source: trunk/source/processes/hadronic/models/rpg/src/G4RPGAntiSigmaPlusInelastic.cc@ 1347

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26// $Id: G4RPGAntiSigmaPlusInelastic.cc,v 1.1 2007/07/18 21:04:20 dennis Exp $
27// GEANT4 tag $Name: geant4-09-03-ref-09 $
28//
29
30#include "G4RPGAntiSigmaPlusInelastic.hh"
31#include "Randomize.hh"
32
33G4HadFinalState*
34G4RPGAntiSigmaPlusInelastic::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 // Choose the target particle
47
48 G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle();
49
50 if( verboseLevel > 1 )
51 {
52 const G4Material *targetMaterial = aTrack.GetMaterial();
53 G4cout << "G4RPGAntiSigmaPlusInelastic::ApplyYourself called" << G4endl;
54 G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy()/MeV << "MeV, ";
55 G4cout << "target material = " << targetMaterial->GetName() << ", ";
56 G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName()
57 << G4endl;
58 }
59
60 // Fermi motion and evaporation
61 // As of Geant3, the Fermi energy calculation had not been Done
62
63 G4double ek = originalIncident->GetKineticEnergy()/MeV;
64 G4double amas = originalIncident->GetDefinition()->GetPDGMass()/MeV;
65 G4ReactionProduct modifiedOriginal;
66 modifiedOriginal = *originalIncident;
67
68 G4double tkin = targetNucleus.Cinema( ek );
69 ek += tkin;
70 modifiedOriginal.SetKineticEnergy( ek*MeV );
71 G4double et = ek + amas;
72 G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) );
73 G4double pp = modifiedOriginal.GetMomentum().mag()/MeV;
74 if( pp > 0.0 )
75 {
76 G4ThreeVector momentum = modifiedOriginal.GetMomentum();
77 modifiedOriginal.SetMomentum( momentum * (p/pp) );
78 }
79 //
80 // calculate black track energies
81 //
82 tkin = targetNucleus.EvaporationEffects( ek );
83 ek -= tkin;
84 modifiedOriginal.SetKineticEnergy( ek*MeV );
85 et = ek + amas;
86 p = std::sqrt( std::abs((et-amas)*(et+amas)) );
87 pp = modifiedOriginal.GetMomentum().mag()/MeV;
88 if( pp > 0.0 )
89 {
90 G4ThreeVector momentum = modifiedOriginal.GetMomentum();
91 modifiedOriginal.SetMomentum( momentum * (p/pp) );
92 }
93 G4ReactionProduct currentParticle = modifiedOriginal;
94 G4ReactionProduct targetParticle;
95 targetParticle = *originalTarget;
96 currentParticle.SetSide( 1 ); // incident always goes in forward hemisphere
97 targetParticle.SetSide( -1 ); // target always goes in backward hemisphere
98 G4bool incidentHasChanged = false;
99 G4bool targetHasChanged = false;
100 G4bool quasiElastic = false;
101 G4FastVector<G4ReactionProduct,GHADLISTSIZE> vec; // vec will contain the secondary particles
102 G4int vecLen = 0;
103 vec.Initialize( 0 );
104
105 const G4double cutOff = 0.1;
106 const G4double anni = std::min( 1.3*currentParticle.GetTotalMomentum()/GeV, 0.4 );
107 if( (currentParticle.GetKineticEnergy()/MeV > cutOff) || (G4UniformRand() > anni) )
108 Cascade( vec, vecLen,
109 originalIncident, currentParticle, targetParticle,
110 incidentHasChanged, targetHasChanged, quasiElastic );
111
112 CalculateMomenta( vec, vecLen,
113 originalIncident, originalTarget, modifiedOriginal,
114 targetNucleus, currentParticle, targetParticle,
115 incidentHasChanged, targetHasChanged, quasiElastic );
116
117 SetUpChange( vec, vecLen,
118 currentParticle, targetParticle,
119 incidentHasChanged );
120
121 delete originalTarget;
122 return &theParticleChange;
123}
124
125
126void G4RPGAntiSigmaPlusInelastic::Cascade(
127 G4FastVector<G4ReactionProduct,GHADLISTSIZE> &vec,
128 G4int& vecLen,
129 const G4HadProjectile *originalIncident,
130 G4ReactionProduct &currentParticle,
131 G4ReactionProduct &targetParticle,
132 G4bool &incidentHasChanged,
133 G4bool &targetHasChanged,
134 G4bool &quasiElastic )
135{
136 // Derived from H. Fesefeldt's original FORTRAN code CASASP
137 // AntiSigmaPlus undergoes interaction with nucleon within a nucleus. Check if it is
138 // energetically possible to produce pions/kaons. In not, assume nuclear excitation
139 // occurs and input particle is degraded in energy. No other particles are produced.
