G4ExcitedStringDecay.cc

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// Historic fragment from M.Komogorov; clean-up still necessary @@@

#include "G4ExcitedStringDecay.hh"
#include "G4SystemOfUnits.hh"
#include "G4KineticTrack.hh"

//#define debug_G4ExcitedStringDecay
//#define debug_G4ExcitedStringCorr

G4ExcitedStringDecay::G4ExcitedStringDecay() : G4VStringFragmentation(),theStringDecay(0)
{}

G4ExcitedStringDecay::G4ExcitedStringDecay(G4VLongitudinalStringDecay * aStringDecay)
: G4VStringFragmentation(),
  theStringDecay(aStringDecay)
{}

G4ExcitedStringDecay::G4ExcitedStringDecay(const G4ExcitedStringDecay &)
: G4VStringFragmentation(),
  theStringDecay(0)
{
  throw G4HadronicException(__FILE__, __LINE__, "G4ExcitedStringDecay::copy ctor not accessible");
} 

G4ExcitedStringDecay::~G4ExcitedStringDecay()
{
}

const G4ExcitedStringDecay & G4ExcitedStringDecay::operator=(const G4ExcitedStringDecay &)
{
  throw G4HadronicException(__FILE__, __LINE__, "G4ExcitedStringDecay::operator= meant to not be accessable");
  return *this;
}

int G4ExcitedStringDecay::operator==(const G4ExcitedStringDecay &) const
{
  return 0;
}

int G4ExcitedStringDecay::operator!=(const G4ExcitedStringDecay &) const
{
  return 1;
}

G4KineticTrackVector *G4ExcitedStringDecay::FragmentString(const G4ExcitedString &theString)
{
  if ( theStringDecay == NULL ) theStringDecay=new G4LundStringFragmentation();
  return theStringDecay->FragmentString(theString);
}
    
G4KineticTrackVector *G4ExcitedStringDecay::FragmentStrings(const G4ExcitedStringVector * theStrings)
{
  G4LorentzVector KTsum(0.,0.,0.,0.);

  #ifdef debug_G4ExcitedStringDecay
  G4cout<<G4endl;
  G4cout<<"--------------------------- G4ExcitedStringDecay ----------------------"<<G4endl;
  G4cout<<"Hadronization of Excited Strings: theStrings->size() "<<theStrings->size()<<G4endl;
  #endif

  for ( unsigned int astring=0; astring < theStrings->size(); astring++)
  {
    if ( theStrings->operator[](astring)->IsExcited() ) {
      KTsum+= theStrings->operator[](astring)->Get4Momentum();
    } else {
      KTsum+=theStrings->operator[](astring)->GetKineticTrack()->Get4Momentum();
    }
  }

  G4LorentzRotation toCms( -1 * KTsum.boostVector() );
  G4LorentzRotation toLab(toCms.inverse());
  G4LorentzVector Ptmp;
  KTsum=G4LorentzVector(0.,0.,0.,0.);
  for ( unsigned int astring=0; astring < theStrings->size(); astring++)
  {
    if ( theStrings->operator[](astring)->IsExcited() ) {
      Ptmp=toCms * theStrings->operator[](astring)->GetLeftParton()->Get4Momentum();
      theStrings->operator[](astring)->GetLeftParton()->Set4Momentum(Ptmp);

      Ptmp=toCms * theStrings->operator[](astring)->GetRightParton()->Get4Momentum();
      theStrings->operator[](astring)->GetRightParton()->Set4Momentum(Ptmp);

      KTsum+= theStrings->operator[](astring)->Get4Momentum();
    } else {
      Ptmp=toCms * theStrings->operator[](astring)->GetKineticTrack()->Get4Momentum();
      theStrings->operator[](astring)->GetKineticTrack()->Set4Momentum(Ptmp);
      KTsum+= theStrings->operator[](astring)->GetKineticTrack()->Get4Momentum();
    }
  }

  G4KineticTrackVector * theResult = new G4KineticTrackVector;
  G4int attempts(0);
  G4bool success=false;
  G4bool NeedEnergyCorrector=false;
  do {
        #ifdef debug_G4ExcitedStringDecay  
        G4cout<<"New try No "<<attempts<<" to hadronize strings"<<G4endl;
        #endif

    std::for_each(theResult->begin() , theResult->end() , DeleteKineticTrack());
    theResult->clear();

    attempts++;

    G4LorentzVector KTsecondaries(0.,0.,0.,0.);
    NeedEnergyCorrector=false;

    for ( unsigned int astring=0; astring < theStrings->size(); astring++)
    {
          #ifdef debug_G4ExcitedStringDecay  
          G4cout<<"String No "<<astring+1<<" Excited?  "<<theStrings->operator[](astring)->IsExcited()<<G4endl;

          G4cout<<"String No "<<astring+1<<" 4Momentum "<<theStrings->operator[](astring)->Get4Momentum()
                <<" "<<theStrings->operator[](astring)->Get4Momentum().mag()<<G4endl;
          #endif

