source: trunk/source/processes/hadronic/models/rpg/src/G4RPGKMinusInelastic.cc@ 1347

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26// $Id: G4RPGKMinusInelastic.cc,v 1.1 2007/07/18 21:04:20 dennis Exp $
[1340]27// GEANT4 tag $Name: geant4-09-03-ref-09 $
[819]28//
29
30#include "G4RPGKMinusInelastic.hh"
31#include "Randomize.hh"
32
33G4HadFinalState*
34G4RPGKMinusInelastic::ApplyYourself( const G4HadProjectile &aTrack,
35 G4Nucleus &targetNucleus )
36{
37 const G4HadProjectile *originalIncident = &aTrack;
38 if (originalIncident->GetKineticEnergy()<= 0.1*MeV)
39 {
40 theParticleChange.SetStatusChange(isAlive);
41 theParticleChange.SetEnergyChange(aTrack.GetKineticEnergy());
42 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
43 return &theParticleChange;
44 }
45
46 // create the target particle
47
48 G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle();
49 G4ReactionProduct targetParticle( originalTarget->GetDefinition() );
50
51 if( verboseLevel > 1 )
52 {
53 const G4Material *targetMaterial = aTrack.GetMaterial();
54 G4cout << "G4RPGKMinusInelastic::ApplyYourself called" << G4endl;
55 G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy() << "MeV, ";
56 G4cout << "target material = " << targetMaterial->GetName() << ", ";
57 G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName()
58 << G4endl;
59 }
60 G4ReactionProduct currentParticle( const_cast<G4ParticleDefinition *>(originalIncident->GetDefinition()) );
61 currentParticle.SetMomentum( originalIncident->Get4Momentum().vect() );
62 currentParticle.SetKineticEnergy( originalIncident->GetKineticEnergy() );
63
64 // Fermi motion and evaporation
65 // As of Geant3, the Fermi energy calculation had not been Done
66
67 G4double ek = originalIncident->GetKineticEnergy();
68 G4double amas = originalIncident->GetDefinition()->GetPDGMass();
69
70 G4double tkin = targetNucleus.Cinema( ek );
71 ek += tkin;
72 currentParticle.SetKineticEnergy( ek );
73 G4double et = ek + amas;
74 G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) );
75 G4double pp = currentParticle.GetMomentum().mag();
76 if( pp > 0.0 )
77 {
78 G4ThreeVector momentum = currentParticle.GetMomentum();
79 currentParticle.SetMomentum( momentum * (p/pp) );
80 }
81
82 // calculate black track energies
83
84 tkin = targetNucleus.EvaporationEffects( ek );
85 ek -= tkin;
86 currentParticle.SetKineticEnergy( ek );
87 et = ek + amas;
88 p = std::sqrt( std::abs((et-amas)*(et+amas)) );
89 pp = currentParticle.GetMomentum().mag();
90 if( pp > 0.0 )
91 {
92 G4ThreeVector momentum = currentParticle.GetMomentum();
93 currentParticle.SetMomentum( momentum * (p/pp) );
94 }
95
96 G4ReactionProduct modifiedOriginal = currentParticle;
97
98 currentParticle.SetSide( 1 ); // incident always goes in forward hemisphere
99 targetParticle.SetSide( -1 ); // target always goes in backward hemisphere
100 G4bool incidentHasChanged = false;
101 G4bool targetHasChanged = false;
102 G4bool quasiElastic = false;
103 G4FastVector<G4ReactionProduct,GHADLISTSIZE> vec; // vec will contain the secondary particles
104 G4int vecLen = 0;
105 vec.Initialize( 0 );
106
107 const G4double cutOff = 0.1*MeV;
108 if( currentParticle.GetKineticEnergy() > cutOff )
109 Cascade( vec, vecLen,
110 originalIncident, currentParticle, targetParticle,
111 incidentHasChanged, targetHasChanged, quasiElastic );
112
113 CalculateMomenta( vec, vecLen,
114 originalIncident, originalTarget, modifiedOriginal,
115 targetNucleus, currentParticle, targetParticle,
116 incidentHasChanged, targetHasChanged, quasiElastic );
117
118 SetUpChange( vec, vecLen,
119 currentParticle, targetParticle,
120 incidentHasChanged );
121
122 delete originalTarget;
123 return &theParticleChange;
124}
125
126
127void G4RPGKMinusInelastic::Cascade(
128 G4FastVector<G4ReactionProduct,GHADLISTSIZE> &vec,
129 G4int& vecLen,
130 const G4HadProjectile *originalIncident,
131 G4ReactionProduct &currentParticle,
132 G4ReactionProduct &targetParticle,
133 G4bool &incidentHasChanged,
134 G4bool &targetHasChanged,
135 G4bool &quasiElastic )
136{
137 // Derived from H. Fesefeldt's original FORTRAN code CASKM
138 //
139 // K- undergoes interaction with nucleon within a nucleus. Check if it is
140 // energetically possible to produce pions/kaons. In not, assume nuclear excitation
141 // occurs and input particle is degraded in energy. No other particles are produced.
