genie::alvarezruso::ARSampledNucleus Class Reference

Nucleus class for Alvarez-Ruso Coherent Pion Production xsec. More...

#include <ARSampledNucleus.h>

Public Member Functions
	ARSampledNucleus (unsigned int ZNumber, unsigned int ANumber, unsigned int sampling=20)
	~ARSampledNucleus ()
unsigned int	A () const
unsigned int	Z () const
unsigned int	N () const
double	Density (const int i, const int j) const
double	DensityOfCentres (const int i, const int j) const
double	Radius (const int i, const int j) const
double	RadiusMax () const
double	SamplePoint1 (const unsigned int i) const
double	SamplePoint2 (const unsigned int i) const
unsigned int	GetSampling (void) const
unsigned int	GetNDensities (void) const
double	CalcMatterDensity (double r) const
double	CalcNumberDensity (double r) const

Private Member Functions
void	Fill ()
void	FillSamplePoints ()
void	FillDensities ()
double	CalcDensity (double radius, double nuc_rad, double nuc_diff) const
double	Density0 (unsigned int number, double diffuseness, double radius) const
TF1 *	Density0Function () const

Static Private Member Functions
static Double_t	Density0FunctionFermiLiquid (Double_t *r, Double_t *parameters)

Private Attributes
const unsigned int	fZ
const unsigned int	fA
unsigned int	fSampling
unsigned int	fNDensities
double	fR_max
double **	fRadii
double **	fDensities
double **	fDensitiesOfCentres
double *	fSample_points_1
double *	fSample_points_2
double *	fSample_weights_1
double *	fSample_weights_2
double	fDiffuseness
double	fNucRadius
double	fNucRadiusSq
double	fDiffusenessCentres
double	fRadiusCentres
double	fUseHarmonicOscillator

Static Private Attributes
static double	mean_radius_squared = 0.69

Detailed Description

Nucleus class for Alvarez-Ruso Coherent Pion Production xsec.

Author

Steve Dennis University of Warwick, Rutherford Appleton Laboratory

05/12/2013

Copyright (c) 2003-2020, The GENIE Collaboration For the full text of the license visit http://copyright.genie-mc.org

Definition at line 30 of file ARSampledNucleus.h.

Constructor & Destructor Documentation

genie::alvarezruso::ARSampledNucleus::ARSampledNucleus	(	unsigned int	ZNumber,
		unsigned int	ANumber,
		unsigned int	sampling = 20
	)

Definition at line 46 of file ARSampledNucleus.cxx.

                                                                                                     :
  fZ(ZNumber),
  fA(ANumber),
  fSampling(fSampling_)
{
  fNDensities = 2*fSampling;

  fDensities = NULL;
  fDensitiesOfCentres = NULL;
  fRadii = NULL;
  fSample_points_1  = NULL;
  fSample_points_2  = NULL;
  fSample_weights_1 = NULL;
  fSample_weights_2 = NULL;

  if(fA>20) { // fermi gas
    if      (fA ==  27) { fNucRadius = 3.07; fDiffuseness = 0.52; }  // aluminum
    else if (fA ==  28) { fNucRadius = 3.07; fDiffuseness = 0.54; }  // silicon
    else if (fA ==  40) { fNucRadius = 3.53; fDiffuseness = 0.54; }  // argon
    else if (fA ==  56) { fNucRadius = 4.10; fDiffuseness = 0.56; }  // iron
    else if (fA == 208) { fNucRadius = 6.62; fDiffuseness = 0.55; }  // lead
    else {
       fNucRadius = pow(fA,0.35); fDiffuseness = 0.54;
    } //others
    fUseHarmonicOscillator = false;
  }
  else {
    if      (fA ==  7) { fNucRadius = 1.77   ; fDiffuseness = 0.327;} // lithium
    else if (fA == 12) { fNucRadius = 1.692  ; fDiffuseness = 1.083;} // carbon
    else if (fA == 14) { fNucRadius = 1.76   ; fDiffuseness = 1.23; } // nitrogen
    else if (fA == 16) { fNucRadius = 1.83   ; fDiffuseness = 1.54; } // oxygen
    else if (fA <= 4 ) { fNucRadius = 1.344  ; fDiffuseness = 0.00; } // helium
    else {
      fNucRadius=1.75; fDiffuseness=-0.4+.12*fA;
    }  //others- fDiffuseness=0.08 if A=4

    fUseHarmonicOscillator = true;
  }

  fNucRadiusSq = fNucRadius*fNucRadius;