140 // If reaction is possible, find the correct number of pions/protons/neutrons
141 // produced using an interpolation to multiplicity data. Replace some pions or
142 // protons/neutrons by kaons or strange baryons according to the average
143 // multiplicity per Inelastic reaction.
144
145 const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass()/MeV;
146 const G4double etOriginal = originalIncident->GetTotalEnergy()/MeV;
147 const G4double pOriginal = originalIncident->GetTotalMomentum()/MeV;
148 const G4double targetMass = targetParticle.GetMass()/MeV;
149 G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
150 targetMass*targetMass +
151 2.0*targetMass*etOriginal );
152 G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal);
153
154 static G4bool first = true;
155 const G4int numMul = 1200;
156 const G4int numMulA = 400;
157 const G4int numSec = 60;
158 static G4double protmul[numMul], protnorm[numSec]; // proton constants
159 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
160 static G4double protmulA[numMulA], protnormA[numSec]; // proton constants
161 static G4double neutmulA[numMulA], neutnormA[numSec]; // neutron constants
162 // np = number of pi+, nm = number of pi-, nz = number of pi0
163 G4int counter, nt=0, np=0, nm=0, nz=0;
164 G4double test;
165 const G4double c = 1.25;
166 const G4double b[] = { 0.7, 0.7 };
167 if( first ) // compute normalization constants, this will only be Done once
168 {
169 first = false;
170 G4int i;
171 for( i=0; i<numMul; ++i )protmul[i] = 0.0;
172 for( i=0; i<numSec; ++i )protnorm[i] = 0.0;
173 counter = -1;
174 for( np=0; np<(numSec/3); ++np )
175 {
176 for( nm=std::max(0,np-1); nm<=(np+1); ++nm )
177 {
178 for( nz=0; nz<numSec/3; ++nz )
179 {
180 if( ++counter < numMul )
181 {
182 nt = np+nm+nz;
183 if( nt>0 && nt<=numSec )
184 {
185 protmul[counter] = Pmltpc(np,nm,nz,nt,b[0],c);
186 protnorm[nt-1] += protmul[counter];
187 }
188 }
189 }
190 }
191 }
192 for( i=0; i<numMul; ++i )neutmul[i] = 0.0;
193 for( i=0; i<numSec; ++i )neutnorm[i] = 0.0;
194 counter = -1;
195 for( np=0; np<numSec/3; ++np )
196 {
197 for( nm=np; nm<=(np+2); ++nm )
198 {
199 for( nz=0; nz<numSec/3; ++nz )
200 {
201 if( ++counter < numMul )
202 {
203 nt = np+nm+nz;
204 if( nt>0 && nt<=numSec )
205 {
206 neutmul[counter] = Pmltpc(np,nm,nz,nt,b[1],c);
207 neutnorm[nt-1] += neutmul[counter];
208 }
209 }
210 }
211 }
212 }
213 for( i=0; i<numSec; ++i )
214 {
215 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
216 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
217 }
218 //
219 // do the same for annihilation channels
220 //
221 for( i=0; i<numMulA; ++i )protmulA[i] = 0.0;
222 for( i=0; i<numSec; ++i )protnormA[i] = 0.0;
223 counter = -1;
224 for( np=1; np<(numSec/3); ++np )
