genie::COHDNuEventGenerator Class Reference

Generates complete COHDNu events. Is a concrete implementation of the EventRecordVisitorI interface. More...

#include <COHDNuEventGenerator.h>

Inheritance diagram for genie::COHDNuEventGenerator:

Collaboration diagram for genie::COHDNuEventGenerator:

Public Member Functions
	COHDNuEventGenerator ()
	COHDNuEventGenerator (string config)
	~COHDNuEventGenerator ()
void	ProcessEventRecord (GHepRecord *event) 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.
virtual AlgStatus_t	GetStatus (void) const
	Get algorithm status.
virtual bool	AllowReconfig (void) const
virtual AlgCmp_t	Compare (const Algorithm *alg) const
	Compare with input algorithm.
virtual void	SetId (const AlgId &id)
	Set algorithm ID.
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.

Private Member Functions
void	LoadConfig (void)
void	GenerateKinematics (GHepRecord *event) const
void	AddFinalStateDarkNeutrino (GHepRecord *event) const
void	AddRecoilNucleus (GHepRecord *event) const

Private Attributes
const XSecAlgorithmI *	fXSecModel
bool	fGenerateUniformly
double	fSafetyFactor
double	fMaxXSecDiffTolerance
double	fDNuMass
double	fDNuMass2

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)
static string	BuildParamMatKey (const std::string &comm_name, unsigned int i, unsigned int j)
static string	BuildParamMatRowSizeKey (const std::string &comm_name)
static string	BuildParamMatColSizeKey (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.
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.
int	GetParamVectKeys (const std::string &comm_name, std::vector< RgKey > &k, bool is_top_call=true) const
template<class T>
int	GetParamMat (const std::string &comm_name, TMatrixT< T > &mat, bool is_top_call=true) const
	Handle to load matrix of parameters.
template<class T>
int	GetParamMatSym (const std::string &comm_name, TMatrixTSym< T > &mat, bool is_top_call=true) const
int	GetParamMatKeys (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
int	AddLowRegistry (Registry *rp, bool owns=true)
	add registry with lowest priority, also update ownership
int	MergeTopRegistry (const Registry &r)
int	AddTopRegisties (const vector< Registry * > &rs, bool owns=false)
	Add registries with top priority, also udated Ownerships.
Protected Attributes inherited from genie::Algorithm
bool	fAllowReconfig
bool	fOwnsSubstruc
	true if it owns its substructure (sub-algs,...)
AlgId	fID
	algorithm name and configuration set
vector< Registry * >	fConfVect
vector< bool >	fOwnerships
	ownership for every registry in fConfVect
AlgStatus_t	fStatus
	algorithm execution status
AlgMap *	fOwnedSubAlgMp
	local pool for owned sub-algs (taken out of the factory pool)

Detailed Description

Generates complete COHDNu events. Is a concrete implementation of the EventRecordVisitorI interface.

Author

Iker de Icaza <i.de-icaza-astiz \at sussex.ac.uk> University of Sussex

Costas Andreopoulos <c.andreopoulos \at cern.ch> University of Liverpool

Created:\n June 30, 2020

License:\n Copyright (c) 2003-2025, The GENIE Collaboration

For the full text of the license visit http://copyright.genie-mc.org

Definition at line 31 of file COHDNuEventGenerator.h.

Constructor & Destructor Documentation

COHDNuEventGenerator() [1/2]

COHDNuEventGenerator::COHDNuEventGenerator

(

)

Definition at line 46 of file COHDNuEventGenerator.cxx.

                                           :
  EventRecordVisitorI("genie::COHDNuEventGenerator")
{
 
}

References genie::EventRecordVisitorI::EventRecordVisitorI().

COHDNuEventGenerator() [2/2]

COHDNuEventGenerator::COHDNuEventGenerator

(

string

config

)

Definition at line 52 of file COHDNuEventGenerator.cxx.

                                                        :
  EventRecordVisitorI("genie::COHDNuEventGenerator", config)
{
 
}

References genie::EventRecordVisitorI::EventRecordVisitorI().

~COHDNuEventGenerator()

COHDNuEventGenerator::~COHDNuEventGenerator

(

)

Definition at line 58 of file COHDNuEventGenerator.cxx.