  // Calculate number densities (density of 'centres'):
  double diff2 = fDiffuseness*fDiffuseness;
  if (fUseHarmonicOscillator) {
    fRadiusCentres =  TMath::Sqrt( (fNucRadiusSq) - (mean_radius_squared / 1.5) );
    double x = (fDiffuseness * fNucRadiusSq) / ((1 + (1.5*fDiffuseness)) * (fRadiusCentres*fRadiusCentres));
    fDiffusenessCentres =   2.*x / (2. - 3.*x ) ;
  }
  else { //fermi liquid
    double numerator = 5.0 * mean_radius_squared * fNucRadius;
    double denominator = (15.0 * (fNucRadiusSq)) + (7.0 * kPi2 * fDiffuseness*fDiffuseness);
    fRadiusCentres = fNucRadius + (numerator / denominator);

    numerator = (fNucRadiusSq*fNucRadius) + (kPi2 * diff2 * fRadiusCentres) - (fRadiusCentres*fRadiusCentres*fRadiusCentres);
    denominator = kPi2 * fRadiusCentres;

    fDiffusenessCentres = sqrt( numerator / denominator );
  }

  this->Fill();
}

genie::alvarezruso::ARSampledNucleus::~ARSampledNucleus

(

)

Definition at line 108 of file ARSampledNucleus.cxx.

{
  for(unsigned int i = 0; i != fNDensities; ++i)
  {
    if (fDensities          && fDensities         [i]) delete[] fDensities[i];
    if (fDensitiesOfCentres && fDensitiesOfCentres[i]) delete[] fDensitiesOfCentres[i];
    if (fRadii              && fRadii             [i]) delete[] fRadii    [i];
  }

  if (fDensities         ) delete[] fDensities;
  if (fDensitiesOfCentres) delete[] fDensitiesOfCentres;
  if (fRadii             ) delete[] fRadii    ;
  if (fSample_points_1   ) delete[] fSample_points_1;
  if (fSample_points_2   ) delete[] fSample_points_2;
  if (fSample_weights_1  ) delete[] fSample_weights_1;
  if (fSample_weights_2  ) delete[] fSample_weights_2;
}

Member Function Documentation

unsigned int genie::alvarezruso::ARSampledNucleus::A ( void  ) const

inline

Definition at line 38 of file ARSampledNucleus.h.

{  return fA;  }

double genie::alvarezruso::ARSampledNucleus::CalcDensity ( double  radius, double  nuc_rad, double  nuc_diff  ) const

private

Definition at line 217 of file ARSampledNucleus.cxx.

{
  double dens_rel;
  if (fUseHarmonicOscillator) {
    dens_rel = (1.0 + nuc_diff*r*r/(nuc_rad*nuc_rad)) * exp(-r*r/(nuc_rad*nuc_rad));
  }
  else { //fermi liquid
    dens_rel = 1.0 / (1.0 + exp((r - nuc_rad)/nuc_diff));
  }

  //~ double dens_0  = utils::nuclear::Density(nuc_rad, fA);
  double dens_0  = Density0(fA,nuc_rad,nuc_diff);

  return dens_0 * dens_rel;
}

double genie::alvarezruso::ARSampledNucleus::CalcMatterDensity

(

double

r

)

const

Definition at line 278 of file ARSampledNucleus.cxx.

{
  return this->CalcDensity(r,fNucRadius,fDiffuseness);
}

double genie::alvarezruso::ARSampledNucleus::CalcNumberDensity

(

double

r

)

const

Definition at line 283 of file ARSampledNucleus.cxx.

{
  return this->CalcDensity(r,fRadiusCentres,fDiffusenessCentres);
}

double genie::alvarezruso::ARSampledNucleus::Density	(	const int	i,
		const int	j
	)		const

Definition at line 140 of file ARSampledNucleus.cxx.

{
  return fDensities[i][j];
}

double genie::alvarezruso::ARSampledNucleus::Density0 ( unsigned int  number, double  diffuseness, double  radius  ) const

private

Definition at line 233 of file ARSampledNucleus.cxx.

