G4INCLNKElasticChannel.cc

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//
// INCL++ intra-nuclear cascade model
// Alain Boudard, CEA-Saclay, France
// Joseph Cugnon, University of Liege, Belgium
// Jean-Christophe David, CEA-Saclay, France
// Pekka Kaitaniemi, CEA-Saclay, France, and Helsinki Institute of Physics, Finland
// Sylvie Leray, CEA-Saclay, France
// Davide Mancusi, CEA-Saclay, France
//
#define INCLXX_IN_GEANT4_MODE 1
 
#include "globals.hh"
 
#include "G4INCLNKElasticChannel.hh"
#include "G4INCLKinematicsUtils.hh"
#include "G4INCLBinaryCollisionAvatar.hh"
#include "G4INCLRandom.hh"
#include "G4INCLGlobals.hh"
#include "G4INCLLogger.hh"
#include <algorithm>
#include "G4INCLPhaseSpaceGenerator.hh"
 
namespace G4INCL {
    
    NKElasticChannel::NKElasticChannel(Particle *p1, Particle *p2)
        : particle1(p1), particle2(p2)
        {}
    
    NKElasticChannel::~NKElasticChannel(){}
    
    void NKElasticChannel::fillFinalState(FinalState *fs) {
        
        Particle *nucleon;
        Particle *kaon;
        
        if(particle1->isNucleon()){
            nucleon = particle1;
            kaon = particle2;
        }
        else{
            nucleon = particle2;
            kaon = particle1;
        }
        
        const G4double norm = KinematicsUtils::momentumInCM(nucleon, kaon);
        
        ThreeVector mom_kaon;
        
//      const G4double pLab = KinematicsUtils::momentumInLab(kaon,nucleon);
        
/*      if(pLab==0) mom_kaon = Random::normVector();
        else{
            const G4double x = kaon->getMomentum().getX();
            const G4double y = kaon->getMomentum().getY();
            const G4double z = kaon->getMomentum().getZ();
            
            const G4double r = std::sqrt(x*x+y*y+z*z);
            const G4double rho = std::sqrt(x*x+y*y);
            
            const G4double b = 12. * pLab/2375.; // correspond to the forward slope description at 2375 MeV/c in K- p elastic
            const G4double cos_theta = std::log(Random::shoot()*(std::exp(b)-std::exp(-b))+std::exp(-b))/b;
            const G4double sin_theta = std::sqrt(1-cos_theta*cos_theta);
            
            const G4double cos_phi = std::cos(Random::shoot()*Math::twoPi);
            const G4double sin_phi = std::sqrt(1-cos_phi*cos_phi);
            
            if(rho == 0) mom_kaon = ThreeVector(sin_theta*cos_phi,sin_theta*sin_phi,cos_theta);
            // Rotation in the direction of the incident kaon
            const G4double px = x/r*cos_theta - y/rho*sin_theta*cos_phi + z/r*x/rho*sin_theta*sin_phi;
            const G4double py = y/r*cos_theta + x/rho*sin_theta*cos_phi + z/r*y/rho*sin_theta*sin_phi;
            const G4double pz = z/r*cos_theta - rho/r*sin_theta*sin_phi;
            
            mom_kaon = ThreeVector(px,py,pz);
        }*/
        
        mom_kaon = Random::normVector();
        
        kaon->setMomentum(mom_kaon*norm);
        nucleon->setMomentum(-mom_kaon*norm);
        
        kaon->adjustEnergyFromMomentum();
        nucleon->adjustEnergyFromMomentum();
        
        fs->addModifiedParticle(nucleon);
        fs->addModifiedParticle(kaon);
                
    }
}