genie::PattonCEvNSPXSec Class Reference

Differential cross section for v+As coherent elastic scattering. Is a concrete implementation of the XSecAlgorithmI interface. More...

#include <PattonCEvNSPXSec.h>

Inheritance diagram for genie::PattonCEvNSPXSec:

Collaboration diagram for genie::PattonCEvNSPXSec:

Public Member Functions
	PattonCEvNSPXSec ()
	PattonCEvNSPXSec (string config)
virtual	~PattonCEvNSPXSec ()
double	XSec (const Interaction *i, KinePhaseSpace_t k) const
	Compute the cross section for the input interaction.
double	Integral (const Interaction *i) const
bool	ValidProcess (const Interaction *i) const
	Can this cross section algorithm handle the input process?
void	Configure (const Registry &config)
void	Configure (string param_set)
Public Member Functions inherited from genie::XSecAlgorithmI
virtual	~XSecAlgorithmI ()
virtual bool	ValidKinematics (const Interaction *i) const
	Is the input kinematical point a physically allowed one?
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.

Private Member Functions
void	LoadConfig (void)
double	NuclearDensityMoment (int A, int k) const

Private Attributes
const XSecIntegratorI *	fXSecIntegrator
	cross section integrator
double	fSin2thw
	sin^2(weinberg angle)
double	fNuclDensMomentCalc_UpperIntegrationLimit
double	fNuclDensMomentCalc_RelativeTolerance
double	fNuclDensMomentCalc_AbsoluteTolerance
int	fNuclDensMomentCalc_MaxNumOfEvaluations

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::XSecAlgorithmI
	XSecAlgorithmI ()
	XSecAlgorithmI (string name)
	XSecAlgorithmI (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

Differential cross section for v+As coherent elastic scattering. Is a concrete implementation of the XSecAlgorithmI interface.

References:\n K.Patton, J.Engel, G.McLaughlin, and N.Schunck, arXiv:1207.0693v1

Author

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

Created:\n July 12, 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 30 of file PattonCEvNSPXSec.h.

Constructor & Destructor Documentation

PattonCEvNSPXSec() [1/2]

PattonCEvNSPXSec::PattonCEvNSPXSec

(

)

Definition at line 34 of file PattonCEvNSPXSec.cxx.

                                   :
XSecAlgorithmI("genie::PattonCEvNSPXSec")
{
 
}

References genie::XSecAlgorithmI::XSecAlgorithmI().

PattonCEvNSPXSec() [2/2]

PattonCEvNSPXSec::PattonCEvNSPXSec

(

string

config

)

Definition at line 40 of file PattonCEvNSPXSec.cxx.

                                                :
XSecAlgorithmI("genie::PattonCEvNSPXSec", config)
{
 
}

References genie::XSecAlgorithmI::XSecAlgorithmI().

~PattonCEvNSPXSec()

PattonCEvNSPXSec::~PattonCEvNSPXSec ( )

virtual

Definition at line 46 of file PattonCEvNSPXSec.cxx.

{
 
}

Member Function Documentation

Configure() [1/2]

void PattonCEvNSPXSec::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 209 of file PattonCEvNSPXSec.cxx.

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

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

Configure() [2/2]

void PattonCEvNSPXSec::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 215 of file PattonCEvNSPXSec.cxx.

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

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

Integral()

double PattonCEvNSPXSec::Integral ( const Interaction * i ) const

virtual

Integrate the model over the kinematic phase space available to the input interaction (kinematical cuts can be included)

Implements genie::XSecAlgorithmI.

Definition at line 189 of file PattonCEvNSPXSec.cxx.

{
  double xsec = fXSecIntegrator->Integrate(this,interaction);
  return xsec;
}

References fXSecIntegrator.

LoadConfig()

void PattonCEvNSPXSec::LoadConfig ( void )

private

Definition at line 221 of file PattonCEvNSPXSec.cxx.