          G4KineticTrackVector * generatedKineticTracks = NULL;
      if ( theStrings->operator[](astring)->IsExcited() )
      {
             #ifdef debug_G4ExcitedStringDecay  
             G4cout<<"Fragment String with partons: "
                   <<theStrings->operator[](astring)->GetLeftParton()->GetPDGcode() <<" "
                   <<theStrings->operator[](astring)->GetRightParton()->GetPDGcode()<<" "
                   <<"Direction "<<theStrings->operator[](astring)->GetDirection()<<G4endl;
             #endif
         generatedKineticTracks=FragmentString(*theStrings->operator[](astring));
             #ifdef debug_G4ExcitedStringDecay  
             G4cout<<"(G4ExcitedStringDecay) Number of produced hadrons = "<<generatedKineticTracks->size()<<G4endl;
             #endif
      } else {
             #ifdef debug_G4ExcitedStringDecay  
             G4cout<<"   GetTrack from the String"<<G4endl;
             #endif
             G4LorentzVector Mom=theStrings->operator[](astring)->GetKineticTrack()->Get4Momentum();
             G4KineticTrack * aTrack= new G4KineticTrack(
                            theStrings->operator[](astring)->GetKineticTrack()->GetDefinition(),
                            theStrings->operator[](astring)->GetKineticTrack()->GetFormationTime(),
                            G4ThreeVector(0), Mom);

             aTrack->SetPosition(theStrings->operator[](astring)->GetKineticTrack()->GetPosition());

             #ifdef debug_G4ExcitedStringDecay  
             G4cout<<"   A particle stored in the track is "<<aTrack->GetDefinition()->GetParticleName()<<G4endl;
             #endif

         generatedKineticTracks = new G4KineticTrackVector;
         generatedKineticTracks->push_back(aTrack);
      }    

          //if (generatedKineticTracks == NULL)
      if (generatedKineticTracks->size() == 0)
      {
             //G4cerr << "G4VPartonStringModel:No KineticTracks produced" << G4endl;
             //continue;
             success=false; NeedEnergyCorrector=false; break;
      }

          G4LorentzVector KTsum1(0.,0.,0.,0.);
          for ( unsigned int aTrack=0; aTrack<generatedKineticTracks->size();aTrack++)
      {
             #ifdef debug_G4ExcitedStringDecay  
             G4cout<<"Prod part No. "<<aTrack+1<<" "
                   <<(*generatedKineticTracks)[aTrack]->GetDefinition()->GetParticleName()<<" "
                   <<(*generatedKineticTracks)[aTrack]->Get4Momentum()<<G4endl;
             #endif
             theResult->push_back(generatedKineticTracks->operator[](aTrack));
             KTsum1+= (*generatedKineticTracks)[aTrack]->Get4Momentum();
      }
      KTsecondaries+=KTsum1;
    
          #ifdef debug_G4ExcitedStringDecay  
          G4cout << "String secondaries(" <<generatedKineticTracks->size()<< ")"<<G4endl
                 <<"Init  string  momentum: "<< theStrings->operator[](astring)->Get4Momentum()<<G4endl
                 <<"Final hadrons momentum: "<< KTsum1 << G4endl;
          #endif

      if  ( KTsum1.e() > 0 && std::abs((KTsum1.e()-theStrings->operator[](astring)->Get4Momentum().e()) / KTsum1.e()) > perMillion )
      {
        NeedEnergyCorrector=true;
      }

          #ifdef debug_G4ExcitedStringDecay  
          G4cout<<"NeedEnergyCorrection yes/no "<<NeedEnergyCorrector<<G4endl;
          #endif

          // clean up
      delete generatedKineticTracks;
      success=true;
    }

        //success=true;

    if ( NeedEnergyCorrector ) success=EnergyAndMomentumCorrector(theResult, KTsum);
  } while(!success && (attempts < 100));  /* Loop checking, 07.08.2015, A.Ribon */

  for ( unsigned int aTrack=0; aTrack<theResult->size();aTrack++)
  {
    Ptmp=(*theResult)[aTrack]->Get4Momentum();
    Ptmp.transform( toLab);
    (*theResult)[aTrack]->Set4Momentum(Ptmp);
  }

  #ifdef debug_G4ExcitedStringDecay  
  G4cout<<"End of the strings fragmentation (G4ExcitedStringDecay)"<<G4endl;

  G4LorentzVector  KTsum1(0.,0.,0.,0.); 

  for ( unsigned int aTrack=0; aTrack<theResult->size();aTrack++)
  {
      G4cout << " corrected tracks .. " << (*theResult)[aTrack]->GetDefinition()->GetParticleName()
             <<"  " << (*theResult)[aTrack]->Get4Momentum() 
             <<"  " << (*theResult)[aTrack]->Get4Momentum().mag()<< G4endl;
      KTsum1+= (*theResult)[aTrack]->Get4Momentum();
  }

  G4cout << "Needcorrector/success " << NeedEnergyCorrector << "/" << success 
         << ", Corrected total  4 momentum " << KTsum1  << G4endl;
  if ( ! success ) G4cout << "failed to correct E/p" << G4endl;  

