genie::CEvNSEventGenerator Class Reference

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

#include <CEvNSEventGenerator.h>

Inheritance diagram for genie::CEvNSEventGenerator:

Collaboration diagram for genie::CEvNSEventGenerator:

Public Member Functions
	CEvNSEventGenerator ()
	CEvNSEventGenerator (string config)
	~CEvNSEventGenerator ()
void	ProcessEventRecord (GHepRecord *event) const
void	Configure (const Registry &config)
void	Configure (string config)
void	LoadConfig (void)
void	GenerateKinematics (GHepRecord *event) const
void	AddFinalStateNeutrino (GHepRecord *event) const
void	AddRecoilNucleus (GHepRecord *event) const
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.

Public Attributes
const XSecAlgorithmI *	fXSecModel
bool	fGenerateUniformly
double	fSafetyFactor
double	fMaxXSecDiffTolerance

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 CEvNS events. Is a concrete implementation of the EventRecordVisitorI interface.

Author

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

Created:\n July 16, 2019

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 29 of file CEvNSEventGenerator.h.

Constructor & Destructor Documentation

CEvNSEventGenerator() [1/2]

CEvNSEventGenerator::CEvNSEventGenerator

(

)

Definition at line 44 of file CEvNSEventGenerator.cxx.

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

References genie::EventRecordVisitorI::EventRecordVisitorI().

CEvNSEventGenerator() [2/2]

CEvNSEventGenerator::CEvNSEventGenerator

(

string

config

)

Definition at line 50 of file CEvNSEventGenerator.cxx.

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

References genie::EventRecordVisitorI::EventRecordVisitorI().

~CEvNSEventGenerator()

CEvNSEventGenerator::~CEvNSEventGenerator

(

)

Definition at line 56 of file CEvNSEventGenerator.cxx.

{
 
}

Member Function Documentation

AddFinalStateNeutrino()

void CEvNSEventGenerator::AddFinalStateNeutrino

(

GHepRecord *

event

)

const

Definition at line 195 of file CEvNSEventGenerator.cxx.

{
  GHepParticle * probe  = event->Probe();
  GHepParticle * target = event->TargetNucleus();
 
  int target_pdgc = target->Pdg();
  double M = PDGLibrary::Instance()->Find(target_pdgc)->Mass(); // units: GeV
 
  double Ev = probe->E(); // neutrino energy, units: GeV
  double Q2 = event->Summary()->Kine().Q2(true); // selected momentum transfer, units: GeV^2
 
  const TLorentzVector & vtx = *(probe->X4());
  TLorentzVector x4l(vtx);  // position 4-vector
 
  // Compute the final state neutino energy
 
  double y  = Q2/(2*M*Ev);
  double El = (1-y)*Ev;
 
  LOG("CEvNS", pNOTICE)
    << "Final state neutrino energy: E = " << El << " GeV";
 
  // Compute the final state neutrino momentum components
  // along and perpendicular to the incoming neutrino direction
 
  double ml2 = 0;
  double plp = El - 0.5*(Q2+ml2)/Ev;                          // p(//)
  double plt = TMath::Sqrt(TMath::Max(0.,El*El-plp*plp-ml2)); // p(-|)
 
  LOG("CEvNS", pNOTICE)
    << "Final state neutrino momentum components: |p//| = "
    << plp << " GeV, [pT] = " << plt << " GeV";
 
  // Randomize transverse components
  RandomGen * rnd = RandomGen::Instance();
  double phi  = 2*kPi * rnd->RndLep().Rndm();
  double pltx = plt * TMath::Cos(phi);
  double plty = plt * TMath::Sin(phi);
 
  // Take a unit vector along the neutrino direction @ the LAB
  TVector3 unit_nudir = probe->P4()->Vect().Unit();
 
  // Rotate lepton momentum vector from the reference frame (x'y'z') where
  // {z':(neutrino direction), z'x':(theta plane)} to the LAB
  TVector3 p3l(pltx,plty,plp);
  p3l.RotateUz(unit_nudir);
 
  // Lepton 4-momentum in the LAB
  TLorentzVector p4l(p3l,El);
 
