G4VDecayChannel.cc

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// G4VDecayChannel
//
// Author: H.Kurashige, 27 July 1996 
// --------------------------------------------------------------------
 
#include "G4ParticleDefinition.hh"
#include "G4SystemOfUnits.hh"
#include "G4ParticleTable.hh"
#include "G4DecayTable.hh"
#include "G4DecayProducts.hh"
#include "G4VDecayChannel.hh"
#include "G4AutoLock.hh"
#include "Randomize.hh"
 
const G4String G4VDecayChannel::noName = " ";
 
// --------------------------------------------------------------------
G4VDecayChannel::G4VDecayChannel()
  : parent_polarization()
{
  // set pointer to G4ParticleTable (static and singleton object)
  particletable = G4ParticleTable::GetParticleTable();
}
 
// --------------------------------------------------------------------
G4VDecayChannel::G4VDecayChannel(const G4String& aName, G4int verbose)
  : kinematics_name(aName), parent_polarization(), verboseLevel(verbose)
{
  // set pointer to G4ParticleTable (static and singleton object)
  particletable = G4ParticleTable::GetParticleTable();
}
 
// --------------------------------------------------------------------
G4VDecayChannel::G4VDecayChannel(const G4String& aName, 
                                 const G4String& theParentName,
                                       G4double  theBR,
                                       G4int     theNumberOfDaughters,
                                 const G4String& theDaughterName1,
                                 const G4String& theDaughterName2,
                                 const G4String& theDaughterName3,
                                 const G4String& theDaughterName4 )
  : kinematics_name(aName), rbranch(theBR), parent_polarization(),
    numberOfDaughters(theNumberOfDaughters) 
{
  // set pointer to G4ParticleTable (static and singleton object)
  particletable = G4ParticleTable::GetParticleTable();
 
  // parent name
  parent_name = new G4String(theParentName);
 
  // cleate array
  daughters_name = new G4String*[numberOfDaughters];
  for (G4int index=0; index<numberOfDaughters; ++index)
  {
    daughters_name[index] = nullptr;
  }
 
  // daughters' name
  if (numberOfDaughters>0) daughters_name[0] = new G4String(theDaughterName1);
  if (numberOfDaughters>1) daughters_name[1] = new G4String(theDaughterName2);
  if (numberOfDaughters>2) daughters_name[2] = new G4String(theDaughterName3);
  if (numberOfDaughters>3) daughters_name[3] = new G4String(theDaughterName4);
 
  if      (rbranch <0.  ) rbranch = 0.0;
  else if (rbranch >1.0 ) rbranch = 1.0;
}
 
// --------------------------------------------------------------------
G4VDecayChannel::G4VDecayChannel(const G4VDecayChannel& right)
{
  kinematics_name = right.kinematics_name;
  verboseLevel = right.verboseLevel;
  rbranch = right.rbranch;
  rangeMass = right.rangeMass;
 
  // copy parent name
  parent_name = new G4String(*right.parent_name);
 
  // create array
  numberOfDaughters = right.numberOfDaughters;
 
  daughters_name = nullptr;
  if ( numberOfDaughters >0 )
  {
    daughters_name = new G4String*[numberOfDaughters];
    // copy daughters name
    for (G4int index=0; index<numberOfDaughters; ++index)
    {
      daughters_name[index] = new G4String(*right.daughters_name[index]);
    }
  }
 
  // particle table
  particletable = G4ParticleTable::GetParticleTable();
 
  parent_polarization = right.parent_polarization;
 
  G4MUTEXINIT(daughtersMutex);
  G4MUTEXINIT(parentMutex);
}
 
// --------------------------------------------------------------------
G4VDecayChannel& G4VDecayChannel::operator=(const G4VDecayChannel& right)
{
  if (this != &right)
  { 
    kinematics_name = right.kinematics_name;
    verboseLevel = right.verboseLevel;
    rbranch = right.rbranch;
    rangeMass =  right.rangeMass;
    parent_polarization = right.parent_polarization;
    // copy parent name
    delete parent_name;
    parent_name = new G4String(*right.parent_name);
 
    // clear daughters_name array
    ClearDaughtersName();
 
