genie::rew::GReWeightINuke Class Reference

Reweighting GENIE INTRANUKE/hA hadron transport model. More...

#include <GReWeightINuke.h>

Inheritance diagram for genie::rew::GReWeightINuke:

Public Member Functions
	GReWeightINuke ()
	~GReWeightINuke ()
bool	IsHandled (GSyst_t syst)
	does the current weight calculator handle the input nuisance param? More...
void	SetSystematic (GSyst_t syst, double val)
	update the value for the specified nuisance param More...
void	Reset (void)
	set all nuisance parameters to default values More...
void	Reconfigure (void)
	propagate updated nuisance parameter values to actual MC, etc More...
double	CalcWeight (const EventRecord &event)
	calculate a weight for the input event using the current nuisance param values More...
Public Member Functions inherited from genie::rew::GReWeightI
virtual	~GReWeightI ()

Private Attributes
GReWeightINukeParams	fINukeRwParams

Additional Inherited Members
Protected Member Functions inherited from genie::rew::GReWeightI
	GReWeightI ()

Detailed Description

Reweighting GENIE INTRANUKE/hA hadron transport model.

The reweighting code considers two sets of physics changes: Change in the hadron mean free path , i.e. change in the total rescattering probability P_{rescat}. Changes in probabilty for rescattering mode X, given a fixed total rescattering probability P(X | ). X = {elastic, inelastic, charge exchange, pion production, absorption + multi-nucleon knockout}.

Physics changes are considered separately for pions and nucleons. Unitarity is explicitly conserved.

Author

Jim Dobson <J.Dobson07 imperial.ac.uk> Imperial College London

Costas Andreopoulos <costas.andreopoulos stfc.ac.uk> University of Liverpool & STFC Rutherford Appleton Lab

Sep 10, 2009

Copyright (c) 2003-2017, GENIE Neutrino MC Generator Collaboration For the full text of the license visit http://copyright.genie-mc.org or see $GENIE/LICENSE

Definition at line 51 of file GReWeightINuke.h.

Constructor & Destructor Documentation

GReWeightINuke::GReWeightINuke

(

)

Definition at line 56 of file GReWeightINuke.cxx.

                               :
GReWeightI()
{
#ifdef _G_REWEIGHT_INUKE_DEBUG_NTP_
  fTestFile = new TFile("./intranuke_reweight_test.root","recreate");
  fTestNtp  = new TNtuple("testntp","","pdg:E:mfp_twk_dial:d:d_mfp:fate:interact:w_mfp:w_fate");
#endif
}

GReWeightINuke::~GReWeightINuke

(

)

Definition at line 65 of file GReWeightINuke.cxx.

{
#ifdef _G_REWEIGHT_INUKE_DEBUG_NTP_
  assert(fTestFile);
  assert(fTestNtp);
  fTestFile->cd();
  fTestNtp->Write();
  fTestFile->Close();
  delete fTestFile;
  //delete fTestNtp;
#endif
}

Member Function Documentation

double GReWeightINuke::CalcWeight ( const EventRecord &  event )

virtual

calculate a weight for the input event using the current nuisance param values

Implements genie::rew::GReWeightI.

Definition at line 123 of file GReWeightINuke.cxx.

{  
  // get the atomic mass number for the hit nucleus
  GHepParticle * tgt = event.TargetNucleus();
  if (!tgt) return 1.0;
  double A = tgt->A();
  double Z = tgt->Z();
  if (A<=1) return 1.0;
  if (Z<=1) return 1.0;

  double event_weight  = 1.0;

  // Loop over stdhep entries and only calculate weights for particles. 
  // All particles that are not hadrons generated inside the nucleus are given weights of 1.0
  int ip=-1;
  GHepParticle * p = 0;
  TIter event_iter(&event);
  while ( (p = dynamic_cast<GHepParticle *>(event_iter.Next())) ) {
     ip++;

     // Skip particles not rescattered by the actual hadron transport code      
     int  pdgc       = p->Pdg();
     bool is_pion    = pdg::IsPion   (pdgc);
     bool is_nucleon = pdg::IsNucleon(pdgc);      
     if(!is_pion && !is_nucleon) 
     { 
        continue; 
     }

     // Skip particles with code other than 'hadron in the nucleus'
     GHepStatus_t ist  = p->Status();
     if(ist != kIStHadronInTheNucleus) 
     {
        continue; 
     }

     // Determine the interaction type for current hadron in nucleus, if any
     int fsi_code = p->RescatterCode();
     LOG("ReW", pDEBUG) 
        << "Attempting to reweight hadron at position = " << ip 
        << " with PDG code = " << pdgc 
        << " and FSI code = "  << fsi_code 
        << " (" << INukeHadroFates::AsString((INukeFateHA_t)fsi_code) << ")";
     if(fsi_code == -1 || fsi_code == (int)kIHAFtUndefined) {
       LOG("ReW", pFATAL) << "INTRANUKE didn't set a valid rescattering code for event in position: " << ip;
       LOG("ReW", pFATAL) << "Here is the problematic event:";
       LOG("ReW", pFATAL) << event;
       exit(1);
     }
     bool escaped    = (fsi_code == (int)kIHAFtNoInteraction);
     bool interacted = !escaped;

