G4INCL::NDeltaOmegaProductionChannel Class Reference

#include <G4INCLNDeltaOmegaProductionChannel.hh>

Inheritance diagram for G4INCL::NDeltaOmegaProductionChannel:

Public Member Functions
void	fillFinalState (FinalState *fs)
FinalState *	getFinalState ()
	NDeltaOmegaProductionChannel (Particle *, Particle *)
virtual	~NDeltaOmegaProductionChannel ()

Private Member Functions
	INCL_DECLARE_ALLOCATION_POOL (NDeltaOmegaProductionChannel)
G4double	sampleDeltaMass (G4double ecm)

Private Attributes
Particle *	particle1
Particle *	particle2

Static Private Attributes
static const G4double	angularSlope = 6.
static const G4int	maxTries = 100000

Detailed Description

Definition at line 48 of file G4INCLNDeltaOmegaProductionChannel.hh.

Constructor & Destructor Documentation

NDeltaOmegaProductionChannel()

G4INCL::NDeltaOmegaProductionChannel::NDeltaOmegaProductionChannel	(	Particle *	p1,
		Particle *	p2
	)

Definition at line 51 of file G4INCLNDeltaOmegaProductionChannel.cc.

    : particle1(p1), particle2(p2)
  {}

~NDeltaOmegaProductionChannel()

G4INCL::NDeltaOmegaProductionChannel::~NDeltaOmegaProductionChannel ( )

virtual

Definition at line 55 of file G4INCLNDeltaOmegaProductionChannel.cc.

{}

Member Function Documentation

fillFinalState()

void G4INCL::NDeltaOmegaProductionChannel::fillFinalState ( FinalState *  fs )

virtual

Unlike NN -> NDelta, NN -> NDeltaOmega is drawn from a phase-space generator

Implements G4INCL::IChannel.

Definition at line 97 of file G4INCLNDeltaOmegaProductionChannel.cc.

                                                                 {
  
  G4int is1=ParticleTable::getIsospin(particle1->getType());
  G4int is2=ParticleTable::getIsospin(particle2->getType());
  
  ParticleList list;
  list.push_back(particle1);
  list.push_back(particle2);
  
//  isospin Repartition of N and Delta;
  G4double ecm = KinematicsUtils::totalEnergyInCM(particle1, particle2);  
  const G4int isospin = is1+is2;
  
  G4double rndm = 0.0;
  G4double xmdel = sampleDeltaMass(ecm);
 
  G4int index2=0;
  if (isospin == 0) { // pn case
   rndm = Random::shoot();
   if (rndm < 0.5) index2=1;
  }
 
  if (isospin == 0) {
   if(index2 == 1) {
    G4int isi=is1;
    is1=is2;
    is2=isi;
   }
//   particle1->setHelicity(0.0);
  } else {
   rndm = Random::shoot();
   if (rndm >= 0.25) {
    is1=3*is1;
    is2=-is2;
   }
//   particle1->setHelicity(ctet*ctet);
  }
  
  if(is1 == ParticleTable::getIsospin(DeltaMinus)) {
   particle1->setType(DeltaMinus);
  } else if(is1 == ParticleTable::getIsospin(DeltaZero)) {
   particle1->setType(DeltaZero);
  } else if(is1 == ParticleTable::getIsospin(DeltaPlus)) {
   particle1->setType(DeltaPlus);
  } else if(is1 == ParticleTable::getIsospin(DeltaPlusPlus)) {
   particle1->setType(DeltaPlusPlus);
  }
  
  if(is2 == ParticleTable::getIsospin(Proton)) {
   particle2->setType(Proton);
  } else if(is2 == ParticleTable::getIsospin(Neutron)) {
   particle2->setType(Neutron);
  }
  
  if(particle1->isDelta()) particle1->setMass(xmdel);
  if(particle2->isDelta()) particle2->setMass(xmdel);
  
  const ThreeVector &rcolnucleon1 = particle1->getPosition();
  const ThreeVector &rcolnucleon2 = particle2->getPosition();
  const ThreeVector rcol = (rcolnucleon1+rcolnucleon2)*0.5;
  const ThreeVector zero;
  Particle *omega = new Particle(Omega,zero,rcol);
  list.push_back(omega);
  fs->addCreatedParticle(omega);
  
  const G4double sqrtS = KinematicsUtils::totalEnergyInCM(particle1, particle2);
  G4int biasIndex = ((Random::shoot()<0.5) ? 0 : 1);
  PhaseSpaceGenerator::generateBiased(sqrtS, list, biasIndex, angularSlope);
  
  const ThreeVector vz(0.0,0.0,1.0);
  G4double ctet=(particle1->getMomentum().dot(vz))/particle1->getMomentum().mag();
  if (isospin == 0)
   particle1->setHelicity(0.0);
  else
   particle1->setHelicity(ctet*ctet);
  
  fs->addModifiedParticle(particle1);
  fs->addModifiedParticle(particle2);
  