  G4cout<<"End of the Hadronization (G4ExcitedStringDecay)"<<G4endl;
  #endif

  for ( unsigned int astring=0; astring < theStrings->size(); astring++)
  {
    if ( theStrings->operator[](astring)->IsExcited() ) {
      Ptmp=theStrings->operator[](astring)->GetLeftParton()->Get4Momentum();
      Ptmp.transform( toLab);
      theStrings->operator[](astring)->GetLeftParton()->Set4Momentum(Ptmp);

      Ptmp=theStrings->operator[](astring)->GetRightParton()->Get4Momentum();
      Ptmp.transform( toLab);
      theStrings->operator[](astring)->GetRightParton()->Set4Momentum(Ptmp);
    } else {
      Ptmp=theStrings->operator[](astring)->GetKineticTrack()->Get4Momentum();
      Ptmp.transform( toLab);
      theStrings->operator[](astring)->GetKineticTrack()->Set4Momentum(Ptmp);
    }
  }

  return theResult;
}

G4bool G4ExcitedStringDecay::EnergyAndMomentumCorrector
        (G4KineticTrackVector* Output, G4LorentzVector& TotalCollisionMom)   
{
    const int    nAttemptScale = 500;
    const double ErrLimit = 1.E-5;
    if (Output->empty()) return TRUE;
    G4LorentzVector SumMom;
    G4double        SumMass = 0;
    G4double        TotalCollisionMass = TotalCollisionMom.m();

    #ifdef debug_G4ExcitedStringCorr
    G4cout<<G4endl<<"EnergyAndMomentumCorrector. Number of particles: "<<Output->size()<<G4endl;
    #endif
    // Calculate sum hadron 4-momenta and summing hadron mass
    unsigned int cHadron;
    for(cHadron = 0; cHadron < Output->size(); cHadron++)
    {
        SumMom  += Output->operator[](cHadron)->Get4Momentum();
        SumMass += Output->operator[](cHadron)->GetDefinition()->GetPDGMass();
    }

    #ifdef debug_G4ExcitedStringCorr
    G4cout<<"Sum part mom "<<SumMom<<" "<<SumMom.mag()<<G4endl
          <<"Sum str  mom "<<TotalCollisionMom<<" "<<TotalCollisionMom.mag()<<G4endl;
    G4cout<<"SumMass TotalCollisionMass "<<SumMass<<" "<<TotalCollisionMass<<G4endl;
    #endif

    // Cannot correct a single particle
    if (Output->size() < 2) return FALSE;

    if (SumMass > TotalCollisionMass) return FALSE;
    SumMass = SumMom.m2();
    if (SumMass < 0) return FALSE;
    SumMass = std::sqrt(SumMass);

    // Compute c.m.s. hadron velocity and boost KTV to hadron c.m.s.
    //G4ThreeVector Beta = -SumMom.boostVector();
    G4ThreeVector Beta = -TotalCollisionMom.boostVector();
    Output->Boost(Beta);

    // Scale total c.m.s. hadron energy (hadron system mass).
    // It should be equal interaction mass
    G4double Scale = 1;
    G4int cAttempt = 0;
    G4double Sum = 0;
    G4bool success = false;
    for(cAttempt = 0; cAttempt < nAttemptScale; cAttempt++)
    {
      Sum = 0;
      for(cHadron = 0; cHadron < Output->size(); cHadron++)
      {
        G4LorentzVector HadronMom = Output->operator[](cHadron)->Get4Momentum();
        HadronMom.setVect(Scale*HadronMom.vect());
        G4double E = std::sqrt(HadronMom.vect().mag2() + sqr(Output->operator[](cHadron)->GetDefinition()->GetPDGMass()));
        HadronMom.setE(E);
        Output->operator[](cHadron)->Set4Momentum(HadronMom);
        Sum += E;
      } 
      Scale = TotalCollisionMass/Sum;    
      #ifdef debug_G4ExcitedStringCorr
      G4cout << "Scale-1=" << Scale -1 
             << ",  TotalCollisionMass=" << TotalCollisionMass
         << ",  Sum=" << Sum
         << G4endl;
      #endif     
      if (std::fabs(Scale - 1) <= ErrLimit) 
      {
        success = true;
    break;
      }
    }
    #ifdef debug_G4ExcitedStringCorr
    if(!success)
    {
      G4cout << "G4ExcitedStringDecay::EnergyAndMomentumCorrector - Warning"<<G4endl;
      G4cout << "   Scale not unity at end of iteration loop: "<<TotalCollisionMass<<" "<<Sum<<" "<<Scale<<G4endl;
      G4cout << "   Number of secondaries: " << Output->size() << G4endl;
      G4cout << "   Wanted total energy: " <<  TotalCollisionMom.e() << G4endl; 
      G4cout << "   Increase number of attempts or increase ERRLIMIT"<<G4endl;
      //throw G4HadronicException(__FILE__, __LINE__, "G4ExcitedStringDecay failed to correct...");
    }
    #endif     
    // Compute c.m.s. interaction velocity and KTV back boost   
    Beta = TotalCollisionMom.boostVector();
    Output->Boost(Beta);

    return success;
}