TtSemiLepKinFitter.cc

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#include "PhysicsTools/KinFitter/interface/TFitConstraintEp.h"
#include "PhysicsTools/KinFitter/interface/TFitConstraintM.h"
#include "PhysicsTools/KinFitter/interface/TAbsFitParticle.h"
#include "PhysicsTools/KinFitter/interface/TFitParticleEMomDev.h"
#include "PhysicsTools/KinFitter/interface/TFitParticleEtEtaPhi.h"
#include "PhysicsTools/KinFitter/interface/TFitParticleEtThetaPhi.h"
#include "PhysicsTools/KinFitter/interface/TFitParticleEScaledMomDev.h"

#include "AnalysisDataFormats/TopObjects/interface/TtSemiLepEvtPartons.h"
#include "TopQuarkAnalysis/TopKinFitter/interface/TtSemiLepKinFitter.h"

#include "FWCore/MessageLogger/interface/MessageLogger.h"

TtSemiLepKinFitter::TtSemiLepKinFitter() : TopKinFitter(), jetParam_(kEMom), lepParam_(kEMom), metParam_(kEMom) {
  setupFitter();
}

TtSemiLepKinFitter::TtSemiLepKinFitter(Param jetParam,
                                       Param lepParam,
                                       Param metParam,
                                       int maxNrIter,
                                       double maxDeltaS,
                                       double maxF,
                                       const std::vector<Constraint>& constraints,
                                       double mW,
                                       double mTop,
                                       const std::vector<edm::ParameterSet>* udscResolutions,
                                       const std::vector<edm::ParameterSet>* bResolutions,
                                       const std::vector<edm::ParameterSet>* lepResolutions,
                                       const std::vector<edm::ParameterSet>* metResolutions,
                                       const std::vector<double>* jetEnergyResolutionScaleFactors,
                                       const std::vector<double>* jetEnergyResolutionEtaBinning)
    : TopKinFitter(maxNrIter, maxDeltaS, maxF, mW, mTop),
      udscResolutions_(udscResolutions),
      bResolutions_(bResolutions),
      lepResolutions_(lepResolutions),
      metResolutions_(metResolutions),
      jetEnergyResolutionScaleFactors_(jetEnergyResolutionScaleFactors),
      jetEnergyResolutionEtaBinning_(jetEnergyResolutionEtaBinning),
      jetParam_(jetParam),
      lepParam_(lepParam),
      metParam_(metParam),
      constrList_(constraints) {
  setupFitter();
}

TtSemiLepKinFitter::~TtSemiLepKinFitter() = default;

void TtSemiLepKinFitter::printSetup() const {
  std::stringstream constr;
  for (unsigned int i = 0; i < constrList_.size(); ++i) {
    switch (constrList_[i]) {
      case kWHadMass:
        constr << "    * hadronic W-mass (" << mW_ << " GeV) \n";
        break;
      case kWLepMass:
        constr << "    * leptonic W-mass (" << mW_ << " GeV) \n";
        break;
      case kTopHadMass:
        constr << "    * hadronic t-mass (" << mTop_ << " GeV) \n";
        break;
      case kTopLepMass:
        constr << "    * leptonic t-mass (" << mTop_ << " GeV) \n";
        break;
      case kNeutrinoMass:
        constr << "    * neutrino   mass (0 GeV) \n";
        break;
      case kEqualTopMasses:
        constr << "    * equal    t-masses \n";
        break;
      case kSumPt:
        constr << "    * summed transverse momentum \n";
        break;
    }
  }
  edm::LogVerbatim("TtSemiLepKinFitter") << "\n"
                                         << "+++++++++++ TtSemiLepKinFitter Setup ++++++++++++ \n"
                                         << "  Parametrization:                                \n"
                                         << "   * jet : " << param(jetParam_) << "\n"
                                         << "   * lep : " << param(lepParam_) << "\n"
                                         << "   * met : " << param(metParam_) << "\n"
                                         << "  Constraints:                                    \n"
                                         << constr.str() << "  Max(No iterations): " << maxNrIter_ << "\n"
                                         << "  Max(deltaS)       : " << maxDeltaS_ << "\n"
                                         << "  Max(F)            : " << maxF_ << "\n"
                                         << "+++++++++++++++++++++++++++++++++++++++++++++++++ \n";
}

