ISRGammaWeightProducer Class Reference

Inheritance diagram for ISRGammaWeightProducer:

List of all members.

Public Member Functions
virtual void	beginJob ()
virtual void	endJob ()
	ISRGammaWeightProducer (const edm::ParameterSet &)
virtual void	produce (edm::Event &, const edm::EventSetup &)
	~ISRGammaWeightProducer ()
Private Attributes
edm::InputTag	genTag_
std::vector< double >	isrBinEdges_
std::vector< double >	ptWeights_

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Detailed Description

Definition at line 20 of file ISRGammaWeightProducer.cc.

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Constructor & Destructor Documentation

ISRGammaWeightProducer::ISRGammaWeightProducer

(

const edm::ParameterSet &

pset

)

[explicit]

Definition at line 38 of file ISRGammaWeightProducer.cc.

References genTag_, and edm::ParameterSet::getUntrackedParameter().

                                                                          {
      genTag_ = pset.getUntrackedParameter<edm::InputTag> ("GenTag", edm::InputTag("genParticles"));

      produces<double>();
} 

ISRGammaWeightProducer::~ISRGammaWeightProducer

(

)

Definition at line 45 of file ISRGammaWeightProducer.cc.

{}

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Member Function Documentation

void ISRGammaWeightProducer::beginJob

(

void

)

[virtual]

Reimplemented from edm::EDProducer.

Definition at line 48 of file ISRGammaWeightProducer.cc.

{}

void ISRGammaWeightProducer::endJob

(

void

)

[virtual]

Reimplemented from edm::EDProducer.

Definition at line 51 of file ISRGammaWeightProducer.cc.

{}

void ISRGammaWeightProducer::produce	(	edm::Event &	iEvent,
		const edm::EventSetup &
	)		[virtual]

Implements edm::EDProducer.

Definition at line 54 of file ISRGammaWeightProducer.cc.

References abs, reco::CompositeRefCandidateT< D >::daughterRef(), genParticleCandidates2GenParticles_cfi::genParticles, genTag_, edm::Event::getByLabel(), i, edm::EventBase::isRealData(), j, reco::LeafCandidate::mass(), reco::CompositeRefCandidateT< D >::motherRef(), reco::CompositeRefCandidateT< D >::numberOfDaughters(), reco::CompositeRefCandidateT< D >::numberOfMothers(), reco::LeafCandidate::p4(), reco::LeafCandidate::pdgId(), edm::Event::put(), alignCSCRings::s, ntuplemaker::status, reco::LeafCandidate::status(), lumiQTWidget::t, and CommonMethods::weight().

                                                                           {

      if (iEvent.isRealData()) return;

      edm::Handle<reco::GenParticleCollection> genParticles;
      iEvent.getByLabel(genTag_, genParticles);
      unsigned int gensize = genParticles->size();

      std::auto_ptr<double> weight (new double);

      // Set a default weight to start with
      (*weight) = 1.;

      // Find the boson at the hard scattering level
      const reco::GenParticle* boson = 0;
      int parton1Key = -1;
      int parton2Key = -1;
      for (unsigned int i = 0; i<gensize; ++i) {
            const reco::GenParticle& part = (*genParticles)[i];
            int status = abs(part.status());
            if (status!=3) continue;
            if (part.numberOfMothers()!=2) continue;
            int partId = abs(part.pdgId());
            if (status==3 && (partId==23||abs(partId)==24)) {
                  boson = &(*genParticles)[i];
                  parton1Key = part.motherRef(0).key();
                  parton2Key = part.motherRef(1).key();
                  break;
            }
      }
      
      // Consider only photons near the hard-scattering process
      const reco::GenParticle* photon = 0;
      if (boson) {
        for (unsigned int i = 0; i<gensize; ++i) {
            photon = 0;
            const reco::GenParticle& part = (*genParticles)[i];
            int status = abs(part.status());
            if (status!=1) continue;
            int partId = abs(part.pdgId());
            if (partId!=22)  continue;
            if (part.numberOfMothers()!=1) continue;
            int keyM = part.motherRef(0).key();
            const reco::GenParticle* mother = &(*genParticles)[keyM];
            if (mother->status()!=3) continue;
            int mId = mother->pdgId();
            if (abs(mId)>6 && mId!=2212) continue;
            for (unsigned int j=0; j<mother->numberOfDaughters(); ++j){ 
                  int keyD = mother->daughterRef(j).key();
                  if (keyD==parton1Key || keyD==parton2Key) {
                        photon = &part;
                        break;
                  }
            }
            if (photon) break;
        }  
      }

      if (boson && photon) {
            math::XYZTLorentzVector smom = boson->p4() + photon->p4();
            double s = smom.M2();
            double sqrts = smom.M();

            // Go to CM using the boost direction of the boson+photon system
            ROOT::Math::Boost cmboost(smom.BoostToCM());
            math::XYZTLorentzVector photonCM(cmboost(photon->p4()));
            double pcostheta = (  smom.x()*photonCM.x()
                               + smom.y()*photonCM.y()
                               + smom.z()*photonCM.z() ) / smom.P();
            
            // Determine kinematic invariants
            double t = - sqrts * (photonCM.t()-pcostheta);
            double MV = boson->mass();
            double u = MV*MV - s - t;
            (*weight) = 1. - 2*t*u/(s*s+MV*MV*MV*MV);
            //printf(">>>>>>>>> s %f t %f u %f, MV %f, weight = %f\n", s, t, u, MV, (*weight));
      }

      iEvent.put(weight);
}

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Member Data Documentation

edm::InputTag ISRGammaWeightProducer::genTag_ [private]

Definition at line 30 of file ISRGammaWeightProducer.cc.

Referenced by ISRGammaWeightProducer(), and produce().

std::vector<double> ISRGammaWeightProducer::isrBinEdges_ [private]

Definition at line 31 of file ISRGammaWeightProducer.cc.

std::vector<double> ISRGammaWeightProducer::ptWeights_ [private]

Definition at line 32 of file ISRGammaWeightProducer.cc.