StKinFitter.cc

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//
//

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

#include "DataFormats/PatCandidates/interface/Particle.h"
#include "TopQuarkAnalysis/TopKinFitter/interface/StKinFitter.h"

//introduced to repair kinFit w/o resolutions from pat
#include "TopQuarkAnalysis/TopObjectResolutions/interface/MET.h"
#include "TopQuarkAnalysis/TopObjectResolutions/interface/Jet.h"
#include "TopQuarkAnalysis/TopObjectResolutions/interface/Muon.h"
#include "TopQuarkAnalysis/TopObjectResolutions/interface/Electron.h"

/* other parametrizations and constraints
#include "PhysicsTools/KinFitter/interface/TFitParticleESpher.h"
#include "PhysicsTools/KinFitter/interface/TFitParticleMCPInvSpher.h"
#include "PhysicsTools/KinFitter/interface/TFitConstraintMGaus.h"
#include "PhysicsTools/KinFitter/interface/TFitConstraintEp.h"*/

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

StKinFitter::StKinFitter(int jetParam,
                         int lepParam,
                         int metParam,
                         int maxNrIter,
                         double maxDeltaS,
                         double maxF,
                         const std::vector<int>& constraints)
    : TopKinFitter(maxNrIter, maxDeltaS, maxF),
      jetParam_((Param)jetParam),
      lepParam_((Param)lepParam),
      metParam_((Param)metParam),
      constraints_(constraints) {
  setupFitter();
}

StKinFitter::StKinFitter(Param jetParam,
                         Param lepParam,
                         Param metParam,
                         int maxNrIter,
                         double maxDeltaS,
                         double maxF,
                         const std::vector<int>& constraints)
    : TopKinFitter(maxNrIter, maxDeltaS, maxF),
      jetParam_(jetParam),
      lepParam_(lepParam),
      metParam_(metParam),
      constraints_(constraints) {
  setupFitter();
}

StKinFitter::~StKinFitter() = default;

StEvtSolution StKinFitter::addKinFitInfo(StEvtSolution* asol) {
  StEvtSolution fitsol(*asol);

  TMatrixD m1(3, 3), m2(3, 3);
  TMatrixD m1b(4, 4), m2b(4, 4);
  TMatrixD m3(3, 3), m4(3, 3);
  m1.Zero();
  m2.Zero();
  m1b.Zero();
  m2b.Zero();
  m3.Zero();
  m4.Zero();

  TLorentzVector bottomVec(
      fitsol.getBottom().px(), fitsol.getBottom().py(), fitsol.getBottom().pz(), fitsol.getBottom().energy());
  TLorentzVector lightVec(
      fitsol.getLight().px(), fitsol.getLight().py(), fitsol.getLight().pz(), fitsol.getLight().energy());
  TLorentzVector leplVec;
  if (fitsol.getDecay() == "electron")
    leplVec = TLorentzVector(
        fitsol.getElectron().px(), fitsol.getElectron().py(), fitsol.getElectron().pz(), fitsol.getElectron().energy());
  if (fitsol.getDecay() == "muon")
    leplVec =
        TLorentzVector(fitsol.getMuon().px(), fitsol.getMuon().py(), fitsol.getMuon().pz(), fitsol.getMuon().energy());
  TLorentzVector lepnVec(fitsol.getNeutrino().px(), fitsol.getNeutrino().py(), 0, fitsol.getNeutrino().et());

