GenSpecificAlgo Class Reference

#include <GenSpecificAlgo.h>

Public Types
typedef math::XYZTLorentzVector	LorentzVector
typedef std::vector< const reco::Candidate * >	ParticleCollection
typedef math::XYZPoint	Point

Public Member Functions
reco::GenMET	addInfo (edm::Handle< edm::View< reco::Candidate > > particles, CommonMETData *met, double globalThreshold, bool onlyFiducial=false, bool usePt=false)
	Make GenMET. Assumes MET is made from MCCandidates. More...

Detailed Description

Adds generator level HEPMC specific information to MET base class Author: R. Cavanaugh (taken from F.Ratnikov, UMd) 6 June, 2006

Definition at line 13 of file GenSpecificAlgo.h.

Member Typedef Documentation

typedef math::XYZTLorentzVector GenSpecificAlgo::LorentzVector

Definition at line 16 of file GenSpecificAlgo.h.

typedef std::vector<const reco::Candidate*> GenSpecificAlgo::ParticleCollection

Definition at line 18 of file GenSpecificAlgo.h.

typedef math::XYZPoint GenSpecificAlgo::Point

Definition at line 17 of file GenSpecificAlgo.h.

Member Function Documentation

reco::GenMET GenSpecificAlgo::addInfo	(	edm::Handle< edm::View< reco::Candidate > >	particles,
		CommonMETData *	met,
		double	globalThreshold,
		bool	onlyFiducial = false,
		bool	usePt = false
	)

Make GenMET. Assumes MET is made from MCCandidates.

Definition at line 17 of file GenSpecificAlgo.cc.

References begin, SpecificGenMETData::ChargedEMEtFraction, SpecificGenMETData::ChargedHadEtFraction, funct::cos(), alignCSCRings::e, end, SpecificGenMETData::InvisibleEtFraction, CommonMETData::met, CommonMETData::mex, CommonMETData::mey, CommonMETData::mez, SpecificGenMETData::MuonEtFraction, SpecificGenMETData::NeutralEMEtFraction, SpecificGenMETData::NeutralHadEtFraction, p4, benchmark_cfg::pdgId, phi, CommonMETData::phi, funct::sin(), timingPdfMaker::specific, mathSSE::sqrt(), CommonMETData::sumet, and theta().

Referenced by cms::METProducer::produce().

{ 

  double sum_et = 0.0;
  double sum_ex = 0.0;
  double sum_ey = 0.0;
  double sum_ez = 0.0;

  // Instantiate the container to hold the calorimeter specific information
  SpecificGenMETData specific = SpecificGenMETData();

  // Initialise the container 
  specific.NeutralEMEtFraction     = 0.0;
  specific.NeutralHadEtFraction    = 0.0;
  specific.ChargedEMEtFraction     = 0.0;
  specific.ChargedHadEtFraction    = 0.0;
  specific.MuonEtFraction          = 0.0;
  specific.InvisibleEtFraction     = 0.0;

  // tally Et contribution from undecayed genparticles that don't fall into the following classifications (for normalization purposes)
  double Et_unclassified = 0.;
  
  for( edm::View<reco::Candidate>::const_iterator iParticle = (particles.product())->begin() ; iParticle != (particles.product())->end() ; iParticle++ )
    {

  
      //  if "onlyFiducial" is true take only particles within fudical volume AND use pT instead of et if "usePt" is true
      if(!onlyFiducial || (onlyFiducial && TMath::Abs(iParticle->eta()) < 5.0)) // 
    {
      if(!usePt)
        {
          if( iParticle->et() > globalThreshold  )
        {
          double phi   = iParticle->phi();
          double theta = iParticle->theta();
          double e     = iParticle->energy();
          double et    = e*sin(theta);
          sum_ez += e*cos(theta);
          sum_et += et;
          sum_ex += et*cos(phi);
          sum_ey += et*sin(phi);
        }
        }
      
      if(usePt)
        {
          if( iParticle->pt() > globalThreshold  )
        {
          double phi   = iParticle->phi();
          double et    = iParticle->pt(); // change et-->pt
          sum_ez += iParticle->pz(); // change ez-->pz
          sum_et += et;
          sum_ex += et*cos(phi);
          sum_ey += et*sin(phi);
        }
        }
    }

