Geant4 9.6.0
Toolkit for the simulation of the passage of particles through matter
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G4LEKaonZeroInelastic.cc
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25//
26//
27// $Id$
28//
29 // Hadronic Process: Low Energy KaonZeroShort Inelastic Process
30 // J.L. Chuma, TRIUMF, 11-Feb-1997
31 // Last modified: 27-Mar-1997
32 // Modified by J.L.Chuma 30-Apr-97: added originalTarget for CalculateMomenta
33
36#include "G4SystemOfUnits.hh"
37#include "Randomize.hh"
38
39void G4LEKaonZeroInelastic::ModelDescription(std::ostream& outFile) const
40{
41 outFile << "G4LEKaonZeroInelastic is one of the Low Energy Parameterized\n"
42 << "(LEP) models used to implement K0 scattering from nuclei. It\n"
43 << "is a re-engineered version of the GHEISHA code of\n"
44 << "H. Fesefeldt. It divides the initial collision products\n"
45 << "into backward- and forward-going clusters which are then\n"
46 << "decayed into final state hadrons. The model does not conserve\n"
47 << "energy on an event-by-event basis. It may be applied to\n"
48 << "K0s with initial energies between 0 and 25 GeV.\n";
49}
50
51
54 G4Nucleus& targetNucleus)
55{
56 const G4HadProjectile *originalIncident = &aTrack;
57
58 // create the target particle
59 G4DynamicParticle* originalTarget = targetNucleus.ReturnTargetParticle();
60
61 if (verboseLevel > 1) {
62 const G4Material *targetMaterial = aTrack.GetMaterial();
63 G4cout << "G4LEKaonZeroInelastic::ApplyYourself called" << G4endl;
64 G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy()/MeV << "MeV, ";
65 G4cout << "target material = " << targetMaterial->GetName() << ", ";
66 G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName()
67 << G4endl;
68 }
69
70 // Fermi motion and evaporation
71 // As of Geant3, the Fermi energy calculation had not been Done
72 G4double ek = originalIncident->GetKineticEnergy()/MeV;
73 G4double amas = originalIncident->GetDefinition()->GetPDGMass()/MeV;
74 G4ReactionProduct modifiedOriginal;
75 modifiedOriginal = *originalIncident;
76
77 G4double tkin = targetNucleus.Cinema(ek);
78 ek += tkin;
79 modifiedOriginal.SetKineticEnergy(ek*MeV);
80 G4double et = ek + amas;
81 G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) );
82 G4double pp = modifiedOriginal.GetMomentum().mag()/MeV;
83 if (pp > 0.0) {
84 G4ThreeVector momentum = modifiedOriginal.GetMomentum();
85 modifiedOriginal.SetMomentum( momentum * (p/pp) );
86 }
87
88 // calculate black track energies
89 tkin = targetNucleus.EvaporationEffects(ek);
90 ek -= tkin;
91 modifiedOriginal.SetKineticEnergy(ek*MeV);
92 et = ek + amas;
93 p = std::sqrt( std::abs((et-amas)*(et+amas)) );
94 pp = modifiedOriginal.GetMomentum().mag()/MeV;
95 if (pp > 0.0) {
96 G4ThreeVector momentum = modifiedOriginal.GetMomentum();
97 modifiedOriginal.SetMomentum( momentum * (p/pp) );
98 }
99 G4ReactionProduct currentParticle = modifiedOriginal;
100 G4ReactionProduct targetParticle;
101 targetParticle = *originalTarget;
102 currentParticle.SetSide( 1 ); // incident always goes in forward hemisphere
103 targetParticle.SetSide( -1 ); // target always goes in backward hemisphere
104 G4bool incidentHasChanged = false;
105 G4bool targetHasChanged = false;
106 G4bool quasiElastic = false;
107 G4FastVector<G4ReactionProduct,GHADLISTSIZE> vec; // vec will contain the secondary particles
108 G4int vecLen = 0;
109 vec.Initialize(0);
110
111 const G4double cutOff = 0.1;
112 if (currentParticle.GetKineticEnergy()/MeV > cutOff)
113 Cascade(vec, vecLen, originalIncident, currentParticle, targetParticle,
114 incidentHasChanged, targetHasChanged, quasiElastic);
115
116 CalculateMomenta(vec, vecLen, originalIncident, originalTarget, modifiedOriginal,
117 targetNucleus, currentParticle, targetParticle,
118 incidentHasChanged, targetHasChanged, quasiElastic);
119
120 SetUpChange(vec, vecLen, currentParticle, targetParticle, incidentHasChanged);
121
122 if (isotopeProduction) DoIsotopeCounting(originalIncident, targetNucleus);
123
124 delete originalTarget;
125 return &theParticleChange;
126}
127
128
129void G4LEKaonZeroInelastic::Cascade(
131 G4int& vecLen,
132 const G4HadProjectile* originalIncident,
133 G4ReactionProduct& currentParticle,
134 G4ReactionProduct& targetParticle,
135 G4bool& incidentHasChanged,
136 G4bool& targetHasChanged,
137 G4bool& quasiElastic)
138{
139 // derived from original FORTRAN code CASK0 by H. Fesefeldt (13-Sep-1987)
140 //
141 // K0Short undergoes interaction with nucleon within a nucleus. Check if it is
142 // energetically possible to produce pions/kaons. In not, assume nuclear excitation
143 // occurs and input particle is degraded in energy. No other particles are produced.
