Computes DIS differential cross sections. Is a concrete implementation of the XSecAlgorithmI interface. More...

#include <QPMDISPXSec.h>

Inheritance diagram for genie::QPMDISPXSec:

Collaboration diagram for genie::QPMDISPXSec:

Public Member Functions
	QPMDISPXSec ()

	QPMDISPXSec (string config)

virtual	~QPMDISPXSec ()

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
DISStructureFunc	fDISSF

bool	fInInitPhase

const DISStructureFuncModelI *	fDISSFModel
	SF model. More...

const XSecIntegratorI *	fXSecIntegrator
	diff. xsec integrator More...

const XSecAlgorithmI *	fCharmProdModel

double	fCCScale
	cross section scaling factor More...

double	fNCScale
	cross section scaling factor More...

double	fEMScale
	cross section scaling factor More...

double	fSin48w
	sin^4(Weingberg angle) More...

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. 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

Computes DIS differential cross sections. Is a concrete implementation of the XSecAlgorithmI interface.

References:: E.A.Paschos and J.Y.Yu, Phys.Rev.D 65.03300

Author: Costas Andreopoulos <c.andreopoulos cern.ch> University of Liverpool

Created:: May 05, 2004

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

Definition at line 33 of file QPMDISPXSec.h.

Constructor & Destructor Documentation

QPMDISPXSec::QPMDISPXSec ( )

Definition at line 44 of file QPMDISPXSec.cxx.

References fInInitPhase.

                          :
 XSecAlgorithmI("genie::QPMDISPXSec")
 {
   fInInitPhase = true;
 }

QPMDISPXSec::QPMDISPXSec ( string config )

Definition at line 50 of file QPMDISPXSec.cxx.

References fInInitPhase.

                                       :
 XSecAlgorithmI("genie::QPMDISPXSec", config)
 {
   fInInitPhase = true;
 }

QPMDISPXSec::~QPMDISPXSec ( )

virtual

Definition at line 56 of file QPMDISPXSec.cxx.

 {
 
 }

Member Function Documentation

void QPMDISPXSec::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 215 of file QPMDISPXSec.cxx.

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

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

void QPMDISPXSec::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 221 of file QPMDISPXSec.cxx.

References genie::Algorithm::Configure(), genie::AlgConfigPool::Instance(), LoadConfig(), and genie::Registry::Set().

 {
   Algorithm::Configure(config);
 
   Registry r( "QPMDISPXSec_specific", false ) ;
 
   RgKey xdefkey = "XSecModel@genie::EventGenerator/DIS-CC-CHARM";
   RgKey local_key = "CharmXSec" ;
   r.Set( local_key, AlgConfigPool::Instance() -> GlobalParameterList() -> GetAlg(xdefkey) ) ;
 
   Algorithm::Configure(r) ;
 
   this->LoadConfig();
 }

double QPMDISPXSec::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 190 of file QPMDISPXSec.cxx.

References fXSecIntegrator, and genie::XSecIntegratorI::Integrate().

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

void QPMDISPXSec::LoadConfig ( void )

private

Definition at line 236 of file QPMDISPXSec.cxx.

References fCCScale, fCharmProdModel, fDISSF, fDISSFModel, fEMScale, fInInitPhase, fNCScale, fSin48w, fXSecIntegrator, genie::Algorithm::GetParam(), genie::Algorithm::Id(), genie::Cache::Instance(), genie::AlgId::Key(), LOG, pDEBUG, genie::Cache::RmMatchedCacheBranches(), genie::DISStructureFunc::SetModel(), and genie::Algorithm::SubAlg().

Referenced by Configure().