{
  double thw = 0.;
  this->GetParam("WeinbergAngle", thw);
  fSin2thw = TMath::Power(TMath::Sin(thw), 2.);
 
  this->GetParamDef(
          "nuclear-density-moment-gsl-upper-limit",
          fNuclDensMomentCalc_UpperIntegrationLimit,
          10.);  // in nuclear radii
  this->GetParamDef(
          "nuclear-density-moment-gsl-rel-tol",
          fNuclDensMomentCalc_RelativeTolerance,
          1E-3);
  this->GetParamDef(
          "nuclear-density-moment-gsl-abs-tol",
          fNuclDensMomentCalc_AbsoluteTolerance,
          1.);
  this->GetParamDef(
          "nuclear-density-moment-gsl-max-eval",
          fNuclDensMomentCalc_MaxNumOfEvaluations,
          10000);
 
  fXSecIntegrator =
      dynamic_cast<const XSecIntegratorI *> (this->SubAlg("XSec-Integrator"));
  assert(fXSecIntegrator);
}

References fNuclDensMomentCalc_AbsoluteTolerance, fNuclDensMomentCalc_MaxNumOfEvaluations, fNuclDensMomentCalc_RelativeTolerance, fNuclDensMomentCalc_UpperIntegrationLimit, fSin2thw, fXSecIntegrator, genie::Algorithm::GetParam(), genie::Algorithm::GetParamDef(), and genie::Algorithm::SubAlg().

Referenced by Configure(), and Configure().

NuclearDensityMoment()

double PattonCEvNSPXSec::NuclearDensityMoment ( int A, int k ) const

private

Definition at line 154 of file PattonCEvNSPXSec.cxx.

{
  // Calculate moments of the nuclear density
  // Inputs:
  //   - atomic mass number, A
  //   - integer k specifying required nuclear density moment
  // Output:
  //   - nuclear density moment in units of fm^k
  //
  // THINGS TO DO:
  // 1) The calculation can be stored, as it is required only once per nucleus.
  //    The calculation is very fast so it doesn't matter.
 
  ROOT::Math::IBaseFunctionOneDim * integrand = new
              utils::gsl::wrap::NuclDensityMomentIntegrand(A,k);
 
  ROOT::Math::IntegrationOneDim::Type ig_type =
          utils::gsl::Integration1DimTypeFromString("adaptive");
 
  double R0 = utils::nuclear::Radius(A); // units: fm
  double rmin = 0; // units: fm
  double rmax = fNuclDensMomentCalc_UpperIntegrationLimit * R0; // units: fm
 
  ROOT::Math::Integrator ig(
    *integrand,ig_type,
    fNuclDensMomentCalc_AbsoluteTolerance,
    fNuclDensMomentCalc_RelativeTolerance,
    fNuclDensMomentCalc_MaxNumOfEvaluations);
  double moment = 2 * constants::kPi * ig.Integral(rmin, rmax); // units: fm^k
 
  delete integrand;
 
  return moment;
}

References fNuclDensMomentCalc_AbsoluteTolerance, fNuclDensMomentCalc_MaxNumOfEvaluations, fNuclDensMomentCalc_RelativeTolerance, fNuclDensMomentCalc_UpperIntegrationLimit, genie::utils::gsl::Integration1DimTypeFromString(), genie::constants::kPi, and genie::utils::nuclear::Radius().

Referenced by XSec().

ValidProcess()

bool PattonCEvNSPXSec::ValidProcess ( const Interaction * i ) const

virtual

Can this cross section algorithm handle the input process?

Implements genie::XSecAlgorithmI.

Definition at line 195 of file PattonCEvNSPXSec.cxx.

{
  if(interaction->TestBit(kISkipProcessChk)) return true;
 
  const ProcessInfo & proc_info = interaction->ProcInfo();
  if(!proc_info.IsCoherentElastic()) return false;
 
  const InitialState & init_state = interaction->InitState();
  const Target & target = init_state.Tgt();
  if(!target.IsNucleus()) return false;
 
  return true;
}

References genie::Interaction::InitState(), genie::ProcessInfo::IsCoherentElastic(), genie::Target::IsNucleus(), genie::kISkipProcessChk, genie::Interaction::ProcInfo(), and genie::InitialState::Tgt().