  LOG("CEvNS", pNOTICE)
     << "Final state neutrino 4-momentum: " << utils::print::P4AsString(&p4l);
 
  event->AddParticle(
    probe->Pdg(), kIStStableFinalState, event->ProbePosition(),
    -1,-1,-1, p4l, x4l);
 
  event->Summary()->KinePtr()->SetFSLeptonP4(p4l);
}

References genie::GHepParticle::E(), genie::PDGLibrary::Find(), genie::PDGLibrary::Instance(), genie::RandomGen::Instance(), genie::kIStStableFinalState, genie::constants::kPi, LOG, genie::GHepParticle::P4(), genie::utils::print::P4AsString(), genie::GHepParticle::Pdg(), pNOTICE, genie::GHepRecord::ProbePosition(), genie::RandomGen::RndLep(), and genie::GHepParticle::X4().

Referenced by ProcessEventRecord().

AddRecoilNucleus()

void CEvNSEventGenerator::AddRecoilNucleus

(

GHepRecord *

event

)

const

Definition at line 255 of file CEvNSEventGenerator.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("CEvNS", pNOTICE)
     << "Recoil 4-momentum: " << utils::print::P4AsString(&p4recoil);
 
  const TLorentzVector & vtx = *(probe->X4());
 
  event->AddParticle(
      event->TargetNucleus()->Pdg(),
      kIStStableFinalState,
      event->TargetNucleusPosition(),
      -1,-1,-1, p4recoil, vtx);
}

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

Referenced by ProcessEventRecord().

Configure() [1/2]

void CEvNSEventGenerator::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 279 of file CEvNSEventGenerator.cxx.

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

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

Configure() [2/2]

void CEvNSEventGenerator::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 285 of file CEvNSEventGenerator.cxx.

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

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

GenerateKinematics()

void CEvNSEventGenerator::GenerateKinematics

(

GHepRecord *

event

)

const

Definition at line 68 of file CEvNSEventGenerator.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 KPhaseSpace & kps = interaction->PhaseSpace();
  Range1D_t Q2 = kps.Q2Lim();
  assert(Q2.min > 0. && Q2.min < Q2.max);
  const InitialState & init_state = interaction -> InitState();
  double E  = init_state.ProbeE(kRfLab);
  const double Q2min = Q2.min;
  const double Q2max = Q2.max;
  const double dQ2   = Q2max - Q2min;
 
  // Access cross section algorithm for running thread
  RunningThreadInfo * rtinfo = RunningThreadInfo::Instance();
  const EventGeneratorI * evg = rtinfo->RunningThread();
  fXSecModel = evg->CrossSectionAlg();
 
  double gQ2   = -1; // generated Q2
  double gxsec = -1; // dsig/dQ2 at generated Q2
 
  // Generate kinematics
  if(fGenerateUniformly) {
    LOG("CEvNS", pFATAL)
      << "Option to generate kinematics uniformly not supported";
    exit(1);
/*
    gQ2 = Q2min + dQ2 * rnd->RndKine().Rndm();
    LOG("CEvNS", pINFO) << "Trying: Q2 = " << gQ2;
    interaction->KinePtr()->SetQ2(gQ2);
 
    // Computing cross section for the current kinematics
    gxsec = fXSecModel->XSec(interaction, kPSQ2fE);
    if(gxsec<=0){
      LOG("CEvNS", pWARN)
        << "Non-positive x-section for selected Q2 = " << gQ2 << "GeV^2";
    }
 
    double weight = 1; // to implement if fGenerateUniformly option is enabled
    LOG("CEvNS", pDEBUG)  << "Kinematics wght = "<< weight;
    // apply computed weight to the current event weight
    weight *= event->Weight();
    LOG("CEvNS", pDEBUG) << "Current event wght = " << weight;
    event->SetWeight(weight);
*/
  }
  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.
    ROOT::Math::IBaseFunctionOneDim * xsec_func =
        new utils::gsl::dXSec_dQ2_E(fXSecModel, interaction,-1.);
    ROOT::Math::BrentMinimizer1D minimizer;
    minimizer.SetFunction(*xsec_func,Q2min,Q2max);
    minimizer.Minimize(1000,1,1E-5);
    double Q2_for_xsec_max = minimizer.XMinimum();
    interaction->KinePtr()->SetQ2(Q2_for_xsec_max);
    double xsec_max = fXSecModel->XSec(interaction, kPSQ2fE);
    delete xsec_func;
    LOG("CEvNS", pNOTICE)
      << "Maximizing dsig(Q2;E = " << E << "GeV)/dQ2 gave a value of "
      << xsec_max/(units::cm2) << " cm2/GeV^2 at Q2 = "
      << Q2_for_xsec_max << " GeV^2";
 
