Concrete implementation of the AxialFormFactorModelI interface. Computes the axial form factor using the model-independent z-expansion technique. More...

#include <ZExpAxialFormFactorModel.h>

Inheritance diagram for genie::ZExpAxialFormFactorModel:

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Collaboration diagram for genie::ZExpAxialFormFactorModel:

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Public Member Functions
	ZExpAxialFormFactorModel ()

	ZExpAxialFormFactorModel (string config)

virtual	~ZExpAxialFormFactorModel ()

double	FA (const Interaction *interaction) const
	Compute the axial form factor. More...

void	Configure (const Registry &config)

void	Configure (string param_set)

Public Member Functions inherited from genie::AxialFormFactorModelI
virtual	~AxialFormFactorModelI ()

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. More...

virtual AlgStatus_t	GetStatus (void) const
	Get algorithm status. More...

virtual bool	AllowReconfig (void) const

virtual AlgCmp_t	Compare (const Algorithm *alg) const
	Compare with input algorithm. More...

virtual void	SetId (const AlgId &id)
	Set algorithm ID. More...

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. More...

Private Member Functions
double	CalculateZ (double q2) const

void	FixCoeffs (void)

void	FixA0 (void)

void	FixQ4Limit (void)

void	LoadConfig (void)

Private Attributes
bool	fQ4limit

int	fKmax

double	fT0

double	fTcut

double	fFA0

double *	fZ_An

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::AxialFormFactorModelI
	AxialFormFactorModelI ()

	AxialFormFactorModelI (string name)

	AxialFormFactorModelI (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. More...

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. More...

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. More...

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 More...

int	AddLowRegistry (Registry *rp, bool owns=true)
	add registry with lowest priority, also update ownership More...

int	MergeTopRegistry (const Registry &r)

int	AddTopRegisties (const vector< Registry * > &rs, bool owns=false)
	Add registries with top priority, also udated Ownerships. More...

Protected Attributes inherited from genie::Algorithm
bool	fAllowReconfig

bool	fOwnsSubstruc
	true if it owns its substructure (sub-algs,...) More...

AlgId	fID
	algorithm name and configuration set More...

vector< Registry * >	fConfVect

vector< bool >	fOwnerships
	ownership for every registry in fConfVect More...

AlgStatus_t	fStatus
	algorithm execution status More...

AlgMap *	fOwnedSubAlgMp
	local pool for owned sub-algs (taken out of the factory pool) More...

Detailed Description

Concrete implementation of the AxialFormFactorModelI interface. Computes the axial form factor using the model-independent z-expansion technique.

References:: Hill et al. arXiv:1008.4619 DOI: 10.1103/PhysRevD.82.113005

Author

Aaron Meyer <asmeyer2012 uchicago.edu>

      based off DipoleELFormFactorsModel by
      Costas Andreopoulos <c.andreopoulos \at cern.ch>
      University of Liverpool

Created:: August 16, 2013

License:: Copyright (c) 2003-2024, The GENIE Collaboration For the full text of the license visit http://copyright.genie-mc.org

Definition at line 35 of file ZExpAxialFormFactorModel.h.

Constructor & Destructor Documentation

ZExpAxialFormFactorModel::ZExpAxialFormFactorModel ( )

Definition at line 31 of file ZExpAxialFormFactorModel.cxx.

                                                    :
 AxialFormFactorModelI("genie::ZExpAxialFormFactorModel")
 {
 
 }

ZExpAxialFormFactorModel::ZExpAxialFormFactorModel ( string config )

Definition at line 37 of file ZExpAxialFormFactorModel.cxx.

                                                                 :
 AxialFormFactorModelI("genie::ZExpAxialFormFactorModel", config)
 {
 
 }

ZExpAxialFormFactorModel::~ZExpAxialFormFactorModel ( )

virtual

Definition at line 43 of file ZExpAxialFormFactorModel.cxx.

References fZ_An.

 {
   delete[] fZ_An;
 }

Member Function Documentation

double ZExpAxialFormFactorModel::CalculateZ ( double q2 ) const

private

Definition at line 67 of file ZExpAxialFormFactorModel.cxx.

References fT0, and fTcut.

Referenced by FA(), FixA0(), and FixQ4Limit().

 {
 
   // calculate z expansion parameter
   double znum  = TMath::Sqrt(fTcut - q2) - TMath::Sqrt(fTcut - fT0);
   double zden  = TMath::Sqrt(fTcut - q2) + TMath::Sqrt(fTcut - fT0);
 
   return znum/zden;
 }

void ZExpAxialFormFactorModel::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 205 of file ZExpAxialFormFactorModel.cxx.

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

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

void ZExpAxialFormFactorModel::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 211 of file ZExpAxialFormFactorModel.cxx.

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

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

double ZExpAxialFormFactorModel::FA ( const Interaction * interaction ) const

virtual

Compute the axial form factor.