 {
   // Access global defaults to use in case of missing parameters
 
   fDISSFModel = 0;
   fDISSFModel =
      dynamic_cast<const DISStructureFuncModelI *> (this->SubAlg("SFAlg"));
   assert(fDISSFModel);
 
   fDISSF.SetModel(fDISSFModel); // <-- attach algorithm
 
   // Cross section scaling factor
   GetParam( "DIS-CC-XSecScale", fCCScale ) ;
   GetParam( "DIS-NC-XSecScale", fNCScale ) ;
   GetParam( "DIS-EM-XSecScale", fEMScale ) ;
 
   // sin^4(theta_weinberg)
   double thw  ;
   GetParam( "WeinbergAngle", thw ) ;
   fSin48w = TMath::Power( TMath::Sin(thw), 4 );
 
 
   // Since this method would be called every time the current algorithm is
   // reconfigured at run-time, remove all the data cached by this algorithm
   // since they depend on the previous configuration
 
   if(!fInInitPhase) {
      Cache * cache = Cache::Instance();
      string keysubstr = this->Id().Key() + "/DIS-RES-Join";
      cache->RmMatchedCacheBranches(keysubstr);
   }
   fInInitPhase = false;
 
   //-- load the differential cross section integrator
   fXSecIntegrator =
       dynamic_cast<const XSecIntegratorI *> (this->SubAlg("XSec-Integrator"));
   assert(fXSecIntegrator);
 
   // Load the charm production cross section model
   RgKey local_key = "CharmXSec" ;
   RgAlg xalg;
   GetParam( local_key, xalg ) ;
   LOG("DISXSec", pDEBUG)
      << "Loading the cross section model: " << xalg;
 
   fCharmProdModel = dynamic_cast<const XSecAlgorithmI *> ( this -> SubAlg(local_key) ) ;
   assert(fCharmProdModel);
 }

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

virtual

Can this cross section algorithm handle the input process?

Implements genie::XSecAlgorithmI.

Definition at line 196 of file QPMDISPXSec.cxx.

References genie::Target::HitNucIsSet(), genie::Target::HitNucPdg(), genie::ProcessInfo::IsDeepInelastic(), genie::pdg::IsLepton(), genie::pdg::IsNeutronOrProton(), genie::kISkipProcessChk, genie::InitialState::ProbePdg(), genie::Interaction::ProcInfo(), and genie::InitialState::Tgt().

Referenced by XSec().

 {
   if(interaction->TestBit(kISkipProcessChk)) return true;
 
   const ProcessInfo & proc_info  = interaction->ProcInfo();
   if(!proc_info.IsDeepInelastic()) return false;
 
   const InitialState & init_state = interaction -> InitState();
   int probe_pdg = init_state.ProbePdg();
   if(!pdg::IsLepton(probe_pdg)) return false;
 
   if(! init_state.Tgt().HitNucIsSet()) return false;
 
   int hitnuc_pdg = init_state.Tgt().HitNucPdg();
   if(!pdg::IsNeutronOrProton(hitnuc_pdg)) return false;
 
   return true;
 }

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

virtual

Compute the cross section for the input interaction.

Implements genie::XSecAlgorithmI.

Definition at line 61 of file QPMDISPXSec.cxx.

References genie::DISStructureFunc::Calculate(), genie::Interaction::ExclTagPtr(), genie::DISStructureFunc::F1(), genie::DISStructureFunc::F2(), genie::DISStructureFunc::F3(), genie::DISStructureFunc::F4(), genie::DISStructureFunc::F5(), fCCScale, fCharmProdModel, fDISSF, fEMScale, fSin48w, genie::Interaction::FSPrimLepton(), genie::Target::HitNucMass(), genie::Target::HitNucPdg(), genie::pdg::IsAntiNeutrino(), genie::ProcessInfo::IsEM(), genie::pdg::IsProton(), genie::ProcessInfo::IsWeakCC(), genie::ProcessInfo::IsWeakNC(), genie::utils::mec::J(), genie::utils::kinematics::Jacobian(), genie::constants::kAem2, genie::constants::kGF2, genie::kIAssumeFreeNucleon, genie::constants::kMw2, genie::constants::kMz2, genie::constants::kPi, genie::constants::kPi2, genie::kPSxyfE, genie::kRfHitNucRest, LOG, genie::Target::N(), pDEBUG, pINFO, genie::InitialState::ProbeE(), genie::InitialState::ProbePdg(), genie::utils::kinematics::Q2(), genie::XclsTag::SetCharm(), genie::InitialState::Tgt(), genie::XclsTag::UnsetCharm(), genie::XSecAlgorithmI::ValidKinematics(), ValidProcess(), genie::Kinematics::x(), genie::XSecAlgorithmI::XSec(), genie::utils::kinematics::XYtoQ2(), genie::Kinematics::y(), and genie::Target::Z().