 }

References G4INCL::FinalState::addCreatedParticle(), G4INCL::FinalState::addModifiedParticle(), angularSlope, G4INCL::DeltaMinus, G4INCL::DeltaPlus, G4INCL::DeltaPlusPlus, G4INCL::DeltaZero, G4INCL::ThreeVector::dot(), G4INCL::PhaseSpaceGenerator::generateBiased(), G4INCL::ParticleTable::getIsospin(), G4INCL::Particle::getMomentum(), G4INCL::Particle::getPosition(), G4INCL::Particle::getType(), G4INCL::Particle::isDelta(), G4INCL::ThreeVector::mag(), G4INCL::Neutron, G4INCL::Omega, particle1, particle2, G4INCL::Proton, sampleDeltaMass(), G4INCL::Particle::setHelicity(), G4INCL::Particle::setMass(), G4INCL::Particle::setType(), G4INCL::Random::shoot(), G4INCL::KinematicsUtils::totalEnergyInCM(), and anonymous_namespace{G4CascadeDeexciteBase.cc}::zero.

getFinalState()

FinalState * G4INCL::IChannel::getFinalState ( )

inherited

Definition at line 50 of file G4INCLIChannel.cc.

                                      {
    FinalState *fs = new FinalState;
    fillFinalState(fs);
    return fs;
  }

References G4INCL::IChannel::fillFinalState().

INCL_DECLARE_ALLOCATION_POOL()

G4INCL::NDeltaOmegaProductionChannel::INCL_DECLARE_ALLOCATION_POOL ( NDeltaOmegaProductionChannel  )

private

sampleDeltaMass()

G4double G4INCL::NDeltaOmegaProductionChannel::sampleDeltaMass ( G4double  ecm )

private

Definition at line 57 of file G4INCLNDeltaOmegaProductionChannel.cc.

                                                                           {
    const G4double ecm = ecmorigin - 783.437; // 783.437 MeV translation to open pion(delta) production in NNOmega
    const G4double maxDeltaMass = ecm - ParticleTable::effectiveNucleonMass - 1.0;
    const G4double maxDeltaMassRndm = std::atan((maxDeltaMass-ParticleTable::effectiveDeltaMass)*2./ParticleTable::effectiveDeltaWidth);
    const G4double deltaMassRndmRange = maxDeltaMassRndm - ParticleTable::minDeltaMassRndm;
// assert(deltaMassRndmRange>0.);
 
    G4double y=ecm*ecm;
    G4double q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2, 6.4E5 = 800^2
    G4double q3=std::pow(std::sqrt(q2), 3.);
    const G4double f3max=q3/(q3+5.832E6); // 5.832E6 = 180^3
    G4double x;
 
    G4int nTries = 0;
    G4bool success = false;
    while(!success) { /* Loop checking, 10.07.2015, D.Mancusi */
      if(++nTries >= maxTries) {
        INCL_WARN("NDeltaOmegaProductionChannel::sampleDeltaMass loop was stopped because maximum number of tries was reached. Minimum delta mass "
                  << ParticleTable::minDeltaMass << " MeV with CM energy " << ecm << " MeV may be unphysical." << '\n');
        return ParticleTable::minDeltaMass;
      }
 
      G4double rndm = ParticleTable::minDeltaMassRndm + Random::shoot() * deltaMassRndmRange;
      y = std::tan(rndm);
      x = ParticleTable::effectiveDeltaMass + 0.5*ParticleTable::effectiveDeltaWidth*y;
// assert(x>=ParticleTable::minDeltaMass && ecm >= x + ParticleTable::effectiveNucleonMass + 1.0);
 
      // generation of the delta mass with the penetration factor
      // (see prc56(1997)2431)
      y=x*x;
      q2=(y-1.157776E6)*(y-6.4E5)/y/4.0; // 1.157776E6 = 1076^2, 6.4E5 = 800^2
      q3=std::pow(std::sqrt(q2), 3.);
      const G4double f3=q3/(q3+5.832E6); // 5.832E6 = 180^3
      rndm = Random::shoot();
      if (rndm*f3max < f3)
        success = true;
    }
    return x;
  }

References G4INCL::ParticleTable::effectiveDeltaMass, G4INCL::ParticleTable::effectiveDeltaWidth, G4INCL::ParticleTable::effectiveNucleonMass, INCL_WARN, maxTries, G4INCL::ParticleTable::minDeltaMass, G4INCL::ParticleTable::minDeltaMassRndm, and G4INCL::Random::shoot().

Referenced by fillFinalState().

Field Documentation

angularSlope

const G4double G4INCL::NDeltaOmegaProductionChannel::angularSlope = 6.

staticprivate

Definition at line 60 of file G4INCLNDeltaOmegaProductionChannel.hh.

Referenced by fillFinalState().

maxTries

const G4int G4INCL::NDeltaOmegaProductionChannel::maxTries = 100000

staticprivate

Definition at line 62 of file G4INCLNDeltaOmegaProductionChannel.hh.

Referenced by sampleDeltaMass().

particle1

Particle* G4INCL::NDeltaOmegaProductionChannel::particle1

private

Definition at line 58 of file G4INCLNDeltaOmegaProductionChannel.hh.

Referenced by fillFinalState().

particle2

Particle * G4INCL::NDeltaOmegaProductionChannel::particle2

private

Definition at line 58 of file G4INCLNDeltaOmegaProductionChannel.hh.

Referenced by fillFinalState().

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

• source/processes/hadronic/models/inclxx/incl_physics/include/G4INCLNDeltaOmegaProductionChannel.hh
• source/processes/hadronic/models/inclxx/incl_physics/src/G4INCLNDeltaOmegaProductionChannel.cc