genie::FermiMover Class Reference

It visits the event record & computes a Fermi motion momentum for initial state nucleons bound in nuclei. Is a concrete implementation of the EventRecordVisitorI interface. More...

#include <FermiMover.h>

Inheritance diagram for genie::FermiMover:

Public Member Functions
	FermiMover ()
	FermiMover (string config)
	~FermiMover ()
void	ProcessEventRecord (GHepRecord *event_rec) const
void	Configure (const Registry &config)
void	Configure (string config)
Public Member Functions inherited from genie::EventRecordVisitorI
virtual	~EventRecordVisitorI ()
Public Member Functions inherited from genie::Algorithm
virtual	~Algorithm ()
virtual void	FindConfig (void)
virtual const Registry &	GetConfig (void) const
Registry *	GetOwnedConfig (void)
virtual const AlgId &	Id (void) const
	Get algorithm ID. More...
virtual AlgStatus_t	GetStatus (void) const
	Get algorithm status. More...
virtual bool	AllowReconfig (void) const
virtual AlgCmp_t	Compare (const Algorithm *alg) const
	Compare with input algorithm. More...
virtual void	SetId (const AlgId &id)
	Set algorithm ID. More...
virtual void	SetId (string name, string config)
const Algorithm *	SubAlg (const RgKey &registry_key) const
void	AdoptConfig (void)
void	AdoptSubstructure (void)
virtual void	Print (ostream &stream) const
	Print algorithm info. More...

Private Member Functions
void	KickHitNucleon (GHepRecord *evrec) const
	give hit nucleon a momentum More...
void	AddTargetNucleusRemnant (GHepRecord *evrec) const
	add a recoiled nucleus remnant More...
void	LoadConfig (void)

Private Attributes
bool	fKeepNuclOnMassShell
	keep hit bound nucleon on the mass shell? More...
const NuclearModelI *	fNuclModel
	nuclear model More...
const SecondNucleonEmissionI *	fSecondEmitter

Additional Inherited Members
Static Public Member Functions inherited from genie::Algorithm
static string	BuildParamVectKey (const std::string &comm_name, unsigned int i)
static string	BuildParamVectSizeKey (const std::string &comm_name)
Protected Member Functions inherited from genie::EventRecordVisitorI
	EventRecordVisitorI ()
	EventRecordVisitorI (string name)
	EventRecordVisitorI (string name, string config)
Protected Member Functions inherited from genie::Algorithm
	Algorithm ()
	Algorithm (string name)
	Algorithm (string name, string config)
void	Initialize (void)
void	DeleteConfig (void)
void	DeleteSubstructure (void)
Registry *	ExtractLocalConfig (const Registry &in) const
Registry *	ExtractLowerConfig (const Registry &in, const string &alg_key) const
	Split an incoming configuration Registry into a block valid for the sub-algo identified by alg_key. More...
template<class T >
bool	GetParam (const RgKey &name, T &p, bool is_top_call=true) const
template<class T >
bool	GetParamDef (const RgKey &name, T &p, const T &def) const
template<class T >
int	GetParamVect (const std::string &comm_name, std::vector< T > &v, bool is_top_call=true) const
	Handle to load vectors of parameters. More...
int	GetParamVectKeys (const std::string &comm_name, std::vector< RgKey > &k, bool is_top_call=true) const
int	AddTopRegistry (Registry *rp, bool owns=true)
	add registry with top priority, also update ownership More...
int	AddLowRegistry (Registry *rp, bool owns=true)
	add registry with lowest priority, also update ownership More...
int	MergeTopRegistry (const Registry &r)
int	AddTopRegisties (const vector< Registry * > &rs, bool owns=false)
	Add registries with top priority, also udated Ownerships. More...
Protected Attributes inherited from genie::Algorithm
bool	fAllowReconfig
bool	fOwnsSubstruc
	true if it owns its substructure (sub-algs,...) More...
AlgId	fID
	algorithm name and configuration set More...
vector< Registry * >	fConfVect
vector< bool >	fOwnerships
	ownership for every registry in fConfVect More...
AlgStatus_t	fStatus
	algorithm execution status More...
AlgMap *	fOwnedSubAlgMp
	local pool for owned sub-algs (taken out of the factory pool) More...