{
  double result = 0.0;
  if( fUseHarmonicOscillator )
  {
    double u = fR_max/radius;
    double dterm = (3*diffuseness+2);
    double term1 = TMath::Sqrt(TMath::Pi())*dterm*TMath::Power(radius,3)*TMath::Exp(u*u)*TMath::Erf(u);
    double term2 = 2*fR_max*(dterm*radius*radius+2*diffuseness*radius*radius);
    result = (0.5)*TMath::Pi()*TMath::Exp(-u*u)*(term1 - term2);
  }
  else
  {
    //Probably faster to do this via the integral for the moment as ROOT doesn't have a builtin
    //PolyLog function
    TF1* f = this->Density0Function();
    f->SetParameter(0, diffuseness);
    f->SetParameter(1, radius);
    result = f->Integral(0.0,fR_max);
    delete f;
  }

  return ( number / result );
}

TF1 * genie::alvarezruso::ARSampledNucleus::Density0Function ( ) const

private

Definition at line 262 of file ARSampledNucleus.cxx.

{
  return (new TF1("density0function", Density0FunctionFermiLiquid, 0.0, fR_max, 2));
}

Double_t genie::alvarezruso::ARSampledNucleus::Density0FunctionFermiLiquid ( Double_t *  r, Double_t *  parameters  )

staticprivate

Definition at line 267 of file ARSampledNucleus.cxx.

{
  double r = (*r_);
  double diffuseness = parameters[0];
  double radius = parameters[1];

  double dens = 1.0 / (1.0 + exp((r - radius)/diffuseness));

  return 4.0*TMath::Pi()*r*r*dens;
}

double genie::alvarezruso::ARSampledNucleus::DensityOfCentres	(	const int	i,
		const int	j
	)		const

Definition at line 145 of file ARSampledNucleus.cxx.

{
  return fDensitiesOfCentres[i][j];
}

void genie::alvarezruso::ARSampledNucleus::Fill ( )

private

Definition at line 125 of file ARSampledNucleus.cxx.

{

  fR_max = 3.0 * TMath::Power(this->A(), (1.0/3.0));

#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
  LOG("AR_PiWFunction_Table", pDEBUG)<< "N:: fR_max = " << fR_max
  << "N:: z = " << fZ
  << "N:: a = " << fA
#endif

  this->FillSamplePoints();
  this->FillDensities();
}

void genie::alvarezruso::ARSampledNucleus::FillDensities ( )

private

Definition at line 174 of file ARSampledNucleus.cxx.

{
  double r;

  for(unsigned int i = 0; i != fNDensities; ++i)
  {
    if (fDensities          && fDensities         [i]) delete[] fDensities         [i];
    if (fDensitiesOfCentres && fDensitiesOfCentres[i]) delete[] fDensitiesOfCentres[i];
    if (fRadii              && fRadii             [i]) delete[] fRadii             [i];
  }
  if (fDensities         ) delete[] fDensities;
  if (fDensitiesOfCentres) delete[] fDensitiesOfCentres;
  if (fRadii             ) delete[] fRadii    ;

  fDensities          = new double*[fNDensities];
  fDensitiesOfCentres = new double*[fNDensities];
  fRadii              = new double*[fNDensities];

  for(unsigned int i = 0; i != fNDensities; ++i)
  {
    fDensities         [i] = new double[fNDensities];
    fDensitiesOfCentres[i] = new double[fNDensities];
    fRadii             [i] = new double[fNDensities];

    for(unsigned int j = 0; j != fNDensities; ++j)
    {
      r = TMath::Sqrt( fSample_points_1[i]*fSample_points_1[i] + fSample_points_2[j]*fSample_points_2[j] );
      fRadii[i][j] = r;
      fDensities         [i][j]=this->CalcMatterDensity(r);
      fDensitiesOfCentres[i][j]=this->CalcNumberDensity(r);
    }
  }
}

void genie::alvarezruso::ARSampledNucleus::FillSamplePoints ( )

private

Definition at line 155 of file ARSampledNucleus.cxx.

