G4VScatteringCollision Class Reference

#include <G4VScatteringCollision.hh>

Inheritance diagram for G4VScatteringCollision:

Public Member Functions
	G4VScatteringCollision ()
virtual	~G4VScatteringCollision ()
G4bool	operator== (const G4VScatteringCollision &right) const
G4bool	operator!= (const G4VScatteringCollision &right) const
virtual G4KineticTrackVector *	FinalState (const G4KineticTrack &trk1, const G4KineticTrack &trk2) const
virtual const G4VAngularDistribution *	GetAngularDistribution () const
Protected Member Functions
virtual const std::vector< const G4ParticleDefinition * > &	GetOutgoingParticles () const =0

---

Detailed Description

Definition at line 55 of file G4VScatteringCollision.hh.

---

Constructor & Destructor Documentation

G4VScatteringCollision::G4VScatteringCollision

(

)

Definition at line 47 of file G4VScatteringCollision.cc.

{ 
  theAngularDistribution = new G4AngularDistribution(true);
}

G4VScatteringCollision::~G4VScatteringCollision

(

)

[virtual]

Definition at line 53 of file G4VScatteringCollision.cc.

{ 
  delete theAngularDistribution;
}

---

Member Function Documentation

G4KineticTrackVector * G4VScatteringCollision::FinalState	(	const G4KineticTrack &	trk1,
		const G4KineticTrack &	trk2
	)			const [virtual]

Implements G4VCollision.

Definition at line 59 of file G4VScatteringCollision.cc.

References G4VAngularDistribution::CosTheta(), G4cerr, G4cout, G4endl, G4KineticTrack::Get4Momentum(), G4KineticTrack::GetActualMass(), GetAngularDistribution(), G4KineticTrack::GetDefinition(), GetOutgoingParticles(), G4ParticleDefinition::GetParticleName(), G4ParticleDefinition::GetPDGCharge(), G4KineticTrack::GetPosition(), G4Neutron::NeutronDefinition(), G4VAngularDistribution::Phi(), and G4PionPlus::PionPlus().

{ 
  const G4VAngularDistribution* angDistribution = GetAngularDistribution();
  G4LorentzVector p = trk1.Get4Momentum() + trk2.Get4Momentum();
  G4double sqrtS = p.m();
  G4double S = sqrtS * sqrtS;

  std::vector<const G4ParticleDefinition*> OutputDefinitions = GetOutgoingParticles();
  if (OutputDefinitions.size() != 2)
    throw G4HadronicException(__FILE__, __LINE__, "G4VScatteringCollision: Too many output particles!");

  if (OutputDefinitions[0]->IsShortLived() && OutputDefinitions[1]->IsShortLived())
  {
    if(getenv("G4KCDEBUG")) G4cerr << "two shortlived for Type = "<<typeid(*this).name()<<G4endl;
    // throw G4HadronicException(__FILE__, __LINE__, "G4VScatteringCollision: can't handle two shortlived particles!"); // @hpw@
  }
  
  G4double outm1 = OutputDefinitions[0]->GetPDGMass();
  G4double outm2 = OutputDefinitions[1]->GetPDGMass();

  if (OutputDefinitions[0]->IsShortLived())
  {
    outm1 = SampleResonanceMass(outm1, 
                OutputDefinitions[0]->GetPDGWidth(),
                G4Neutron::NeutronDefinition()->GetPDGMass()+G4PionPlus::PionPlus()->GetPDGMass(),
                sqrtS-(G4Neutron::NeutronDefinition()->GetPDGMass()+G4PionPlus::PionPlus()->GetPDGMass()));

  }
  if (OutputDefinitions[1]->IsShortLived())
  {
    outm2 = SampleResonanceMass(outm2, OutputDefinitions[1]->GetPDGWidth(),
                        G4Neutron::NeutronDefinition()->GetPDGMass()+G4PionPlus::PionPlus()->GetPDGMass(),
                        sqrtS-outm1);
  }
  
  // Angles of outgoing particles
  G4double cosTheta = angDistribution->CosTheta(S, trk1.GetActualMass(), trk2.GetActualMass());
  G4double phi = angDistribution->Phi();