Referenced by XSec().

XSec()

double PattonCEvNSPXSec::XSec ( const Interaction * i, KinePhaseSpace_t k ) const

virtual

Compute the cross section for the input interaction.

Implements genie::XSecAlgorithmI.

Definition at line 51 of file PattonCEvNSPXSec.cxx.

{
  if(! this -> ValidProcess    (interaction) ) return 0.;
  if(! this -> ValidKinematics (interaction) ) return 0.;
 
  const InitialState & init_state = interaction -> InitState();
  const Kinematics &   kinematics = interaction -> Kine();
  const Target &       target     = init_state.Tgt();
 
  // User inputs to the calculation
  double E  = init_state.ProbeE(kRfLab); // neutrino energy, units: GeV
  double Q2 = kinematics.Q2(); // momentum transfer, units: GeV^2
  int    Z  = target.Z(); // number of protons
  int    N  = target.N(); // number of nucleons
 
  // Target atomic mass number and mass calculated from inputs
  int A   = Z+N;
  int target_nucleus_pdgc = pdg::IonPdgCode(A,Z);
  double M = PDGLibrary::Instance()->Find(target_nucleus_pdgc)->Mass(); // units: GeV
  LOG("CEvNS", pDEBUG) << "M = " << M << " GeV";
 
  // Calculation of nuclear recoil kinetic energy computed from input Q2
  double TA = Q2*E / (2*E*M+Q2); // nuclear recoil kinetic energy
 
  LOG("CEvNS", pDEBUG)
    << "Q2 = " << Q2 << " GeV^2, E = " << E << " GeV "
    << "--> TA = " << TA << " GeV";
 
  // auxiliary variables
  double E2  = E*E;
  double TA2 = TA*TA;
  double Q4  = Q2*Q2;
  double Q6  = Q2*Q4;
 
  // Calculation of weak charge
  // double Qw = N - Z*(1-fSin2thw);
  // Qw^2/4 x-section factor in arXiv:1207.0693v1 not needed here.
  // 1/4 was absorbed in the constant front factor (below) and Qw^2 factor would
  // have cancelled with ignored 1/Qw factor in the form factor F.
 
  // Calculation of nuclear density moments used for the evaluation
  // of the neutron form factor
  double avg_density = this->NuclearDensityMoment(A, 0); // units:: fm^-3
  double Rn2 = this->NuclearDensityMoment(A, 2) / avg_density; // units: fm^2
  double Rn4 = this->NuclearDensityMoment(A, 4) / avg_density; // units: fm^4
  double Rn6 = this->NuclearDensityMoment(A, 6) / avg_density; // units: fm^6
 
  LOG("CEvNS", pDEBUG)
    << "Nuclear density moments:"
    << " <Rn^2> = " << Rn2 << " fm^2,"
    << " <Rn^4> = " << Rn4 << " fm^4,"
    << " <Rn^6> = " << Rn6 << " fm^6";
 
  Rn2 *= TMath::Power(units::fm, 2.); // units: GeV^-2
  Rn4 *= TMath::Power(units::fm, 4.); // units: GeV^-4
  Rn6 *= TMath::Power(units::fm, 6.); // units: GeV^-6
 
  // Calculation of proton form factor
  // Form factor is neglected since it is multiplied with a small factor 1-4sin^2(\theta_{w})
  double Fp = 0; // units: -
  // Calculation of neutron form factor
  // Using a Taylor expansion of sin(Qr) and keeping the first three terms (shown to be
  // sufficient for approximating the full Fn calculation, even for heavy nuclei)
  double Fn = N * (1 - Q2*Rn2/6. + Q4*Rn4/120. - Q6*Rn6/5040.); // units: -
  // Overall form factor
  double F  = (Fn - (1-4*fSin2thw)*Fp); // units: -
  F = TMath::Max(0.,F);
  double F2 = F*F; // units: -
 