{
  if (fSample_points_1)  delete[] fSample_points_1;
  if (fSample_points_2)  delete[] fSample_points_2;
  if (fSample_weights_1) delete[] fSample_weights_1;
  if (fSample_weights_2) delete[] fSample_weights_2;

  fSample_points_1 = new double[fNDensities];
  fSample_points_2 = new double[fNDensities];

  fSample_weights_1 = new double[fNDensities];
  fSample_weights_2 = new double[fNDensities];
  unsigned int decoy;

  integrationtools::SGNR(    0.0, fR_max, 2, fSampling, fSample_points_1, decoy, fSample_weights_1);
  integrationtools::SGNR(-fR_max, fR_max, 2, fSampling, fSample_points_2, decoy, fSample_weights_2);

}

unsigned int genie::alvarezruso::ARSampledNucleus::GetNDensities

(

void

)

const

Definition at line 212 of file ARSampledNucleus.cxx.

{
  return fNDensities;
}

unsigned int genie::alvarezruso::ARSampledNucleus::GetSampling

(

void

)

const

Definition at line 208 of file ARSampledNucleus.cxx.

{
  return fSampling;
}

unsigned int genie::alvarezruso::ARSampledNucleus::N ( void  ) const

inline

Definition at line 42 of file ARSampledNucleus.h.

{  return (fA-fZ);  }

double genie::alvarezruso::ARSampledNucleus::Radius	(	const int	i,
		const int	j
	)		const

Definition at line 150 of file ARSampledNucleus.cxx.

{
  return fRadii[i][j];
}

double genie::alvarezruso::ARSampledNucleus::RadiusMax ( ) const

inline

Definition at line 48 of file ARSampledNucleus.h.

    {
      return fR_max;
    }

double genie::alvarezruso::ARSampledNucleus::SamplePoint1 ( const unsigned int  i ) const

inline

Definition at line 52 of file ARSampledNucleus.h.

    {
      return fSample_points_1[i];
    }

double genie::alvarezruso::ARSampledNucleus::SamplePoint2 ( const unsigned int  i ) const

inline

Definition at line 56 of file ARSampledNucleus.h.

    {
      return fSample_points_2[i];
    }

unsigned int genie::alvarezruso::ARSampledNucleus::Z ( void  ) const

inline

Definition at line 40 of file ARSampledNucleus.h.

{  return fZ;  }

Member Data Documentation

const unsigned int genie::alvarezruso::ARSampledNucleus::fA

private

Definition at line 83 of file ARSampledNucleus.h.

double** genie::alvarezruso::ARSampledNucleus::fDensities

private

Definition at line 90 of file ARSampledNucleus.h.

double** genie::alvarezruso::ARSampledNucleus::fDensitiesOfCentres

private

Definition at line 91 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::fDiffuseness

private

Definition at line 97 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::fDiffusenessCentres

private

Definition at line 100 of file ARSampledNucleus.h.

unsigned int genie::alvarezruso::ARSampledNucleus::fNDensities

private

Definition at line 86 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::fNucRadius

private

Definition at line 98 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::fNucRadiusSq

private

Definition at line 99 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::fR_max

private

Definition at line 88 of file ARSampledNucleus.h.

double** genie::alvarezruso::ARSampledNucleus::fRadii

private

Definition at line 89 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::fRadiusCentres

private

Definition at line 101 of file ARSampledNucleus.h.

double* genie::alvarezruso::ARSampledNucleus::fSample_points_1

private

Definition at line 92 of file ARSampledNucleus.h.

double* genie::alvarezruso::ARSampledNucleus::fSample_points_2

private

Definition at line 93 of file ARSampledNucleus.h.

double* genie::alvarezruso::ARSampledNucleus::fSample_weights_1

private

Definition at line 94 of file ARSampledNucleus.h.

double* genie::alvarezruso::ARSampledNucleus::fSample_weights_2

private

Definition at line 95 of file ARSampledNucleus.h.

unsigned int genie::alvarezruso::ARSampledNucleus::fSampling

private

Definition at line 84 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::fUseHarmonicOscillator

private

Definition at line 103 of file ARSampledNucleus.h.

const unsigned int genie::alvarezruso::ARSampledNucleus::fZ

private

Definition at line 82 of file ARSampledNucleus.h.

double genie::alvarezruso::ARSampledNucleus::mean_radius_squared = 0.69

staticprivate

Definition at line 109 of file ARSampledNucleus.h.

---

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

• Generator/src/Physics/Coherent/XSection/ARSampledNucleus.h
• Generator/src/Physics/Coherent/XSection/ARSampledNucleus.cxx