evgen::NeutronOsc Class Reference

Inheritance diagram for evgen::NeutronOsc:

Public Member Functions
	NeutronOsc (fhicl::ParameterSet const &p)
	NeutronOsc (NeutronOsc const &)=delete
	NeutronOsc (NeutronOsc &&)=delete
NeutronOsc &	operator= (NeutronOsc const &)=delete
NeutronOsc &	operator= (NeutronOsc &&)=delete
void	produce (art::Event &e) override
void	beginRun (art::Run &run) override

Private Member Functions
int	SelectAnnihilationMode (int pdg_code)

Private Attributes
const genie::EventRecordVisitorI *	mcgen
genie::NNBarOscMode_t	gOptDecayMode = genie::kNONull
CLHEP::RandFlat	flatDist

Detailed Description

Definition at line 72 of file NeutronOsc_module.cc.

Constructor & Destructor Documentation

evgen::NeutronOsc::NeutronOsc ( fhicl::ParameterSet const &  p )

explicit

Definition at line 103 of file NeutronOsc_module.cc.

  : art::EDProducer{p}
  // create a default random engine; obtain the random seed from NuRandomService,
  // unless overridden in configuration with key "Seed"
  , flatDist{art::ServiceHandle<rndm::NuRandomService>{}->createEngine(*this, p, "Seed")}

evgen::NeutronOsc::NeutronOsc ( NeutronOsc const &  )

delete

evgen::NeutronOsc::NeutronOsc ( NeutronOsc &&  )

delete

Member Function Documentation

void evgen::NeutronOsc::beginRun ( art::Run &  run )

override

Definition at line 217 of file NeutronOsc_module.cc.

{
  art::ServiceHandle<geo::Geometry const> geo;
  run.put(std::make_unique<sumdata::RunData>(geo->DetectorName()));
}

NeutronOsc& evgen::NeutronOsc::operator= ( NeutronOsc const &  )

delete

NeutronOsc& evgen::NeutronOsc::operator= ( NeutronOsc &&  )

delete

void evgen::NeutronOsc::produce ( art::Event &  e )

override

Definition at line 133 of file NeutronOsc_module.cc.

{
  // Implementation of required member function here.
  genie::EventRecord * event = new genie::EventRecord;
  int target = 1000180400;  //Only use argon target
  int decay  = SelectAnnihilationMode(target);
  genie::Interaction * interaction = genie::Interaction::NOsc(target,decay);
  event->AttachSummary(interaction);

  // Simulate decay
  mcgen->ProcessEventRecord(event);

//  genie::Interaction *inter = event->Summary();
//  const genie::InitialState &initState = inter->InitState();
//  std::cout<<"initState = "<<initState.AsString()<<std::endl;
//  const genie::ProcessInfo &procInfo = inter->ProcInfo();
//  std::cout<<"procInfo = "<<procInfo.AsString()<<std::endl;
  MF_LOG_DEBUG("NeutronOsc")
    << "Generated event: " << *event;

  std::unique_ptr< std::vector<simb::MCTruth> > truthcol(new std::vector<simb::MCTruth>);
  simb::MCTruth truth;

  art::ServiceHandle<geo::Geometry const> geo;

  // Find boundary of active volume
  double minx = 1e9;
  double maxx = -1e9;
  double miny = 1e9;
  double maxy = -1e9;
  double minz = 1e9;
  double maxz = -1e9;
  for (size_t i = 0; i<geo->NTPC(); ++i){
    const geo::TPCGeo &tpc = geo->TPC(i);
    if (minx>tpc.MinX()) minx = tpc.MinX();
    if (maxx<tpc.MaxX()) maxx = tpc.MaxX();
    if (miny>tpc.MinY()) miny = tpc.MinY();
    if (maxy<tpc.MaxY()) maxy = tpc.MaxY();
    if (minz>tpc.MinZ()) minz = tpc.MinZ();
    if (maxz<tpc.MaxZ()) maxz = tpc.MaxZ();
  }

