genie::PhotonCOHPXSec Class Reference

Differential cross section for W boson production. More...

#include <PhotonCOHPXSec.h>

Inheritance diagram for genie::PhotonCOHPXSec:

Collaboration diagram for genie::PhotonCOHPXSec:

Public Member Functions
	PhotonCOHPXSec ()
	PhotonCOHPXSec (string config)
virtual	~PhotonCOHPXSec ()
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 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?
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	F2_Q (double Q, double r0) const

Private Attributes
const XSecIntegratorI *	fXSecIntegrator
	diff. xsec integrator
Born *	born

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 W boson production.

Author

Alfonso Garcia <aagarciasoto \at km3net.de> IFIC & Harvard University

References:\n Phys. Rev. D 100, 091301 (2019)

Created:\n Dec 8, 2021

License:\n Copyright (c) 2003-2025, The GENIE Collaboration

For the full text of the license visit http://copyright.genie-mc.org or see $GENIE/LICENSE

Definition at line 31 of file PhotonCOHPXSec.h.

Constructor & Destructor Documentation

PhotonCOHPXSec() [1/2]

PhotonCOHPXSec::PhotonCOHPXSec

(

)

Definition at line 28 of file PhotonCOHPXSec.cxx.

                               :
XSecAlgorithmI("genie::PhotonCOHPXSec")
{
  born = new Born();
}

References born, and genie::XSecAlgorithmI::XSecAlgorithmI().

PhotonCOHPXSec() [2/2]

PhotonCOHPXSec::PhotonCOHPXSec

(

string

config

)

Definition at line 34 of file PhotonCOHPXSec.cxx.

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

References genie::XSecAlgorithmI::XSecAlgorithmI().

~PhotonCOHPXSec()

PhotonCOHPXSec::~PhotonCOHPXSec ( )

virtual

Definition at line 40 of file PhotonCOHPXSec.cxx.

{
 
}

Member Function Documentation

Configure() [1/2]

void PhotonCOHPXSec::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 146 of file PhotonCOHPXSec.cxx.

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

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

Configure() [2/2]

void PhotonCOHPXSec::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 152 of file PhotonCOHPXSec.cxx.

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

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

F2_Q()

double PhotonCOHPXSec::F2_Q ( double Q, double r0 ) const

private

Definition at line 112 of file PhotonCOHPXSec.cxx.

{
  // Analytic Woods-Saxon, A.3 of https://arxiv.org/pdf/1807.10973.pdf
  double FF = 0.0;
  double coth = 1./TMath::TanH(kPi*Q*a);
  FF = 3.*kPi*a/(TMath::Power(r0,2)+TMath::Power(kPi*a,2)) / (Q*r0* TMath::SinH(kPi*Q*a));
  FF *= (kPi*a*coth*TMath::Sin(Q*r0) - r0 * TMath::Cos(Q*r0));        
  return TMath::Power(FF,2);
}

References a, genie::constants::kPi, and r0.

Referenced by XSec().

Integral()

double PhotonCOHPXSec::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 122 of file PhotonCOHPXSec.cxx.

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

References fXSecIntegrator.

LoadConfig()

void PhotonCOHPXSec::LoadConfig ( void )

private

Definition at line 158 of file PhotonCOHPXSec.cxx.

{
 
  //-- load the differential cross section integrator
  fXSecIntegrator = dynamic_cast<const XSecIntegratorI *> (this->SubAlg("XSec-Integrator"));
  assert(fXSecIntegrator);
 
}

References fXSecIntegrator, and genie::Algorithm::SubAlg().

Referenced by Configure(), and Configure().

ValidProcess()

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

virtual

Can this cross section algorithm handle the input process?

Implements genie::XSecAlgorithmI.

Definition at line 128 of file PhotonCOHPXSec.cxx.

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

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

Referenced by XSec().

XSec()

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

virtual

Compute the cross section for the input interaction.

Implements genie::XSecAlgorithmI.

Definition at line 45 of file PhotonCOHPXSec.cxx.

{
 
  if(! this -> ValidProcess    (interaction) ) return 0.;
 
  const InitialState & init_state = interaction -> InitState();
  const Kinematics &   kinematics = interaction -> Kine();
 
  int probepdg = init_state.ProbePdg();
  double E     = init_state.ProbeE(kRfLab);
 
  double mlout = 0;
  if      (pdg::IsNuE  (TMath::Abs(probepdg))) mlout = kElectronMass;
  else if (pdg::IsNuMu (TMath::Abs(probepdg))) mlout = kMuonMass;
  else if (pdg::IsNuTau(TMath::Abs(probepdg))) mlout = kTauMass;
  double mlout2 = mlout*mlout;
 
  int A        = init_state.Tgt().A(); 
  int Z        = init_state.Tgt().Z(); 
  double Mtgt = Z*kProtonMass + (A-Z)*kNeutronMass;
 
  double n1 = kinematics.GetKV(kKVn1);
  double n2 = kinematics.GetKV(kKVn2);
  double n3 = kinematics.GetKV(kKVn3);
 
  double mL = mlout+kMw;
  
  double Delta = TMath::Power(2.*E*Mtgt-mL*mL,2)-4.*TMath::Power(Mtgt*mL,2);
  if (Delta<0) return 0.;
 
  double s12_min = E/(2.*E+Mtgt)*(mL*mL+2.*E*Mtgt-TMath::Sqrt(Delta));
  double s12_max = E/(2.*E+Mtgt)*(mL*mL+2.*E*Mtgt+TMath::Sqrt(Delta));
  double s12 = TMath::Exp( TMath::Log(s12_min)+(TMath::Log(s12_max)-TMath::Log(s12_min))*n2);
 
  double Q2_min = TMath::Power(s12,2)*Mtgt/2./E/(2.*E*Mtgt-s12);
  double Q2_max = s12 - mL*mL;
  double Q2 = TMath::Exp( TMath::Log(Q2_min) + (TMath::Log(Q2_max)-TMath::Log(Q2_min))*n3 );
 
  double s = s12 - Q2;
  double s13 = s12/2.*((1.+kMw2/s-mlout2/s)-TMath::Sqrt(born->Lambda(1.,kMw2/s,mlout2/s))*n1);
 
  double ME_T = born->PXSecPhoton_T(s12,s13,Q2,mlout2) * (1.-s12/2./E/Mtgt-TMath::Power(s12/2./E,2)/Q2);
  double ME_L = born->PXSecPhoton_L(s12,s13,Q2,mlout2) * TMath::Power(1.-s12/4./E/Mtgt,2);
 
  double ME   = ME_T+ME_L;
  double dps2 = 1/32./kPi2/s12 * TMath::Sqrt( born->Lambda(1.,kMw2/s,mlout2/s) ) * (TMath::Log(Q2_max)-TMath::Log(Q2_min)) * (TMath::Log(s12_max)-TMath::Log(s12_min));    
  double dP   = born->GetReAlpha()*TMath::Power(Z,2)*F2_Q( TMath::Sqrt(Q2), r0*TMath::Power(A,1./3.) );
 
  double xsec = ME * dps2 * dP;
   
  if(kps!=kPSn1n2n3fE) {
      LOG("PhotonCOHPXSec", pWARN)
          << "Doesn't support transformation from "
          << KinePhaseSpace::AsString(kPSn1n2n3fE) << " to "
          << KinePhaseSpace::AsString(kps);
      xsec = 0;
  }
 
  // If requested return the free nucleon xsec even for input nuclear tgt 
  if( interaction->TestBit(kIAssumeFreeNucleon) ) return xsec;
 
  LOG("PhotonCOHPXSec", pINFO) << "dxsec/dn1dn2dn3 (E= " << E << ", n1= " << n1 << ", n2=" << n2 << ", n3=" << n3 << ") = " << xsec;
 
  return xsec;
}

References genie::Target::A(), genie::KinePhaseSpace::AsString(), born, F2_Q(), genie::Kinematics::GetKV(), genie::pdg::IsNuE(), genie::pdg::IsNuMu(), genie::pdg::IsNuTau(), genie::constants::kElectronMass, genie::kIAssumeFreeNucleon, genie::kKVn1, genie::kKVn2, genie::kKVn3, genie::constants::kMuonMass, genie::constants::kMw, genie::constants::kMw2, genie::constants::kNeutronMass, genie::constants::kPi2, genie::constants::kProtonMass, genie::kPSn1n2n3fE, genie::kRfLab, genie::constants::kTauMass, LOG, pINFO, genie::InitialState::ProbeE(), genie::InitialState::ProbePdg(), pWARN, r0, genie::InitialState::Tgt(), ValidProcess(), and genie::Target::Z().

Member Data Documentation

born

Born* genie::PhotonCOHPXSec::born

private

Definition at line 55 of file PhotonCOHPXSec.h.

Referenced by PhotonCOHPXSec(), and XSec().

fXSecIntegrator

const XSecIntegratorI* genie::PhotonCOHPXSec::fXSecIntegrator

private

diff. xsec integrator

Definition at line 53 of file PhotonCOHPXSec.h.

Referenced by Integral(), and LoadConfig().

---

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

• PhotonCOHPXSec.h
• PhotonCOHPXSec.cxx