StatusCode ConstPtParticleGun::getNextEvent(HepMC::GenEvent& theEvent) {
Gaudi::LorentzVector theFourMomentum;
Gaudi::LorentzVector origin;
// note: pgdid is set in function generateParticle
int thePdgId;
generateParticle(theFourMomentum, origin, thePdgId);
// create HepMC Vertex --
// by calling add_vertex(), the hepmc event is given ownership of the vertex
HepMC::GenVertex* v = new HepMC::GenVertex(HepMC::FourVector(origin.X(), origin.Y(), origin.Z(), origin.T()));
// create HepMC particle --
// by calling add_particle_out(), the hepmc vertex is given ownership of the particle
HepMC::GenParticle* p = new HepMC::GenParticle(
HepMC::FourVector(theFourMomentum.Px(), theFourMomentum.Py(), theFourMomentum.Pz(), theFourMomentum.E()),
thePdgId,
1); // hepmc status code for final state particle
v->add_particle_out(p);
theEvent.add_vertex(v);
theEvent.set_signal_process_vertex(v);
return StatusCode::SUCCESS;
}
bool HepMC2_Interface::Sherpa2HepMC(ATOOLS::Blob_List *const blobs,
HepMC::GenEvent& event, double weight)
{
#ifdef USING__HEPMC2__UNITS
event.use_units(HepMC::Units::GEV,
HepMC::Units::MM);
#endif
event.set_event_number(ATOOLS::rpa->gen.NumberOfGeneratedEvents());
size_t decid(11);
std::map<size_t,size_t> decids;
Blob *sp(blobs->FindFirst(btp::Signal_Process));
if (sp) {
Blob_Data_Base *info((*sp)["Decay_Info"]);
if (info) {
DecayInfo_Vector decs(info->Get<DecayInfo_Vector>());
for (size_t i(0);i<decs.size();++i) decids[decs[i]->m_id]=++decid;
}
}
m_blob2genvertex.clear();
m_particle2genparticle.clear();
HepMC::GenVertex * vertex;
std::vector<HepMC::GenParticle*> beamparticles;
for (ATOOLS::Blob_List::iterator blit=blobs->begin();
blit!=blobs->end();++blit) {
if (Sherpa2HepMC(*(blit),vertex,decids)) {
event.add_vertex(vertex);
if ((*blit)->Type()==ATOOLS::btp::Signal_Process) {
if ((**blit)["NLO_subeventlist"]) {
THROW(fatal_error,"Events containing correlated subtraction events"
+std::string(" cannot be translated into the full HepMC event")
+std::string(" format.\n")
+std::string(" Try 'EVENT_OUTPUT=HepMC_Short' instead."));
}
event.set_signal_process_vertex(vertex);
if((*blit)->NInP()==2) {
kf_code fl1=(*blit)->InParticle(0)->Flav().HepEvt();
kf_code fl2=(*blit)->InParticle(1)->Flav().HepEvt();
double x1=(*blit)->InParticle(0)->Momentum()[0]/rpa->gen.PBeam(0)[0];
double x2=(*blit)->InParticle(1)->Momentum()[0]/rpa->gen.PBeam(1)[0];
double q(0.0), p1(0.0), p2(0.0);
Blob_Data_Base *facscale((**blit)["Factorisation_Scale"]);
if (facscale) q=sqrt(facscale->Get<double>());
Blob_Data_Base *xf1((**blit)["XF1"]);
Blob_Data_Base *xf2((**blit)["XF2"]);
if (xf1) p1=xf1->Get<double>();
if (xf2) p2=xf2->Get<double>();
HepMC::PdfInfo pdfinfo(fl1, fl2, x1, x2, q, p1, p2);
event.set_pdf_info(pdfinfo);
}
}
else if ((*blit)->Type()==ATOOLS::btp::Beam ||
(*blit)->Type()==ATOOLS::btp::Bunch) {
for (HepMC::GenVertex::particles_in_const_iterator
pit=vertex->particles_in_const_begin();
pit!=vertex->particles_in_const_end(); ++pit) {
if ((*pit)->production_vertex()==NULL) {
beamparticles.push_back(*pit);
}
}
}
}
}
if (beamparticles.size()==2) {
event.set_beam_particles(beamparticles[0],beamparticles[1]);
}
std::vector<double> weights;
weights.push_back(weight);
if (sp) {
Blob_Data_Base *info((*sp)["MEWeight"]);
if (!info) THROW(fatal_error,"Missing weight info.");
double meweight(info->Get<double>());
weights.push_back(meweight);
Blob_Data_Base *ofni((*sp)["Weight_Norm"]);
if (!ofni) THROW(fatal_error,"Missing weight normalisation.");
double weightnorm(ofni->Get<double>());
weights.push_back(weightnorm);
ofni=(*sp)["Trials"];
if (!ofni) THROW(fatal_error,"Missing nof trials.");
double trials(ofni->Get<double>());
weights.push_back(trials);
}
event.weights()=weights;
return true;
}