Computes the differential cross section for an exclusive 1-pion reaction through resonance neutrinoproduction according to the Rein-Sehgal model. More...

#include <ReinSehgalSPPPXSec.h>

Inheritance diagram for genie::ReinSehgalSPPPXSec:

Public Member Functions
	ReinSehgalSPPPXSec ()

	ReinSehgalSPPPXSec (string config)

virtual	~ReinSehgalSPPPXSec ()

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)

double	XSecNRES (const Interaction *i, KinePhaseSpace_t k) const

double	XSec1RES (const Interaction *i, KinePhaseSpace_t k) const

Private Attributes
BaryonResList	fResList

const XSecAlgorithmI *	fSingleResXSecModel

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

Computes the differential cross section for an exclusive 1-pion reaction through resonance neutrinoproduction according to the Rein-Sehgal model.

The cross section is computed for an input list of resonances as the sum of the Rein-Sehgal single resonance cross sections weighted:

With the value of their Breit-Wigner distributions at the given W,Q^2 (The code for BW weighting is included in the single resonance cross section algorithm. The user needs to make sure that he does not run the single resonance cross section code with a configuration that inhibits weighting).

With the isospin Glebsch-Gordon coefficient determining the contribution of each resonance to the exclusive final state.

With the BR for the produced resonance to decay into the given exclusive final state.

In this algorithm we follow the non-coherent approach: we sum the weighted resonance production cross sections rather than the resonance production amplitudes.

Is a concrete implementation of the XSecAlgorithmI interface.

D.Rein and L.M.Sehgal, Neutrino Excitation of Baryon Resonances and Single Pion Production, Ann.Phys.133, 79 (1981)

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

November 22, 2004

Definition at line 55 of file ReinSehgalSPPPXSec.h.

Constructor & Destructor Documentation

ReinSehgalSPPPXSec::ReinSehgalSPPPXSec ( )

Definition at line 27 of file ReinSehgalSPPPXSec.cxx.

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

ReinSehgalSPPPXSec::ReinSehgalSPPPXSec ( string config )

Definition at line 33 of file ReinSehgalSPPPXSec.cxx.

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

ReinSehgalSPPPXSec::~ReinSehgalSPPPXSec ( )

virtual

Definition at line 39 of file ReinSehgalSPPPXSec.cxx.

 {
 
 }

Member Function Documentation

void ReinSehgalSPPPXSec::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 160 of file ReinSehgalSPPPXSec.cxx.

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

void ReinSehgalSPPPXSec::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 166 of file ReinSehgalSPPPXSec.cxx.

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

double ReinSehgalSPPPXSec::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 137 of file ReinSehgalSPPPXSec.cxx.

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

void ReinSehgalSPPPXSec::LoadConfig ( void )

private

Definition at line 172 of file ReinSehgalSPPPXSec.cxx.

 {
 // load the single resonance cross section algorithm specified in the config.
 
   fSingleResXSecModel =
    dynamic_cast<const XSecAlgorithmI *> (this->SubAlg("SingleRESDiffXSecAlg"));
   assert(fSingleResXSecModel);
 
   //-- Create a BaryonResList by decoding the resonance list from
   //   the XML input
   //   The list of resonances can be specified as a string with
   //   comma separated resonance names (eg "P33(1233),S11(1535),D13(1520)")
   //   The BaryonResList can also decode lists of pdg-codes or
   //   resonance-ids (Resonance_t enumerations).
   //   Support for this will be added here as well.
 
   fResList.Clear();
 
 
   string resonances ;
   GetParam( "ResonanceNameList", resonances ) ;
   fResList.DecodeFromNameList(resonances);
 
   //-- load the differential cross section integrator
   fXSecIntegrator =
       dynamic_cast<const XSecIntegratorI *> (this->SubAlg("XSec-Integrator"));
   assert(fXSecIntegrator);
 }

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

virtual

Can this cross section algorithm handle the input process?

Implements genie::XSecAlgorithmI.

Definition at line 142 of file ReinSehgalSPPPXSec.cxx.

 {
   if(interaction->TestBit(kISkipProcessChk)) return true;
 
   //-- Get the requested SPP channel
   SppChannel_t spp_channel = SppChannel::FromInteraction(interaction);
   if( spp_channel == kSppNull ) {
     LOG("ReinSehgalSpp", pERROR)
             << "\n *** Insufficient SPP exclusive final state information!";
     return false;
   }
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("ReinSehgalSpp", pDEBUG)
                        << "Reaction: " << SppChannel::AsString(spp_channel);
 #endif
   return true;
 }

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

virtual

Compute the cross section for the input interaction.