142 // If reaction is possible, find the correct number of pions/protons/neutrons
143 // produced using an interpolation to multiplicity data. Replace some pions or
144 // protons/neutrons by kaons or strange baryons according to the average
145 // multiplicity per Inelastic reaction.
146 //
147 const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass();
148 const G4double etOriginal = originalIncident->GetTotalEnergy();
149 const G4double pOriginal = originalIncident->GetTotalMomentum();
150 const G4double targetMass = targetParticle.GetMass();
151 G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
152 targetMass*targetMass +
153 2.0*targetMass*etOriginal );
154 G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal);
155
156 static G4bool first = true;
157 const G4int numMul = 1200;
158 const G4int numSec = 60;
159 static G4double protmul[numMul], protnorm[numSec]; // proton constants
160 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
161 // np = number of pi+, nm = number of pi-, nz = number of pi0
162 G4int nt(0), np(0), nm(0), nz(0);
163 const G4double c = 1.25;
164 const G4double b[] = { 0.70, 0.70 };
165 if( first ) // compute normalization constants, this will only be Done once
166 {
167 first = false;
168 G4int i;
169 for( i=0; i<numMul; ++i )protmul[i] = 0.0;
170 for( i=0; i<numSec; ++i )protnorm[i] = 0.0;
171 G4int counter = -1;
172 for( np=0; np<(numSec/3); ++np )
173 {
174 for( nm=std::max(0,np-1); nm<=(np+1); ++nm )
175 {
176 for( nz=0; nz<numSec/3; ++nz )
177 {
178 if( ++counter < numMul )
179 {
180 nt = np+nm+nz;
181 if( (nt>0) && (nt<=numSec) )
182 {
183 protmul[counter] = Pmltpc(np,nm,nz,nt,b[0],c);
184 protnorm[nt-1] += protmul[counter];
185 }
186 }
187 }
188 }
189 }
190 for( i=0; i<numMul; ++i )neutmul[i] = 0.0;
191 for( i=0; i<numSec; ++i )neutnorm[i] = 0.0;
192 counter = -1;
193 for( np=0; np<numSec/3; ++np )
194 {
195 for( nm=np; nm<=(np+2); ++nm )
196 {
197 for( nz=0; nz<numSec/3; ++nz )
198 {
199 if( ++counter < numMul )
200 {
201 nt = np+nm+nz;
202 if( (nt>0) && (nt<=numSec) )
203 {
204 neutmul[counter] = Pmltpc(np,nm,nz,nt,b[1],c);
205 neutnorm[nt-1] += neutmul[counter];
206 }
207 }
208 }
209 }
210 }
211 for( i=0; i<numSec; ++i )
212 {
213 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
214 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
215 }
216 } // end of initialization
217
218 const G4double expxu = 82.; // upper bound for arg. of exp
219 const G4double expxl = -expxu; // lower bound for arg. of exp
220 G4ParticleDefinition *aKaonMinus = G4KaonMinus::KaonMinus();
221 G4ParticleDefinition *aKaonZS = G4KaonZeroShort::KaonZeroShort();
222 G4ParticleDefinition *aKaonZL = G4KaonZeroLong::KaonZeroLong();
223 G4ParticleDefinition *aNeutron = G4Neutron::Neutron();
224 G4ParticleDefinition *aProton = G4Proton::Proton();
225 G4ParticleDefinition *aPiPlus = G4PionPlus::PionPlus();
226 G4ParticleDefinition *aPiMinus = G4PionMinus::PionMinus();
227 G4ParticleDefinition *aPiZero = G4PionZero::PionZero();
228 G4ParticleDefinition *aLambda = G4Lambda::Lambda();
229 G4ParticleDefinition *aSigmaPlus = G4SigmaPlus::SigmaPlus();
230 G4ParticleDefinition *aSigmaMinus = G4SigmaMinus::SigmaMinus();
231 G4ParticleDefinition *aSigmaZero = G4SigmaZero::SigmaZero();
232 const G4double cech[] = {1.,1.,1.,0.70,0.60,0.55,0.35,0.25,0.18,0.15};
233 G4int iplab = G4int(std::min( 9.0, pOriginal/GeV*5.0 ));
234 if( (pOriginal <= 2.0*GeV) && (G4UniformRand() < cech[iplab]) )
235 {
236 np = nm = nz = nt = 0;
237 iplab = G4int(std::min( 19.0, pOriginal/GeV*10.0 ));
238 const G4double cnk0[] = {0.17,0.18,0.17,0.24,0.26,0.20,0.22,0.21,0.34,0.45,
239 0.58,0.55,0.36,0.29,0.29,0.32,0.32,0.33,0.33,0.33};
240 if( G4UniformRand() <= cnk0[iplab] )
241 {
242 quasiElastic = true;
243 if( targetParticle.GetDefinition() == aProton )