    // Try to select a valid Q2
    unsigned int iter = 0;
    while(1) {
       iter++;
       if(iter > kRjMaxIterations) {
          LOG("CEvNS", pWARN)
            << "*** Could not select a valid Q2 after " << iter << " iterations";
          event->EventFlags()->SetBitNumber(kKineGenErr, true);
          genie::exceptions::EVGThreadException exception;
          exception.SetReason("Couldn't select kinematics");
          exception.SwitchOnFastForward();
          throw exception;
       } // max iterations
 
       gQ2 = Q2min + dQ2 * rnd->RndKine().Rndm();
       LOG("CEvNS", pINFO) << "Trying: Q2 = " << gQ2;
       interaction->KinePtr()->SetQ2(gQ2);
 
       // Computing cross section for the current kinematics
       gxsec = fXSecModel->XSec(interaction, kPSQ2fE);
 
       if(gxsec > xsec_max) {
          double frac = TMath::Abs(gxsec-xsec_max)/xsec_max;
          if(frac > fMaxXSecDiffTolerance) {
            LOG("CEvNS", 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("CEvNS", 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
 
  LOG("CEvNS", pNOTICE) << "Selected Q2 = " << gQ2 << " GeV^2";
 
  // reset bits
  interaction->ResetBit(kISkipProcessChk);
  interaction->ResetBit(kISkipKinematicChk);
 
  // lock selected kinematics & clear running values
  interaction->KinePtr()->SetQ2(gQ2, true);
  interaction->KinePtr()->ClearRunningValues();
 
  // Set the cross section for the selected kinematics
  event->SetDiffXSec(gxsec,kPSQ2fE);
}

References genie::Kinematics::ClearRunningValues(), genie::units::cm2, genie::EventGeneratorI::CrossSectionAlg(), fGenerateUniformly, fMaxXSecDiffTolerance, fSafetyFactor, fXSecModel, gQ2, genie::RandomGen::Instance(), genie::RunningThreadInfo::Instance(), genie::Interaction::KinePtr(), genie::kISkipKinematicChk, genie::kISkipProcessChk, genie::kKineGenErr, genie::kPSQ2fE, genie::kRfLab, genie::controls::kRjMaxIterations, LOG, pFATAL, genie::Interaction::PhaseSpace(), pINFO, pNOTICE, genie::InitialState::ProbeE(), pWARN, genie::KPhaseSpace::Q2Lim(), genie::RandomGen::RndKine(), genie::RunningThreadInfo::RunningThread(), genie::Kinematics::SetQ2(), genie::exceptions::EVGThreadException::SetReason(), and genie::exceptions::EVGThreadException::SwitchOnFastForward().

Referenced by ProcessEventRecord().

LoadConfig()

void CEvNSEventGenerator::LoadConfig

(

void

)

Definition at line 291 of file CEvNSEventGenerator.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);
}

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

Referenced by Configure(), and Configure().

ProcessEventRecord()

void CEvNSEventGenerator::ProcessEventRecord ( GHepRecord * event ) const

virtual

Implements genie::EventRecordVisitorI.

Definition at line 61 of file CEvNSEventGenerator.cxx.

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

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

Member Data Documentation

fGenerateUniformly

bool genie::CEvNSEventGenerator::fGenerateUniformly

Definition at line 56 of file CEvNSEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fMaxXSecDiffTolerance

double genie::CEvNSEventGenerator::fMaxXSecDiffTolerance

Definition at line 58 of file CEvNSEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fSafetyFactor

double genie::CEvNSEventGenerator::fSafetyFactor

Definition at line 57 of file CEvNSEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

fXSecModel

const XSecAlgorithmI* genie::CEvNSEventGenerator::fXSecModel

mutable

Definition at line 54 of file CEvNSEventGenerator.h.

Referenced by GenerateKinematics(), and LoadConfig().

---

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

• CEvNSEventGenerator.h
• CEvNSEventGenerator.cxx