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| #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"
namespace Rivet {
/// ttbar l+jets cross sections at 13 TeV
class ATLAS_2018_I1656578 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(ATLAS_2018_I1656578);
/// Book cuts and projections
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);
// Get photons to dress leptons
IdentifiedFinalState all_photons(fs);
all_photons.acceptIdPair(PID::PHOTON);
PromptFinalState photons(Cuts::abspid == PID::PHOTON, true);
declare(photons, "photons");
// Projection to find the electrons
PromptFinalState electrons(Cuts::abspid == PID::ELECTRON, 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
PromptFinalState muons(Cuts::abspid == PID::MUON, 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");
// Jet clustering.
VetoedFinalState vfs(fs);
vfs.addVetoOnThisFinalState(ewdressedelectrons);
vfs.addVetoOnThisFinalState(ewdressedmuons);
FastJets jets(vfs, FastJets::ANTIKT, 0.4, JetAlg::Muons::ALL, JetAlg::Invisibles::DECAY);
declare(jets, "jets");
book(_h["absPout_inc"], 114, 1, 1);
book(_h["absPout_inc_norm"], 115, 1, 1);
book(_h["ptpseudotophadron_r1"], 98, 1, 1);
book(_h["ptpseudotophadron_r1_norm"], 99, 1, 1);
book(_h["ptttbar_r1"], 100, 1, 1);
book(_h["ptttbar_r1_norm"], 101, 1, 1);
book(_h["absPout_r1"], 96, 1, 1);
book(_h["absPout_r1_norm"], 97, 1, 1);
book(_h["ptpseudotophadron_r2"], 110, 1, 1);
book(_h["ptpseudotophadron_r2_norm"], 111, 1, 1);
book(_h["ptttbar_r2"], 112, 1, 1);
book(_h["ptttbar_r2_norm"], 113, 1, 1);
book(_h["absPout_r2"], 108, 1, 1);
book(_h["absPout_r2_norm"], 109, 1, 1);
book(_h["ptpseudotophadron_r3"], 104, 1, 1);
book(_h["ptpseudotophadron_r3_norm"], 105, 1, 1);
book(_h["ptttbar_r3"], 106, 1, 1);
book(_h["ptttbar_r3_norm"], 107, 1, 1);
book(_h["absPout_r3"], 102, 1, 1);
book(_h["absPout_r3_norm"], 103, 1, 1);
}
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 Vector3 met = apply<MissingMomentum>(event, "MET").vectorMPT();
Jets bjets, lightjets;
for (Jet jet : jets) {
bool b_tagged = jet.bTagged(Cuts::pT > 5*GeV);
if ( b_tagged && bjets.size() < 2) bjets += jet;
else lightjets += jet;
}
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 num_b_tagged_jets = (bjets.size() == 2);
if (!num_b_tagged_jets) vetoEvent;
if (jets.size() < 4) vetoEvent;
bool reg_4jex2bin = (jets.size() == 4);
bool reg_5jex2bin = (jets.size() == 5);
bool reg_6jin2bin = (jets.size() >= 6);
FourMomentum pbjet1; //Momentum of bjet1
FourMomentum pbjet2; //Momentum of bjet
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;
int Wj1index = -1, Wj2index = -1;
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;
Vector3 z_versor(0,0,1);
Vector3 vpseudotophadron = ppseudotophadron.vector3();
Vector3 vpseudotoplepton = ppseudotoplepton.vector3();
// Variables
double absPout = fabs(vpseudotophadron.dot((vpseudotoplepton.cross(z_versor))/(vpseudotoplepton.cross(z_versor).mod())));
//pseudotop hadrons and leptons fill histogram
if (reg_4jex2bin) {
_h["ptpseudotophadron_r1"]->fill(ppseudotophadron.pt()); //pT of pseudo top hadron
_h["ptpseudotophadron_r1_norm"]->fill(ppseudotophadron.pt()); //pT of pseudo top hadron
_h["ptttbar_r1"]->fill(pttbar.pt()); //fill pT of ttbar in combined channel
_h["ptttbar_r1_norm"]->fill(pttbar.pt()); //fill pT of ttbar in combined channel
_h["absPout_r1"]->fill(absPout);
_h["absPout_r1_norm"]->fill(absPout);
}
if (reg_5jex2bin) {
_h["ptpseudotophadron_r2"]->fill(ppseudotophadron.pt()); //pT of pseudo top hadron
_h["ptpseudotophadron_r2_norm"]->fill(ppseudotophadron.pt()); //pT of pseudo top hadron
_h["ptttbar_r2"]->fill(pttbar.pt()); //fill pT of ttbar in combined channel
_h["ptttbar_r2_norm"]->fill(pttbar.pt()); //fill pT of ttbar in combined channel
_h["absPout_r2"]->fill(absPout);
_h["absPout_r2_norm"]->fill(absPout);
}
if (reg_6jin2bin) {
_h["ptpseudotophadron_r3"]->fill(ppseudotophadron.pt()); //pT of pseudo top hadron
_h["ptpseudotophadron_r3_norm"]->fill(ppseudotophadron.pt()); //pT of pseudo top hadron
_h["ptttbar_r3"]->fill(pttbar.pt()); //fill pT of ttbar in combined channel
_h["ptttbar_r3_norm"]->fill(pttbar.pt()); //fill pT of ttbar in combined channel
_h["absPout_r3"]->fill(absPout);
_h["absPout_r3_norm"]->fill(absPout);
}
_h["absPout_inc"]->fill(absPout);
_h["absPout_inc_norm"]->fill(absPout);
}
void finalize() {
// Normalize to cross-section
const double sf = (crossSection() / sumOfWeights());
for (auto hist : _h) {
scale(hist.second, sf);
// Normalized distributions
if (hist.first.find("_norm") != string::npos) normalize(hist.second);
}
}
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
map<string, Histo1DPtr> _h;
};
// The hook for the plugin system
RIVET_DECLARE_PLUGIN(ATLAS_2018_I1656578);
}
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