244 {
245 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
246 incidentHasChanged = true;
247 targetParticle.SetDefinitionAndUpdateE( aNeutron );
248 targetHasChanged = true;
249 }
250 }
251 else // random number > cnk0[iplab]
252 {
253 G4double ran = G4UniformRand();
254 if( ran < 0.25 ) // k- p --> pi- s+
255 {
256 if( targetParticle.GetDefinition() == aProton )
257 {
258 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
259 targetParticle.SetDefinitionAndUpdateE( aSigmaPlus );
260 incidentHasChanged = true;
261 targetHasChanged = true;
262 }
263 }
264 else if( ran < 0.50 ) // k- p --> pi0 s0 or k- n --> pi- s0
265 {
266 if( targetParticle.GetDefinition() == aNeutron )
267 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
268 else
269 currentParticle.SetDefinitionAndUpdateE( aPiZero );
270 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
271 incidentHasChanged = true;
272 targetHasChanged = true;
273 }
274 else if( ran < 0.75 ) // k- p --> pi+ s- or k- n --> pi0 s-
275 {
276 if( targetParticle.GetDefinition() == aNeutron )
277 currentParticle.SetDefinitionAndUpdateE( aPiZero );
278 else
279 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
280 targetParticle.SetDefinitionAndUpdateE( aSigmaMinus );
281 incidentHasChanged = true;
282 targetHasChanged = true;
283 }
284 else // k- p --> pi0 L or k- n --> pi- L
285 {
286 if( targetParticle.GetDefinition() == aNeutron )
287 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
288 else
289 currentParticle.SetDefinitionAndUpdateE( aPiZero );
290 targetParticle.SetDefinitionAndUpdateE( aLambda );
291 incidentHasChanged = true;
292 targetHasChanged = true;
293 }
294 }
295 }
296 else // (pOriginal > 2.0*GeV) || (random number >= cech[iplab])
297 {
298 if( availableEnergy < aPiPlus->GetPDGMass() )
299 { // not energetically possible to produce pion(s)
300 quasiElastic = true;
301 return;
302 }
303 G4double n, anpn;
304 GetNormalizationConstant( availableEnergy, n, anpn );
305 G4double ran = G4UniformRand();
306 G4double dum, test, excs = 0.0;
307 if( targetParticle.GetDefinition() == aProton )
308 {
309 G4int counter = -1;
310 for( np=0; np<numSec/3 && ran>=excs; ++np )
311 {
312 for( nm=std::max(0,np-1); nm<=(np+1) && ran>=excs; ++nm )
313 {
314 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
315 {
316 if( ++counter < numMul )
317 {
318 nt = np+nm+nz;
319 if( nt > 0 )
320 {
321 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
322 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
323 if( std::fabs(dum) < 1.0 )
324 {
325 if( test >= 1.0e-10 )excs += dum*test;
326 }
327 else
328 excs += dum*test;
329 }
330 }
331 }
332 }
333 }
334 if( ran >= excs ) // 3 previous loops continued to the end
335 {
336 quasiElastic = true;
337 return;
338 }
339 np--; nm--; nz--;
340 if( np == nm )
341 {
342 if( G4UniformRand() >= 0.75 )
343 {
344 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
345 targetParticle.SetDefinitionAndUpdateE( aNeutron );
346 incidentHasChanged = true;
347 targetHasChanged = true;
348 }
349 }
350 else if( np == nm+1 )
351 {
352 targetParticle.SetDefinitionAndUpdateE( aNeutron );
353 targetHasChanged = true;
354 }
355 else
356 {
357 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
358 incidentHasChanged = true;
359 }
360 }
361 else // target must be a neutron
362 {
363 G4int counter = -1;
364 for( np=0; np<numSec/3 && ran>=excs; ++np )
365 {
366 for( nm=np; nm<=(np+2) && ran>=excs; ++nm )
367 {
368 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
369 {
370 if( ++counter < numMul )
371 {
372 nt = np+nm+nz;
373 if( (nt>=1) && (nt<=numSec) )
374 {
375 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
376 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
377 if( std::fabs(dum) < 1.0 )
378 {
379 if( test >= 1.0e-10 )excs += dum*test;
380 }
