genie::rew::GReWeightFZone Class Reference

Reweighting the formation zone model. More...

#include <GReWeightFZone.h>

Inheritance diagram for genie::rew::GReWeightFZone:

Public Member Functions
	GReWeightFZone ()
	~GReWeightFZone ()
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...
void	SetR0 (double R0)
void	SetNR (double NR)
void	SetCT0Pion (double ct0)
void	SetCT0Nucleon (double ct0)
void	SetK (double k)
Public Member Functions inherited from genie::rew::GReWeightI
virtual	~GReWeightI ()

Private Member Functions
void	Init (void)

Private Attributes
double	fFZoneTwkDial
	formation zone tweaking dial More...
double	fNR
double	fR0
double	fct0pion
double	fct0nucleon
double	fK

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

Detailed Description

Reweighting the formation zone model.

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 20, 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 33 of file GReWeightFZone.h.

Constructor & Destructor Documentation

GReWeightFZone::GReWeightFZone

(

)

Definition at line 42 of file GReWeightFZone.cxx.

                               :
GReWeightI()
{
  this->Init();
}

GReWeightFZone::~GReWeightFZone

(

)

Definition at line 48 of file GReWeightFZone.cxx.

{

}

Member Function Documentation

double GReWeightFZone::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 87 of file GReWeightFZone.cxx.

{  
  // Physics parameter tweaked?
  bool tweaked = (TMath::Abs(fFZoneTwkDial) > controls::kASmallNum);
  if(!tweaked) return 1.;

  // Skip events not involving nuclear targets.
  GHepParticle * tgt = event.TargetNucleus();
  if (!tgt) return 1.;
  double A = tgt->A();
  double Z = tgt->Z();
  if (A<=1) return 1.;
  if (Z<=1) return 1.0;


  // Skip event if was not DIS scattering.
  bool is_dis = event.Summary()->ProcInfo().IsDeepInelastic();
  if(!is_dis) {
    LOG("ReW", pDEBUG) << "Not a DIS event";
    return 1.;
  }

  //
  // Calculate event weight.
  //

  double event_weight = 1.;

  // hadronic system 4-/3-momentum
  TLorentzVector p4hadr = utils::rew::Hadronic4pLAB(event);
  TVector3 p3hadr = p4hadr.Vect();

  // vertex
  assert(event.HitNucleon());
  const TLorentzVector & vtx = *(event.HitNucleon()->X4());

  // formation zone: fractional 1sigma err
  GSystUncertainty * uncertainty = GSystUncertainty::Instance();
  double fracerr = uncertainty->OneSigmaErr(kHadrNuclTwkDial_FormZone);

  // Loop over particles calculate weights for all primary hadrons inside the nucleus.
  int ip=-1;
  GHepParticle * p = 0;
  TIter event_iter(&event);
  while ( (p = dynamic_cast<GHepParticle *>(event_iter.Next())) ) {
      ip++;

     // Skip particles with code other than 'hadron in the nucleus'
     GHepStatus_t ist  = p->Status();
     if(ist != kIStHadronInTheNucleus)
     {
        continue;
     }
     // JIMTODO - Skip if is not a hadron 
     // I am not sure why the above conditional would not catch this out - need to investigate.
     int pdgc = p->Pdg();   // hadron pdg code
     if (pdg::IsHadron(pdgc) == false) 
     {
        continue;
     } 

     // Determine whether it interacted or not
     int fsi_code = p->RescatterCode();
     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);
      fsi_code = kIHAFtNoInteraction;
     }
     bool escaped    = (fsi_code == (int)kIHAFtNoInteraction);
     bool interacted = !escaped;

     LOG("ReW", pDEBUG)
        << "Attempting to reweight hadron at position = " << ip
        << " with PDG code = " << pdgc
        << ". The hadron "
        << ((interacted) ? "re-interacted" : "did not re-interact");
     
     // Default formation zone
     double m = p->Mass();
     TLorentzVector * p4  = p->P4();
 
     double ct0=0.;
     pdg::IsNucleon(pdgc) ? ct0=fct0nucleon : ct0=fct0pion;
     double fz_def = phys::FormationZone(m,*p4,p3hadr,ct0,fK);

     double fz_scale_factor  = (1 + fFZoneTwkDial * fracerr);
     double fz_twk  = fz_def * fz_scale_factor;
     fz_twk = TMath::Max(0.,fz_twk);