{
 
}

Member Function Documentation

AddFinalStateDarkNeutrino()

void COHDNuEventGenerator::AddFinalStateDarkNeutrino ( GHepRecord * event ) const

private

Definition at line 185 of file COHDNuEventGenerator.cxx.

{
  GHepParticle * probe  = event->Probe();
 
  const TLorentzVector & vtx = *(probe->X4());
  TLorentzVector x4l(vtx);  // position 4-vector
 
  event->AddParticle(probe -> Pdg() > 0 ? kPdgDarkNeutrino : kPdgAntiDarkNeutrino,
                     kIStDecayedState,
                     event->ProbePosition(), event->TargetNucleusPosition(),
                     -1,-1, event->Summary()->Kine().FSLeptonP4(), x4l);
}

References genie::Kinematics::FSLeptonP4(), genie::Interaction::Kine(), genie::kIStDecayedState, genie::kPdgAntiDarkNeutrino, genie::kPdgDarkNeutrino, genie::GHepRecord::ProbePosition(), genie::GHepRecord::Summary(), genie::GHepRecord::TargetNucleusPosition(), and genie::GHepParticle::X4().

Referenced by ProcessEventRecord().

AddRecoilNucleus()

void COHDNuEventGenerator::AddRecoilNucleus ( GHepRecord * event ) const

private

Definition at line 198 of file COHDNuEventGenerator.cxx.

{
  GHepParticle * probe  = event->Probe();
  GHepParticle * target = event->TargetNucleus();
  GHepParticle * fsl    = event->Particle(probe->FirstDaughter());
 
  const TLorentzVector & p4probe  = * ( probe  -> P4() );
  const TLorentzVector & p4target = * ( target -> P4() );
  const TLorentzVector & p4fsl    = * ( fsl    -> P4() );
 
  const TLorentzVector & p4recoil = p4probe + p4target - p4fsl;
 
  LOG("COHDNu", pNOTICE)
    << "Recoil 4-momentum: " << utils::print::P4AsString(&p4recoil);
 
  const TLorentzVector & vtx = *(probe->X4());
 
  event->AddParticle(event->TargetNucleus()->Pdg(),
                     kIStStableFinalState,
                     event->TargetNucleusPosition(), event->ProbePosition(),
                     -1,-1, p4recoil, vtx);
}

References genie::GHepParticle::FirstDaughter(), genie::kIStStableFinalState, LOG, genie::utils::print::P4AsString(), genie::GHepParticle::Pdg(), pNOTICE, genie::GHepRecord::ProbePosition(), genie::GHepRecord::TargetNucleus(), genie::GHepRecord::TargetNucleusPosition(), and genie::GHepParticle::X4().

Referenced by ProcessEventRecord().

Configure() [1/2]

void COHDNuEventGenerator::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 221 of file COHDNuEventGenerator.cxx.

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

References genie::Algorithm::Configure(), and LoadConfig().

Configure() [2/2]

void COHDNuEventGenerator::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 227 of file COHDNuEventGenerator.cxx.

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

References genie::Algorithm::Configure(), and LoadConfig().

GenerateKinematics()

void COHDNuEventGenerator::GenerateKinematics ( GHepRecord * event ) const

private

Definition at line 70 of file COHDNuEventGenerator.cxx.

{
  Interaction * interaction = event->Summary();
  interaction->SetBit(kISkipProcessChk);
  interaction->SetBit(kISkipKinematicChk);
 
  // Get the random number generators
  RandomGen * rnd = RandomGen::Instance();
 
  // Get the kinematical limits
  const InitialState & init_state = interaction -> InitState();
  double E_nu  = init_state.ProbeE(kRfLab);
 
  // Access cross section algorithm for running thread
  RunningThreadInfo * rtinfo = RunningThreadInfo::Instance();
  const EventGeneratorI * evg = rtinfo->RunningThread();
  fXSecModel = evg->CrossSectionAlg();
 
  double gDNuE   = -1; // generated Dark Neutrino Energy
  double gxsec = -1; // dsig/dDENu at generated DNuE
 
