G4ExcitedStringDecay.cc

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// Historic fragment from M.Komogorov; clean-up still necessary @@@
 
#include "G4ExcitedStringDecay.hh"
#include "G4SystemOfUnits.hh"
#include "G4KineticTrack.hh"
#include "G4LundStringFragmentation.hh"
#include "G4HadronicInteractionRegistry.hh"
 
#include "G4SampleResonance.hh"
 
//#define debug_G4ExcitedStringDecay
//#define debug_G4ExcitedStringCorr
 
G4ExcitedStringDecay::G4ExcitedStringDecay(G4VLongitudinalStringDecay* ptr)
  : G4VStringFragmentation(), theStringDecay(ptr)
{
  if(!ptr) { 
    G4HadronicInteraction* p =
      G4HadronicInteractionRegistry::Instance()->FindModel("LundStringFragmentation");
    theStringDecay = static_cast<G4VLongitudinalStringDecay*>(p);
    if(!theStringDecay) { theStringDecay = new G4LundStringFragmentation(); }
  } 
  SetModelName(theStringDecay->GetModelName());
}
 
G4ExcitedStringDecay::~G4ExcitedStringDecay()
{}
 
G4KineticTrackVector *G4ExcitedStringDecay::FragmentString(const G4ExcitedString &theString)
{
  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++)
  // for ( unsigned int astring=0; astring < 1; astring++)
  {
    // G4cout<<"theStrings->operator[](astring)->IsExcited() "<<" "<<astring<<" "<<theStrings->operator[](astring)->IsExcited()<<G4endl;
    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++)
  // for ( unsigned int astring=0; astring < 1; 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();
    }
  }
 
  G4SampleResonance BrW;
  const G4ParticleDefinition* TrackDefinition=0;
 
  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++)
        // for ( unsigned int astring=0; astring < 1; astring++)  // Proj. Last Str. Decay for FTF
        // for ( unsigned int astring=1; astring < 2; astring++)  // Proj. Last Str. Decay for QGS
        // for ( unsigned int astring=0; astring < 1; astring++)  // For testing purposes
    {
          #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 == nullptr || generatedKineticTracks->size() == 0)
      {
             // G4cerr << "G4VPartonStringModel:No KineticTracks produced" << G4endl; 
             continue;
      }
 
          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()
                   <<(*generatedKineticTracks)[aTrack]->Get4Momentum().mag()<<G4endl;
             #endif
             // --------------- Sampling mass of unstable hadronic resonances ----------------
             TrackDefinition = (*generatedKineticTracks)[aTrack]->GetDefinition();
 
         if (TrackDefinition->IsShortLived())
             {
               G4double NewTrackMass = 
                 BrW.SampleMass( TrackDefinition->GetPDGMass(), TrackDefinition->GetPDGWidth(),
                                 BrW.GetMinimumMass( TrackDefinition ) + 10.0*MeV, 
                                 TrackDefinition->GetPDGMass() + 5.0*TrackDefinition->GetPDGWidth() );
               G4LorentzVector Tmp=G4LorentzVector((*generatedKineticTracks)[aTrack]->Get4Momentum());
               Tmp.setE(std::sqrt(sqr(NewTrackMass) + Tmp.vect().mag2()));
 
               (*generatedKineticTracks)[aTrack]->Set4Momentum(Tmp);
 
               #ifdef debug_G4ExcitedStringDecay  
               G4cout<<"Resonance *** "<<aTrack+1<<" "
                     <<(*generatedKineticTracks)[aTrack]->GetDefinition()->GetParticleName()<<" "
                     <<(*generatedKineticTracks)[aTrack]->Get4Momentum()
                     <<(*generatedKineticTracks)[aTrack]->Get4Momentum().mag()<<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;                          
    }
 
    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
 
  if (!success)
  {
    if (theResult->size() != 0)
    {
      std::for_each(theResult->begin() , theResult->end() , DeleteKineticTrack());
      theResult->clear();
      delete theResult; theResult=0;
    }
    for ( unsigned int astring=0; astring < theStrings->size(); astring++)
    // for ( unsigned int astring=0; astring < 1; astring++) // Need more correct. For testing purposes.
    {
      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();
 
    std::vector<G4double> HadronMass; G4double HadronM(0.);
 
    #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();
        HadronM=Output->operator[](cHadron)->Get4Momentum().mag(); HadronMass.push_back(HadronM);
        SumMass += Output->operator[](cHadron)->Get4Momentum().mag();  //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++)
      {
        HadronM = HadronMass.at(cHadron);
        G4LorentzVector HadronMom = Output->operator[](cHadron)->Get4Momentum();
        HadronMom.setVect(Scale*HadronMom.vect());
        G4double E = std::sqrt(HadronMom.vect().mag2() + sqr(HadronM));
                                                       //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;
}