144 // If reaction is possible, find the correct number of pions/protons/neutrons
145 // produced using an interpolation to multiplicity data. Replace some pions or
146 // protons/neutrons by kaons or strange baryons according to the average
147 // multiplicity per Inelastic reaction.
148
149 const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass()/MeV;
150 const G4double etOriginal = originalIncident->GetTotalEnergy()/MeV;
151 const G4double targetMass = targetParticle.GetMass()/MeV;
152 G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
153 targetMass*targetMass +
154 2.0*targetMass*etOriginal );
155 G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal);
156 if( availableEnergy <= G4PionPlus::PionPlus()->GetPDGMass()/MeV )
157 {
158 quasiElastic = true;
159 return;
160 }
161 static G4bool first = true;
162 const G4int numMul = 1200;
163 const G4int numSec = 60;
164 static G4double protmul[numMul], protnorm[numSec]; // proton constants
165 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
166 // npos = number of pi+, nneg = number of pi-, nzero = number of pi0
167 G4int counter, nt=0, npos=0, nneg=0, nzero=0;
168 const G4double c = 1.25;
169 const G4double b[] = { 0.7, 0.7 };
170 if( first ) // compute normalization constants, this will only be Done once
171 {
172 first = false;
173 G4int i;
174 for( i=0; i<numMul; ++i )protmul[i] = 0.0;
175 for( i=0; i<numSec; ++i )protnorm[i] = 0.0;
176 counter = -1;
177 for( npos=0; npos<(numSec/3); ++npos )
178 {
179 for( nneg=std::max(0,npos-1); nneg<=(npos+1); ++nneg )
180 {
181 for( nzero=0; nzero<numSec/3; ++nzero )
182 {
183 if( ++counter < numMul )
184 {
185 nt = npos+nneg+nzero;
186 if( nt>0 && nt<=numSec )
187 {
188 protmul[counter] = Pmltpc(npos,nneg,nzero,nt,b[0],c);
189 protnorm[nt-1] += protmul[counter];
190 }
191 }
192 }
193 }
194 }
195 for( i=0; i<numMul; ++i )neutmul[i] = 0.0;
196 for( i=0; i<numSec; ++i )neutnorm[i] = 0.0;
197 counter = -1;
198 for( npos=0; npos<numSec/3; ++npos )
199 {
200 for( nneg=std::max(0,npos-2); nneg<=npos; ++nneg )
201 {
202 for( nzero=0; nzero<numSec/3; ++nzero )
203 {
204 if( ++counter < numMul )
205 {
206 nt = npos+nneg+nzero;
207 if( nt>0 && nt<=numSec )
208 {
209 neutmul[counter] = Pmltpc(npos,nneg,nzero,nt,b[1],c);
210 neutnorm[nt-1] += neutmul[counter];
211 }
212 }
213 }
214 }
215 }
216 for( i=0; i<numSec; ++i )
217 {
218 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
219 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
220 }
221 } // end of initialization
222
223 const G4double expxu = 82.; // upper bound for arg. of exp
224 const G4double expxl = -expxu; // lower bound for arg. of exp
230 G4int ieab = static_cast<G4int>(5.0*availableEnergy*MeV/GeV);
231 const G4double supp[] = {0.,0.4,0.55,0.65,0.75,0.82,0.86,0.90,0.94,0.98};
232 G4double test, w0, wp, wt, wm;
233 if( (availableEnergy*MeV/GeV < 2.0) && (G4UniformRand() >= supp[ieab]) )
234 {
235 //
236 // suppress high multiplicity events at low momentum
237 // only one pion will be produced
238 //
239 nneg = npos = nzero = 0;
240 if( targetParticle.GetDefinition() == aNeutron )
241 {
242 test = std::exp( std::min( expxu, std::max( expxl, -(1.0+b[0])*(1.0+b[0])/(2.0*c*c) ) ) );
243 w0 = test/2.0;
244 test = std::exp( std::min( expxu, std::max( expxl, -(-1.0+b[0])*(1.0+b[0])/(2.0*c*c) ) ) );