void TtSemiLepKinFitter::setupJets() {
  TMatrixD empty3x3(3, 3);
  TMatrixD empty4x4(4, 4);
  switch (jetParam_) {  // setup jets according to parameterization
    case kEMom:
      hadB_ = std::make_unique<TFitParticleEMomDev>("Jet1", "Jet1", nullptr, &empty4x4);
      hadP_ = std::make_unique<TFitParticleEMomDev>("Jet2", "Jet2", nullptr, &empty4x4);
      hadQ_ = std::make_unique<TFitParticleEMomDev>("Jet3", "Jet3", nullptr, &empty4x4);
      lepB_ = std::make_unique<TFitParticleEMomDev>("Jet4", "Jet4", nullptr, &empty4x4);
      break;
    case kEtEtaPhi:
      hadB_ = std::make_unique<TFitParticleEtEtaPhi>("Jet1", "Jet1", nullptr, &empty3x3);
      hadP_ = std::make_unique<TFitParticleEtEtaPhi>("Jet2", "Jet2", nullptr, &empty3x3);
      hadQ_ = std::make_unique<TFitParticleEtEtaPhi>("Jet3", "Jet3", nullptr, &empty3x3);
      lepB_ = std::make_unique<TFitParticleEtEtaPhi>("Jet4", "Jet4", nullptr, &empty3x3);
      break;
    case kEtThetaPhi:
      hadB_ = std::make_unique<TFitParticleEtThetaPhi>("Jet1", "Jet1", nullptr, &empty3x3);
      hadP_ = std::make_unique<TFitParticleEtThetaPhi>("Jet2", "Jet2", nullptr, &empty3x3);
      hadQ_ = std::make_unique<TFitParticleEtThetaPhi>("Jet3", "Jet3", nullptr, &empty3x3);
      lepB_ = std::make_unique<TFitParticleEtThetaPhi>("Jet4", "Jet4", nullptr, &empty3x3);
      break;
  }
}

void TtSemiLepKinFitter::setupLeptons() {
  TMatrixD empty3x3(3, 3);
  switch (lepParam_) {  // setup lepton according to parameterization
    case kEMom:
      lepton_ = std::make_unique<TFitParticleEScaledMomDev>("Lepton", "Lepton", nullptr, &empty3x3);
      break;
    case kEtEtaPhi:
      lepton_ = std::make_unique<TFitParticleEtEtaPhi>("Lepton", "Lepton", nullptr, &empty3x3);
      break;
    case kEtThetaPhi:
      lepton_ = std::make_unique<TFitParticleEtThetaPhi>("Lepton", "Lepton", nullptr, &empty3x3);
      break;
  }
  switch (metParam_) {  // setup neutrino according to parameterization
    case kEMom:
      neutrino_ = std::make_unique<TFitParticleEScaledMomDev>("Neutrino", "Neutrino", nullptr, &empty3x3);
      break;
    case kEtEtaPhi:
      neutrino_ = std::make_unique<TFitParticleEtEtaPhi>("Neutrino", "Neutrino", nullptr, &empty3x3);
      break;
    case kEtThetaPhi:
      neutrino_ = std::make_unique<TFitParticleEtThetaPhi>("Neutrino", "Neutrino", nullptr, &empty3x3);
      break;
  }
}

void TtSemiLepKinFitter::setupConstraints() {
  massConstr_[kWHadMass] = std::make_unique<TFitConstraintM>("WMassHad", "WMassHad", nullptr, nullptr, mW_);
  massConstr_[kWLepMass] = std::make_unique<TFitConstraintM>("WMassLep", "WMassLep", nullptr, nullptr, mW_);
  massConstr_[kTopHadMass] = std::make_unique<TFitConstraintM>("TopMassHad", "TopMassHad", nullptr, nullptr, mTop_);
  massConstr_[kTopLepMass] = std::make_unique<TFitConstraintM>("TopMassLep", "TopMassLep", nullptr, nullptr, mTop_);
  massConstr_[kNeutrinoMass] = std::make_unique<TFitConstraintM>("NeutrinoMass", "NeutrinoMass", nullptr, nullptr, 0.);
  massConstr_[kEqualTopMasses] =
      std::make_unique<TFitConstraintM>("EqualTopMasses", "EqualTopMasses", nullptr, nullptr, 0.);
  sumPxConstr_ = std::make_unique<TFitConstraintEp>("SumPx", "SumPx", nullptr, TFitConstraintEp::pX, 0.);
  sumPyConstr_ = std::make_unique<TFitConstraintEp>("SumPy", "SumPy", nullptr, TFitConstraintEp::pY, 0.);

  massConstr_[kWHadMass]->addParticles1(hadP_.get(), hadQ_.get());
  massConstr_[kWLepMass]->addParticles1(lepton_.get(), neutrino_.get());
  massConstr_[kTopHadMass]->addParticles1(hadP_.get(), hadQ_.get(), hadB_.get());
  massConstr_[kTopLepMass]->addParticles1(lepton_.get(), neutrino_.get(), lepB_.get());
  massConstr_[kNeutrinoMass]->addParticle1(neutrino_.get());
  massConstr_[kEqualTopMasses]->addParticles1(hadP_.get(), hadQ_.get(), hadB_.get());
  massConstr_[kEqualTopMasses]->addParticles2(lepton_.get(), neutrino_.get(), lepB_.get());
  sumPxConstr_->addParticles(lepton_.get(), neutrino_.get(), hadP_.get(), hadQ_.get(), hadB_.get(), lepB_.get());
  sumPyConstr_->addParticles(lepton_.get(), neutrino_.get(), hadP_.get(), hadQ_.get(), hadB_.get(), lepB_.get());

