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Conversion.cc

Go to the documentation of this file.

#include "DataFormats/EgammaCandidates/interface/Conversion.h"
#include "DataFormats/TrackReco/interface/Track.h" 
#include "DataFormats/CaloRecHit/interface/CaloCluster.h" 


using namespace reco;

Conversion::Conversion(  const reco::CaloClusterPtrVector sc, 
                         const std::vector<reco::TrackRef> tr, 
                         const std::vector<math::XYZPoint> trackPositionAtEcal, 
                         const reco::Vertex  & convVtx,
                         const std::vector<reco::CaloClusterPtr> & matchingBC):  
                         

  caloCluster_(sc), tracks_(tr), 
  thePositionAtEcal_(trackPositionAtEcal), 
  theConversionVertex_(convVtx), 
  theMatchingBCs_(matchingBC)  {
  
}


Conversion::~Conversion() { }


Conversion * Conversion::clone() const { 
  return new Conversion( * this ); 
}

reco::CaloClusterPtrVector Conversion::caloCluster() const {
  return caloCluster_;
}



std::vector<reco::TrackRef>  Conversion::tracks() const { 
   return tracks_;
}



bool Conversion::isConverted() const {
  
  if ( this->nTracks() > 0) 
    return true;
  else
    return false;
}


double  Conversion::zOfPrimaryVertexFromTracks()  const  {
  double theZOfPrimaryVertexFromTracks=-9999.;

  float pTrkMag=this->pairMomentum().mag();
  
  if ( pTrkMag>0 && sqrt(this->conversionVertex().position().perp2()) !=0 ) {
    float theta=acos(this->pairMomentum().z() /pTrkMag);
    theZOfPrimaryVertexFromTracks = this->conversionVertex().position().z()  - sqrt(this->conversionVertex().position().perp2())*(1./tan(theta));
    
  }

  return  theZOfPrimaryVertexFromTracks;

}


double Conversion::pairInvariantMass() const{
  double invMass=-99.;
  const float mElec= 0.000511;
  if ( nTracks()==2 ) {
    double px= tracks()[0]->innerMomentum().x() + tracks()[1]->innerMomentum().x();
    double py= tracks()[0]->innerMomentum().y() + tracks()[1]->innerMomentum().y();
    double pz= tracks()[0]->innerMomentum().z() + tracks()[1]->innerMomentum().z();
    double mom1=tracks()[0]->innerMomentum().Mag2() ;
    double mom2=tracks()[1]->innerMomentum().Mag2() ;
    double e = sqrt( mom1+ mElec*mElec ) + sqrt( mom2 + mElec*mElec );
    invMass= ( e*e - px*px -py*py - pz*pz);
  }
  
  return invMass;
}

double  Conversion::pairCotThetaSeparation() const  {
  double dCotTheta=-99.;
  
  if ( nTracks()==2 ) {
    double theta1=tracks()[0]->innerMomentum().Theta();
    double theta2=tracks()[1]->innerMomentum().Theta();
    dCotTheta =  1./tan(theta1) - 1./tan(theta2) ;
  }

  return dCotTheta;

}

GlobalVector  Conversion::pairMomentum() const  {

  double px=0.;
  double py=0.;
  double pz=0.;
  
  if ( nTracks()==2 ) {
    px= tracks()[0]->innerMomentum().x() + tracks()[1]->innerMomentum().x();
    py= tracks()[0]->innerMomentum().y() + tracks()[1]->innerMomentum().y();
    pz= tracks()[0]->innerMomentum().z() + tracks()[1]->innerMomentum().z();

  } else if (  nTracks()==1 ) {
    px= tracks()[0]->innerMomentum().x() ;
    py= tracks()[0]->innerMomentum().y() ;
    pz= tracks()[0]->innerMomentum().z() ;
  }

  GlobalVector momTracks(px,py,pz);
  return momTracks;


}




double  Conversion::EoverP() const  {


  double ep=-99.;

  if ( nTracks() > 0  ) {
    unsigned int size= this->caloCluster().size();
    float etot=0.;
    for ( unsigned int i=0; i<size; i++) {
      etot+= caloCluster()[i]->energy();
    }
    ep= etot/this->pairMomentum().mag();
  }



  return ep;  

}

 

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