      

      int pdgId = TMath::Abs( iParticle->pdgId() ) ;
      
      switch (pdgId) {

      case 22 : // photon
            if(usePt){
          specific.NeutralEMEtFraction += iParticle->pt();
            }else{
          specific.NeutralEMEtFraction += iParticle->et();
        }
        break;
      case 11 : // e
        if(usePt){
        specific.ChargedEMEtFraction += iParticle->pt();
            }else{
            specific.ChargedEMEtFraction += iParticle->et();
        }
        break;
      case 130 : // K_long
      case 310 : // K_short
      case 3122: // Lambda
      case 2112: // n
      case 3222: // Neutral Cascade
            if(usePt){
          specific.NeutralHadEtFraction += iParticle->pt();
            }else{
          specific.NeutralHadEtFraction += iParticle->et();
        }
        break;
      case 211 : // pi
      case 321 : // K+/K-
      case 2212: // p
      case 3312: // Cascade -
      case 3112: // Sigma -
      case 3322: // Sigma + 
      case 3334: // Omega - 
            if(usePt){
          specific.ChargedHadEtFraction += iParticle->pt();
            }else{
          specific.ChargedHadEtFraction += iParticle->et();
            }
        break;
      case 13 : //muon
            if(usePt){
          specific.MuonEtFraction += iParticle->pt();
            }else{
              specific.MuonEtFraction += iParticle->et();
        }
        break;
      case 12 : // e_nu
      case 14 : // mu_nu
      case 16 : // tau_nu
      case 1000022 : // Neutral ~Chi_0 
      case 1000012 :  // LH ~e_nu  
      case 1000014 :  // LH ~mu_nu
      case 1000016 :  // LH ~tau_nu
      case 2000012 :  // RH ~e_nu  
      case 2000014 :  // RH ~mu_nu
      case 2000016 :  // RH ~tau_nu
      case 39 :       //  G
      case 1000039 :  // ~G
      case 5100039 :  // KK G
      case 4000012 :  // excited e_nu
      case 4000014 :  // excited mu_nu 
      case 4000016 :  // excited tau_nu 
      case 9900012 :  // Maj e_nu
      case 9900014 :  // Maj mu_nu 
      case 9900016 :  // Maj tau_nu 
            if(usePt){
        specific.InvisibleEtFraction   += iParticle->pt();
            }else {
          specific.InvisibleEtFraction   += iParticle->et();
            }
        break;
      default : 
            if(usePt){
        Et_unclassified += iParticle->pt();
            }else{
          Et_unclassified += iParticle->et(); 
        }
        //  cout << "PdgId : "<< iParticle->pdgId() << "    " << iParticle->status() << "  does not fall into a category " << endl;
     
     
      }
    }
  
  met->mex   = -sum_ex;
  met->mey   = -sum_ey;
  met->mez   = -sum_ez;
  met->met   = sqrt( sum_ex*sum_ex + sum_ey*sum_ey );
  // cout << "MET = " << met->met << endl;
  met->sumet = sum_et;
  met->phi   = atan2( -sum_ey, -sum_ex );

  double Et_Total = specific.NeutralEMEtFraction + specific.NeutralHadEtFraction + specific.ChargedEMEtFraction + 
    specific.ChargedHadEtFraction + specific.MuonEtFraction + specific.InvisibleEtFraction + Et_unclassified;
  
  //Normalize
  if( Et_Total ) 
    {
      specific.NeutralEMEtFraction /= Et_Total;
      specific.NeutralHadEtFraction /= Et_Total;
      specific.ChargedEMEtFraction /= Et_Total;
      specific.ChargedHadEtFraction /= Et_Total;
      specific.MuonEtFraction /= Et_Total;
      specific.InvisibleEtFraction /= Et_Total;
    }

  // Instantiate containers for the MET candidate and initialise them with
  // the MET information in "met" (of type CommonMETData)
  const LorentzVector p4( met->mex, met->mey, met->mez, met->met );
  const Point vtx( 0.0, 0.0, 0.0 );
  // Create and return an object of type GenMET, which is a MET object with 
  // the extra calorimeter specfic information added
  GenMET specificmet( specific, met->sumet, p4, vtx );
  return specificmet;
}