#include <SPPEventGenerator.h>

Inheritance diagram for genie::utils::gsl::d4XSecMK_dWQ2CosThetaPhi_E:

Collaboration diagram for genie::utils::gsl::d4XSecMK_dWQ2CosThetaPhi_E:

Public Member Functions
	d4XSecMK_dWQ2CosThetaPhi_E (const XSecAlgorithmI m, const Interaction i, double wcut)

	~d4XSecMK_dWQ2CosThetaPhi_E ()

unsigned int	NDim (void) const

double	DoEval (const double *xin) const

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

Private Attributes
const XSecAlgorithmI *	fModel

Interaction *	fInteraction

Range1D_t	Wl

double	fWcut

bool	isZero

KPhaseSpace *	kps

Detailed Description

Definition at line 128 of file SPPEventGenerator.h.

Constructor & Destructor Documentation

genie::utils::gsl::d4XSecMK_dWQ2CosThetaPhi_E::d4XSecMK_dWQ2CosThetaPhi_E	(	const XSecAlgorithmI *	m,
		const Interaction *	i,
		double	wcut
	)

Definition at line 469 of file SPPEventGenerator.cxx.

References fInteraction, fWcut, isZero, genie::kISkipKinematicChk, genie::kISkipProcessChk, kps, genie::kRfHitNucRest, genie::Range1D_t::max, genie::Range1D_t::min, genie::Interaction::PhaseSpacePtr(), genie::InitialState::ProbeE(), Wl, and genie::KPhaseSpace::WLim_SPP_iso().

                                                                              :
 ROOT::Math::IBaseFunctionMultiDim(), fModel(m), fWcut(wcut)
 {
 
   isZero = false;
   fInteraction = const_cast<Interaction*>(interaction);
   // skip process and kinematic checks
   fInteraction->SetBit(kISkipProcessChk);
   fInteraction->SetBit(kISkipKinematicChk);
   
   kps = fInteraction->PhaseSpacePtr();
   
   // Get kinematical parameters
   const InitialState & init_state = interaction -> InitState();
   double Enu = init_state.ProbeE(kRfHitNucRest);
 
 
   if (Enu < kps->Threshold_SPP_iso())
   {
     isZero = true;
     return;
   }
   
   Wl  = kps->WLim_SPP_iso();
   if (fWcut >= Wl.min)
     Wl.max = TMath::Min(fWcut,Wl.max);
   
 }

genie::utils::gsl::d4XSecMK_dWQ2CosThetaPhi_E::~d4XSecMK_dWQ2CosThetaPhi_E ( )

Definition at line 498 of file SPPEventGenerator.cxx.

 {
 
 }

Member Function Documentation

ROOT::Math::IBaseFunctionMultiDim * genie::utils::gsl::d4XSecMK_dWQ2CosThetaPhi_E::Clone ( void ) const

Definition at line 530 of file SPPEventGenerator.cxx.

 {
   return
     new genie::utils::gsl::d4XSecMK_dWQ2CosThetaPhi_E(fModel,fInteraction, fWcut);
 }

double genie::utils::gsl::d4XSecMK_dWQ2CosThetaPhi_E::DoEval ( const double * xin ) const

Definition at line 506 of file SPPEventGenerator.cxx.

References genie::units::cm2, genie::kKVctp, genie::kKVphip, genie::constants::kPi, genie::kPSWQ2ctpphipfE, genie::Range1D_t::max, genie::Range1D_t::min, genie::utils::kinematics::Q2(), and genie::utils::kinematics::W().

 {
 
 // outputs:
 //   differential cross section [10^-38 cm^2/GeV^3] for resonance single pion production production
 //
   if (isZero) return 0.;
   
   double W  = Wl.min + (Wl.max - Wl.min)*xin[0];
   fInteraction->KinePtr()->SetW(W);
    
   Range1D_t Q2l = kps->Q2Lim_W_SPP_iso(); 
   double Q2 = Q2l.min + (Q2l.max - Q2l.min)*xin[1];
   fInteraction->KinePtr()->SetQ2(Q2);
   
   fInteraction->KinePtr()->SetKV(kKVctp, -1. + 2.*xin[2]); // cosine of pion theta in resonance rest frame
   
   fInteraction->KinePtr()->SetKV(kKVphip , 2.*kPi*xin[3]); // pion phi in resonance rest frame
     
   double xsec = fModel->XSec(fInteraction, kPSWQ2ctpphipfE);
   xsec *= 4*kPi*(Wl.max - Wl.min)*(Q2l.max - Q2l.min);
   return -xsec/(1E-38 * units::cm2);
 }