pt()/GeV);
fillHists("top_absrap_res", ppseudotophadron.absrap());
fillHists("ttbar_pt_res", pttbar.pt()/GeV);
fillHists("ttbar_absrap_res", pttbar.absrap());
fillHists("ttbar_m_res", pttbar.mass()/GeV);
}
if (pass_boosted) {// Boosted selection
double hadtop_pt= momentum(trimmed_jets.at(fatJetIndex)).pt() / GeV;
double hadtop_absrap= momentum(trimmed_jets.at(fatJetIndex)).absrap();
fillHists("top_pt_boost", hadtop_pt);
fillHists("top_absrap_boost", hadtop_absrap);
}
}
void finalize() {
// Normalize to cross-section
const double sf = (crossSection() / sumOfWeights());
for (HistoMap::value_type& hist : _h) {
scale(hist.second, sf);
if (hist.first.find("_norm") != string::npos) normalize(hist.second);
}
}
void bookHists(std::string name, unsigned int index) {
book(_h[name], index, 1 ,1);
book(_h[name + "_norm"], index + 1, 1, 1);
}
void fillHists(std::string name, double value) {
_h[name]->fill(value);
_h[name + "_norm"]->fill(value);
}
double _mT(const FourMomentum &l, const Vector3 &met) const {
return sqrt(2.0 * l.pT() * met.mod() * (1 - cos(deltaPhi(l, met))) );
}
double tau32(const fastjet::PseudoJet &jet, double jet_rad) const {
double alpha = 1.0;
fjcontrib::NormalizedCutoffMeasure normalized_measure(alpha, jet_rad, 1000000);
// WTA definition
// Nsubjettiness::OnePass_WTA_KT_Axes wta_kt_axes;
// as in JetSubStructure recommendations
fjcontrib::KT_Axes kt_axes;
/// NsubjettinessRatio uses the results from Nsubjettiness to calculate the ratio
/// tau_N/tau_M, where N and M are specified by the user. The ratio of different tau values
/// is often used in analyses, so this class is helpful to streamline code.
fjcontrib::NsubjettinessRatio tau32_kt(3, 2, kt_axes, normalized_measure);
double tau32 = tau32_kt.result(jet);
return tau32;
}
double computeneutrinoz(const FourMomentum& lepton, const Vector3 &met) const {
//computing z component of neutrino momentum given lepton and met
double pzneutrino;
double m_W = 80.399; // in GeV, given in the paper
double k = (( sqr( m_W ) - sqr( lepton.mass() ) ) / 2 ) + (lepton.px() * met.x() + lepton.py() * met.y());
double a = sqr ( lepton.E() )- sqr ( lepton.pz() );
double b = -2*k*lepton.pz();
double c = sqr( lepton.E() ) * sqr( met.mod() ) - sqr( k );
double discriminant = sqr(b) - 4 * a * c;
double quad[2] = { (- b - sqrt(discriminant)) / (2 * a), (- b + sqrt(discriminant)) / (2 * a) }; //two possible quadratic solns
if (discriminant < 0) pzneutrino = - b / (2 * a); //if the discriminant is negative
else { //if the discriminant is greater than or equal to zero, take the soln with smallest absolute value
double absquad[2];
for (int n=0; n<2; ++n) absquad[n] = fabs(quad[n]);
if (absquad[0] < absquad[1]) pzneutrino = quad[0];
else pzneutrino = quad[1];
}
return pzneutrino;
}
private:
/// @name Objects that are used by the event selection decisions
typedef map<string, Histo1DPtr> HistoMap;
HistoMap _h;
};
RIVET_DECLARE_PLUGIN(ATLAS_2017_I1614149);
}
|