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// $Id: G4FTFModel.hh 110870 2018-06-22 12:14:16Z gcosmo $
// GEANT4 tag $Name:  $
//
// Class Description
// Final state production code for hadron inelastic scattering above 3 GeV
// based on the modeling ansatz used in FRITIOF.
// To be used in your physics list in case you need this physics.
// In this case you want to register an object of this class with an object
// of G4TheoFSGenerator. 
// Class Description - End

#ifndef G4FTFModel_h
#define G4FTFModel_h 1

// ------------------------------------------------------------
//      GEANT 4 class header file
//
//      ---------------- G4FTFModel ----------------
//             by Gunter Folger, May 1998.
//       class implementing the excitation in the FTF Parton String Model
// ------------------------------------------------------------

#include "G4VPartonStringModel.hh"
#include "G4FTFParameters.hh"
#include "G4FTFParticipants.hh"
#include "G4ExcitedStringVector.hh"
#include "G4DiffractiveExcitation.hh"
#include "G4ElasticHNScattering.hh"
#include "G4FTFAnnihilation.hh"
#include "G4Proton.hh"
#include "G4Neutron.hh"

class G4VSplitableHadron;
class G4ExcitedString;


class G4FTFModel : public G4VPartonStringModel {
  public:
    G4FTFModel( const G4String& modelName = "FTF" );
    ~G4FTFModel();

    void Init( const G4Nucleus& aNucleus, const G4DynamicParticle& aProjectile );
    G4ExcitedStringVector* GetStrings();
    G4V3DNucleus* GetWoundedNucleus() const;
    G4V3DNucleus* GetTargetNucleus() const;
    G4V3DNucleus* GetProjectileNucleus() const;

    virtual void ModelDescription( std::ostream& ) const;

  private:
    G4FTFModel( const G4FTFModel& right );
    const G4FTFModel& operator=( const G4FTFModel& right );
    int operator==( const G4FTFModel& right ) const;
    int operator!=( const G4FTFModel& right ) const;

    void StoreInvolvedNucleon();              
    void ReggeonCascade();
    G4bool PutOnMassShell();
    G4bool ExciteParticipants();
    G4ExcitedStringVector* BuildStrings();
    void GetResiduals();
      
    G4bool AdjustNucleons( G4VSplitableHadron* SelectedAntiBaryon,
                           G4Nucleon*          ProjectileNucleon,
                           G4VSplitableHadron* SelectedTargetNucleon,
                           G4Nucleon*          TargetNucleon,
                           G4bool              Annihilation ); 
    // The "AdjustNucleons" method uses the following struct and 3 new utility methods:
    struct CommonVariables {
      G4int TResidualMassNumber = 0, TResidualCharge = 0, PResidualMassNumber = 0, 
        PResidualCharge = 0;
      G4double SqrtS = 0.0, S = 0.0, SumMasses = 0.0,
        TResidualExcitationEnergy = 0.0, TResidualMass = 0.0, TNucleonMass = 0.0,
        PResidualExcitationEnergy = 0.0, PResidualMass = 0.0, PNucleonMass = 0.0,
        Mprojectile = 0.0, M2projectile = 0.0, Pzprojectile = 0.0, Eprojectile = 0.0, 
        WplusProjectile = 0.0,
        Mtarget = 0.0, M2target = 0.0, Pztarget = 0.0, Etarget = 0.0, WminusTarget = 0.0,
        Mt2targetNucleon = 0.0, PztargetNucleon = 0.0, EtargetNucleon = 0.0,
        Mt2projectileNucleon = 0.0, PzprojectileNucleon = 0.0, EprojectileNucleon = 0.0,
        YtargetNucleus = 0.0, YprojectileNucleus = 0.0,
        XminusNucleon = 0.0, XplusNucleon = 0.0, XminusResidual = 0.0, XplusResidual = 0.0;
      G4ThreeVector PtNucleon, PtResidual, PtNucleonP, PtResidualP, PtNucleonT, PtResidualT;
      G4LorentzVector Psum, Pprojectile, Ptmp, Ptarget, TResidual4Momentum, PResidual4Momentum;
      G4LorentzRotation toCms, toLab;
    };
    G4int AdjustNucleonsAlgorithm_beforeSampling( G4int               interactionCase, 
                                                  G4VSplitableHadron* SelectedAntiBaryon,
                                                  G4Nucleon*          ProjectileNucleon,
                                                  G4VSplitableHadron* SelectedTargetNucleon,
                                                  G4Nucleon*          TargetNucleon,
                                                  G4bool              Annihilation,
                                                  CommonVariables&    common );  
    G4bool AdjustNucleonsAlgorithm_Sampling(      G4int interactionCase, 
                                                  CommonVariables& common );
    void AdjustNucleonsAlgorithm_afterSampling( G4int               interactionCase, 
                                                G4VSplitableHadron* SelectedAntiBaryon,
                                                G4VSplitableHadron* SelectedTargetNucleon,
                                                CommonVariables&    common ); 