Detailed Description

It visits the event record & computes a Fermi motion momentum for initial state nucleons bound in nuclei. Is a concrete implementation of the EventRecordVisitorI interface.

Author

Costas Andreopoulos <constantinos.andreopoulos cern.ch> University of Liverpool & STFC Rutherford Appleton Laboratory

October 08, 2004

Copyright (c) 2003-2020, The GENIE Collaboration For the full text of the license visit http://copyright.genie-mc.org

Definition at line 35 of file FermiMover.h.

Constructor & Destructor Documentation

FermiMover::FermiMover

(

)

Definition at line 65 of file FermiMover.cxx.

                       :
EventRecordVisitorI("genie::FermiMover")
{

}

FermiMover::FermiMover

(

string

config

)

Definition at line 71 of file FermiMover.cxx.

                                    :
EventRecordVisitorI("genie::FermiMover", config)
{

}

FermiMover::~FermiMover

(

)

Definition at line 77 of file FermiMover.cxx.

{

}

Member Function Documentation

void FermiMover::AddTargetNucleusRemnant ( GHepRecord *  evrec ) const

private

add a recoiled nucleus remnant

Definition at line 224 of file FermiMover.cxx.

{
// add the remnant nuclear target at the GHEP record

  LOG("FermiMover", pINFO) << "Adding final state nucleus";

  double Px = 0;
  double Py = 0;
  double Pz = 0;
  double E  = 0;

  GHepParticle * nucleus = evrec->TargetNucleus();
  int A = nucleus->A();
  int Z = nucleus->Z();

  int fd = nucleus->FirstDaughter();
  int ld = nucleus->LastDaughter();

  for(int id = fd; id <= ld; id++) {

    // compute A,Z for final state nucleus & get its PDG code and its mass
    GHepParticle * particle = evrec->Particle(id);
    assert(particle);
    int  pdgc = particle->Pdg();
    bool is_p  = pdg::IsProton (pdgc);
    bool is_n  = pdg::IsNeutron(pdgc);

    if (is_p) Z--;
    if (is_p || is_n) A--;

    Px += particle->Px();
    Py += particle->Py();
    Pz += particle->Pz();
    E  += particle->E();

  }//daughters

  TParticlePDG * remn = 0;
  int ipdgc = pdg::IonPdgCode(A, Z);
  remn = PDGLibrary::Instance()->Find(ipdgc);
  if(!remn) {
    LOG("HadronicVtx", pFATAL)
          << "No particle with [A = " << A << ", Z = " << Z
                            << ", pdgc = " << ipdgc << "] in PDGLibrary!";
    assert(remn);
  }

  double Mi = nucleus->Mass();
  Px *= -1;
  Py *= -1;
  Pz *= -1;
  E = Mi-E;

  // Add the nucleus to the event record
  LOG("FermiMover", pINFO)
     << "Adding nucleus [A = " << A << ", Z = " << Z
     << ", pdgc = " << ipdgc << "]";

  int imom = evrec->TargetNucleusPosition();
  evrec->AddParticle(
       ipdgc,kIStStableFinalState, imom,-1,-1,-1, Px,Py,Pz,E, 0,0,0,0);
}

void FermiMover::Configure ( const Registry &  config )

virtual

Configure the algorithm with an external registry The registry is merged with the top level registry if it is owned, Otherwise a copy of it is added with the highest priority

Reimplemented from genie::Algorithm.

Definition at line 287 of file FermiMover.cxx.