  // Unit vector of three-momentum
  G4LorentzRotation fromCMSFrame(p.boostVector());
  G4LorentzRotation toCMSFrame(fromCMSFrame.inverse());
  G4LorentzVector TempPtr = toCMSFrame*trk1.Get4Momentum();
  G4LorentzRotation toZ;
  toZ.rotateZ(-1*TempPtr.phi());
  toZ.rotateY(-1*TempPtr.theta());
  G4LorentzRotation toCMS(toZ.inverse());

  G4ThreeVector pFinal1(std::sin(std::acos(cosTheta))*std::cos(phi), std::sin(std::acos(cosTheta))*std::sin(phi), cosTheta);

  // Three momentum in cm system
  G4double pCM = std::sqrt( (S-(outm1+outm2)*(outm1+outm2)) * (S-(outm1-outm2)*(outm1-outm2)) /(4.*S));
  pFinal1 = pFinal1 * pCM;
  G4ThreeVector pFinal2 = -pFinal1;

  G4double eFinal1 = std::sqrt(pFinal1.mag2() + outm1*outm1);
  G4double eFinal2 = std::sqrt(pFinal2.mag2() + outm2*outm2);

  G4LorentzVector p4Final1(pFinal1, eFinal1);
  G4LorentzVector p4Final2(pFinal2, eFinal2);
  p4Final1 = toCMS*p4Final1;
  p4Final2 = toCMS*p4Final2;


  // Lorentz transformation
  G4LorentzRotation toLabFrame(p.boostVector());
  p4Final1 *= toLabFrame;
  p4Final2 *= toLabFrame;

  // Final tracks are copies of incoming ones, with modified 4-momenta

  G4double chargeBalance = OutputDefinitions[0]->GetPDGCharge()+OutputDefinitions[1]->GetPDGCharge();
  chargeBalance-= trk1.GetDefinition()->GetPDGCharge();
  chargeBalance-= trk2.GetDefinition()->GetPDGCharge();
  if(std::abs(chargeBalance) >.1)
  {
    G4cout << "Charges in "<<typeid(*this).name()<<G4endl;
    G4cout << OutputDefinitions[0]->GetPDGCharge()<<" "<<OutputDefinitions[0]->GetParticleName()
           << OutputDefinitions[1]->GetPDGCharge()<<" "<<OutputDefinitions[1]->GetParticleName()
           << trk1.GetDefinition()->GetPDGCharge()<<" "<<trk1.GetDefinition()->GetParticleName()
           << trk2.GetDefinition()->GetPDGCharge()<<" "<<trk2.GetDefinition()->GetParticleName()<<G4endl;
  }
  G4KineticTrack* final1 = new G4KineticTrack(const_cast<G4ParticleDefinition *>(OutputDefinitions[0]), 0.0,
                                              trk1.GetPosition(), p4Final1);
  G4KineticTrack* final2 = new G4KineticTrack(const_cast<G4ParticleDefinition *>(OutputDefinitions[1]), 0.0,
                                              trk2.GetPosition(), p4Final2);

  G4KineticTrackVector* finalTracks = new G4KineticTrackVector;

  finalTracks->push_back(final1);
  finalTracks->push_back(final2);

  return finalTracks;
}

virtual const G4VAngularDistribution* G4VScatteringCollision::GetAngularDistribution

(

)

const [inline, virtual]

Implements G4VCollision.

Definition at line 69 of file G4VScatteringCollision.hh.

Referenced by FinalState().

  {
    return theAngularDistribution;
  }

virtual const std::vector<const G4ParticleDefinition*>& G4VScatteringCollision::GetOutgoingParticles

(

)

const [protected, pure virtual]

Implemented in G4ConcreteNNTwoBodyResonance.

Referenced by FinalState().

G4bool G4VScatteringCollision::operator!=

(

const G4VScatteringCollision &

right

)

const

G4bool G4VScatteringCollision::operator==

(

const G4VScatteringCollision &

right

)

const

---

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

• G4VScatteringCollision.hh
• G4VScatteringCollision.cc

---