    G4ThreeVector GaussianPt( G4double AveragePt2, G4double maxPtSquare ) const;

    G4bool ComputeNucleusProperties( G4V3DNucleus* nucleus, G4LorentzVector& nucleusMomentum, 
                                     G4LorentzVector& residualMomentum, G4double& sumMasses,   
                                     G4double& residualExcitationEnergy, G4double& residualMass,
                                     G4int& residualMassNumber, G4int& residualCharge );
    // Utility method used by PutOnMassShell.

    G4bool GenerateDeltaIsobar( const G4double sqrtS, const G4int numberOfInvolvedNucleons,
                                G4Nucleon* involvedNucleons[], G4double& sumMasses );
    // Utility method used by PutOnMassShell.

    G4bool SamplingNucleonKinematics( G4double averagePt2, const G4double maxPt2,
                                      G4double dCor, G4V3DNucleus* nucleus,
                                      const G4LorentzVector& pResidual, 
                                      const G4double residualMass, const G4int residualMassNumber,
                                      const G4int numberOfInvolvedNucleons,
                                      G4Nucleon* involvedNucleons[], G4double& mass2 );

    // Utility method used by PutOnMassShell.

    G4bool CheckKinematics( const G4double sValue, const G4double sqrtS, 
                            const G4double projectileMass2, const G4double targetMass2,
                            const G4double nucleusY, const G4bool isProjectileNucleus,
                            const G4int numberOfInvolvedNucleons, G4Nucleon* involvedNucleons[],
                            G4double& targetWminus, G4double& projectileWplus, G4bool& success );
    // Utility method used by PutOnMassShell.

    G4bool FinalizeKinematics( const G4double w, const G4bool isProjectileNucleus, 
                               const G4LorentzRotation& boostFromCmsToLab,
                               const G4double residualMass, const G4int residualMassNumber,
                               const G4int numberOfInvolvedNucleons, 
                               G4Nucleon* involvedNucleons[],
	                       G4LorentzVector& residual4Momentum );
    // Utility method used by PutOnMassShell.

    G4ReactionProduct theProjectile;       
    G4FTFParticipants theParticipants;
       
    G4Nucleon* TheInvolvedNucleonsOfTarget[250];
    G4int NumberOfInvolvedNucleonsOfTarget;

    G4Nucleon* TheInvolvedNucleonsOfProjectile[250];
    G4int NumberOfInvolvedNucleonsOfProjectile;

    G4FTFParameters* theParameters;
    G4DiffractiveExcitation* theExcitation;
    G4ElasticHNScattering* theElastic;
    G4FTFAnnihilation* theAnnihilation;  

    std::vector< G4VSplitableHadron* > theAdditionalString; 

    G4double LowEnergyLimit;
    G4bool HighEnergyInter;

    G4LorentzVector ProjectileResidual4Momentum;
    G4int           ProjectileResidualMassNumber;
    G4int           ProjectileResidualCharge;
    G4double        ProjectileResidualExcitationEnergy;

    G4LorentzVector TargetResidual4Momentum;
    G4int           TargetResidualMassNumber;
    G4int           TargetResidualCharge;
    G4double        TargetResidualExcitationEnergy;
};


inline G4V3DNucleus* G4FTFModel::GetWoundedNucleus() const {
  return theParticipants.GetWoundedNucleus();
}


inline G4V3DNucleus* G4FTFModel::GetTargetNucleus() const {
  return theParticipants.GetWoundedNucleus();
}


inline G4V3DNucleus* G4FTFModel::GetProjectileNucleus() const {
  return theParticipants.GetProjectileNucleus();
}

#endif