  // jet resolutions
  {
    //FIXME this dirty hack needs a clean solution soon!
    double pt = fitsol.getBottom().pt();
    double eta = fitsol.getBottom().eta();
    res::HelperJet jetRes;
    if (jetParam_ == kEMom) {
      m1b(0, 0) = pow(jetRes.pt(pt, eta, res::HelperJet::kB), 2);
      m1b(1, 1) = pow(jetRes.pt(pt, eta, res::HelperJet::kB), 2);
      m1b(2, 2) = pow(jetRes.pt(pt, eta, res::HelperJet::kB), 2);
      m1b(3, 3) = pow(jetRes.pt(pt, eta, res::HelperJet::kB), 2);
      m2b(0, 0) = pow(jetRes.pt(pt, eta, res::HelperJet::kUds), 2);
      m2b(1, 1) = pow(jetRes.pt(pt, eta, res::HelperJet::kUds), 2);
      m2b(2, 2) = pow(jetRes.pt(pt, eta, res::HelperJet::kUds), 2);
      m2b(3, 3) = pow(jetRes.pt(pt, eta, res::HelperJet::kUds), 2);
    } else if (jetParam_ == kEtEtaPhi) {
      m1(0, 0) = pow(jetRes.pt(pt, eta, res::HelperJet::kB), 2);
      m1(1, 1) = pow(jetRes.eta(pt, eta, res::HelperJet::kB), 2);
      m1(2, 2) = pow(jetRes.phi(pt, eta, res::HelperJet::kB), 2);
      m2(0, 0) = pow(jetRes.pt(pt, eta, res::HelperJet::kUds), 2);
      m2(1, 1) = pow(jetRes.eta(pt, eta, res::HelperJet::kUds), 2);
      m2(2, 2) = pow(jetRes.phi(pt, eta, res::HelperJet::kUds), 2);
    } else if (jetParam_ == kEtThetaPhi) {
      m1(0, 0) = pow(jetRes.pt(pt, eta, res::HelperJet::kB), 2);
      m1(1, 1) = pow(jetRes.eta(pt, eta, res::HelperJet::kB), 2);
      m1(2, 2) = pow(jetRes.phi(pt, eta, res::HelperJet::kB), 2);
      m2(0, 0) = pow(jetRes.pt(pt, eta, res::HelperJet::kUds), 2);
      m2(1, 1) = pow(jetRes.eta(pt, eta, res::HelperJet::kUds), 2);
      m2(2, 2) = pow(jetRes.phi(pt, eta, res::HelperJet::kUds), 2);
    }
  }
  // lepton resolutions
  {
    //FIXME this dirty hack needs a clean solution soon!
    double pt = fitsol.getElectron().pt();
    double eta = fitsol.getElectron().eta();
    res::HelperMuon muonRes;
    res::HelperElectron elecRes;
    if (lepParam_ == kEMom) {
      if (fitsol.getDecay() == "electron") {
        m3(0, 0) = pow(elecRes.pt(pt, eta), 2);
        m3(1, 1) = pow(elecRes.pt(pt, eta), 2);
        m3(2, 2) = pow(elecRes.pt(pt, eta), 2);
      }
      if (fitsol.getDecay() == "muon") {
        m3(0, 0) = pow(muonRes.pt(pt, eta), 2);
        m3(1, 1) = pow(muonRes.pt(pt, eta), 2);
        m3(2, 2) = pow(muonRes.pt(pt, eta), 2);
      }
    } else if (lepParam_ == kEtEtaPhi) {
      if (fitsol.getDecay() == "electron") {
        m3(0, 0) = pow(elecRes.pt(pt, eta), 2);
        m3(1, 1) = pow(elecRes.eta(pt, eta), 2);
        m3(2, 2) = pow(elecRes.phi(pt, eta), 2);
      }
      if (fitsol.getDecay() == "muon") {
        m3(0, 0) = pow(muonRes.pt(pt, eta), 2);
        m3(1, 1) = pow(muonRes.eta(pt, eta), 2);
        m3(2, 2) = pow(muonRes.phi(pt, eta), 2);
      }
    } else if (lepParam_ == kEtThetaPhi) {
      if (fitsol.getDecay() == "electron") {
        m3(0, 0) = pow(elecRes.pt(pt, eta), 2);
        m3(1, 1) = pow(elecRes.eta(pt, eta), 2);
        m3(2, 2) = pow(elecRes.phi(pt, eta), 2);
      }
      if (fitsol.getDecay() == "muon") {
        m3(0, 0) = pow(muonRes.pt(pt, eta), 2);
        m3(1, 1) = pow(muonRes.eta(pt, eta), 2);
        m3(2, 2) = pow(muonRes.phi(pt, eta), 2);
      }
    }
  }
  // neutrino resolutions
  {
    //FIXME this dirty hack needs a clean solution soon!
    double met = fitsol.getNeutrino().pt();
    res::HelperMET metRes;
    if (metParam_ == kEMom) {
      m4(0, 0) = pow(metRes.met(met), 2);
      m4(1, 1) = pow(9999., 2);
      m4(2, 2) = pow(metRes.met(met), 2);
    } else if (metParam_ == kEtEtaPhi) {
      m4(0, 0) = pow(metRes.met(met), 2);
      m4(1, 1) = pow(9999., 2);
      m4(2, 2) = pow(metRes.phi(met), 2);
    } else if (metParam_ == kEtThetaPhi) {
      m4(0, 0) = pow(metRes.met(met), 2);
      m4(1, 1) = pow(9999., 2);
      m4(2, 2) = pow(metRes.phi(met), 2);
    }
  }
  // set the kinematics of the objects to be fitted
  fitBottom_->setIni4Vec(&bottomVec);
  fitLight_->setIni4Vec(&lightVec);
  fitLepton_->setIni4Vec(&leplVec);
  fitNeutrino_->setIni4Vec(&lepnVec);
  if (jetParam_ == kEMom) {
    fitBottom_->setCovMatrix(&m1b);
    fitLight_->setCovMatrix(&m2b);
  } else {
    fitBottom_->setCovMatrix(&m1);
    fitLight_->setCovMatrix(&m2);
  }
  fitLepton_->setCovMatrix(&m3);
  fitNeutrino_->setCovMatrix(&m4);

