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geant4/source/processes/hadronic/models/rpg/src/G4RPGAntiSigmaPlusInelastic.cc
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2016-06-10 14:11:04 +02:00

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//
// ********************************************************************
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// * *
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// * work make any representation or warranty, express or implied, *
// * regarding this software system or assume any liability for its *
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// * *
// * This code implementation is the result of the scientific and *
// * technical work of the GEANT4 collaboration. *
// * By using, copying, modifying or distributing the software (or *
// * any work based on the software) you agree to acknowledge its *
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//
// $Id: G4RPGAntiSigmaPlusInelastic.cc 94214 2015-11-09 08:18:05Z gcosmo $
//
#include "G4RPGAntiSigmaPlusInelastic.hh"
#include "G4Exp.hh"
#include "G4PhysicalConstants.hh"
#include "G4SystemOfUnits.hh"
#include "Randomize.hh"
G4HadFinalState*
G4RPGAntiSigmaPlusInelastic::ApplyYourself( const G4HadProjectile &aTrack,
G4Nucleus &targetNucleus )
{
const G4HadProjectile *originalIncident = &aTrack;
if (originalIncident->GetKineticEnergy()<= 0.1*MeV)
{
theParticleChange.SetStatusChange(isAlive);
theParticleChange.SetEnergyChange(aTrack.GetKineticEnergy());
theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
return &theParticleChange;
}
// Choose the target particle
G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle();
if( verboseLevel > 1 )
{
const G4Material *targetMaterial = aTrack.GetMaterial();
G4cout << "G4RPGAntiSigmaPlusInelastic::ApplyYourself called" << G4endl;
G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy()/MeV << "MeV, ";
G4cout << "target material = " << targetMaterial->GetName() << ", ";
G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName()
<< G4endl;
}
// Fermi motion and evaporation
// As of Geant3, the Fermi energy calculation had not been Done
G4double ek = originalIncident->GetKineticEnergy()/MeV;
G4double amas = originalIncident->GetDefinition()->GetPDGMass()/MeV;
G4ReactionProduct modifiedOriginal;
modifiedOriginal = *originalIncident;
G4double tkin = targetNucleus.Cinema( ek );
ek += tkin;
modifiedOriginal.SetKineticEnergy( ek*MeV );
G4double et = ek + amas;
G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) );
G4double pp = modifiedOriginal.GetMomentum().mag()/MeV;
if( pp > 0.0 )
{
G4ThreeVector momentum = modifiedOriginal.GetMomentum();
modifiedOriginal.SetMomentum( momentum * (p/pp) );
}
//
// calculate black track energies
//
tkin = targetNucleus.EvaporationEffects( ek );
ek -= tkin;
modifiedOriginal.SetKineticEnergy( ek*MeV );
et = ek + amas;
p = std::sqrt( std::abs((et-amas)*(et+amas)) );
pp = modifiedOriginal.GetMomentum().mag()/MeV;
if( pp > 0.0 )
{
G4ThreeVector momentum = modifiedOriginal.GetMomentum();
modifiedOriginal.SetMomentum( momentum * (p/pp) );
}
G4ReactionProduct currentParticle = modifiedOriginal;
G4ReactionProduct targetParticle;
targetParticle = *originalTarget;
currentParticle.SetSide( 1 ); // incident always goes in forward hemisphere
targetParticle.SetSide( -1 ); // target always goes in backward hemisphere
G4bool incidentHasChanged = false;
G4bool targetHasChanged = false;
G4bool quasiElastic = false;
G4FastVector<G4ReactionProduct,GHADLISTSIZE> vec; // vec will contain the secondary particles
G4int vecLen = 0;
vec.Initialize( 0 );
const G4double cutOff = 0.1;
const G4double anni = std::min( 1.3*currentParticle.GetTotalMomentum()/GeV, 0.4 );
if( (currentParticle.GetKineticEnergy()/MeV > cutOff) || (G4UniformRand() > anni) )
Cascade( vec, vecLen,
originalIncident, currentParticle, targetParticle,
incidentHasChanged, targetHasChanged, quasiElastic );
CalculateMomenta( vec, vecLen,
originalIncident, originalTarget, modifiedOriginal,
targetNucleus, currentParticle, targetParticle,
incidentHasChanged, targetHasChanged, quasiElastic );
SetUpChange( vec, vecLen,
currentParticle, targetParticle,
incidentHasChanged );
delete originalTarget;
return &theParticleChange;
}
void G4RPGAntiSigmaPlusInelastic::Cascade(
G4FastVector<G4ReactionProduct,GHADLISTSIZE> &vec,
G4int& vecLen,
const G4HadProjectile *originalIncident,
G4ReactionProduct &currentParticle,
G4ReactionProduct &targetParticle,
G4bool &incidentHasChanged,
G4bool &targetHasChanged,
G4bool &quasiElastic )
{
// Derived from H. Fesefeldt's original FORTRAN code CASASP
// AntiSigmaPlus undergoes interaction with nucleon within a nucleus. Check if it is
// energetically possible to produce pions/kaons. In not, assume nuclear excitation
// occurs and input particle is degraded in energy. No other particles are produced.