     LOG("ReW", pDEBUG)  
        << "Formation zone = " << fz_def << " fm (nominal), "
        << fz_twk << " fm (tweaked) - scale factor = " << fz_scale_factor;

     // Calculate hadron's position at the end of the formation zone step
     TVector3 step3v = p4->Vect(); 
     step3v.SetMag(fz_def);
     TLorentzVector step4v(step3v, 0.);

     TLorentzVector x4 = vtx + step4v;  
     LOG("ReW", pDEBUG)  << "Vtx position: "<< print::X4AsString(&vtx);
     LOG("ReW", pDEBUG)  << "Hadron position: "<< print::X4AsString(&x4);
 
     // Calculate particle weight
     double hadron_weight = genie::utils::rew::FZoneWeight(
        pdgc, vtx, x4, *p4, A, Z, fz_scale_factor, interacted);

     // Update event weight
     event_weight *= hadron_weight;
  }

  return event_weight;
}

void GReWeightFZone::Init ( void  )

private

Definition at line 202 of file GReWeightFZone.cxx.

{
  fFZoneTwkDial = 0.;

  this->SetR0         (1.3);//fm
  this->SetNR         (3.);
  this->SetCT0Pion    (0.342);//fm
  this->SetCT0Nucleon (2.300);//fm
  this->SetK          (0.);
}

bool GReWeightFZone::IsHandled ( GSyst_t  syst )

virtual

does the current weight calculator handle the input nuisance param?

Implements genie::rew::GReWeightI.

Definition at line 53 of file GReWeightFZone.cxx.

{
  switch(syst) {
    case (kHadrNuclTwkDial_FormZone) :
      return true;
      break;
    default:
      return false;
      break;
  }
  return false;
}

void GReWeightFZone::Reconfigure ( void  )

virtual

propagate updated nuisance parameter values to actual MC, etc

Implements genie::rew::GReWeightI.

Definition at line 82 of file GReWeightFZone.cxx.

{

}

void GReWeightFZone::Reset ( void  )

virtual

set all nuisance parameters to default values

Implements genie::rew::GReWeightI.

Definition at line 77 of file GReWeightFZone.cxx.

{
  fFZoneTwkDial = 0.;
}

void genie::rew::GReWeightFZone::SetCT0Nucleon ( double  ct0 )

inline

Definition at line 51 of file GReWeightFZone.h.

{ fct0nucleon = ct0; }

void genie::rew::GReWeightFZone::SetCT0Pion ( double  ct0 )

inline

Definition at line 50 of file GReWeightFZone.h.

{ fct0pion    = ct0; }

void genie::rew::GReWeightFZone::SetK ( double  k )

inline

Definition at line 52 of file GReWeightFZone.h.

{ fK          = k;   }

void genie::rew::GReWeightFZone::SetNR ( double  NR )

inline

Definition at line 49 of file GReWeightFZone.h.

{ fNR         = NR;  }

void genie::rew::GReWeightFZone::SetR0 ( double  R0 )

inline

Definition at line 48 of file GReWeightFZone.h.

{ fR0         = R0;  }

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

virtual

update the value for the specified nuisance param

Implements genie::rew::GReWeightI.

Definition at line 66 of file GReWeightFZone.cxx.

{
  switch(syst) {
    case (kHadrNuclTwkDial_FormZone) :
      fFZoneTwkDial = twk_dial;
      break;
    default:
      return;
  }
}

Member Data Documentation

double genie::rew::GReWeightFZone::fct0nucleon

private

Definition at line 63 of file GReWeightFZone.h.

double genie::rew::GReWeightFZone::fct0pion

private

Definition at line 62 of file GReWeightFZone.h.

double genie::rew::GReWeightFZone::fFZoneTwkDial

private

formation zone tweaking dial

Definition at line 58 of file GReWeightFZone.h.

double genie::rew::GReWeightFZone::fK

private

Definition at line 64 of file GReWeightFZone.h.

double genie::rew::GReWeightFZone::fNR

private

Definition at line 60 of file GReWeightFZone.h.

double genie::rew::GReWeightFZone::fR0

private

Definition at line 61 of file GReWeightFZone.h.

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

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