{
  Algorithm::Configure(config);
  this->LoadConfig();
}

void FermiMover::Configure ( string  config )

virtual

Configure the algorithm from the AlgoConfigPool based on param_set string given in input An algorithm contains a vector of registries coming from different xml configuration files, which are loaded according a very precise prioriy This methods will load a number registries in order of priority: 1) "Tunable" parameter set from CommonParametes. This is loaded with the highest prioriry and it is designed to be used for tuning procedure Usage not expected from the user. 2) For every string defined in "CommonParame" the corresponding parameter set will be loaded from CommonParameter.xml 3) parameter set specified by the config string and defined in the xml file of the algorithm 4) if config is not "Default" also the Default parameter set from the same xml file will be loaded Effectively this avoids the repetion of a parameter when it is not changed in the requested configuration

Reimplemented from genie::Algorithm.

Definition at line 293 of file FermiMover.cxx.

{
  Algorithm::Configure(config);
  this->LoadConfig();
}

void FermiMover::KickHitNucleon ( GHepRecord *  evrec ) const

private

give hit nucleon a momentum

Definition at line 100 of file FermiMover.cxx.

{
  Interaction *  interaction = evrec       -> Summary();
  InitialState * init_state  = interaction -> InitStatePtr();
  Target *       tgt         = init_state  -> TgtPtr();

  // do nothing for non-nuclear targets
  if(!tgt->IsNucleus()) return;

  TLorentzVector * p4 = tgt->HitNucP4Ptr();

  // do nothing if the struct nucleon 4-momentum was set (eg as part of the
  // initial state selection)
  if(p4->Px()>0 || p4->Py()>0 || p4->Pz()>0) return;

  // access the hit nucleon and target nucleus at the GHEP record
  GHepParticle * nucleon = evrec->HitNucleon();
  GHepParticle * nucleus = evrec->TargetNucleus();
  assert(nucleon);
  assert(nucleus);

  // generate a Fermi momentum & removal energy
  // call GenerateNucleon with a radius in case the model is LocalFGM
  double rad = nucleon->X4()->Vect().Mag();
  fNuclModel->GenerateNucleon(*tgt,rad);

  TVector3 p3 = fNuclModel->Momentum3();
  double w    = fNuclModel->RemovalEnergy();

  LOG("FermiMover", pINFO)
     << "Generated nucleon momentum: ("
     << p3.Px() << ", " << p3.Py() << ", " << p3.Pz() << "), "
     << "|p| = " << p3.Mag();
  LOG("FermiMover", pINFO)
     << "Generated nucleon removal energy: w = " << w;

  double pF2 = p3.Mag2(); // (fermi momentum)^2

  nucleon->SetRemovalEnergy(w);

  // struck nucleon energy:
  // two possible prescriptions depending on whether you want to force
  // the sruck nucleon to be on the mass-shell or not...

  double EN=0;
  FermiMoverInteractionType_t interaction_type = fNuclModel->GetFermiMoverInteractionType();

  // EffectiveSF treatment
  if (interaction_type == kFermiMoveEffectiveSF1p1h) {
    EN = nucleon->Mass() - w - pF2 / (2 * (nucleus->Mass() - nucleon->Mass()));
  } else if (interaction_type == kFermiMoveEffectiveSF2p2h_eject ||
             interaction_type == kFermiMoveEffectiveSF2p2h_noeject) {

                int other_nucleon_pdg = nucleon->Pdg() == kPdgProton ? kPdgNeutron : kPdgProton ;
                TParticlePDG * other_nucleon = PDGLibrary::Instance()->Find( other_nucleon_pdg );

    TParticlePDG * deuteron = PDGLibrary::Instance()->Find(1000010020);
    EN = deuteron->Mass() - 2 * w - TMath::Sqrt(pF2 + other_nucleon->Mass() * other_nucleon->Mass());

  // Do default Fermi Moving
  } else  {
    if (!fKeepNuclOnMassShell) {
      //-- compute A,Z for final state nucleus & get its PDG code
      int nucleon_pdgc = nucleon->Pdg();
      bool is_p  = pdg::IsProton(nucleon_pdgc);
      int Z = (is_p) ? nucleus->Z()-1 : nucleus->Z();
      int A = nucleus->A() - 1;