Implements genie::AxialFormFactorModelI.

Definition at line 48 of file ZExpAxialFormFactorModel.cxx.

References CalculateZ(), fKmax, fQ4limit, fZ_An, genie::Interaction::KinePtr(), LOG, pWARN, and genie::Kinematics::q2().

 {
   // calculate and return FA
   double q2 = interaction->KinePtr()->q2();
   double zparam = this->CalculateZ(q2);
   if (zparam != zparam) // checks for nan
   {
     LOG("ZExpAxialFormFactorModel",pWARN) << "Undefined expansion parameter";
     return 0.;
   }
   double fa = 0.;
   for (int ki=0;ki<=fKmax+(fQ4limit ? 4 : 0);ki++)
   {
     fa = fa + TMath::Power(zparam,ki) * fZ_An[ki];
   }
 
   return fa;
 }

void ZExpAxialFormFactorModel::FixA0 ( void )

private

Definition at line 86 of file ZExpAxialFormFactorModel.cxx.

References CalculateZ(), fFA0, fKmax, and fZ_An.

Referenced by FixCoeffs().

 {
   // Function to fix form factor such that FA(q2=0) = gA
   // For T0 = 0, this will set A0 = gA
   double zparam = this->CalculateZ(0.);
   double fa = 0.;
   for (int ki=1;ki<=fKmax;ki++)                    
   {
     fa = fa + TMath::Power(zparam,ki) * fZ_An[ki];
   }
   fZ_An[0] = fFA0 - fa; 
 
 }

void ZExpAxialFormFactorModel::FixCoeffs ( void )

private

Definition at line 77 of file ZExpAxialFormFactorModel.cxx.

References FixA0(), FixQ4Limit(), and fQ4limit.

Referenced by LoadConfig().

 {
   //if      (fKmax < 1 ) { fKmax = 1;  }
   //else if (fKmax > 10) { fKmax = 10; }
 
   if (fQ4limit) this->FixQ4Limit();
   else          this->FixA0();
 }

void ZExpAxialFormFactorModel::FixQ4Limit ( void )

private

Definition at line 100 of file ZExpAxialFormFactorModel.cxx.

References CalculateZ(), fFA0, fKmax, and fZ_An.

Referenced by FixCoeffs().

 {
   // fixes parameters such that the model limits to 1/Q^4 at large t
   // -- requires at least 5 parameters to do so --
   // 4 parameters for Q^4 behavior, 1 for normalization to FA(q2=0)=gA
 
   // will use A_0 and A_Kmax through A_Kmax-3 to do the fitting
   // calculate some useful numbers (redundancy for readability)
   double kp4 = (double)fKmax+4;
   double kp3 = (double)fKmax+3;
   double kp2 = (double)fKmax+2;
   double kp1 = (double)fKmax+1;
   double kp0 = (double)fKmax  ;
   //double km5 = (double)fKmax-5;
   double z0   = this->CalculateZ(0.);
   double zkp4 = TMath::Power(z0,(int)kp4);
   double zkp3 = TMath::Power(z0,(int)kp3);
   double zkp2 = TMath::Power(z0,(int)kp2);
   double zkp1 = TMath::Power(z0,(int)kp1);
 
   // denominator
   double denom = \
   6. -    kp4*kp3*kp2*zkp1 + 3.*kp4*kp3*kp1*zkp2 \
      - 3.*kp4*kp2*kp1*zkp3 +    kp3*kp2*kp1*zkp4;
 
   // extra parameters (effectively constants)
   // number refers to the number of derivatives
   double b0  = 0.;
   for (int ki = 1;ki <= fKmax;ki++)
   {
     b0 = b0 + fZ_An[ki];
   }
 
   double b0z = -fFA0;
   for (int ki = 1;ki <= fKmax;ki++) 
   {
     b0z = b0z + fZ_An[ki]*TMath::Power(z0,ki);
   }
 
   double b1  = 0.;
   for (int ki = 1;ki <= fKmax;ki++) 
   {
     b1 = b1 + ki*fZ_An[ki];
   }
   
   double b2  = 0.;
   for (int ki = 1;ki <= fKmax;ki++) 
   {
     b2 = b2 + ki*(ki-1)*fZ_An[ki];
   }
 
   double b3  = 0.;
   for (int ki = 1;ki <= fKmax;ki++) 
   {
     b3 = b3 + ki*(ki-1)*(ki-2)*fZ_An[ki];
   }
 