245 wm = test*1.5;
246 if( G4UniformRand() < w0/(w0+wm) )
247 nzero = 1;
248 else
249 nneg = 1;
250 }
251 else // target is a proton
252 {
253 test = std::exp( std::min( expxu, std::max( expxl, -(1.0+b[1])*(1.0+b[1])/(2.0*c*c) ) ) );
254 w0 = test;
255 wp = test;
256 test = std::exp( std::min( expxu, std::max( expxl, -(-1.0+b[1])*(-1.0+b[1])/(2.0*c*c) ) ) );
257 wm = test;
258 wt = w0+wp+wm;
259 wp += w0;
260 G4double ran = G4UniformRand();
261 if( ran < w0/wt )
262 nzero = 1;
263 else if( ran < wp/wt )
264 npos = 1;
265 else
266 nneg = 1;
267 }
268 }
269 else // (availableEnergy*MeV/GeV >= 2.0) || (G4UniformRand() < supp[ieab])
270 {
271 G4double n, anpn;
272 GetNormalizationConstant( availableEnergy, n, anpn );
273 G4double ran = G4UniformRand();
274 G4double dum, excs = 0.0;
275 if( targetParticle.GetDefinition() == aProton )
276 {
277 counter = -1;
278 for( npos=0; npos<numSec/3 && ran>=excs; ++npos )
279 {
280 for( nneg=std::max(0,npos-1); nneg<=(npos+1) && ran>=excs; ++nneg )
281 {
282 for( nzero=0; nzero<numSec/3 && ran>=excs; ++nzero )
283 {
284 if( ++counter < numMul )
285 {
286 nt = npos+nneg+nzero;
287 if( nt>0 && nt<=numSec )
288 {
289 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
290 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
291 if( std::fabs(dum) < 1.0 )
292 {
293 if( test >= 1.0e-10 )excs += dum*test;
294 }
295 else
296 excs += dum*test;
297 }
298 }
299 }
300 }
301 }
302 if( ran >= excs ) // 3 previous loops continued to the end
303 {
304 quasiElastic = true;
305 return;
306 }
307 npos--; nneg--; nzero--;
308 }
309 else // target must be a neutron
310 {
311 counter = -1;
312 for( npos=0; npos<numSec/3 && ran>=excs; ++npos )
313 {
314 for( nneg=std::max(0,npos-2); nneg<=npos && ran>=excs; ++nneg )
315 {
316 for( nzero=0; nzero<numSec/3 && ran>=excs; ++nzero )
317 {
318 if( ++counter < numMul )
319 {
320 nt = npos+nneg+nzero;
321 if( nt>0 && nt<=numSec )
322 {
323 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
324 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
325 if( std::fabs(dum) < 1.0 )
326 {
327 if( test >= 1.0e-10 )excs += dum*test;
328 }
329 else
330 excs += dum*test;
331 }
332 }
333 }
334 }
335 }
336 if( ran >= excs ) // 3 previous loops continued to the end
337 {
338 quasiElastic = true;
339 return;
340 }
341 npos--; nneg--; nzero--;
342 }
343 }
344 if( targetParticle.GetDefinition() == aProton )
345 {
346 switch( npos-nneg )
347 {
348 case 0:
349 if( G4UniformRand() < 0.25 )
350 {
351 currentParticle.SetDefinitionAndUpdateE( aKaonPlus );
352 targetParticle.SetDefinitionAndUpdateE( aNeutron );
353 incidentHasChanged = true;
354 targetHasChanged = true;
355 }
356 break;
357 case 1:
358 targetParticle.SetDefinitionAndUpdateE( aNeutron );
359 targetHasChanged = true;
360 break;
361 default:
362 targetParticle.SetDefinitionAndUpdateE( aNeutron );
363 targetHasChanged = true;
364 break;
365 }
366 }
367 else // targetParticle is a neutron
368 {
369 switch( npos-nneg ) // seems wrong, charge not conserved
370 {
371 case 1:
372 if( G4UniformRand() < 0.5 )
373 {
374 currentParticle.SetDefinitionAndUpdateE( aKaonPlus );
375 incidentHasChanged = true;
376 }
377 else
378 {
379 targetParticle.SetDefinitionAndUpdateE( aProton );
380 targetHasChanged = true;
381 }
382 break;
383 case 2:
