int PHSartre::process_event(PHCompositeNode *topNode) {
if (verbosity > 1) cout << "PHSartre::process_event - event: " << _eventcount << endl;
bool passedTrigger = false;
Event *event = NULL;
TLorentzVector *eIn = NULL;
TLorentzVector *pIn = NULL;
TLorentzVector *eOut = NULL;
TLorentzVector *gamma = NULL;
TLorentzVector *vm = NULL;
TLorentzVector *PomOut = NULL;
TLorentzVector *pOut = NULL;
TLorentzVector *vmDecay1 = NULL;
TLorentzVector *vmDecay2 = NULL;
unsigned int preVMDecaySize = 0;
while (!passedTrigger) {
++_gencount;
// Generate a Sartre event
event = _sartre->generateEvent();
//
// If Sartre is run in UPC mode, half of the events needs to be
// rotated around and axis perpendicular to z:
// (only for symmetric events)
//
if(settings->UPC() and settings->A()==settings->UPCA()){
randomlyReverseBeams(event);
}
// for sPHENIX/RHIC p+Au
// (see comments in ReverseBeams)
// reverse when the proton emits the virtual photon
if(settings->UPC() and settings->A()==197){
ReverseBeams(event);
}
// Set pointers to the parts of the event we will need:
eIn = &event->particles[0].p;
pIn = &event->particles[1].p;
eOut = &event->particles[2].p;
gamma = &event->particles[3].p;
vm = &event->particles[4].p;
PomOut = &event->particles[5].p;
pOut = &event->particles[6].p;
// To allow the triggering to work properly, we need to decay the vector meson here
preVMDecaySize = event->particles.size();
if(doPerformDecay) {
if( decay->SetDecay(*vm, 2, daughterMasses) ){
double weight = decay->Generate(); // weight is always 1 here
if ( (weight-1) > FLT_EPSILON) {
cout << "PHSartre: Warning decay weight != 1, weight = " << weight << endl;
}
TLorentzVector *vmDaughter1 = decay->GetDecay(0);
TLorentzVector *vmDaughter2 = decay->GetDecay(1);
event->particles[4].status = 2; // set VM status
Particle vmDC1;
vmDC1.index = event->particles.size();
vmDC1.pdgId = daughterID;
vmDC1.status = 1; // final state
vmDC1.p = *vmDaughter1;
vmDC1.parents.push_back(4);
event->particles.push_back(vmDC1);
vmDecay1 = &event->particles[event->particles.size()-1].p;
Particle vmDC2;
vmDC2.index = event->particles.size();
vmDC2.pdgId = -daughterID;
vmDC2.status = 1; // final state
vmDC2.p = *vmDaughter2;
vmDC2.parents.push_back(4);
event->particles.push_back(vmDC2);
vmDecay2 = &event->particles[event->particles.size()-1].p;
}
else {
cout << "PHSartre: WARNING: Kinematics of Vector Meson does not allow decay!" << endl;
}
}
// test trigger logic
bool andScoreKeeper = true;
if (verbosity > 2) {
cout << "PHSartre::process_event - triggersize: " << _registeredTriggers.size() << endl;
}
for (unsigned int tr = 0; tr < _registeredTriggers.size(); tr++) {
bool trigResult = _registeredTriggers[tr]->Apply(event);
if (verbosity > 2) {
cout << "PHSartre::process_event trigger: "
<< _registeredTriggers[tr]->GetName() << " " << trigResult << endl;
}
if (_triggersOR && trigResult) {
passedTrigger = true;
break;
} else if (_triggersAND) {
andScoreKeeper &= trigResult;
}
if (verbosity > 2 && !passedTrigger) {
cout << "PHSartre::process_event - failed trigger: "
<< _registeredTriggers[tr]->GetName() << endl;
}
}
if ((andScoreKeeper && _triggersAND) || (_registeredTriggers.size() == 0)) {
passedTrigger = true;
}
}
// fill HepMC object with event
HepMC::GenEvent *genevent = new HepMC::GenEvent(HepMC::Units::GEV, HepMC::Units::MM);
// add some information to the event
genevent->set_event_number(_eventcount);
// Set the PDF information
HepMC::PdfInfo pdfinfo;
pdfinfo.set_scalePDF(event->Q2);
genevent->set_pdf_info(pdfinfo);
// We would also like to save:
//
// event->t;
// event->x;
// event->y;
// event->s;
// event->W;
// event->xpom;
// (event->polarization == transverse ? 0 : 1);
// (event->diffractiveMode == coherent ? 0 : 1);
//
// but there doesn't seem to be a good place to do so
// within the HepMC event information?
//
// t, W and Q^2 form a minial set of good variables for diffractive events
// Maybe what I do is record the input particles to the event at the HepMC
// vertices and reconstruct the kinematics from there?
// Create HepMC vertices and add final state particles to them
// First, the emitter(electron)-virtual photon vertex:
HepMC::GenVertex* egammavtx = new HepMC::GenVertex(CLHEP::HepLorentzVector(0.0,0.0,0.0,0.0));
genevent->add_vertex(egammavtx);
egammavtx->add_particle_in(
new HepMC::GenParticle( CLHEP::HepLorentzVector(eIn->Px(),
eIn->Py(),
eIn->Pz(),
eIn->E()),
event->particles[0].pdgId,
3 )
);
HepMC::GenParticle *hgamma = new HepMC::GenParticle( CLHEP::HepLorentzVector(gamma->Px(),
gamma->Py(),
gamma->Pz(),
gamma->E()),
event->particles[3].pdgId,
3 );
egammavtx->add_particle_out(hgamma);
egammavtx->add_particle_out(
new HepMC::GenParticle( CLHEP::HepLorentzVector(eOut->Px(),
eOut->Py(),
eOut->Pz(),
eOut->E()),
event->particles[2].pdgId,
1 )
);
// Next, the hadron-pomeron vertex:
HepMC::GenVertex* ppomvtx = new HepMC::GenVertex(CLHEP::HepLorentzVector(0.0,0.0,0.0,0.0));
genevent->add_vertex(ppomvtx);
ppomvtx->add_particle_in(
new HepMC::GenParticle( CLHEP::HepLorentzVector(pIn->Px(),
pIn->Py(),
pIn->Pz(),
pIn->E()),
event->particles[1].pdgId,
3 )
);
HepMC::GenParticle *hPomOut = new HepMC::GenParticle( CLHEP::HepLorentzVector(PomOut->Px(),
PomOut->Py(),
PomOut->Pz(),
PomOut->E()),
event->particles[5].pdgId,
3 );
ppomvtx->add_particle_out(hPomOut);
// If this is a nuclear breakup, add in the nuclear fragments
// Otherwise, add in the outgoing hadron
//If the event is incoherent, and nuclear breakup is enabled, fill the remnants to the tree
if(settings->enableNuclearBreakup() and event->diffractiveMode == incoherent){
for(unsigned int iParticle=7; iParticle < preVMDecaySize; iParticle++){
if(event->particles[iParticle].status == 1) { // Final-state particle
const Particle& particle = event->particles[iParticle];
ppomvtx->add_particle_out(
new HepMC::GenParticle( CLHEP::HepLorentzVector(particle.p.Px(),
particle.p.Py(),
particle.p.Pz(),
particle.p.E()),
particle.pdgId,
1 )
);
}
}
}
else{
ppomvtx->add_particle_out(
new HepMC::GenParticle( CLHEP::HepLorentzVector(pOut->Px(),
pOut->Py(),
pOut->Pz(),
pOut->E()),
event->particles[6].pdgId,
1 )
);
}
// The Pomeron-Photon vertex
HepMC::GenVertex* gammapomvtx = new HepMC::GenVertex(CLHEP::HepLorentzVector(0.0,0.0,0.0,0.0));
genevent->add_vertex(gammapomvtx);
gammapomvtx->add_particle_in(hgamma);
gammapomvtx->add_particle_in(hPomOut);
int isVMFinal = 1;
if(doPerformDecay) isVMFinal = 2;
HepMC::GenParticle *hvm = new HepMC::GenParticle( CLHEP::HepLorentzVector(vm->Px(),
vm->Py(),
vm->Pz(),
vm->E()),
event->particles[4].pdgId,
isVMFinal ) ;
gammapomvtx->add_particle_out( hvm );
// Add the VM decay to the event
if(doPerformDecay) {
if(vmDecay1 && vmDecay2){
HepMC::GenVertex* fvtx = new HepMC::GenVertex(CLHEP::HepLorentzVector(0.0,0.0,0.0,0.0));
genevent->add_vertex(fvtx);
fvtx->add_particle_in( hvm );
fvtx->add_particle_out(
new HepMC::GenParticle( CLHEP::HepLorentzVector(vmDecay1->Px(),
vmDecay1->Py(),
vmDecay1->Pz(),
vmDecay1->E()),
daughterID,
1 )
);
fvtx->add_particle_out(
new HepMC::GenParticle( CLHEP::HepLorentzVector(vmDecay2->Px(),
vmDecay2->Py(),
vmDecay2->Pz(),
vmDecay2->E()),
-daughterID,
1 )
);
}
else {
cout << "PHSartre: WARNING: Kinematics of Vector Meson does not allow decay!" << endl;
}
}
// pass HepMC to PHNode
PHHepMCGenEvent * success = hepmc_helper . insert_event(genevent);
if (!success) {
cout << "PHSartre::process_event - Failed to add event to HepMC record!" << endl;
return Fun4AllReturnCodes::ABORTRUN;
}
// print outs
if (verbosity > 2) cout << "PHSartre::process_event - FINISHED WHOLE EVENT" << endl;
++_eventcount;
return Fun4AllReturnCodes::EVENT_OK;
}