      TParticlePDG * fnucleus = 0;
      int ipdgc = pdg::IonPdgCode(A, Z);
      fnucleus = PDGLibrary::Instance()->Find(ipdgc);
      if(!fnucleus) {
        LOG("FermiMover", pFATAL)
              << "No particle with [A = " << A << ", Z = " << Z
              << ", pdgc = " << ipdgc << "] in PDGLibrary!";
        exit(1);
      }
      //-- compute the energy of the struck (off the mass-shell) nucleus

      double Mf  = fnucleus -> Mass(); // remnant nucleus mass
      double Mi  = nucleus  -> Mass(); // initial nucleus mass

      EN = Mi - TMath::Sqrt(pF2 + Mf*Mf);
    } else {
      double MN  = nucleon->Mass();
      double MN2 = TMath::Power(MN,2);
      EN = TMath::Sqrt(MN2+pF2);
    }

  }

  //-- update the struck nucleon 4p at the interaction summary and at
  //   the GHEP record
  p4->SetPx( p3.Px() );
  p4->SetPy( p3.Py() );
  p4->SetPz( p3.Pz() );
  p4->SetE ( EN      );

  nucleon->SetMomentum(*p4); // update GHEP value

  // Sometimes, for interactions near threshold, Fermi momentum might bring
  // the neutrino energy in the nucleon rest frame below threshold (for the
  // selected interaction). In this case mark the event as unphysical and
  // abort the current thread.
  const KPhaseSpace & kps = interaction->PhaseSpace();
  if(!kps.IsAboveThreshold()) {
     LOG("FermiMover", pNOTICE)
                  << "Event below threshold after generating Fermi momentum";

     double Ethr = kps.Threshold();
     double Ev   = init_state->ProbeE(kRfHitNucRest);
     LOG("FermiMover", pNOTICE)
              << "Ev (@ nucleon rest frame) = " << Ev << ", Ethr = " << Ethr;

     evrec->EventFlags()->SetBitNumber(kBelowThrNRF, true);
     genie::exceptions::EVGThreadException exception;
     exception.SetReason("E < Ethr after generating nucleon Fermi momentum");
     exception.SwitchOnFastForward();
     throw exception;
  }


}

void FermiMover::LoadConfig ( void  )

private

Definition at line 299 of file FermiMover.cxx.

{
  RgKey nuclkey = "NuclearModel";
  fNuclModel = 0;
  fNuclModel = dynamic_cast<const NuclearModelI *> (this->SubAlg(nuclkey));
  assert(fNuclModel);

  this->GetParamDef("KeepHitNuclOnMassShell", fKeepNuclOnMassShell, false);

  RgKey nuclearrecoilkey = "SecondNucleonEmitter" ;
  fSecondEmitter = dynamic_cast<const SecondNucleonEmissionI *> (this->SubAlg(nuclearrecoilkey));
  
  assert(fSecondEmitter);

}

void FermiMover::ProcessEventRecord ( GHepRecord *  event_rec ) const

virtual

Implements genie::EventRecordVisitorI.

Definition at line 82 of file FermiMover.cxx.

{
  // skip if not a nuclear target
  if(! evrec->Summary()->InitState().Tgt().IsNucleus()) return;

  // skip if no hit nucleon is set
  if(! evrec->HitNucleon()) return;

  // give hit nucleon a Fermi momentum
  this->KickHitNucleon(evrec);

  // handle the addition of the recoil nucleon
  if ( fSecondEmitter ) fSecondEmitter -> ProcessEventRecord( evrec ) ;

  // add a recoiled nucleus remnant
  this->AddTargetNucleusRemnant(evrec);
}

Member Data Documentation

bool genie::FermiMover::fKeepNuclOnMassShell

private

keep hit bound nucleon on the mass shell?

Definition at line 58 of file FermiMover.h.

const NuclearModelI* genie::FermiMover::fNuclModel

private

nuclear model

Definition at line 59 of file FermiMover.h.

const SecondNucleonEmissionI* genie::FermiMover::fSecondEmitter

private

Definition at line 61 of file FermiMover.h.

---

The documentation for this class was generated from the following files:

• Generator/src/Physics/NuclearState/FermiMover.h
• Generator/src/Physics/NuclearState/FermiMover.cxx