  // perform the fit!
  fitter_->fit();

  // add fitted information to the solution
  if (fitter_->getStatus() == 0) {
    // read back the jet kinematics and resolutions
    pat::Particle aFitBottom(reco::LeafCandidate(0,
                                                 math::XYZTLorentzVector(fitBottom_->getCurr4Vec()->X(),
                                                                         fitBottom_->getCurr4Vec()->Y(),
                                                                         fitBottom_->getCurr4Vec()->Z(),
                                                                         fitBottom_->getCurr4Vec()->E()),
                                                 math::XYZPoint()));
    pat::Particle aFitLight(reco::LeafCandidate(0,
                                                math::XYZTLorentzVector(fitLight_->getCurr4Vec()->X(),
                                                                        fitLight_->getCurr4Vec()->Y(),
                                                                        fitLight_->getCurr4Vec()->Z(),
                                                                        fitLight_->getCurr4Vec()->E()),
                                                math::XYZPoint()));

    // read back the lepton kinematics and resolutions
    pat::Particle aFitLepton(reco::LeafCandidate(0,
                                                 math::XYZTLorentzVector(fitLepton_->getCurr4Vec()->X(),
                                                                         fitLepton_->getCurr4Vec()->Y(),
                                                                         fitLepton_->getCurr4Vec()->Z(),
                                                                         fitLepton_->getCurr4Vec()->E()),
                                                 math::XYZPoint()));

    // read back the MET kinematics and resolutions
    pat::Particle aFitNeutrino(reco::LeafCandidate(0,
                                                   math::XYZTLorentzVector(fitNeutrino_->getCurr4Vec()->X(),
                                                                           fitNeutrino_->getCurr4Vec()->Y(),
                                                                           fitNeutrino_->getCurr4Vec()->Z(),
                                                                           fitNeutrino_->getCurr4Vec()->E()),
                                                   math::XYZPoint()));

    // finally fill the fitted particles
    fitsol.setFitBottom(aFitBottom);
    fitsol.setFitLight(aFitLight);
    fitsol.setFitLepton(aFitLepton);
    fitsol.setFitNeutrino(aFitNeutrino);

    // store the fit's chi2 probability
    fitsol.setChi2Prob(fitProb());
  }

  return fitsol;
}

//
// Setup the fitter
//
void StKinFitter::setupFitter() {
  // FIXME: replace by messagelogger!!!