 {
   if(! this -> ValidProcess    (interaction) ) return 0.;
   if(! this -> ValidKinematics (interaction) ) return 0.;
 
   // Get kinematical & init-state parameters
   const Kinematics &   kinematics = interaction -> Kine();
   const InitialState & init_state = interaction -> InitState();
   const ProcessInfo &  proc_info  = interaction -> ProcInfo();
 
   double E     = init_state.ProbeE(kRfHitNucRest);
   double ml    = interaction->FSPrimLepton()->Mass();
   double Mnuc  = init_state.Tgt().HitNucMass();
   double x     = kinematics.x();
   double y     = kinematics.y();
 
   double E2    = E    * E;
   double ml2   = ml   * ml;
   double ml4   = ml2  * ml2;
   double Mnuc2 = Mnuc * Mnuc;
 
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("DISPXSec", pDEBUG)
    << "Computing d2xsec/dxdy @ E = " << E << ", x = " << x << ", y = " << y;
 #endif
 
   // One of the xsec terms changes sign for antineutrinos @ DIS/CC
 
   bool is_nubar_cc = pdg::IsAntiNeutrino(init_state.ProbePdg()) &&
                      proc_info.IsWeakCC();
   int sign = (is_nubar_cc) ? -1 : 1;
 
   // Calculate the DIS structure functions
   fDISSF.Calculate(interaction);
 
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("DISPXSec", pDEBUG) << fDISSF;
 #endif
 
   //
   // Compute the differential cross section
   //
 
   double g2 = kGF2;
   // For EM interaction replace  G_{Fermi} with :
   // a_{em} * pi / ( sqrt(2) * sin^2(theta_weinberg) * Mass_{W}^2 }
   // See C.Quigg, Gauge Theories of the Strong, Weak and E/M Interactions,
   // ISBN 0-8053-6021-2, p.112 (6.3.57)
   // Also, take int account that the photon propagator is 1/p^2 but the
   // W propagator is 1/(p^2-Mass_{W}^2), so weight the EM case with
   // Mass_{W}^4 / q^4
   // So, overall:
   // G_{Fermi}^2 --> a_{em}^2 * pi^2 / (2 * sin^4(theta_weinberg) * q^{4})
   //
   double Q2 = utils::kinematics::XYtoQ2(E,Mnuc,x,y);
   double Q4 = Q2*Q2;
   if(proc_info.IsEM()) {
     g2 = kAem2 * kPi2 / (2.0 * fSin48w * Q4);
   }
   if (proc_info.IsWeakCC()) {
     g2 = kGF2 * kMw2 * kMw2 / TMath::Power((Q2 + kMw2), 2);
   } else if (proc_info.IsWeakNC()) {
     g2 = kGF2 * kMz2 * kMz2 / TMath::Power((Q2 + kMz2), 2);
   }
   double front_factor = (g2*Mnuc*E) / kPi;
 
   // Build all dxsec/dxdy terms
   double term1 = y * ( x*y + ml2/(2*E*Mnuc) );
   double term2 = 1 - y - Mnuc*x*y/(2*E) - ml2/(4*E2);
   double term3 = sign * (x*y*(1-y/2) - y*ml2/(4*Mnuc*E));
   double term4 = x*y*ml2/(2*Mnuc*E) + ml4/(4*Mnuc2*E2);
   double term5 = -1.*ml2/(2*Mnuc*E);
 