    // recreate array
    numberOfDaughters = right.numberOfDaughters;
    if ( numberOfDaughters >0 )
    {
      daughters_name = new G4String*[numberOfDaughters];
      // copy daughters name
      for (G4int index=0; index<numberOfDaughters; ++index)
      {
        daughters_name[index] = new G4String(*right.daughters_name[index]);
      }
    }
  }
 
  // particle table
  particletable = G4ParticleTable::GetParticleTable();
 
  G4MUTEXINIT(daughtersMutex);
  G4MUTEXINIT(parentMutex);
 
  return *this;
}
 
// --------------------------------------------------------------------
G4VDecayChannel::~G4VDecayChannel()
{
  ClearDaughtersName();
  delete parent_name;
  parent_name = nullptr;
  delete [] G4MT_daughters_mass;
  G4MT_daughters_mass = nullptr;
  delete [] G4MT_daughters_width;
  G4MT_daughters_width = nullptr;
  G4MUTEXDESTROY(daughtersMutex);
  G4MUTEXDESTROY(parentMutex);
} 
 
// --------------------------------------------------------------------
void G4VDecayChannel::ClearDaughtersName()
{
  G4AutoLock l(&daughtersMutex);
  if ( daughters_name != nullptr)
  {
    if (numberOfDaughters>0)
    {
#ifdef G4VERBOSE
      if (verboseLevel>1)
      {
        G4cout << "G4VDecayChannel::ClearDaughtersName() "
               << " for " << *parent_name << G4endl;
      }
#endif
      for (G4int index=0; index<numberOfDaughters; ++index)
      { 
        delete daughters_name[index];
      }
    }
    delete [] daughters_name;
    daughters_name = nullptr;
  }
 
  delete [] G4MT_daughters;
  delete [] G4MT_daughters_mass;
  delete [] G4MT_daughters_width;
  G4MT_daughters_width = nullptr;
  G4MT_daughters = nullptr;
  G4MT_daughters_mass = nullptr;
 
  numberOfDaughters = 0;
}
 
// --------------------------------------------------------------------
void G4VDecayChannel::SetNumberOfDaughters(G4int size)
{
  if (size >0)
  {
    // remove old contents
    ClearDaughtersName();
    // cleate array
    daughters_name = new G4String*[size];
    for (G4int index=0; index<size; ++index)
    {
      daughters_name[index] = nullptr;
    }
    numberOfDaughters = size;
  }
}
 
// --------------------------------------------------------------------
void G4VDecayChannel::SetDaughter(G4int anIndex, const G4String& particle_name)
{
  // check numberOfDaughters is positive
  if (numberOfDaughters<=0)
  {
#ifdef G4VERBOSE
    if (verboseLevel>0)
    {
      G4cout << "G4VDecayChannel::SetDaughter() - "
             << "Number of daughters is not defined" << G4endl;
    }
#endif
    return;
  }
 
  // An analysis of this code, shows that this method is called
  // only in the constructor of derived classes.
  // The general idea of this method is probably to support
  // the possibility to re-define daughters on the fly, however
  // this design is extremely problematic for MT mode, we thus
  // require (as practically happens) that the method is called only
  // at construction, i.e. when G4MT_daughters == 0
  // moreover this method can be called only after SetNumberOfDaugthers()
  // has been called (see previous if), in such a case daughters_name != nullptr
  //
  if ( daughters_name == nullptr )
  {
    G4Exception("G4VDecayChannel::SetDaughter()", "PART112", FatalException,
      "Trying to add a daughter without specifying number of secondaries!");
    return;
  }
  if ( G4MT_daughters != nullptr )
  {
    G4Exception("G4VDecayChannel::SetDaughter()", "PART111", FatalException,
                "Trying to modify a daughter of a decay channel, \
                 but decay channel already has daughters.");
    return;
  }
 
