Plugin to shift the jet energy scale and recalculate the MET accordingly. More...

Inheritance diagram for JetEnergyShift:

Public Member Functions
	JetEnergyShift (const edm::ParameterSet &)
	default constructor
	~JetEnergyShift ()
	default destructor
Private Member Functions
virtual void	produce (edm::Event &, const edm::EventSetup &)
	rescale jet energy and recalculated MET
Private Attributes
edm::InputTag	inputJets_
	jet input collection
edm::InputTag	inputMETs_
	met input collection
double	jetEMLimitForMET_
	limit on the emf of the jet for Type1 MET corrections
double	jetPTThresholdForMET_
	threshold on (raw!) jet pt for Type1 MET corrections
std::string	outputJets_
	jet output collection
std::string	outputMETs_
	MET output collection.
double	scaleFactor_
	scale factor for the rescaling

Detailed Description

Plugin to shift the jet energy scale and recalculate the MET accordingly.

Plugin to shift the jet energy scale and recalculate the MET accordingly. The module mimics the assumption that the jet energy scale (JES) has been estimated wrong by a factor of _scaleFactor_, corresponding to a L2L3 corrected jet. The p4 of the patJet is beeing rescaled. All other patJet properties stay the same. The MET is recalculated taking the shifted JES into account for the Type1 MET correction. For the patMET the rescaled sumET and the p4 are stored. The different correction levels are lost for the new collection. The module has the following parameters:

inputJets : input collection for MET (expecting patMET). inputMETs : input collection for jets (expecting patJets). scaleFactor : scale factor to which to shift the JES. jetPTThresholdForMET : pt threshold for (uncorrected!) jets considered for Type1 MET corrections. jetEMLimitForMET : limit in em fraction for Type1 MET correction.

For expected parameters for _jetPTThresholdForMET_ and _jetEMLimitForMET_ have a look at: JetMETCorrections/Type1MET/python/MetType1Corrections_cff.py. Two output collections are written to file with instance label corresponding to the input label of the jet and met input collections.

Definition at line 31 of file JetEnergyShift.cc.

Constructor & Destructor Documentation

JetEnergyShift::JetEnergyShift ( const edm::ParameterSet & cfg ) [explicit]

default constructor

Definition at line 64 of file JetEnergyShift.cc.

References inputJets_, inputMETs_, edm::InputTag::label(), outputJets_, and outputMETs_.

                                                        :
  inputJets_           (cfg.getParameter<edm::InputTag>("inputJets"           )),
  inputMETs_           (cfg.getParameter<edm::InputTag>("inputMETs"           )),
  scaleFactor_         (cfg.getParameter<double>       ("scaleFactor"         )),
  jetPTThresholdForMET_(cfg.getParameter<double>       ("jetPTThresholdForMET")),
  jetEMLimitForMET_    (cfg.getParameter<double>       ("jetEMLimitForMET"    ))
{
  // use label of input to create label for output
  outputJets_ = inputJets_.label();
  outputMETs_ = inputMETs_.label();
  // register products
  produces<std::vector<pat::Jet> >(outputJets_);
  produces<std::vector<pat::MET> >(outputMETs_);
}

JetEnergyShift::~JetEnergyShift ( ) [inline]

default destructor

Definition at line 37 of file JetEnergyShift.cc.

{};

Member Function Documentation

void JetEnergyShift::produce	(	edm::Event &	event,
		const edm::EventSetup &	setup
	)		`[private, virtual]`

rescale jet energy and recalculated MET

Implements edm::EDProducer.

Definition at line 80 of file JetEnergyShift.cc.

References reco::LeafCandidate::et(), inputJets_, inputMETs_, metsig::jet, jetEMLimitForMET_, jetPTThresholdForMET_, analyzePatCleaning_cfg::jets, CaloMET_cfi::met, outputJets_, outputMETs_, reco::LeafCandidate::px(), reco::LeafCandidate::py(), reco::Jet::scaleEnergy(), scaleFactor_, mathSSE::sqrt(), and reco::MET::sumEt().

{
  edm::Handle<std::vector<pat::Jet> > jets;
  event.getByLabel(inputJets_, jets);

  edm::Handle<std::vector<pat::MET> > mets;
  event.getByLabel(inputMETs_, mets);
  
  std::auto_ptr<std::vector<pat::Jet> > pJets(new std::vector<pat::Jet>);
  std::auto_ptr<std::vector<pat::MET> > pMETs(new std::vector<pat::MET>);

  double dPx    = 0.;
  double dPy    = 0.;
  double dSumEt = 0.;

  for(std::vector<pat::Jet>::const_iterator jet = jets->begin(); jet != jets->end(); ++jet) {
    pat::Jet scaledJet = *jet;
    scaledJet.scaleEnergy( scaleFactor_ );
    pJets->push_back( scaledJet );
    // consider jet scale shift only if the raw jet pt and emf 
    // is above the thresholds given in the module definition
    if(jet->correctedJet("raw").pt() > jetPTThresholdForMET_
       && jet->emEnergyFraction() < jetEMLimitForMET_) {
      dPx    += scaledJet.px() - jet->px();
      dPy    += scaledJet.py() - jet->py();
      dSumEt += scaledJet.et() - jet->et();
    }
  }

  // scale MET accordingly
  pat::MET met = *(mets->begin());
  double scaledMETPx = met.px() - dPx;
  double scaledMETPy = met.py() - dPy;
  pat::MET scaledMET(reco::MET(met.sumEt()+dSumEt, reco::MET::LorentzVector(scaledMETPx, scaledMETPy, 0, sqrt(scaledMETPx*scaledMETPx+scaledMETPy*scaledMETPy)), reco::MET::Point(0,0,0)));
  pMETs->push_back( scaledMET );
  event.put(pJets, outputJets_);
  event.put(pMETs, outputMETs_);
}