  // Generate kinematics
  if(fGenerateUniformly) {
    LOG("COHDNu", pFATAL)
      << "Option to generate kinematics uniformly not supported";
    exit(1);
  }
  else {
    // For the subsequent kinematic selection with the rejection method:
    // Calculate the max differential cross section.
    // Always at Q^2 = 0 for energies and model tested,
    // but go ahead and do the calculation nevertheless.
    utils::gsl::dXSec_dEDNu_E xsec_func(fXSecModel, interaction, fDNuMass, -1.);
    Range1D_t DNuEnergy = xsec_func.IntegrationRange();
    double dDNuE = DNuEnergy.max - DNuEnergy.min;
    ROOT::Math::BrentMinimizer1D minimizer;
    minimizer.SetFunction( xsec_func, DNuEnergy.min, DNuEnergy.max);
    minimizer.Minimize(1000, 1, 1E-5);
    double DNuE_for_xsec_max = minimizer.XMinimum();
    double xsec_max = -1. * xsec_func(DNuE_for_xsec_max); // xsec in units of 1E-38 cm2/GeV
 
    // Try to select a valid E_N
    unsigned int iter = 0;
    while(1) {
      iter++;
      if(iter > kRjMaxIterations) {
        LOG("COHDNu", pWARN)
          << "*** Could not select a valid DNuE after " << iter << " iterations";
        event->EventFlags()->SetBitNumber(kKineGenErr, true);
        genie::exceptions::EVGThreadException exception;
        exception.SetReason("Couldn't select kinematics");
        exception.SwitchOnFastForward();
        throw exception;
      } // max iterations
 
      gDNuE = DNuEnergy.min + dDNuE * rnd->RndKine().Rndm();
      LOG("COHDNu", pINFO) << "Trying: E_N = " << gDNuE;
 
      // Computing cross section for the current kinematics
      gxsec = -1. * xsec_func(gDNuE);
 
      if(gxsec > xsec_max) {
        double frac = TMath::Abs(gxsec-xsec_max)/xsec_max;
        if(frac > fMaxXSecDiffTolerance) {
          LOG("COHDNu", pWARN)
            << "Current computed cross-section (" << gxsec/(units::cm2)
            << " cm2/GeV^2) exceeds the maximum cross-section ("
            << xsec_max/(units::cm2) << " beyond the specified tolerance";
        }
      }
 
      // Decide whether to accept the current kinematic point
      double t = fSafetyFactor * xsec_max * rnd->RndKine().Rndm();
      //this->AssertXSecLimits(interaction, gxsec, xsec_max);
      LOG("COHDNu", pINFO)
        << "dxsec/dQ2 = " << gxsec/(units::cm2) << " cm2/GeV^2"
        << "J = 1, rnd = " << t;
      bool accept = (t<gxsec);
      if(accept) break; // exit loop
    } // 1
  } // generate uniformly
 
  // reset bits
  interaction->ResetBit(kISkipProcessChk);
  interaction->ResetBit(kISkipKinematicChk);
 
  double M_target = interaction->InitState().Tgt().Mass();
 
  double ETimesM = E_nu * M_target;
  double EPlusM  = E_nu + M_target;
 
  double p_DNu = TMath::Sqrt(gDNuE*gDNuE - fDNuMass2);
  double cos_theta_DNu = (gDNuE*EPlusM - ETimesM - 0.5*fDNuMass2) / (E_nu * p_DNu);
  double theta_DNu = TMath::ACos(cos_theta_DNu);
 
  // Take a unit vector along the neutrino direction @ the LAB
  GHepParticle * probe  = event->Probe();
  TVector3 unit_nudir = probe->P4()->Vect().Unit();
 
  TVector3 DNu_3vector = TVector3(0,0,0);
  double phi = 2.*kPi * rnd->RndKine().Rndm();
  DNu_3vector.SetMagThetaPhi(p_DNu, theta_DNu, phi);
  DNu_3vector.RotateUz(unit_nudir);
  TLorentzVector P4_DNu = TLorentzVector(DNu_3vector, gDNuE);
  interaction->KinePtr()->SetFSLeptonP4(P4_DNu);
 
  // lock selected kinematics & clear running values
  double gQ2 = -(P4_DNu - *(probe->P4())).M2();
  interaction->KinePtr()->SetQ2(gQ2, true);
  interaction->KinePtr()->ClearRunningValues();
 