  if (std::find(constrList_.begin(), constrList_.end(), kSumPt) != constrList_.end())
    constrainSumPt_ = true;
  constrainSumPt_ = false;
}

void TtSemiLepKinFitter::setupFitter() {
  printSetup();

  setupJets();
  setupLeptons();
  setupConstraints();

  // add measured particles
  fitter_->addMeasParticle(hadB_.get());
  fitter_->addMeasParticle(hadP_.get());
  fitter_->addMeasParticle(hadQ_.get());
  fitter_->addMeasParticle(lepB_.get());
  fitter_->addMeasParticle(lepton_.get());
  fitter_->addMeasParticle(neutrino_.get());

  // add constraints
  for (unsigned int i = 0; i < constrList_.size(); i++) {
    if (constrList_[i] != kSumPt)
      fitter_->addConstraint(massConstr_[constrList_[i]].get());
  }
  if (constrainSumPt_) {
    fitter_->addConstraint(sumPxConstr_.get());
    fitter_->addConstraint(sumPyConstr_.get());
  }

  // initialize helper class used to bring the resolutions into covariance matrices
  if (!udscResolutions_->empty() && !bResolutions_->empty() && !lepResolutions_->empty() && !metResolutions_->empty())
    covM_ = std::make_unique<CovarianceMatrix>(*udscResolutions_,
                                               *bResolutions_,
                                               *lepResolutions_,
                                               *metResolutions_,
                                               *jetEnergyResolutionScaleFactors_,
                                               *jetEnergyResolutionEtaBinning_);
  else
    covM_ = std::make_unique<CovarianceMatrix>();
}

int TtSemiLepKinFitter::fit(const TLorentzVector& p4HadP,
                            const TLorentzVector& p4HadQ,
                            const TLorentzVector& p4HadB,
                            const TLorentzVector& p4LepB,
                            const TLorentzVector& p4Lepton,
                            const TLorentzVector& p4Neutrino,
                            const int leptonCharge,
                            const CovarianceMatrix::ObjectType leptonType) {
  // initialize covariance matrices
  TMatrixD covHadP = covM_->setupMatrix(p4HadP, CovarianceMatrix::kUdscJet, jetParam_);
  TMatrixD covHadQ = covM_->setupMatrix(p4HadQ, CovarianceMatrix::kUdscJet, jetParam_);
  TMatrixD covHadB = covM_->setupMatrix(p4HadB, CovarianceMatrix::kBJet, jetParam_);
  TMatrixD covLepB = covM_->setupMatrix(p4LepB, CovarianceMatrix::kBJet, jetParam_);
  TMatrixD covLepton = covM_->setupMatrix(p4Lepton, leptonType, lepParam_);
  TMatrixD covNeutrino = covM_->setupMatrix(p4Neutrino, CovarianceMatrix::kMet, metParam_);

  // now do the part that is fully independent of PAT features
  return fit(p4HadP,
             p4HadQ,
             p4HadB,
             p4LepB,
             p4Lepton,
             p4Neutrino,
             covHadP,
             covHadQ,
             covHadB,
             covLepB,
             covLepton,
             covNeutrino,
             leptonCharge);
}

int TtSemiLepKinFitter::fit(const TLorentzVector& p4HadP,
                            const TLorentzVector& p4HadQ,
                            const TLorentzVector& p4HadB,
                            const TLorentzVector& p4LepB,
                            const TLorentzVector& p4Lepton,
                            const TLorentzVector& p4Neutrino,
                            const TMatrixD& covHadP,
                            const TMatrixD& covHadQ,
                            const TMatrixD& covHadB,
                            const TMatrixD& covLepB,
                            const TMatrixD& covLepton,
                            const TMatrixD& covNeutrino,
                            const int leptonCharge) {
  // set the kinematics of the objects to be fitted
  hadP_->setIni4Vec(&p4HadP);
  hadQ_->setIni4Vec(&p4HadQ);
  hadB_->setIni4Vec(&p4HadB);
  lepB_->setIni4Vec(&p4LepB);
  lepton_->setIni4Vec(&p4Lepton);
  neutrino_->setIni4Vec(&p4Neutrino);