  // check an index    
  if ( (anIndex<0) || (anIndex>=numberOfDaughters) )
  {
#ifdef G4VERBOSE
    if (verboseLevel>0)
    {
      G4cout << "G4VDecayChannel::SetDaughter() - "
             << "index out of range " << anIndex << G4endl;
    }
#endif
  }
  else
  {
    // fill the name
    daughters_name[anIndex] = new G4String(particle_name);
#ifdef G4VERBOSE
    if (verboseLevel>1)
    {
      G4cout << "G4VDecayChannel::SetDaughter[" << anIndex <<"] :";
      G4cout << daughters_name[anIndex] << ":"
             << *daughters_name[anIndex]<<G4endl;
    }
#endif
  }
}
 
// --------------------------------------------------------------------
void G4VDecayChannel::
SetDaughter(G4int anIndex, const G4ParticleDefinition* parent_type)
{
  if (parent_type != nullptr)
    SetDaughter(anIndex, parent_type->GetParticleName());
}
 
// --------------------------------------------------------------------
void G4VDecayChannel::FillDaughters()
{
  G4AutoLock lock(&daughtersMutex);
 
  // Double check, check again if another thread has already filled this, in
  // case do not need to do anything
  if ( G4MT_daughters != nullptr ) return;
 
  G4int index;
  
#ifdef G4VERBOSE
  if (verboseLevel>1) G4cout << "G4VDecayChannel::FillDaughters()" << G4endl;
#endif
  if (G4MT_daughters != nullptr)
  {
    delete [] G4MT_daughters;
    G4MT_daughters = nullptr;
  }
 
  // parent mass
  CheckAndFillParent();
  G4double parentmass = G4MT_parent->GetPDGMass();
 
  //
  G4double sumofdaughtermass = 0.0;
  G4double sumofdaughterwidthsq = 0.0;
 
  if ((numberOfDaughters <=0) || (daughters_name == nullptr) )
  {
#ifdef G4VERBOSE
    if (verboseLevel>0)
    {
      G4cout << "G4VDecayChannel::FillDaughters() - "
             << "[ " << G4MT_parent->GetParticleName() << " ]"
             << "numberOfDaughters is not defined yet";
    }
#endif
    G4MT_daughters = nullptr;
    G4Exception("G4VDecayChannel::FillDaughters()",
                "PART011", FatalException,
                "Cannot fill daughters: numberOfDaughters is not defined yet");
  } 
 
  // create and set the array of pointers to daughter particles
  G4MT_daughters = new G4ParticleDefinition*[numberOfDaughters];
  if (G4MT_daughters_mass != nullptr) delete [] G4MT_daughters_mass;
  if (G4MT_daughters_width != nullptr) delete [] G4MT_daughters_width;
  G4MT_daughters_mass = new G4double[numberOfDaughters];
  G4MT_daughters_width = new G4double[numberOfDaughters];
  // loop over all daughters
  for (index=0; index<numberOfDaughters; ++index)
  { 
    if (daughters_name[index] == nullptr)
    {
      // daughter name is not defined
#ifdef G4VERBOSE
      if (verboseLevel>0)
      {
        G4cout << "G4VDecayChannel::FillDaughters() - "
               << "[ " << G4MT_parent->GetParticleName() << " ]"
               << index << "-th daughter is not defined yet" << G4endl;
      }
#endif
      G4MT_daughters[index] = nullptr;
      G4Exception("G4VDecayChannel::FillDaughters()",
                  "PART011", FatalException,
                  "Cannot fill daughters: name of daughter is not defined yet");
    } 
    // search daughter particles in the particle table 
    G4MT_daughters[index] = particletable->FindParticle(*daughters_name[index]);
    if (G4MT_daughters[index] == nullptr )
    {
      // cannot find the daughter particle
#ifdef G4VERBOSE
      if (verboseLevel>0)
      {
        G4cout << "G4VDecayChannel::FillDaughters() - "
                << "[ " << G4MT_parent->GetParticleName() << " ]"
               << index << ":" << *daughters_name[index]
               << " is not defined !!" << G4endl;
        G4cout << " The BR of this decay mode is set to zero." << G4endl;
      }
#endif
      SetBR(0.0);
      return;
    }
#ifdef G4VERBOSE
    if (verboseLevel>1)
    {
      G4cout << index << ":" << *daughters_name[index];
      G4cout << ":" << G4MT_daughters[index] << G4endl;
    }
#endif
    G4MT_daughters_mass[index] = G4MT_daughters[index]->GetPDGMass();
    G4double d_width = G4MT_daughters[index]->GetPDGWidth();
    G4MT_daughters_width[index] = d_width;
    sumofdaughtermass += G4MT_daughters[index]->GetPDGMass();
    sumofdaughterwidthsq += d_width*d_width;
  }  // end loop over all daughters
 