// If reaction is possible, find the correct number of pions/protons/neutrons
// produced using an interpolation to multiplicity data. Replace some pions or
// protons/neutrons by kaons or strange baryons according to the average
// multiplicity per Inelastic reaction.
const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass()/MeV;
const G4double etOriginal = originalIncident->GetTotalEnergy()/MeV;
const G4double pOriginal = originalIncident->GetTotalMomentum()/MeV;
const G4double targetMass = targetParticle.GetMass()/MeV;
G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
targetMass*targetMass +
2.0*targetMass*etOriginal );
G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal);
static G4ThreadLocal G4bool first = true;
const G4int numMul = 1200;
const G4int numMulA = 400;
const G4int numSec = 60;
static G4ThreadLocal G4double protmul[numMul], protnorm[numSec]; // proton constants
static G4ThreadLocal G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
static G4ThreadLocal G4double protmulA[numMulA], protnormA[numSec]; // proton constants
static G4ThreadLocal G4double neutmulA[numMulA], neutnormA[numSec]; // neutron constants
// np = number of pi+, nneg = number of pi-, nz = number of pi0
G4int counter, nt=0, np=0, nneg=0, nz=0;
G4double test;
const G4double c = 1.25;
const G4double b[] = { 0.7, 0.7 };
if( first ) // compute normalization constants, this will only be Done once
{
first = false;
G4int i;
for( i=0; i<numMul; ++i )protmul[i] = 0.0;
for( i=0; i<numSec; ++i )protnorm[i] = 0.0;
counter = -1;
for( np=0; np<(numSec/3); ++np )
{
for( nneg=std::max(0,np-1); nneg<=(np+1); ++nneg )
{
for( nz=0; nz<numSec/3; ++nz )
{
if( ++counter < numMul )
{
nt = np+nneg+nz;
if( nt>0 && nt<=numSec )
{
protmul[counter] = Pmltpc(np,nneg,nz,nt,b[0],c);
protnorm[nt-1] += protmul[counter];
}
}
}
}
}
for( i=0; i<numMul; ++i )neutmul[i] = 0.0;
for( i=0; i<numSec; ++i )neutnorm[i] = 0.0;
counter = -1;
for( np=0; np<numSec/3; ++np )
{
for( nneg=np; nneg<=(np+2); ++nneg )
{
for( nz=0; nz<numSec/3; ++nz )
{
if( ++counter < numMul )
{
nt = np+nneg+nz;
if( nt>0 && nt<=numSec )
{
neutmul[counter] = Pmltpc(np,nneg,nz,nt,b[1],c);
neutnorm[nt-1] += neutmul[counter];
}
}
}
}
}
for( i=0; i<numSec; ++i )
{
if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
}
//
// do the same for annihilation channels
//
for( i=0; i<numMulA; ++i )protmulA[i] = 0.0;
for( i=0; i<numSec; ++i )protnormA[i] = 0.0;
counter = -1;
for( np=1; np<(numSec/3); ++np )
{
nneg = np;
for( nz=0; nz<numSec/3; ++nz )
{
if( ++counter < numMulA )
{
nt = np+nneg+nz;
if( nt>1 && nt<=numSec )
{
protmulA[counter] = Pmltpc(np,nneg,nz,nt,b[0],c);
protnormA[nt-1] += protmulA[counter];
}
}
}
}
for( i=0; i<numMulA; ++i )neutmulA[i] = 0.0;
for( i=0; i<numSec; ++i )neutnormA[i] = 0.0;
counter = -1;
for( np=0; np<numSec/3; ++np )
{
nneg = np+1;
for( nz=0; nz<numSec/3; ++nz )
{
if( ++counter < numMulA )
{
nt = np+nneg+nz;
if( nt>1 && nt<=numSec )
{
neutmulA[counter] = Pmltpc(np,nneg,nz,nt,b[1],c);
neutnormA[nt-1] += neutmulA[counter];
}
}
}
}
for( i=0; i<numSec; ++i )
{
if( protnormA[i] > 0.0 )protnormA[i] = 1.0/protnormA[i];
if( neutnormA[i] > 0.0 )neutnormA[i] = 1.0/neutnormA[i];
}
} // end of initialization