  // Assign vertice position
  double X0 = flatDist.fire( minx, maxx );
  double Y0 = flatDist.fire( miny, maxy );
  double Z0 = flatDist.fire( minz, maxz );

  TIter partitr(event);
  genie::GHepParticle *part = 0;
  // GHepParticles return units of GeV/c for p.  the V_i are all in fermis
  // and are relative to the center of the struck nucleus.
  // add the vertex X/Y/Z to the V_i for status codes 0 and 1
  int trackid = 0;
  std::string primary("primary");

  while( (part = dynamic_cast<genie::GHepParticle *>(partitr.Next())) ){

    simb::MCParticle tpart(trackid,
                           part->Pdg(),
                           primary,
                           part->FirstMother(),
                           part->Mass(),
                           part->Status());

    TLorentzVector pos(X0, Y0, Z0, 0);
    TLorentzVector mom(part->Px(), part->Py(), part->Pz(), part->E());
    tpart.AddTrajectoryPoint(pos,mom);
    if(part->PolzIsSet()) {
      TVector3 polz;
      part->GetPolarization(polz);
      tpart.SetPolarization(polz);
    }
    truth.Add(tpart);

    ++trackid;
  }// end loop to convert GHepParticles to MCParticles
  truth.SetOrigin(simb::kUnknown);
  truthcol->push_back(truth);
  //FillHistograms(truth);
  e.put(std::move(truthcol));

  delete event;
}

int evgen::NeutronOsc::SelectAnnihilationMode ( int  pdg_code )

private

Definition at line 224 of file NeutronOsc_module.cc.

{
  // if the mode is set to 'random' (the default), pick one at random!
  if ((int)gOptDecayMode == 0) {
    int mode;

    std::string pdg_string = std::to_string(static_cast<long long>(pdg_code));
    if (pdg_string.size() != 10) {
      std::cout << "Expecting PDG code to be a 10-digit integer; instead, it's the following: " << pdg_string << std::endl;
      exit(1);
    }

    // count number of protons & neutrons
    int n_nucleons = std::stoi(pdg_string.substr(6,3)) - 1;
    int n_protons  = std::stoi(pdg_string.substr(3,3));

    // factor proton / neutron ratio into branching ratios
    double proton_frac  = ((double)n_protons) / ((double)n_nucleons);
    double neutron_frac = 1 - proton_frac;

    // set branching ratios, taken from bubble chamber data
    const int n_modes = 16;
    double br [n_modes] = { 0.010, 0.080, 0.100, 0.220,
                            0.360, 0.160, 0.070, 0.020,
                            0.015, 0.065, 0.110, 0.280,
                            0.070, 0.240, 0.100, 0.100 };

    for (int i = 0; i < n_modes; i++) {
      if (i < 7)
        br[i] *= proton_frac;
      else
        br[i] *= neutron_frac;
    }

    // randomly generate a number between 1 and 0
    double p = flatDist.fire();

    // loop through all modes, figure out which one our random number corresponds to
    double threshold = 0;
    for (int i = 0; i < n_modes; i++) {
      threshold += br[i];
      if (p < threshold) {
        // once we've found our mode, return it!
        mode = i + 1;
        return mode;
      }
    }

    // error message, in case the random number selection fails
    std::cout << "Random selection of final state failed!" << std::endl;
    exit(1);
  }

  // if specific annihilation mode specified, just use that
  else {
    int mode = (int) gOptDecayMode;
    return mode;
  }
}

Member Data Documentation

CLHEP::RandFlat evgen::NeutronOsc::flatDist

private

Definition at line 98 of file NeutronOsc_module.cc.

genie::NNBarOscMode_t evgen::NeutronOsc::gOptDecayMode = genie::kNONull

private

Definition at line 97 of file NeutronOsc_module.cc.

const genie::EventRecordVisitorI* evgen::NeutronOsc::mcgen

private

Definition at line 96 of file NeutronOsc_module.cc.

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

• NeutronOsc_module.cc