genie::utils::gsl::d4Xsec_dEldThetaldOmegapi Class Reference

#include "/cvmfs/nova.opensciencegrid.org/externals/genie/v3_00_06_p01/Linux64bit+3.10-2.17-e17-debug/GENIE-Generator/src/Physics/XSectionIntegration/GSLXSecFunc.h"

Inheritance diagram for genie::utils::gsl::d4Xsec_dEldThetaldOmegapi:

Public Member Functions
	d4Xsec_dEldThetaldOmegapi (const XSecAlgorithmI *m, const Interaction *i)
	~d4Xsec_dEldThetaldOmegapi ()
unsigned int	NDim (void) const
double	DoEval (const double *xin) const
ROOT::Math::IBaseFunctionMultiDim *	Clone (void) const
double	GetFactor () const
void	SetFactor (double factor)

Private Attributes
const XSecAlgorithmI *	fModel
const Interaction *	fInteraction
double	fFactor

Detailed Description

.....................................................................................

genie::utils::gsl::d4Xsec_dEldThetaldOmegapi A 4-D cross section function (fixed E_nu) DANIEL - for the Alvarez-Russo cross-section

Definition at line 319 of file GSLXSecFunc.h.

Constructor & Destructor Documentation

genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::d4Xsec_dEldThetaldOmegapi	(	const XSecAlgorithmI *	m,
		const Interaction *	i
	)

Definition at line 671 of file GSLXSecFunc.cxx.

                                                      :
ROOT::Math::IBaseFunctionMultiDim(),
fModel(m),
fInteraction(i)
{
  
}

genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::~d4Xsec_dEldThetaldOmegapi

(

)

Definition at line 679 of file GSLXSecFunc.cxx.

{

}

Member Function Documentation

ROOT::Math::IBaseFunctionMultiDim * genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::Clone

(

void

)

const

Definition at line 760 of file GSLXSecFunc.cxx.

References fInteraction, and fModel.

{
  return 
    new genie::utils::gsl::d4Xsec_dEldThetaldOmegapi(fModel,fInteraction);
}

double genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::DoEval

(

const double *

xin

)

const

Definition at line 687 of file GSLXSecFunc.cxx.

References genie::units::cm2, E, fFactor, fInteraction, fModel, genie::Interaction::FSPrimLepton(), genie::InitialState::GetProbeP4(), genie::Interaction::InitStatePtr(), genie::ProcessInfo::IsWeakCC(), kinematics(), genie::Interaction::KinePtr(), genie::constants::kNucleonMass, genie::constants::kPi0Mass, genie::constants::kPionMass, genie::kPSElOlTpifE, genie::kRfLab, Mag2(), genie::Range1D_t::max, genie::Interaction::PhaseSpace(), genie::Interaction::ProcInfo(), genie::utils::kinematics::Q2(), genie::Kinematics::SetFSLeptonP4(), genie::Kinematics::SetHadSystP4(), genie::Kinematics::Setx(), genie::Kinematics::Sety(), ana::Sqrt(), genie::utils::kinematics::UpdateWQ2FromXY(), submit_syst::x, genie::KPhaseSpace::XLim(), genie::XSecAlgorithmI::XSec(), xsec, and submit_syst::y.

{
// inputs:  
//    El [GeV]
//    theta l [rad]
//    theta pi [rad]
//    phi pi [rad]
// outputs: 
//   differential cross section [10^-38 cm^2]
//
  Kinematics * kinematics = fInteraction->KinePtr();
  const TLorentzVector * P4_nu = fInteraction->InitStatePtr()->GetProbeP4(kRfLab);
  double E_nu       = P4_nu->E();
  
  double E_l       = xin[0];
  double theta_l   = xin[1];
  double phi_l     = 0.0;
  double theta_pi  = xin[2];
  double phi_pi    = xin[3];
  
  double sin_theta_l  = TMath::Sin(theta_l);
  double sin_theta_pi = TMath::Sin(theta_pi);
  
  double E_pi= E_nu-E_l;
    
  double y = E_pi/E_nu;
  
  double m_l = fInteraction->FSPrimLepton()->Mass();
  if (E_l < m_l) {
    return 0.;
  }
  
  double m_pi;
  if ( fInteraction->ProcInfo().IsWeakCC() ) {
    m_pi = constants::kPionMass;
  }
  else {
    m_pi = constants::kPi0Mass;
  }
  
  double p_l = TMath::Sqrt(E_l*E_l - m_l*m_l);
  TVector3 lepton_3vector = TVector3(0,0,0);
  lepton_3vector.SetMagThetaPhi(p_l,theta_l,phi_l);
  TLorentzVector P4_lep    = TLorentzVector(lepton_3vector , E_l );
  
  double p_pi = TMath::Sqrt(E_pi*E_pi - m_pi*m_pi);
  TVector3 pion_3vector = TVector3(0,0,0);
  pion_3vector.SetMagThetaPhi(p_pi,theta_pi,phi_pi);
  TLorentzVector P4_pion   = TLorentzVector(pion_3vector   , E_pi);
  
  double Q2 = -(*P4_nu-P4_lep).Mag2();
  
  double x = Q2/(2*E_pi*constants::kNucleonMass);
  
  Range1D_t xlim = fInteraction->PhaseSpace().XLim();
  
  if ( x <  xlim.min || x > xlim.max ) {
    return 0.;
  }
  
  kinematics->Setx(x);
  kinematics->Sety(y);
  kinematics::UpdateWQ2FromXY(fInteraction);
  
  kinematics->SetFSLeptonP4(P4_lep );
  kinematics->SetHadSystP4 (P4_pion); // use Hadronic System variable to store pion momentum
  
  delete P4_nu;
  
  double xsec = sin_theta_l * sin_theta_pi * fModel->XSec(fInteraction,kPSElOlTpifE);
  return fFactor * xsec/(1E-38 * units::cm2);
}

double genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::GetFactor

(

void

)

const

Definition at line 769 of file GSLXSecFunc.cxx.

References fFactor.

{
  return fFactor;
}

unsigned int genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::NDim

(

void

)

const

Definition at line 683 of file GSLXSecFunc.cxx.

{
  return 4;
}

void genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::SetFactor

(

double

factor

)

Definition at line 765 of file GSLXSecFunc.cxx.

References fFactor.

Referenced by genie::COHKinematicsGenerator::MaxXSec_AlvarezRuso().

{
  fFactor = factor;
}

Member Data Documentation

double genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::fFactor

private

Definition at line 336 of file GSLXSecFunc.h.

Referenced by DoEval(), GetFactor(), and SetFactor().

const Interaction* genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::fInteraction

private

Definition at line 335 of file GSLXSecFunc.h.

Referenced by Clone(), and DoEval().

const XSecAlgorithmI* genie::utils::gsl::d4Xsec_dEldThetaldOmegapi::fModel

private

Definition at line 334 of file GSLXSecFunc.h.

Referenced by Clone(), and DoEval().

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

• Physics/XSectionIntegration/GSLXSecFunc.h
• Physics/XSectionIntegration/GSLXSecFunc.cxx