  hadP_->setCovMatrix(&covHadP);
  hadQ_->setCovMatrix(&covHadQ);
  hadB_->setCovMatrix(&covHadB);
  lepB_->setCovMatrix(&covLepB);
  lepton_->setCovMatrix(&covLepton);
  neutrino_->setCovMatrix(&covNeutrino);

  if (constrainSumPt_) {
    // setup Px and Py constraint for curent event configuration so that sum Pt will be conserved
    sumPxConstr_->setConstraint(p4HadP.Px() + p4HadQ.Px() + p4HadB.Px() + p4LepB.Px() + p4Lepton.Px() +
                                p4Neutrino.Px());
    sumPyConstr_->setConstraint(p4HadP.Py() + p4HadQ.Py() + p4HadB.Py() + p4LepB.Py() + p4Lepton.Py() +
                                p4Neutrino.Py());
  }

  // now do the fit
  fitter_->fit();

  // read back the resulting particles if the fit converged
  if (fitter_->getStatus() == 0) {
    // read back jet kinematics
    fittedHadP_ = pat::Particle(reco::LeafCandidate(
        0,
        math::XYZTLorentzVector(
            hadP_->getCurr4Vec()->X(), hadP_->getCurr4Vec()->Y(), hadP_->getCurr4Vec()->Z(), hadP_->getCurr4Vec()->E()),
        math::XYZPoint()));
    fittedHadQ_ = pat::Particle(reco::LeafCandidate(
        0,
        math::XYZTLorentzVector(
            hadQ_->getCurr4Vec()->X(), hadQ_->getCurr4Vec()->Y(), hadQ_->getCurr4Vec()->Z(), hadQ_->getCurr4Vec()->E()),
        math::XYZPoint()));
    fittedHadB_ = pat::Particle(reco::LeafCandidate(
        0,
        math::XYZTLorentzVector(
            hadB_->getCurr4Vec()->X(), hadB_->getCurr4Vec()->Y(), hadB_->getCurr4Vec()->Z(), hadB_->getCurr4Vec()->E()),
        math::XYZPoint()));
    fittedLepB_ = pat::Particle(reco::LeafCandidate(
        0,
        math::XYZTLorentzVector(
            lepB_->getCurr4Vec()->X(), lepB_->getCurr4Vec()->Y(), lepB_->getCurr4Vec()->Z(), lepB_->getCurr4Vec()->E()),
        math::XYZPoint()));

    // read back lepton kinematics
    fittedLepton_ = pat::Particle(reco::LeafCandidate(leptonCharge,
                                                      math::XYZTLorentzVector(lepton_->getCurr4Vec()->X(),
                                                                              lepton_->getCurr4Vec()->Y(),
                                                                              lepton_->getCurr4Vec()->Z(),
                                                                              lepton_->getCurr4Vec()->E()),
                                                      math::XYZPoint()));

    // read back the MET kinematics
    fittedNeutrino_ = pat::Particle(reco::LeafCandidate(0,
                                                        math::XYZTLorentzVector(neutrino_->getCurr4Vec()->X(),
                                                                                neutrino_->getCurr4Vec()->Y(),
                                                                                neutrino_->getCurr4Vec()->Z(),
                                                                                neutrino_->getCurr4Vec()->E()),
                                                        math::XYZPoint()));
  }
  return fitter_->getStatus();
}

TtSemiEvtSolution TtSemiLepKinFitter::addKinFitInfo(TtSemiEvtSolution* asol) {
  TtSemiEvtSolution fitsol(*asol);

  std::vector<pat::Jet> jets;
  jets.resize(4);
  jets[TtSemiLepEvtPartons::LightQ] = fitsol.getCalHadp();
  jets[TtSemiLepEvtPartons::LightQBar] = fitsol.getCalHadq();
  jets[TtSemiLepEvtPartons::HadB] = fitsol.getCalHadb();
  jets[TtSemiLepEvtPartons::LepB] = fitsol.getCalLepb();

  // perform the fit, either using the electron or the muon
  if (fitsol.getDecay() == "electron")
    fit(jets, fitsol.getCalLepe(), fitsol.getCalLepn());
  if (fitsol.getDecay() == "muon")
    fit(jets, fitsol.getCalLepm(), fitsol.getCalLepn());

  // add fitted information to the solution
  if (fitter_->getStatus() == 0) {
    // fill the fitted particles
    fitsol.setFitHadb(fittedHadB());
    fitsol.setFitHadp(fittedHadP());
    fitsol.setFitHadq(fittedHadQ());
    fitsol.setFitLepb(fittedLepB());
    fitsol.setFitLepl(fittedLepton());
    fitsol.setFitLepn(fittedNeutrino());
    // store the fit's chi2 probability
    fitsol.setProbChi2(fitProb());
  }
  return fitsol;
}