  LOG("CEvNS", pDEBUG)
    << "Form factors: Fp = " << Fp << ", Fn = " << Fn << ", F = " << F;
 
  // dsig/dTA calculation
  double const_factor = 0.125*kGF2/kPi; // units: GeV^-4
  double kinematic_term = M * (2 - 2*TA/E + TA2/E2 - M*TA/E2); // units: GeV
  kinematic_term = TMath::Max(0., kinematic_term);
 
  LOG("CEvNS", pDEBUG)
    << "kinematic term: " << kinematic_term;
 
  double xsec = const_factor * kinematic_term * F2; // units: GeV^-3 (area/GeV)
 
  LOG("CEvNS", pINFO)
    << "dsig[vA,CEvNS]/dTA (Ev =  "
    << E << " GeV, Q2 = "<< Q2 << " GeV^2; TA = " << TA << " GeV) = "
    << xsec/(units::cm2) << " cm^2/GeV";
 
  // The algorithm computes dxsec/dTA
  // Check whether variable tranformation is needed
  if(kps!=kPSTAfE) {
    // TODO: Move the calculation in utils::kinematics
    // double J = utils::kinematics::Jacobian(interaction,kPSQ2fE,kps);
    double J = 0;
    if(kps==kPSQ2fE) {
        J = 2*E2*M / TMath::Power(2*E*M+Q2, 2.); // units: GeV^-1
    }
    xsec *= J; // units: GeV^-4 (area/GeV^2)
  }
 
  return xsec;
}

References genie::units::cm2, genie::PDGLibrary::Find(), genie::units::fm, fSin2thw, genie::PDGLibrary::Instance(), genie::pdg::IonPdgCode(), genie::constants::kGF2, genie::constants::kPi, genie::kPSQ2fE, genie::kPSTAfE, genie::kRfLab, LOG, genie::Target::N(), NuclearDensityMoment(), pDEBUG, pINFO, genie::InitialState::ProbeE(), genie::InitialState::Tgt(), genie::XSecAlgorithmI::ValidKinematics(), ValidProcess(), and genie::Target::Z().

Member Data Documentation

fNuclDensMomentCalc_AbsoluteTolerance

double genie::PattonCEvNSPXSec::fNuclDensMomentCalc_AbsoluteTolerance

private

Definition at line 60 of file PattonCEvNSPXSec.h.

Referenced by LoadConfig(), and NuclearDensityMoment().

fNuclDensMomentCalc_MaxNumOfEvaluations

int genie::PattonCEvNSPXSec::fNuclDensMomentCalc_MaxNumOfEvaluations

private

Definition at line 61 of file PattonCEvNSPXSec.h.

Referenced by LoadConfig(), and NuclearDensityMoment().

fNuclDensMomentCalc_RelativeTolerance

double genie::PattonCEvNSPXSec::fNuclDensMomentCalc_RelativeTolerance

private

Definition at line 59 of file PattonCEvNSPXSec.h.

Referenced by LoadConfig(), and NuclearDensityMoment().

fNuclDensMomentCalc_UpperIntegrationLimit

double genie::PattonCEvNSPXSec::fNuclDensMomentCalc_UpperIntegrationLimit

private

Definition at line 58 of file PattonCEvNSPXSec.h.

Referenced by LoadConfig(), and NuclearDensityMoment().

fSin2thw

double genie::PattonCEvNSPXSec::fSin2thw

private

sin^2(weinberg angle)

Definition at line 55 of file PattonCEvNSPXSec.h.

Referenced by LoadConfig(), and XSec().

fXSecIntegrator

const XSecIntegratorI* genie::PattonCEvNSPXSec::fXSecIntegrator

private

cross section integrator

Definition at line 54 of file PattonCEvNSPXSec.h.

Referenced by Integral(), and LoadConfig().

---

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

• PattonCEvNSPXSec.h
• PattonCEvNSPXSec.cxx