Inheritance diagram for LHECOMWeightProducer:

Public Member Functions
	LHECOMWeightProducer (const edm::ParameterSet &)
	~LHECOMWeightProducer ()
Private Member Functions
virtual void	beginJob ()
virtual void	beginRun (edm::Run &run, const edm::EventSetup &es)
virtual void	endJob ()
virtual void	produce (edm::Event &, const edm::EventSetup &)
Private Attributes
std::string	_label
double	_newECMS
double	_origECMS
int	_pdfmember
int	_pdfset
edm::InputTag	lheTag_

Detailed Description

Definition at line 23 of file LHECOMWeightProducer.cc.

Constructor & Destructor Documentation

LHECOMWeightProducer::LHECOMWeightProducer ( const edm::ParameterSet & pset ) [explicit]

Definition at line 56 of file LHECOMWeightProducer.cc.

References _label, and _newECMS.

                                                                      :
 lheTag_(pset.getParameter<edm::InputTag> ("lheSrc")),
 _newECMS(pset.getParameter< double > ("NewECMS"))
{
  std::stringstream labelStr;
  labelStr << "com" << "To" << _newECMS;
  _label = labelStr.str();
  produces<GenEventInfoProduct>(_label);
}

LHECOMWeightProducer::~LHECOMWeightProducer ( )

Definition at line 67 of file LHECOMWeightProducer.cc.

{}

Member Function Documentation

void LHECOMWeightProducer::beginJob ( void ) [private, virtual]

Reimplemented from edm::EDProducer.

Definition at line 86 of file LHECOMWeightProducer.cc.

                                    {
  //LHAPDF::initPDFSet(1,pdfSetName_);
}

void LHECOMWeightProducer::beginRun	(	edm::Run &	run,
		const edm::EventSetup &	es
	)		`[private, virtual]`

Reimplemented from edm::EDProducer.

Definition at line 70 of file LHECOMWeightProducer.cc.

References _newECMS, _origECMS, _pdfmember, _pdfset, Exception, edm::Run::getByLabel(), LHAPDF::initPDFSet(), and lheTag_.

                                                                       {
  using namespace edm;
  Handle<LHERunInfoProduct> lheRun;
  run.getByLabel(lheTag_, lheRun);
  //assumes the same pdf is used for both beams
  _pdfset    = lheRun->heprup().PDFSUP.first;
  _pdfmember = lheRun->heprup().PDFGUP.first;
  _origECMS  = lheRun->heprup().EBMUP.first + lheRun->heprup().EBMUP.second;
  edm::LogInfo("LHECOMWeightProducer") << "PDFSET: " << _pdfset << "; member: " << _pdfmember << "; COM energy: " << _origECMS;
  if ( _newECMS > _origECMS )
      throw cms::Exception("LHECOMWeightProducer") << "You cannot reweight COM energy to a higher than original energy ";
  LHAPDF::initPDFSet(1,_pdfset, _pdfmember);
}

void LHECOMWeightProducer::endJob ( void ) [private, virtual]

Reimplemented from edm::EDProducer.

Definition at line 91 of file LHECOMWeightProducer.cc.

{}

void LHECOMWeightProducer::produce	(	edm::Event &	iEvent,
		const edm::EventSetup &
	)		`[private, virtual]`

Implements edm::EDProducer.

Definition at line 94 of file LHECOMWeightProducer.cc.

References _label, _newECMS, _origECMS, _pdfmember, _pdfset, gather_cfg::cout, edm::Event::getByLabel(), info, edm::EventBase::isRealData(), lheTag_, LogTrace, edm::Event::put(), LHAPDF::usePDFMember(), CommonMethods::weight(), and LHAPDF::xfx().

                                                                         {

      using namespace std;
      bool verbose = false;

      if (iEvent.isRealData()) return;

      edm::Handle<LHEEventProduct> lheevent;
      iEvent.getByLabel(lheTag_, lheevent);

      float Q = lheevent->hepeup().SCALUP;

      int id1        = lheevent->hepeup().IDUP[0];
      double x1      = fabs(lheevent->hepeup().PUP[0][2]/(_origECMS/2));
      double x1prime = fabs(lheevent->hepeup().PUP[0][2]/(_newECMS/2));

      int id2        = lheevent->hepeup().IDUP[1];
      double x2      = fabs(lheevent->hepeup().PUP[1][2]/(_origECMS/2));
      double x2prime = fabs(lheevent->hepeup().PUP[1][2]/(_newECMS/2));

      LogTrace("LHECOMWeightProducer") << "*******LHECOMWeightProducer*******\n" << 
                                          " Q  : " << Q << "\n" <<
                                          " id1: " << id1 << "\n" <<
                                          " x1 : " << x1  << "\n" <<
                                          " x1': " << x1prime << "\n" <<
                                          " id2: " << id2 << "\n" <<
                                          " x2 : " << x2  << "\n" <<
                                          " x2': " << x2prime ;
      //gluon is 0 in the LHAPDF numbering
      if (id1 == 21)
        id1 = 0;
      if (id2 == 21)
        id2 = 0;

      // Put PDF weights in the event
      if (verbose)
        cout << " Set : " << _pdfset << "  member : " << _pdfmember << endl;
     
      LHAPDF::usePDFMember(1,_pdfmember);
      double oldpdf1 = LHAPDF::xfx(1, x1, Q, id1)/x1;
      double oldpdf2 = LHAPDF::xfx(1, x2, Q, id2)/x2;
      double newpdf1 = LHAPDF::xfx(1, x1prime, Q, id1)/x1prime;
      double newpdf2 = LHAPDF::xfx(1, x2prime, Q, id2)/x2prime;
      LogTrace("LHECOMWeightProducer") <<
          "     xfx1 : " << oldpdf1 << "\n" <<
          "     xfx2 : " << oldpdf2 << "\n" <<
          "     xfx1': " << newpdf1 << "\n" <<
          "     xfx2': " << newpdf2 << "\n" <<
          "     weight:" << (newpdf1/oldpdf1)*(newpdf2/oldpdf2);
      double weight = (newpdf1/oldpdf1)*(newpdf2/oldpdf2);
      std::vector<double> weights;
      weights.push_back(weight);
      std::auto_ptr<GenEventInfoProduct> info(new GenEventInfoProduct());
      info->setWeights(weights);
      iEvent.put(info, _label);
}