const G4double expxu = 82.; // upper bound for arg. of exp
const G4double expxl = -expxu; // lower bound for arg. of exp
G4ParticleDefinition *aNeutron = G4Neutron::Neutron();
G4ParticleDefinition *aProton = G4Proton::Proton();
G4ParticleDefinition *aPiPlus = G4PionPlus::PionPlus();
G4ParticleDefinition *anAntiLambda = G4AntiLambda::AntiLambda();
G4ParticleDefinition *aKaonMinus = G4KaonMinus::KaonMinus();
G4ParticleDefinition *aKaonPlus = G4KaonPlus::KaonPlus();
G4ParticleDefinition *aKaonZL = G4KaonZeroLong::KaonZeroLong();
G4ParticleDefinition *anAntiSigmaZero = G4AntiSigmaZero::AntiSigmaZero();
const G4double anhl[] = {1.00,1.00,1.00,1.00,1.00,1.00,1.00,1.00,0.97,0.88,
0.85,0.81,0.75,0.64,0.64,0.55,0.55,0.45,0.47,0.40,
0.39,0.36,0.33,0.10,0.01};
G4int iplab = G4int( pOriginal/GeV*10.0 );
if( iplab > 9 )iplab = G4int( (pOriginal/GeV- 1.0)*5.0 ) + 10;
if( iplab > 14 )iplab = G4int( pOriginal/GeV- 2.0 ) + 15;
if( iplab > 22 )iplab = G4int( (pOriginal/GeV-10.0)/10.0 ) + 23;
if( iplab > 24 )iplab = 24;
if( G4UniformRand() > anhl[iplab] )
{
if( availableEnergy <= aPiPlus->GetPDGMass()/MeV )
{
quasiElastic = true;
return;
}
G4double n, anpn;
GetNormalizationConstant( availableEnergy, n, anpn );
G4double ran = G4UniformRand();
G4double dum, excs = 0.0;
if( targetParticle.GetDefinition() == aProton )
{
counter = -1;
for( np=0; np<numSec/3 && ran>=excs; ++np )
{
for( nneg=std::max(0,np-1); nneg<=(np+1) && ran>=excs; ++nneg )
{
for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
{
if( ++counter < numMul )
{
nt = np+nneg+nz;
if( (nt>0) && (nt<=numSec) )
{
test = G4Exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
if( std::fabs(dum) < 1.0 )
{
if( test >= 1.0e-10 )excs += dum*test;
}
else
excs += dum*test;
}
}
}
}
}
if( ran >= excs ) // 3 previous loops continued to the end
{
quasiElastic = true;
return;
}
np--; nneg--; nz--;
G4int ncht = std::min( 3, std::max( 1, np-nneg+2 ) );
switch( ncht )
{
case 1:
if( G4UniformRand() < 0.5 )
currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
else
currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
incidentHasChanged = true;
break;
case 2:
if( G4UniformRand() >= 0.5 )
{
if( G4UniformRand() < 0.5 )
currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
else
currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
incidentHasChanged = true;
}
targetParticle.SetDefinitionAndUpdateE( aNeutron );
targetHasChanged = true;
break;
case 3:
targetParticle.SetDefinitionAndUpdateE( aNeutron );
targetHasChanged = true;
break;
}
}
else // target must be a neutron
{
counter = -1;
for( np=0; np<numSec/3 && ran>=excs; ++np )
{
for( nneg=np; nneg<=(np+2) && ran>=excs; ++nneg )
{
for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
{
if( ++counter < numMul )
{
nt = np+nneg+nz;
if( (nt>0) && (nt<=numSec) )
{
test = G4Exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
if( std::fabs(dum) < 1.0 )
{
if( test >= 1.0e-10 )excs += dum*test;
}
else
excs += dum*test;
}
}
}
}
}
if( ran >= excs ) // 3 previous loops continued to the end
{
quasiElastic = true;
return;
}
np--; nneg--; nz--;
G4int ncht = std::min( 3, std::max( 1, np-nneg+3 ) );
switch( ncht )
{
case 1:
if( G4UniformRand() < 0.5 )
currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
else
currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
incidentHasChanged = true;
targetParticle.SetDefinitionAndUpdateE( aProton );
targetHasChanged = true;
break;
case 2:
if( G4UniformRand() < 0.5 )
{
if( G4UniformRand() < 0.5 )
{
currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
incidentHasChanged = true;
}
else
{
targetParticle.SetDefinitionAndUpdateE( aProton );
targetHasChanged = true;
}
}
else
{
if( G4UniformRand() < 0.5 )
{
currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
incidentHasChanged = true;
}
else
{
targetParticle.SetDefinitionAndUpdateE( aProton );
targetHasChanged = true;
}
}
break;
case 3:
break;
}
}
}
else // random number <= anhl[iplab]
{
if( centerofmassEnergy <= aPiPlus->GetPDGMass()/MeV+aKaonPlus->GetPDGMass()/MeV )
{
quasiElastic = true;
return;
}
G4double n, anpn;
GetNormalizationConstant( -centerofmassEnergy, n, anpn );
G4double ran = G4UniformRand();
G4double dum, excs = 0.0;
if( targetParticle.GetDefinition() == aProton )
{
counter = -1;
for( np=1; np<numSec/3 && ran>=excs; ++np )
{
nneg = np;
for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
{
if( ++counter < numMulA )
{
nt = np+nneg+nz;
if( nt>1 && nt<=numSec )
{
test = G4Exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
dum = (pi/anpn)*nt*protmulA[counter]*protnormA[nt-1]/(2.0*n*n);
if( std::fabs(dum) < 1.0 )
{
if( test >= 1.0e-10 )excs += dum*test;
}
else
excs += dum*test;
}
}
}
}
if( ran >= excs ) // 3 previous loops continued to the end
{
quasiElastic = true;
return;
}
np--; nz--;
}
else // target must be a neutron
{
counter = -1;
for( np=0; np<numSec/3 && ran>=excs; ++np )
{
nneg = np+1;
for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
{
if( ++counter < numMulA )
{
nt = np+nneg+nz;
if( nt>1 && nt<=numSec )
{
test = G4Exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
dum = (pi/anpn)*nt*neutmulA[counter]*neutnormA[nt-1]/(2.0*n*n);
if( std::fabs(dum) < 1.0 )
{
if( test >= 1.0e-10 )excs += dum*test;
}
else
excs += dum*test;
}
}
}
}
if( ran >= excs ) // 3 previous loops continued to the end
{
quasiElastic = true;
return;
}
np--; nz--;
}
if( nz > 0 )
{
if( nneg > 0 )
{
if( G4UniformRand() < 0.5 )
{
vec.Initialize( 1 );
G4ReactionProduct *p= new G4ReactionProduct;
p->SetDefinition( aKaonMinus );
(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
vec.SetElement( vecLen++, p );
--nneg;
}
else
{
vec.Initialize( 1 );
G4ReactionProduct *p= new G4ReactionProduct ;
p->SetDefinition( aKaonZL );
(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
vec.SetElement( vecLen++, p );
--nz;
}
}
else // nneg == 0
{
vec.Initialize( 1 );
G4ReactionProduct *p = new G4ReactionProduct;
p->SetDefinition( aKaonZL );
(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
vec.SetElement( vecLen++, p );
--nz;
}
}
else // nz == 0
{
if( nneg > 0 )
{
vec.Initialize( 1 );
G4ReactionProduct *p = new G4ReactionProduct;
p->SetDefinition( aKaonMinus );
(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
vec.SetElement( vecLen++, p );
--nneg;
}
}
currentParticle.SetMass( 0.0 );
targetParticle.SetMass( 0.0 );
}
SetUpPions( np, nneg, nz, vec, vecLen );
return;
}
/* end of file */