   // Assign new parameters
   fZ_An[(int)kp4] = (1./denom) *                           \
   ( (b0-b0z)*kp3*kp2*kp1                                   \
   + b3*( -1. + .5*kp3*kp2*zkp1 - kp3*kp1*zkp2              \
          +.5*kp2*kp1*zkp3                               )  \
   + b2*(  3.*kp1 - kp3*kp2*kp1*zkp1                        \
          +kp3*kp1*(2*fKmax+1)*zkp2 - kp2*kp1*kp0*zkp3   )  \
   + b1*( -3.*kp2*kp1 + .5*kp3*kp2*kp2*kp1*zkp1             \
          -kp3*kp2*kp1*kp0*zkp2 + .5*kp2*kp1*kp1*kp0*zkp3)  );
 
   fZ_An[(int)kp3] = (1./denom) *                           \
   ( -3.*(b0-b0z)*kp4*kp2*kp1                               \
   + b3*(  3. - kp4*kp2*zkp1 + (3./2.)*kp4*kp1*zkp2         \
          -.5*kp2*kp1*zkp4                               )  \
   + b2*( -3.*(3*fKmax+4) + kp4*kp2*(2*fKmax+3)*zkp1        \
          -3.*kp4*kp1*kp1*zkp2 + kp2*kp1*kp0*zkp4        )  \
   + b1*(  3.*kp1*(3*fKmax+8) - kp4*kp3*kp2*kp1*zkp1        \
   +(3./2.)*kp4*kp3*kp1*kp0*zkp2 - .5*kp2*kp1*kp1*kp0*zkp4) );
 
   fZ_An[(int)kp2] = (1./denom) *                           \
   ( 3.*(b0-b0z)*kp4*kp3*kp1                                \
   + b3*( -3. + .5*kp4*kp3*zkp1 - (3./2.)*kp4*kp1*zkp3      \
          +kp3*kp1*zkp4                                  )  \
   + b2*(  3.*(3*fKmax+5) - kp4*kp3*kp2*zkp1                \
          +3.*kp4*kp1*kp1*zkp3 - kp3*kp1*(2*fKmax+1)*zkp4)  \
   + b1*( -3.*kp3*(3*fKmax+4) + .5*kp4*kp3*kp3*kp2*zkp1     \
     -(3./2.)*kp4*kp3*kp1*kp0*zkp3 + kp3*kp2*kp1*kp0*zkp4)  );
 
   fZ_An[(int)kp1] = (1./denom) *                           \
   ( -(b0-b0z)*kp4*kp3*kp2                                  \
   + b3*(  1. - .5*kp4*kp3*zkp2 + kp4*kp2*zkp3              \
          -.5*kp3*kp2*zkp4                               )  \
   + b2*( -3.*kp2 + kp4*kp3*kp2*zkp2                        \
          -kp4*kp2*(2*fKmax+3)*zkp3 + kp3*kp2*kp1*zkp4)     \
   + b1*(  3.*kp3*kp2 - .5*kp4*kp3*kp3*kp2*zkp2             \
          +kp4*kp3*kp2*kp1*zkp3 - .5*kp3*kp2*kp2*kp1*zkp4)  );
 
   fZ_An[0] = (1./denom) *                                  \
   ( -6.*b0z                                                \
   + b0*(  kp4*kp3*kp2*zkp1 - 3.*kp4*kp3*kp1*zkp2           \
          +3.*kp4*kp2*kp1*zkp3 - kp3*kp2*kp1*zkp4        )  \
   + b3*( -zkp1 + 3.*zkp2 - 3.*zkp3 + zkp4               )  \
   + b2*(  3.*kp2*zkp1 - 3.*(3*fKmax+5)*zkp2                \
          +3.*(3*fKmax+4)*zkp3 - 3.*kp1*zkp4             )  \
   + b1*( -3.*kp3*kp2*zkp1 + 3.*kp3*(3*fKmax+4)*zkp2        \
          -3.*kp1*(3*fKmax+8)*zkp3 + 3.*kp2*kp1*zkp4     )  );
 }

void ZExpAxialFormFactorModel::LoadConfig ( void )

private

Definition at line 217 of file ZExpAxialFormFactorModel.cxx.

References fFA0, FixCoeffs(), fKmax, fQ4limit, fT0, fTcut, fZ_An, and genie::Algorithm::GetParam().

Referenced by Configure().

 {
 // get config options from the configuration registry or set defaults 
 // from the global parameter list
 
   GetParam( "QEL-Q4limit", fQ4limit ) ;
   GetParam( "QEL-Kmax", fKmax ) ;
 
   GetParam( "QEL-T0", fT0 ) ;
   GetParam( "QEL-T0", fT0 ) ;
   GetParam( "QEL-Tcut", fTcut ) ;
 
   GetParam( "QEL-FA0", fFA0 ) ;
   assert(fKmax > 0);
 
   // z expansion coefficients
   if (fQ4limit) fZ_An = new double [fKmax+5];
   else          fZ_An = new double [fKmax+1];
 
   // load the user-defined coefficient values
   // -- A0 and An for n<fKmax are calculated from other means
   for (int ip=1;ip<fKmax+1;ip++) {
     ostringstream alg_key;
     alg_key << "QEL-Z_A" << ip;
     GetParam( alg_key.str(), fZ_An[ip] ) ;
   }
 
   this->FixCoeffs();
 }