  std::cout << std::endl << std::endl << "+++++++++++ KINFIT SETUP ++++++++++++" << std::endl;
  std::cout << "  jet parametrisation:     " << param(jetParam_) << std::endl;
  std::cout << "  lepton parametrisation:  " << param(lepParam_) << std::endl;
  std::cout << "  met parametrisation:     " << param(metParam_) << std::endl;
  std::cout << "  constraints:  " << std::endl;
  for (unsigned int i = 0; i < constraints_.size(); i++) {
    if (constraints_[i] == 1)
      std::cout << "    - hadronic W-mass" << std::endl;
    if (constraints_[i] == 2)
      std::cout << "    - leptonic W-mass" << std::endl;
    if (constraints_[i] == 3)
      std::cout << "    - hadronic top mass" << std::endl;
    if (constraints_[i] == 4)
      std::cout << "    - leptonic top mass" << std::endl;
    if (constraints_[i] == 5)
      std::cout << "    - neutrino mass" << std::endl;
  }
  std::cout << "Max. number of iterations: " << maxNrIter_ << std::endl;
  std::cout << "Max. deltaS: " << maxDeltaS_ << std::endl;
  std::cout << "Max. F: " << maxF_ << std::endl;
  std::cout << "++++++++++++++++++++++++++++++++++++++++++++" << std::endl << std::endl << std::endl;

  TMatrixD empty3(3, 3);
  TMatrixD empty4(4, 4);
  if (jetParam_ == kEMom) {
    fitBottom_ = std::make_unique<TFitParticleEMomDev>("Jet1", "Jet1", nullptr, &empty4);
    fitLight_ = std::make_unique<TFitParticleEMomDev>("Jet2", "Jet2", nullptr, &empty4);
  } else if (jetParam_ == kEtEtaPhi) {
    fitBottom_ = std::make_unique<TFitParticleEtEtaPhi>("Jet1", "Jet1", nullptr, &empty3);
    fitLight_ = std::make_unique<TFitParticleEtEtaPhi>("Jet2", "Jet2", nullptr, &empty3);
  } else if (jetParam_ == kEtThetaPhi) {
    fitBottom_ = std::make_unique<TFitParticleEtThetaPhi>("Jet1", "Jet1", nullptr, &empty3);
    fitLight_ = std::make_unique<TFitParticleEtThetaPhi>("Jet2", "Jet2", nullptr, &empty3);
  }
  if (lepParam_ == kEMom) {
    fitLepton_ = std::make_unique<TFitParticleEScaledMomDev>("Lepton", "Lepton", nullptr, &empty3);
  } else if (lepParam_ == kEtEtaPhi) {
    fitLepton_ = std::make_unique<TFitParticleEtEtaPhi>("Lepton", "Lepton", nullptr, &empty3);
  } else if (lepParam_ == kEtThetaPhi) {
    fitLepton_ = std::make_unique<TFitParticleEtThetaPhi>("Lepton", "Lepton", nullptr, &empty3);
  }
  if (metParam_ == kEMom) {
    fitNeutrino_ = std::make_unique<TFitParticleEScaledMomDev>("Neutrino", "Neutrino", nullptr, &empty3);
  } else if (metParam_ == kEtEtaPhi) {
    fitNeutrino_ = std::make_unique<TFitParticleEtEtaPhi>("Neutrino", "Neutrino", nullptr, &empty3);
  } else if (metParam_ == kEtThetaPhi) {
    fitNeutrino_ = std::make_unique<TFitParticleEtThetaPhi>("Neutrino", "Neutrino", nullptr, &empty3);
  }

  cons1_ = std::make_unique<TFitConstraintM>("MassConstraint", "Mass-Constraint", nullptr, nullptr, mW_);
  cons1_->addParticles1(fitLepton_.get(), fitNeutrino_.get());
  cons2_ = std::make_unique<TFitConstraintM>("MassConstraint", "Mass-Constraint", nullptr, nullptr, mTop_);
  cons2_->addParticles1(fitLepton_.get(), fitNeutrino_.get(), fitBottom_.get());
  cons3_ = std::make_unique<TFitConstraintM>("MassConstraint", "Mass-Constraint", nullptr, nullptr, 0.);
  cons3_->addParticle1(fitNeutrino_.get());

  for (unsigned int i = 0; i < constraints_.size(); i++) {
    if (constraints_[i] == 1)
      fitter_->addConstraint(cons1_.get());
    if (constraints_[i] == 2)
      fitter_->addConstraint(cons2_.get());
    if (constraints_[i] == 3)
      fitter_->addConstraint(cons3_.get());
  }
  fitter_->addMeasParticle(fitBottom_.get());
  fitter_->addMeasParticle(fitLight_.get());
  fitter_->addMeasParticle(fitLepton_.get());
  fitter_->addMeasParticle(fitNeutrino_.get());
}