384 currentParticle.SetDefinitionAndUpdateE( aKaonPlus );
385 incidentHasChanged = true;
386 targetParticle.SetDefinitionAndUpdateE( aProton );
387 targetHasChanged = true;
388 break;
389 default:
390 break;
391 }
392 }
393 if( currentParticle.GetDefinition() == aKaonZS )
394 {
395 if( G4UniformRand() >= 0.5 )
396 {
397 currentParticle.SetDefinitionAndUpdateE( aKaonZL);
398 incidentHasChanged = true;
399 }
400 }
401 if( targetParticle.GetDefinition() == aKaonZS )
402 {
403 if( G4UniformRand() >= 0.5 )
404 {
405 targetParticle.SetDefinitionAndUpdateE( aKaonZL );
406 targetHasChanged = true;
407 }
408 }
409 SetUpPions( npos, nneg, nzero, vec, vecLen );
410 return;
411}
412
413 /* end of file */
414
double G4double
Definition: G4Types.hh:64
int G4int
Definition: G4Types.hh:66
bool G4bool
Definition: G4Types.hh:67
#define G4endl
Definition: G4ios.hh:52
G4DLLIMPORT std::ostream G4cout
#define G4UniformRand()
Definition: Randomize.hh:53
double mag() const
G4ParticleDefinition * GetDefinition() const
void Initialize(G4int items)
Definition: G4FastVector.hh:63
const G4Material * GetMaterial() const
const G4ParticleDefinition * GetDefinition() const
G4double GetKineticEnergy() const
G4double GetTotalEnergy() const
G4double Pmltpc(G4int np, G4int nm, G4int nz, G4int n, G4double b, G4double c)
void GetNormalizationConstant(const G4double availableEnergy, G4double &n, G4double &anpn)
void SetUpPions(const G4int np, const G4int nm, const G4int nz, G4FastVector< G4ReactionProduct, GHADLISTSIZE > &vec, G4int &vecLen)
void CalculateMomenta(G4FastVector< G4ReactionProduct, GHADLISTSIZE > &vec, G4int &vecLen, const G4HadProjectile *originalIncident, const G4DynamicParticle *originalTarget, G4ReactionProduct &modifiedOriginal, G4Nucleus &targetNucleus, G4ReactionProduct &currentParticle, G4ReactionProduct &targetParticle, G4bool &incidentHasChanged, G4bool &targetHasChanged, G4bool quasiElastic)
void DoIsotopeCounting(const G4HadProjectile *theProjectile, const G4Nucleus &aNucleus)
void SetUpChange(G4FastVector< G4ReactionProduct, GHADLISTSIZE > &vec, G4int &vecLen, G4ReactionProduct &currentParticle, G4ReactionProduct &targetParticle, G4bool &incidentHasChanged)
static G4KaonPlus * KaonPlus()
Definition: G4KaonPlus.cc:113
static G4KaonZeroLong * KaonZeroLong()
static G4KaonZeroShort * KaonZeroShort()
virtual void ModelDescription(std::ostream &outFile) const
G4HadFinalState * ApplyYourself(const G4HadProjectile &aTrack, G4Nucleus &targetNucleus)
const G4String & GetName() const
Definition: G4Material.hh:177
static G4Neutron * Neutron()
Definition: G4Neutron.cc:104
G4double EvaporationEffects(G4double kineticEnergy)
Definition: G4Nucleus.cc:264
G4double Cinema(G4double kineticEnergy)
Definition: G4Nucleus.cc:368
G4DynamicParticle * ReturnTargetParticle() const
Definition: G4Nucleus.cc:227
const G4String & GetParticleName() const
static G4PionPlus * PionPlus()
Definition: G4PionPlus.cc:98
static G4Proton * Proton()
Definition: G4Proton.cc:93
void SetMomentum(const G4double x, const G4double y, const G4double z)
G4double GetKineticEnergy() const
G4ThreeVector GetMomentum() const
void SetSide(const G4int sid)
void SetDefinitionAndUpdateE(G4ParticleDefinition *aParticleDefinition)
void SetKineticEnergy(const G4double en)
G4ParticleDefinition * GetDefinition() const
G4double GetMass() const
const G4double pi