381 else
382 excs += dum*test;
383 }
384 }
385 }
386 }
387 }
388 if( ran >= excs ) // 3 previous loops continued to the end
389 {
390 quasiElastic = true;
391 return;
392 }
393 np--; nm--; nz--;
394 if( np == nm-1 )
395 {
396 if( G4UniformRand() < 0.5 )
397 {
398 targetParticle.SetDefinitionAndUpdateE( aProton );
399 targetHasChanged = true;
400 }
401 else
402 {
403 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
404 incidentHasChanged = true;
405 }
406 }
407 else if( np != nm )
408 {
409 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
410 incidentHasChanged = true;
411 }
412 }
413 if( G4UniformRand() >= 0.5 )
414 {
415 if( (currentParticle.GetDefinition() == aKaonMinus &&
416 targetParticle.GetDefinition() == aNeutron ) ||
417 (currentParticle.GetDefinition() == aKaonZL &&
418 targetParticle.GetDefinition() == aProton ) )
419 {
420 ran = G4UniformRand();
421 if( ran < 0.68 )
422 {
423 if( targetParticle.GetDefinition() == aProton )
424 {
425 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
426 targetParticle.SetDefinitionAndUpdateE( aLambda );
427 incidentHasChanged = true;
428 targetHasChanged = true;
429 }
430 else
431 {
432 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
433 targetParticle.SetDefinitionAndUpdateE( aLambda );
434 incidentHasChanged = true;
435 targetHasChanged = true;
436 }
437 }
438 else if( ran < 0.84 )
439 {
440 if( targetParticle.GetDefinition() == aProton )
441 {
442 currentParticle.SetDefinitionAndUpdateE( aPiZero );
443 targetParticle.SetDefinitionAndUpdateE( aSigmaPlus );
444 incidentHasChanged = true;
445 targetHasChanged = true;
446 }
447 else
448 {
449 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
450 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
451 incidentHasChanged = true;
452 targetHasChanged = true;
453 }
454 }
455 else
456 {
457 if( targetParticle.GetDefinition() == aProton )
458 {
459 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
460 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
461 incidentHasChanged = true;
462 targetHasChanged = true;
463 }
464 else
465 {
466 currentParticle.SetDefinitionAndUpdateE( aPiZero );
467 targetParticle.SetDefinitionAndUpdateE( aSigmaMinus );
468 incidentHasChanged = true;
469 targetHasChanged = true;
470 }
471 }
472 }
473 else // ( current != aKaonMinus || target != aNeutron ) &&
474 // ( current != aKaonZL || target != aProton )
475 {
476 ran = G4UniformRand();
477 if( ran < 0.67 )
478 {
479 currentParticle.SetDefinitionAndUpdateE( aPiZero );
480 targetParticle.SetDefinitionAndUpdateE( aLambda );
481 incidentHasChanged = true;
482 targetHasChanged = true;
483 }
484 else if( ran < 0.78 )
485 {
486 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
487 targetParticle.SetDefinitionAndUpdateE( aSigmaPlus );
488 incidentHasChanged = true;
489 targetHasChanged = true;
490 }
491 else if( ran < 0.89 )
492 {
493 currentParticle.SetDefinitionAndUpdateE( aPiZero );
494 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
495 incidentHasChanged = true;
496 targetHasChanged = true;
497 }
498 else
499 {
500 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
501 targetParticle.SetDefinitionAndUpdateE( aSigmaMinus );
502 incidentHasChanged = true;
503 targetHasChanged = true;
504 }
505 }
506 }
507 }
508 if( currentParticle.GetDefinition() == aKaonZL )
509 {
510 if( G4UniformRand() >= 0.5 )
511 {
512 currentParticle.SetDefinitionAndUpdateE( aKaonZS );
513 incidentHasChanged = true;
514 }
515 }
516 if( targetParticle.GetDefinition() == aKaonZL )
517 {
518 if( G4UniformRand() >= 0.5 )
519 {
520 targetParticle.SetDefinitionAndUpdateE( aKaonZS );
521 targetHasChanged = true;
522 }
523 }
524 SetUpPions( np, nm, nz, vec, vecLen );
525 return;
526}
527
528 /* end of file */
529
530
531
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