genie::ReinDFRPXSec Class Reference

Neutrino diffractive pion production cross section. More...

#include <ReinDFRPXSec.h>

Inheritance diagram for genie::ReinDFRPXSec:

Public Member Functions
	ReinDFRPXSec ()
	ReinDFRPXSec (const std::string &config)
virtual	~ReinDFRPXSec ()
double	XSec (const Interaction *i, KinePhaseSpace_t k) const
	Compute the cross section for the input interaction. More...
double	Integral (const Interaction *i) const
bool	ValidProcess (const Interaction *i) const
	Can this cross section algorithm handle the input process? More...
void	Configure (const Registry &config)
void	Configure (string config)
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? More...
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
void	LoadConfig (void)

Private Attributes
double	fMa
	axial mass More...
double	fBeta
	b in dsig{piN}/dt = dsig0{piN}/dt * exp(-b(t-tmin)), b ~ 0.333 (nucleon_size)^2 More...
const XSecIntegratorI *	fXSecIntegrator

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)
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. 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
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

Neutrino diffractive pion production cross section.

D.Rein, Nucl.Phys.B278(1986) 61-77

Author

Costas Andreopoulos <constantinos.andreopoulos cern.ch> University of Liverpool & STFC Rutherford Appleton Laboratory

Feb 17th, 2009

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

Definition at line 32 of file ReinDFRPXSec.h.

Constructor & Destructor Documentation

ReinDFRPXSec::ReinDFRPXSec

(

)

Definition at line 32 of file ReinDFRPXSec.cxx.

                           :
XSecAlgorithmI("genie::ReinDFRPXSec")
{

}

ReinDFRPXSec::ReinDFRPXSec

(

const std::string &

config

)

Definition at line 38 of file ReinDFRPXSec.cxx.

                                                   :
XSecAlgorithmI("genie::ReinDFRPXSec", config)
{

}

ReinDFRPXSec::~ReinDFRPXSec ( )

virtual

Definition at line 44 of file ReinDFRPXSec.cxx.

{

}

Member Function Documentation

void ReinDFRPXSec::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 141 of file ReinDFRPXSec.cxx.

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

void ReinDFRPXSec::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 147 of file ReinDFRPXSec.cxx.

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

double ReinDFRPXSec::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 121 of file ReinDFRPXSec.cxx.

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

void ReinDFRPXSec::LoadConfig ( void  )

private

Definition at line 153 of file ReinDFRPXSec.cxx.

{
        GetParam( "DFR-Ma", fMa ) ;
        GetParam( "DFR-Beta",fBeta ) ;

        fXSecIntegrator =
                        dynamic_cast<const XSecIntegratorI *> (this->SubAlg("XSec-Integrator") );
        assert(fXSecIntegrator);
}

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

virtual

Can this cross section algorithm handle the input process?

Implements genie::XSecAlgorithmI.

Definition at line 127 of file ReinDFRPXSec.cxx.

{
  //expect only free protons as target
  const InitialState & init_state = interaction -> InitState();
  const Target &       target     = init_state.Tgt();
  if(target.A() > 1 || target.Z() != 1)
    return false;

  if(interaction->TestBit(kISkipProcessChk)) return true;

  if(interaction->ProcInfo().IsDiffractive()) return true;
  return false;
}

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

virtual

Compute the cross section for the input interaction.

Implements genie::XSecAlgorithmI.

Definition at line 49 of file ReinDFRPXSec.cxx.

{
  if(! this -> ValidProcess    (interaction) ) return 0.;
  if(! this -> ValidKinematics (interaction) ) return 0.;

  const Kinematics &   kinematics = interaction -> Kine();
  const InitialState & init_state = interaction -> InitState();
  const Target &       target     = init_state.Tgt();

  bool   isCC    = interaction->ProcInfo().IsWeakCC();
  double E       = init_state.ProbeE(kRfHitNucRest);          // neutrino energy
  double x       = kinematics.x();                            // bjorken x
  double y       = kinematics.y();                            // inelasticity y
  double t       = kinematics.t();                            // (magnitude of) square of four-momentum xferred to proton
  double M       = target.HitNucMass();                       //
  double Q2      = 2.*x*y*M*E;                                // momentum transfer Q2>0
  double Gf      = kGF2 * M/(16*kPi3);                        // GF/pi/etc factor
  double fp      = 0.93 * kPionMass;                          // pion decay constant (cc)
  double fp2     = TMath::Power(fp,2.);
  double Epi     = y*E - t/(2*M);                             // pion energy.  note we use - instead of + like Rein's paper b/c our t is magnitude only
  double b       = fBeta;
  double ma2     = TMath::Power(fMa,2);
  double propg   = TMath::Power(ma2/(ma2+Q2),2.);             // propagator term
  double sTot    = utils::hadxs::TotalPionNucleonXSec(Epi, isCC);   // pi+N total cross section; CC process always produces a charged pion
  double sTot2   = TMath::Power(sTot,2.);
  double tFac    = TMath::Exp(-b*t);

#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
  LOG("ReinDFR", pDEBUG)
    << "E = " << E << ", x = " << x << ", y = " << y << ", Q2 = " << Q2;
  LOG("ReinDFR", pDEBUG)
    << "Epi = " << Epi << ", s^{piN}_{tot} = " << sTot;
  LOG("ReinDFR", pDEBUG)
    << "b = " << b << ", t = [" << tmin << ", " << tmax << "]";
#endif

  // fixme: WARNING: don't leave this in here!!!
  // only needed for comparison to Rein's paper
//  double W2 = M*M + 2 * M * y * E - Q2;
//  if (W2 < 4)
//    return 0;

  //----- compute d^2sigma/dxdydt
  double xsec = Gf*E*fp2*(1-y)*propg*sTot2*tFac;

  // NC XS is half of CC
  if (!isCC)
    xsec *= 0.5;

  //----- Check whether variable tranformation is needed
  if(kps!=kPSxytfE) {
    double J = utils::kinematics::Jacobian(interaction,kPSxytfE,kps);
#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
    LOG("ReinDFR", pDEBUG)
     << "Jacobian for transformation to: "
                  << KinePhaseSpace::AsString(kps) << ", J = " << J;
#endif
    xsec *= J;
  }

  //----- if requested return the free nucleon xsec even for input nuclear tgt
  if( interaction->TestBit(kIAssumeFreeNucleon) ) return xsec;

  //----- number of scattering centers in the target
  int nucpdgc = target.HitNucPdg();
  int NNucl = (pdg::IsProton(nucpdgc)) ? target.Z() : target.N();
  xsec *= NNucl;

  return xsec;
}

Member Data Documentation

double genie::ReinDFRPXSec::fBeta

private

b in dsig{piN}/dt = dsig0{piN}/dt * exp(-b(t-tmin)), b ~ 0.333 (nucleon_size)^2

Definition at line 54 of file ReinDFRPXSec.h.

double genie::ReinDFRPXSec::fMa

private

axial mass

Definition at line 53 of file ReinDFRPXSec.h.

const XSecIntegratorI* genie::ReinDFRPXSec::fXSecIntegrator

private

Definition at line 56 of file ReinDFRPXSec.h.

---

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

• Generator/src/Physics/Diffractive/XSection/ReinDFRPXSec.h
• Generator/src/Physics/Diffractive/XSection/ReinDFRPXSec.cxx