  // check sum of daghter mass
  G4double widthMass = std::sqrt(G4MT_parent->GetPDGWidth()
                                *G4MT_parent->GetPDGWidth()
                                +sumofdaughterwidthsq);
  if ( (G4MT_parent->GetParticleType() != "nucleus")
    && (numberOfDaughters !=1)
    && (sumofdaughtermass > parentmass + rangeMass*widthMass) )
  {
    // !!! illegal mass  !!!
#ifdef G4VERBOSE
    if (GetVerboseLevel()>0)
    {
      G4cout << "G4VDecayChannel::FillDaughters() - "
             << "[ " << G4MT_parent->GetParticleName() << " ]"
             << "    Energy/Momentum conserevation breaks " << G4endl;
     if (GetVerboseLevel()>1)
     {
       G4cout << "    parent:" << *parent_name
              << " mass:" << parentmass/GeV << "[GeV/c/c]" << G4endl;
       for (index=0; index<numberOfDaughters; ++index)
       {
         G4cout << "     daughter " << index << ":" << *daughters_name[index]
                << " mass:" << G4MT_daughters[index]->GetPDGMass()/GeV
                << "[GeV/c/c]" << G4endl;
       }
     }
   }
#endif
 }
}
 
// --------------------------------------------------------------------
void G4VDecayChannel::FillParent()
{
  G4AutoLock lock(&parentMutex);
 
  // Double check, check again if another thread has already filled this, in
  // case do not need to do anything
  if ( G4MT_parent != nullptr ) return;
 
  if (parent_name == nullptr)
  {
    // parent name is not defined
#ifdef G4VERBOSE
    if (verboseLevel>0)
    {
      G4cout << "G4VDecayChannel::FillParent() - "
             << "parent name is not defined !!" << G4endl;
    }
#endif
    G4MT_parent = nullptr;
    G4Exception("G4VDecayChannel::FillParent()",
                "PART012", FatalException,
                "Cannot fill parent: parent name is not defined yet");    
    return;
  }
 
  // search parent particle in the particle table
  G4MT_parent = particletable->FindParticle(*parent_name);
  if (G4MT_parent == nullptr)
  {
    // parent particle does not exist
#ifdef G4VERBOSE
    if (verboseLevel>0)
    {
      G4cout << "G4VDecayChannel::FillParent() - "
             << *parent_name << " does not exist !!" << G4endl;
    }
#endif
    G4Exception("G4VDecayChannel::FillParent()",
                "PART012", FatalException,
                "Cannot fill parent: parent does not exist");
    return;
  }
  G4MT_parent_mass = G4MT_parent->GetPDGMass();
}
 
// --------------------------------------------------------------------
void G4VDecayChannel::SetParent(const G4ParticleDefinition* parent_type)
{
  if (parent_type != nullptr) SetParent(parent_type->GetParticleName());
}
 
// --------------------------------------------------------------------
G4int G4VDecayChannel::GetAngularMomentum()
{
  // determine angular momentum
 
  // fill pointers to daughter particles if not yet set  
  CheckAndFillDaughters();
 