Implements genie::XSecAlgorithmI.

Definition at line 44 of file ReinSehgalSPPPXSec.cxx.

 {
   if(! this -> ValidProcess    (interaction) ) return 0.;
   if(! this -> ValidKinematics (interaction) ) return 0.;
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("ReinSehgalSpp", pDEBUG)
                  << "Computing a cross section for " << *interaction;
 #endif
   //-- Check whether a resonance has been specified
   //   If yes, compute only the contribution of this resonance at the
   //   specified exclusive state
 
   Resonance_t inpres = interaction->ExclTag().Resonance();
   if(inpres != kNoResonance) {
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
         LOG("ReinSehgalSpp", pDEBUG)
                << "Computing only the contribution from: " << utils::res::AsString(inpres);
 #endif
     if(!fResList.Find(inpres)) {
        LOG("ReinSehgalSpp", pWARN)
            << "Resonance: " << utils::res::AsString(inpres) << " was not found in my list";
        return 0;
     }
     //-- Compute the contribution of this resonance
     //-- Get the Breit-Wigner weighted xsec for exciting the resonance
 
     return fSingleResXSecModel->XSec(interaction,kps);
   }
 
   //-- Loop over the specified list of baryon resonances and compute
   //   the cross section for the input exclusive channel
 
   return this->XSecNRES(interaction,kps);
 }

double genie::ReinSehgalSPPPXSec::XSec1RES	(	const Interaction *	i,
		KinePhaseSpace_t	k
	)		const

private

double ReinSehgalSPPPXSec::XSecNRES	(	const Interaction *	i,
		KinePhaseSpace_t	k
	)		const

private

Definition at line 80 of file ReinSehgalSPPPXSec.cxx.

 {
 // computes the 1pi cros section taking into account the contribution of all
 // specified baryon resonances
 
   unsigned int nres = fResList.NResonances();
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("ReinSehgalSpp", pDEBUG)
     << "Computing SPP cross section using " << nres << " resonances";
 #endif
 
   //-- Get 1pi exclusive channel
   SppChannel_t spp_channel = SppChannel::FromInteraction(interaction);
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("ReinSehgalSpp", pDEBUG)
               << "SPP channel " << SppChannel::AsString(spp_channel);
 #endif
 
   double xsec = 0;
   for(unsigned int ires = 0; ires < nres; ires++) {
 
      //-- Get next resonance from the resonance list
      Resonance_t res = fResList.ResonanceId(ires);
 
      //-- Set current resonance to interaction object
      interaction->ExclTagPtr()->SetResonance(res);
 
      //-- Get the BR for the (resonance) -> (exclusive final state)
          double br = SppChannel::BranchingRatio(spp_channel, res);
 
          //-- Get the Isospin Clebsch-Gordon coefficient for the given resonance
          //   and exclusive final state
          double igg = SppChannel::IsospinWeight(spp_channel, res);
 
          //-- Compute the weighted xsec
          //  (total weight = Breit-Wigner * BR * isospin Clebsch-Gordon)
          double res_xsec_contrib = fSingleResXSecModel->XSec(interaction,kps)*br*igg;
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
          LOG("ReinSehgalSpp", pDEBUG)
      << "Contrib. from [" << utils::res::AsString(res) << "] = "
      << "<Clebsch-Gordon = " << igg
      << "> * <BR(->1pi) = " << br
      << "> * <Breit-Wigner * d^nxsec/dK^n = " << rxsec
      << "> = " << res_xsec_contrib;
 #endif
 
      //-- Add contribution of this resonance to the cross section
      xsec += res_xsec_contrib;
   }
 
   //-- delete the resonance from the input interaction
   interaction->ExclTagPtr()->SetResonance(kNoResonance);
 
   return xsec;
 }

Member Data Documentation

BaryonResList genie::ReinSehgalSPPPXSec::fResList

private

Definition at line 81 of file ReinSehgalSPPPXSec.h.

const XSecAlgorithmI* genie::ReinSehgalSPPPXSec::fSingleResXSecModel

private

Definition at line 82 of file ReinSehgalSPPPXSec.h.

const XSecIntegratorI* genie::ReinSehgalSPPPXSec::fXSecIntegrator

private

Definition at line 83 of file ReinSehgalSPPPXSec.h.

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

Generator/src/Physics/Resonance/XSection/ReinSehgalSPPPXSec.h
Generator/src/Physics/Resonance/XSection/ReinSehgalSPPPXSec.cxx

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation