#include <PetrukhinShestakovModel.h>

Inheritance diagram for genie::mueloss::gsl::PetrukhinShestakovIntegrand:

Collaboration diagram for genie::mueloss::gsl::PetrukhinShestakovIntegrand:

Public Member Functions
	PetrukhinShestakovIntegrand (double E, double Z)

	~PetrukhinShestakovIntegrand ()

unsigned int	NDim (void) const

double	DoEval (double xin) const

ROOT::Math::IBaseFunctionOneDim *	Clone (void) const

Private Attributes
double	fE

double	fZ

Detailed Description

Definition at line 81 of file PetrukhinShestakovModel.h.

Constructor & Destructor Documentation

gsl::PetrukhinShestakovIntegrand::PetrukhinShestakovIntegrand	(	double	E,
		double	Z
	)

Definition at line 86 of file PetrukhinShestakovModel.cxx.

References fE, and fZ.

                                                                               :
 ROOT::Math::IBaseFunctionOneDim()
 {
   fE = E;
   fZ = Z;
 }

gsl::PetrukhinShestakovIntegrand::~PetrukhinShestakovIntegrand ( )

Definition at line 93 of file PetrukhinShestakovModel.cxx.

 {
 
 }

Member Function Documentation

ROOT::Math::IBaseFunctionOneDim * gsl::PetrukhinShestakovIntegrand::Clone ( void ) const

Definition at line 143 of file PetrukhinShestakovModel.cxx.

 { 
   return new gsl::PetrukhinShestakovIntegrand(fE, fZ);
 }

double gsl::PetrukhinShestakovIntegrand::DoEval ( double xin ) const

Definition at line 103 of file PetrukhinShestakovModel.cxx.

References a, genie::units::b, genie::constants::kAem, genie::constants::kElectronMass, genie::constants::kLe2, genie::constants::kMuonMass, genie::constants::kMuonMass2, and genie::constants::kSqrtNapierConst.

 {
 // Calculate the Bethe-Heitler cross section ds/dv for muon bremsstrahlung
 // Returns v*(ds/dv)
 
   double v  = xin; // v, the fraction of energy transfered to the photon
   double v2 = TMath::Power(v,2.);
 
   if (! (v >0)) return 0;
   if (   v >1)  return 0;
   if (! (fE>0)) return 0;
 
   // Some constants...
   double Z2    = TMath::Power(fZ,2.);
   double Zm13  = TMath::Power(fZ,-1./3.);
   double Zm23  = TMath::Power(fZ,-2./3.);
   double a3    = TMath::Power(kAem,3.); // (e/m coupling const)^3
   double me    = kElectronMass;
   double mmu   = kMuonMass;
   double mmu2  = kMuonMass2;
   double mmue  = mmu/me;
   double memu  = me/mmu;
   double memu2 = TMath::Power(memu,2);
 
   // Calculate the minimum monentum transfer to the nucleus (in GeV)
   double delta = (mmu2/fE) * 0.5*v/(1.-v);
 
   // Calculate the fi(delta) factor for the bremsstrahlung cross section
   // ds/dv according to the Petrukhin/Shestakov formula (dimensionless)
   double a  = ( (fZ<10) ? 189.*mmue * Zm13 : 189.*mmue * (2./3.)*Zm23 );
   double b  = 1. + (189./me) * Zm13 * kSqrtNapierConst * delta;
   double fi = TMath::Log(a/b);
 
   // Calculate the Bethe-Heitler cross section ds/dv for muon bremsstrahlung
   double ds_dv  = (a3*memu2*kLe2) * (4*Z2) * (fi) * (4/3.-4*v/3.+v2)/v;
   double vds_dv = v*ds_dv;
   return vds_dv; // in GeV^-2
 }