  const G4int PiSpin = G4MT_parent->GetPDGiSpin();
  const G4int PParity = G4MT_parent->GetPDGiParity();
  if (2==numberOfDaughters) // up to now we can only handle two particle decays
  {
    const G4int D1iSpin  = G4MT_daughters[0]->GetPDGiSpin();
    const G4int D1Parity = G4MT_daughters[0]->GetPDGiParity();
    const G4int D2iSpin  = G4MT_daughters[1]->GetPDGiSpin();
    const G4int D2Parity = G4MT_daughters[1]->GetPDGiParity();
    const G4int MiniSpin = std::abs (D1iSpin - D2iSpin);
    const G4int MaxiSpin = D1iSpin + D2iSpin;
    const G4int lMax = (PiSpin+D1iSpin+D2iSpin)/2; // l is always int
    G4int lMin;
#ifdef G4VERBOSE
    if (verboseLevel>1)
    {
      G4cout << "iSpin: " << PiSpin << " -> " << D1iSpin
             << " + " << D2iSpin << G4endl;
      G4cout << "2*jmin, 2*jmax, lmax " << MiniSpin << " " << MaxiSpin
             << " " << lMax << G4endl;
    }
#endif
    for (G4int j=MiniSpin; j<=MaxiSpin; j+=2) // loop over all possible
    {                                         // spin couplings
      lMin = std::abs(PiSpin-j)/2;
#ifdef G4VERBOSE 
      if (verboseLevel>1)
        G4cout << "-> checking 2*j=" << j << G4endl;
#endif
      for (G4int l=lMin; l<=lMax; ++l)
      {
#ifdef G4VERBOSE
        if (verboseLevel>1)
          G4cout << " checking l=" << l << G4endl;
#endif
        if (l%2==0)
        {
          if (PParity == D1Parity*D2Parity)    // check parity for this l
            return l;
        }
        else
        {
          if (PParity == -1*D1Parity*D2Parity) // check parity for this l
            return l;
        }
      }
    }
  }
  else
  {
    G4Exception("G4VDecayChannel::GetAngularMomentum()",
                "PART111", JustWarning,
                "Sorry, can't handle 3 particle decays (up to now)");
    return 0;
  }
  G4Exception ("G4VDecayChannel::GetAngularMomentum()",
                "PART111", JustWarning,
                "Can't find angular momentum for this decay");
  return 0;
}
 
// --------------------------------------------------------------------
void G4VDecayChannel::DumpInfo()
{
  G4cout << " BR:  " << rbranch << "  [" << kinematics_name << "]";
  G4cout << "   :  " ;
  for (G4int index=0; index<numberOfDaughters; ++index)
  {
    if(daughters_name[index] != nullptr)
    {
      G4cout << " " << *(daughters_name[index]);
    }
    else
    {
      G4cout << " not defined ";
    }
  }
  G4cout << G4endl;
}
 
// --------------------------------------------------------------------
const G4String& G4VDecayChannel::GetNoName() const
{
  return noName;
}
 
// --------------------------------------------------------------------
G4double G4VDecayChannel::
DynamicalMass(G4double massPDG, G4double width, G4double maxDev ) const
{ 
  if (width<=0.0) return massPDG;
  if (maxDev >rangeMass) maxDev = rangeMass;
  if (maxDev <=-1.*rangeMass) return massPDG;  // cannot calculate
 
  G4double x = G4UniformRand()*(maxDev+rangeMass) - rangeMass;
  G4double y = G4UniformRand();
  const std::size_t MAX_LOOP=10000;
  for (std::size_t loop_counter=0; loop_counter <MAX_LOOP; ++loop_counter)
  {
    if ( y * (width*width*x*x + massPDG*massPDG*width*width)
       <= massPDG*massPDG*width*width  ) break;
    x = G4UniformRand()*(maxDev+rangeMass) - rangeMass;
    y = G4UniformRand();
  }
  G4double mass = massPDG + x*width;
  return mass;
}
   
// --------------------------------------------------------------------
G4bool G4VDecayChannel::IsOKWithParentMass(G4double parentMass)
{
  G4double sumOfDaughterMassMin = 0.0;
  CheckAndFillParent();
  CheckAndFillDaughters();
  // skip one body decay
  if (numberOfDaughters==1) return true;
  
  for (G4int index=0; index<numberOfDaughters; ++index)
  { 
    sumOfDaughterMassMin += 
      G4MT_daughters_mass[index] - rangeMass*G4MT_daughters_width[index];
  }
  return (parentMass >= sumOfDaughterMassMin); 
}
 
// --------------------------------------------------------------------
void  G4VDecayChannel::SetBR(G4double value)
{ 
  rbranch = value; 
  if      (rbranch <0.  ) rbranch = 0.0;
  else if (rbranch >1.0 ) rbranch = 1.0;
}