  // Set the cross section for the selected kinematics
  event->SetDiffXSec(gxsec * (1E-38*units::cm2), kPSEDNufE);
}

References genie::Kinematics::ClearRunningValues(), genie::units::cm2, genie::EventGeneratorI::CrossSectionAlg(), fDNuMass, fDNuMass2, fGenerateUniformly, fMaxXSecDiffTolerance, fSafetyFactor, fXSecModel, gQ2, genie::Interaction::InitState(), genie::RandomGen::Instance(), genie::RunningThreadInfo::Instance(), genie::utils::gsl::dXSec_dEDNu_E::IntegrationRange(), genie::Interaction::KinePtr(), genie::kISkipKinematicChk, genie::kISkipProcessChk, genie::kKineGenErr, genie::constants::kPi, genie::kPSEDNufE, genie::kRfLab, genie::controls::kRjMaxIterations, LOG, genie::Target::Mass(), genie::Range1D_t::max, genie::Range1D_t::min, genie::GHepParticle::P4(), pFATAL, pINFO, genie::InitialState::ProbeE(), pWARN, genie::RandomGen::RndKine(), genie::RunningThreadInfo::RunningThread(), genie::Kinematics::SetFSLeptonP4(), genie::Kinematics::SetQ2(), genie::exceptions::EVGThreadException::SetReason(), genie::exceptions::EVGThreadException::SwitchOnFastForward(), and genie::InitialState::Tgt().

Referenced by ProcessEventRecord().

LoadConfig()

void COHDNuEventGenerator::LoadConfig ( void )

private

Definition at line 233 of file COHDNuEventGenerator.cxx.

{
  fXSecModel = 0;
 
  // max xsec safety factor (for rejection method) and min cached energy
  this->GetParamDef( "MaxXSec-SafetyFactor", fSafetyFactor, 1.05 ) ;
 
  // Generate kinematics uniformly over allowed phase space and compute
  // an event weight?
  this->GetParamDef( "UniformOverPhaseSpace", fGenerateUniformly, false ) ;
 
  // Maximum allowed fractional cross section deviation from maxim cross
  // section used in rejection method
  this->GetParamDef( "MaxXSec-DiffTolerance", fMaxXSecDiffTolerance, 999999. ) ;
  assert(fMaxXSecDiffTolerance>=0);
 
  fDNuMass = 0.;
  this->GetParam("Dark-NeutrinoMass", fDNuMass);
  fDNuMass2 = fDNuMass * fDNuMass;
 
}

References fDNuMass, fDNuMass2, fGenerateUniformly, fMaxXSecDiffTolerance, fSafetyFactor, fXSecModel, genie::Algorithm::GetParam(), and genie::Algorithm::GetParamDef().

Referenced by Configure(), and Configure().

ProcessEventRecord()

void COHDNuEventGenerator::ProcessEventRecord ( GHepRecord * event ) const

virtual

Implements genie::EventRecordVisitorI.

Definition at line 63 of file COHDNuEventGenerator.cxx.

{
  this -> GenerateKinematics        (event);
  this -> AddFinalStateDarkNeutrino (event);
  this -> AddRecoilNucleus          (event);
}

References AddFinalStateDarkNeutrino(), AddRecoilNucleus(), and GenerateKinematics().

Member Data Documentation

fDNuMass

double genie::COHDNuEventGenerator::fDNuMass

private

Definition at line 62 of file COHDNuEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fDNuMass2

double genie::COHDNuEventGenerator::fDNuMass2

private

Definition at line 62 of file COHDNuEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fGenerateUniformly

bool genie::COHDNuEventGenerator::fGenerateUniformly

private

Definition at line 58 of file COHDNuEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fMaxXSecDiffTolerance

double genie::COHDNuEventGenerator::fMaxXSecDiffTolerance

private

Definition at line 60 of file COHDNuEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fSafetyFactor

double genie::COHDNuEventGenerator::fSafetyFactor

private

Definition at line 59 of file COHDNuEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fXSecModel

const XSecAlgorithmI* genie::COHDNuEventGenerator::fXSecModel

mutableprivate

Definition at line 56 of file COHDNuEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

---

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

• COHDNuEventGenerator.h
• COHDNuEventGenerator.cxx