     // Get 4-momentum and 4-position
     TLorentzVector x4 (p->Vx(), p->Vy(), p->Vz(), 0.    );
     TLorentzVector p4 (p->Px(), p->Py(), p->Pz(), p->E());

     // Init current hadron weights
     double w_mfp  = 1.0;
     double w_fate = 1.0;

     // Check which weights need to be calculated (only if relevant params were tweaked)
     bool calc_w_mfp  = fINukeRwParams.MeanFreePathParams(pdgc)->IsTweaked();
     bool calc_w_fate = fINukeRwParams.FateParams(pdgc)->IsTweaked();

     // Compute weight to account for changes in the total rescattering probability
     double mfp_scale_factor = 1.;
     if(calc_w_mfp)
     {
        mfp_scale_factor = fINukeRwParams.MeanFreePathParams(pdgc)->ScaleFactor();
        w_mfp = utils::rew::MeanFreePathWeight(pdgc,x4,p4,A,Z,mfp_scale_factor,interacted);
     } // calculate mfp weight?

     // Compute weight to account for changes in relative fractions of reaction channels
     if(calc_w_fate && interacted)
     {    
        double fate_fraction_scale_factor = 
             fINukeRwParams.FateParams(pdgc)->ScaleFactor(
                  GSyst::INukeFate2GSyst((INukeFateHA_t)fsi_code,pdgc), p4);
        w_fate = fate_fraction_scale_factor;
     } 

     // Calculate the current hadron weight
     double hadron_weight = w_mfp * w_fate;

     LOG("ReW", pNOTICE) 
        << "Reweighted hadron at position = " << ip
        << " with PDG code = " << pdgc 
        << ", FSI code = "  << fsi_code 
        << " (" << INukeHadroFates::AsString((INukeFateHA_t)fsi_code) << ") :"
        << " w_mfp = "  << w_mfp
        <<", w_fate = " << w_fate;

     // Debug info
#ifdef _G_REWEIGHT_INUKE_DEBUG_NTP_
     double d        = utils::intranuke::Dist2Exit(x4,p4,A);
     double d_mfp    = utils::intranuke::Dist2ExitMFP(pdgc,x4,p4,A,Z);
     double Eh       = p->E();
     double iflag    = (interacted) ? 1 : 0;
     fTestNtp->Fill(pdgc, Eh, mfp_scale_factor, d, d_mfp, fsi_code, iflag, w_mfp, w_fate);
#endif

     // Update the current event weight
     event_weight *= hadron_weight;
     
  }//particle loop
  
  return event_weight;
}

bool GReWeightINuke::IsHandled ( GSyst_t  syst )

virtual

does the current weight calculator handle the input nuisance param?

Implements genie::rew::GReWeightI.

Definition at line 78 of file GReWeightINuke.cxx.

{
   bool handle;

   switch(syst) {
     case ( kINukeTwkDial_MFP_pi      ) :
     case ( kINukeTwkDial_MFP_N       ) :
     case ( kINukeTwkDial_FrCEx_pi    ) :
     case ( kINukeTwkDial_FrElas_pi   ) :
     case ( kINukeTwkDial_FrInel_pi   ) :
     case ( kINukeTwkDial_FrAbs_pi    ) :
     case ( kINukeTwkDial_FrPiProd_pi ) :
     case ( kINukeTwkDial_FrCEx_N     ) :
     case ( kINukeTwkDial_FrElas_N    ) :
     case ( kINukeTwkDial_FrInel_N    ) :
     case ( kINukeTwkDial_FrAbs_N     ) :
     case ( kINukeTwkDial_FrPiProd_N  ) :
          handle = true;
          break;

     default:
          handle = false;
   }

   return handle;
}

void GReWeightINuke::Reconfigure ( void  )

virtual

propagate updated nuisance parameter values to actual MC, etc

Implements genie::rew::GReWeightI.

Definition at line 118 of file GReWeightINuke.cxx.

{
  fINukeRwParams.Reconfigure();  
}

void GReWeightINuke::Reset ( void  )

virtual

set all nuisance parameters to default values

Implements genie::rew::GReWeightI.

Definition at line 112 of file GReWeightINuke.cxx.

{
  fINukeRwParams.Reset();
  this->Reconfigure();
}

void GReWeightINuke::SetSystematic ( GSyst_t  syst, double  val  )

virtual

update the value for the specified nuisance param

Implements genie::rew::GReWeightI.

Definition at line 105 of file GReWeightINuke.cxx.

{
  if(this->IsHandled(syst)) {
     fINukeRwParams.SetTwkDial(syst, val);
  }
}

Member Data Documentation

GReWeightINukeParams genie::rew::GReWeightINuke::fINukeRwParams

private

Definition at line 66 of file GReWeightINuke.h.

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

• GENIE/src/ReWeight/GReWeightINuke.h
• GENIE/src/ReWeight/GReWeightINuke.cxx