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Public Member Functions | |
| FSRWeightProducer (const edm::ParameterSet &) | |
| ~FSRWeightProducer () | |
Private Member Functions | |
| double | alphaRatio (double) |
| virtual void | beginJob () |
| virtual void | endJob () |
| virtual void | produce (edm::Event &, const edm::EventSetup &) |
Private Attributes | |
| edm::InputTag | genTag_ |
Definition at line 20 of file FSRWeightProducer.cc.
| FSRWeightProducer::FSRWeightProducer | ( | const edm::ParameterSet & | pset | ) | [explicit] |
Definition at line 37 of file FSRWeightProducer.cc.
References genTag_, and edm::ParameterSet::getUntrackedParameter().
{
genTag_ = pset.getUntrackedParameter<edm::InputTag> ("GenTag", edm::InputTag("genParticles"));
produces<double>();
}
| FSRWeightProducer::~FSRWeightProducer | ( | ) |
Definition at line 44 of file FSRWeightProducer.cc.
{}
| double FSRWeightProducer::alphaRatio | ( | double | pt | ) | [private] |
Definition at line 126 of file FSRWeightProducer.cc.
References funct::A, funct::C, funct::log(), and M_PI.
Referenced by produce().
{
double pigaga = 0.;
// Leptonic contribution (just one loop, precise at < 0.3% level)
const double alphapi = 1/137.036/M_PI;
const double mass_e = 0.0005;
const double mass_mu = 0.106;
const double mass_tau = 1.777;
const double mass_Z = 91.2;
if (pt>mass_e) pigaga += alphapi * (2*log(pt/mass_e)/3.-5./9.);
if (pt>mass_mu) pigaga += alphapi * (2*log(pt/mass_mu)/3.-5./9.);
if (pt>mass_tau) pigaga += alphapi * (2*log(pt/mass_tau)/3.-5./9.);
// Hadronic vaccum contribution
// Using simple effective parametrization from Physics Letters B 513 (2001) 46.
// Top contribution neglected
double A = 0.;
double B = 0.;
double C = 0.;
if (pt<0.7) {
A = 0.0; B = 0.0023092; C = 3.9925370;
} else if (pt<2.0) {
A = 0.0; B = 0.0022333; C = 4.2191779;
} else if (pt<4.0) {
A = 0.0; B = 0.0024402; C = 3.2496684;
} else if (pt<10.0) {
A = 0.0; B = 0.0027340; C = 2.0995092;
} else if (pt<mass_Z) {
A = 0.0010485; B = 0.0029431; C = 1.0;
} else if (pt<10000.) {
A = 0.0012234; B = 0.0029237; C = 1.0;
} else {
A = 0.0016894; B = 0.0028984; C = 1.0;
}
pigaga += A + B*log(1.+C*pt*pt);
// Done
return 1./(1.-pigaga);
}
| void FSRWeightProducer::beginJob | ( | void | ) | [private, virtual] |
| void FSRWeightProducer::endJob | ( | void | ) | [private, virtual] |
| void FSRWeightProducer::produce | ( | edm::Event & | iEvent, |
| const edm::EventSetup & | |||
| ) | [private, virtual] |
Implements edm::EDProducer.
Definition at line 53 of file FSRWeightProducer.cc.
References abs, alphaRatio(), funct::cos(), reco::CompositeRefCandidateT< D >::daughter(), reco::CompositeRefCandidateT< D >::daughterRef(), delta, reco::Candidate::energy(), reco::LeafCandidate::energy(), genParticleCandidates2GenParticles_cfi::genParticles, genTag_, edm::Event::getByLabel(), i, edm::EventBase::isRealData(), j, reco::Candidate::mass(), reco::LeafCandidate::mass(), reco::CompositeRefCandidateT< D >::mother(), reco::CompositeRefCandidateT< D >::numberOfDaughters(), reco::CompositeRefCandidateT< D >::numberOfMothers(), reco::LeafCandidate::pdgId(), reco::Candidate::pdgId(), reco::LeafCandidate::phi(), reco::Candidate::phi(), funct::pow(), edm::Event::put(), funct::sin(), mathSSE::sqrt(), reco::LeafCandidate::status(), reco::LeafCandidate::theta(), reco::Candidate::theta(), and CommonMethods::weight().
{
if (iEvent.isRealData()) return;
edm::Handle<reco::GenParticleCollection> genParticles;
iEvent.getByLabel(genTag_, genParticles);
std::auto_ptr<double> weight (new double);
// Set a default weight to start with
(*weight) = 1.;
unsigned int gensize = genParticles->size();
for (unsigned int i = 0; i<gensize; ++i) {
const reco::GenParticle& lepton = (*genParticles)[i];
if (lepton.status()!=3) continue;
int leptonId = lepton.pdgId();
if (abs(leptonId)!=11 && abs(leptonId)!=13 && abs(leptonId)!=15) continue;
if (lepton.numberOfMothers()!=1) continue;
const reco::Candidate * boson = lepton.mother();
int bosonId = abs(boson->pdgId());
if (bosonId!=23 && bosonId!=24) continue;
double bosonMass = boson->mass();
double leptonMass = lepton.mass();
double leptonEnergy = lepton.energy();
double cosLeptonTheta = cos(lepton.theta());
double sinLeptonTheta = sin(lepton.theta());
double leptonPhi = lepton.phi();
int trueKey = i;
if (lepton.numberOfDaughters()==0) {
continue;
} else if (lepton.numberOfDaughters()==1) {
int otherleptonKey = lepton.daughterRef(0).key();
const reco::GenParticle& otherlepton = (*genParticles)[otherleptonKey];
if (otherlepton.pdgId()!=leptonId) continue;
if (otherlepton.numberOfDaughters()<=1) continue;
trueKey = otherleptonKey;
}
const reco::GenParticle& trueLepton = (*genParticles)[trueKey];
unsigned int nDaughters = trueLepton.numberOfDaughters();
for (unsigned int j = 0; j<nDaughters; ++j) {
const reco::Candidate * photon = trueLepton.daughter(j);
if (photon->pdgId()!=22) continue;
double photonEnergy = photon->energy();
double cosPhotonTheta = cos(photon->theta());
double sinPhotonTheta = sin(photon->theta());
double photonPhi = photon->phi();
double costheta = sinLeptonTheta*sinPhotonTheta*cos(leptonPhi-photonPhi)
+ cosLeptonTheta*cosPhotonTheta;
// Missing O(alpha) terms in soft-collinear approach
// Only for W, from hep-ph/0303260
if (bosonId==24) {
double betaLepton = sqrt(1-pow(leptonMass/leptonEnergy,2));
double delta = - 8*photonEnergy *(1-betaLepton*costheta)
/ pow(bosonMass,3)
/ (1-pow(leptonMass/bosonMass,2))
/ (4-pow(leptonMass/bosonMass,2))
* leptonEnergy * (pow(leptonMass,2)/bosonMass+2*photonEnergy);
(*weight) *= (1 + delta);
}
// Missing NLO QED orders in QED parton shower approach
// Change coupling scale from 0 to kT to estimate this effect
(*weight) *= alphaRatio(photonEnergy*sqrt(1-pow(costheta,2)));
}
}
iEvent.put(weight);
}
edm::InputTag FSRWeightProducer::genTag_ [private] |
Definition at line 31 of file FSRWeightProducer.cc.
Referenced by FSRWeightProducer(), and produce().
1.7.3