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("DISPXSec", pDEBUG)
     << "\nd2xsec/dxdy ~ (" << term1 << ")*F1+(" << term2 << ")*F2+("
                   << term3 << ")*F3+(" << term4 << ")*F4+(" << term5 << ")*F5";
 #endif
 
   term1 *= fDISSF.F1();
   term2 *= fDISSF.F2();
   term3 *= fDISSF.F3();
   term4 *= fDISSF.F4();
   term5 *= fDISSF.F5();
 
   double xsec = front_factor * (term1 + term2 + term3 + term4 + term5);
   xsec = TMath::Max(xsec,0.);
 
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("DISPXSec", pINFO)
         << "d2xsec/dxdy[FreeN] (E= " << E
                       << ", x= " << x << ", y= " << y << ") = " << xsec;
 #endif
 
    // The algorithm computes d^2xsec/dxdy
   // Check whether variable tranformation is needed
   if(kps!=kPSxyfE) {
     double J = utils::kinematics::Jacobian(interaction,kPSxyfE,kps);
     xsec *= J;
   }
 
   // If requested return the free nucleon xsec even for input nuclear tgt
   if( interaction->TestBit(kIAssumeFreeNucleon) ) return xsec;
 
   // Compute nuclear cross section (simple scaling here, corrections must
   // have been included in the structure functions)
   const Target & target = init_state.Tgt();
   int nucpdgc = target.HitNucPdg();
   int NNucl = (pdg::IsProton(nucpdgc)) ? target.Z() : target.N();
   xsec *= NNucl;
 
   // Apply scaling / if required to reach well known asymmptotic value
   if( proc_info.IsWeakCC() )  xsec *= fCCScale;
   else if( proc_info.IsWeakNC() )  xsec *= fEMScale;
   else if( proc_info.IsEM() )  xsec *= fEMScale;
 
   // Subtract the inclusive charm production cross section
   interaction->ExclTagPtr()->SetCharm();
   double xsec_charm = fCharmProdModel->XSec(interaction,kps);
   interaction->ExclTagPtr()->UnsetCharm();
 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
   LOG("DISPXSec", pINFO)
        << "Subtracting charm piece: " << xsec_charm << " / out of " << xsec;
 #endif
   xsec = TMath::Max(0., xsec-xsec_charm);
   return xsec;
 }

Member Data Documentation

double genie::QPMDISPXSec::fCCScale

private

cross section scaling factor

Definition at line 61 of file QPMDISPXSec.h.

Referenced by LoadConfig(), and XSec().

const XSecAlgorithmI* genie::QPMDISPXSec::fCharmProdModel

private

Definition at line 59 of file QPMDISPXSec.h.

Referenced by LoadConfig(), and XSec().

DISStructureFunc genie::QPMDISPXSec::fDISSF

mutableprivate

Definition at line 53 of file QPMDISPXSec.h.

Referenced by LoadConfig(), and XSec().

const DISStructureFuncModelI* genie::QPMDISPXSec::fDISSFModel

private

SF model.

Definition at line 56 of file QPMDISPXSec.h.

Referenced by LoadConfig().

double genie::QPMDISPXSec::fEMScale

private

cross section scaling factor

Definition at line 63 of file QPMDISPXSec.h.

Referenced by LoadConfig(), and XSec().

bool genie::QPMDISPXSec::fInInitPhase

private

Definition at line 54 of file QPMDISPXSec.h.

Referenced by LoadConfig(), and QPMDISPXSec().

double genie::QPMDISPXSec::fNCScale

private

cross section scaling factor

Definition at line 62 of file QPMDISPXSec.h.

Referenced by LoadConfig().

double genie::QPMDISPXSec::fSin48w

private

sin^4(Weingberg angle)

Definition at line 64 of file QPMDISPXSec.h.

Referenced by LoadConfig(), and XSec().

const XSecIntegratorI* genie::QPMDISPXSec::fXSecIntegrator

private

diff. xsec integrator

Definition at line 57 of file QPMDISPXSec.h.

Referenced by Integral(), and LoadConfig().

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

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation