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//
// INCL++ intra-nuclear cascade model
// Alain Boudard, CEA-Saclay, France
// Joseph Cugnon, University of Liege, Belgium
// Jean-Christophe David, CEA-Saclay, France
// Pekka Kaitaniemi, CEA-Saclay, France, and Helsinki Institute of Physics, Finland
// Sylvie Leray, CEA-Saclay, France
// Davide Mancusi, CEA-Saclay, France
//
#define INCLXX_IN_GEANT4_MODE 1

#include "globals.hh"

#include "G4INCLPiNToOmegaChannel.hh"
#include "G4INCLKinematicsUtils.hh"
#include "G4INCLBinaryCollisionAvatar.hh"
#include "G4INCLRandom.hh"
#include "G4INCLGlobals.hh"
#include "G4INCLLogger.hh"

namespace G4INCL {

    PiNToOmegaChannel::PiNToOmegaChannel(Particle *p1, Particle *p2)
    : particle1(p1), particle2(p2)
    {

    }

    PiNToOmegaChannel::~PiNToOmegaChannel(){

    }

    void PiNToOmegaChannel::fillFinalState(FinalState *fs) {
        Particle * nucleon;
        Particle * pion;
        if(particle1->isNucleon()) {
            nucleon = particle1;
            pion = particle2;
        } else {
            nucleon = particle2;
            pion = particle1;
        }

        G4int iso=ParticleTable::getIsospin(nucleon->getType())+ParticleTable::getIsospin(pion->getType());
// assert(iso == 1 || iso == -1);
        if (iso == 1) {
			nucleon->setType(Proton);
		}
		else if (iso == -1) {
			nucleon->setType(Neutron);
        }
		pion->setType(Omega);

                // Erase the parent resonance information of the nucleon and pion
	        nucleon->setParentResonancePDGCode(0);
	        nucleon->setParentResonanceID(0);
                pion->setParentResonancePDGCode(0);
                pion->setParentResonanceID(0);
		
//        nucleon->setEnergy(std::sqrt((nucleon->getMass())*(nucleon->getMass())+(mom_nucleon.mag()*mom_nucleon.mag())));
//        pion->setEnergy(std::sqrt((pion->getMass())*(pion->getMass())+(mom_nucleon.mag()*mom_nucleon.mag())));
  G4double sh=nucleon->getEnergy()+pion->getEnergy();
		G4double mn=nucleon->getMass();
		G4double me=pion->getMass();
		G4double en=(sh*sh+mn*mn-me*me)/(2*sh);
		nucleon->setEnergy(en);
		G4double ee=std::sqrt(en*en-mn*mn+me*me);
		pion->setEnergy(ee);
		G4double pn=std::sqrt(en*en-mn*mn);

		ThreeVector mom_nucleon = Random::normVector(pn);
		
		nucleon->setMomentum(mom_nucleon);
		pion->setMomentum(-mom_nucleon);
        
  fs->addModifiedParticle(nucleon);
  fs->addModifiedParticle(pion);
  }

}