225 {
226 nm = np;
227 for( nz=0; nz<numSec/3; ++nz )
228 {
229 if( ++counter < numMulA )
230 {
231 nt = np+nm+nz;
232 if( nt>1 && nt<=numSec )
233 {
234 protmulA[counter] = Pmltpc(np,nm,nz,nt,b[0],c);
235 protnormA[nt-1] += protmulA[counter];
236 }
237 }
238 }
239 }
240 for( i=0; i<numMulA; ++i )neutmulA[i] = 0.0;
241 for( i=0; i<numSec; ++i )neutnormA[i] = 0.0;
242 counter = -1;
243 for( np=0; np<numSec/3; ++np )
244 {
245 nm = np+1;
246 for( nz=0; nz<numSec/3; ++nz )
247 {
248 if( ++counter < numMulA )
249 {
250 nt = np+nm+nz;
251 if( nt>1 && nt<=numSec )
252 {
253 neutmulA[counter] = Pmltpc(np,nm,nz,nt,b[1],c);
254 neutnormA[nt-1] += neutmulA[counter];
255 }
256 }
257 }
258 }
259 for( i=0; i<numSec; ++i )
260 {
261 if( protnormA[i] > 0.0 )protnormA[i] = 1.0/protnormA[i];
262 if( neutnormA[i] > 0.0 )neutnormA[i] = 1.0/neutnormA[i];
263 }
264 } // end of initialization
265
266 const G4double expxu = 82.; // upper bound for arg. of exp
267 const G4double expxl = -expxu; // lower bound for arg. of exp
268 G4ParticleDefinition *aNeutron = G4Neutron::Neutron();
269 G4ParticleDefinition *aProton = G4Proton::Proton();
270 G4ParticleDefinition *aPiPlus = G4PionPlus::PionPlus();
271 G4ParticleDefinition *anAntiLambda = G4AntiLambda::AntiLambda();
272 G4ParticleDefinition *aKaonMinus = G4KaonMinus::KaonMinus();
273 G4ParticleDefinition *aKaonPlus = G4KaonPlus::KaonPlus();
274 G4ParticleDefinition *aKaonZL = G4KaonZeroLong::KaonZeroLong();
275 G4ParticleDefinition *anAntiSigmaZero = G4AntiSigmaZero::AntiSigmaZero();
276 const G4double anhl[] = {1.00,1.00,1.00,1.00,1.00,1.00,1.00,1.00,0.97,0.88,
277 0.85,0.81,0.75,0.64,0.64,0.55,0.55,0.45,0.47,0.40,
278 0.39,0.36,0.33,0.10,0.01};
279 G4int iplab = G4int( pOriginal/GeV*10.0 );
280 if( iplab > 9 )iplab = G4int( (pOriginal/GeV- 1.0)*5.0 ) + 10;
281 if( iplab > 14 )iplab = G4int( pOriginal/GeV- 2.0 ) + 15;
282 if( iplab > 22 )iplab = G4int( (pOriginal/GeV-10.0)/10.0 ) + 23;
283 if( iplab > 24 )iplab = 24;
284 if( G4UniformRand() > anhl[iplab] )
285 {
286 if( availableEnergy <= aPiPlus->GetPDGMass()/MeV )
287 {
288 quasiElastic = true;
289 return;
290 }
291 G4double n, anpn;
292 GetNormalizationConstant( availableEnergy, n, anpn );
293 G4double ran = G4UniformRand();
294 G4double dum, excs = 0.0;
295 if( targetParticle.GetDefinition() == aProton )
296 {
297 counter = -1;
298 for( np=0; np<numSec/3 && ran>=excs; ++np )
299 {
300 for( nm=std::max(0,np-1); nm<=(np+1) && ran>=excs; ++nm )
301 {
302 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
303 {
304 if( ++counter < numMul )
305 {
306 nt = np+nm+nz;
307 if( (nt>0) && (nt<=numSec) )
308 {
309 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
310 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
311 if( std::fabs(dum) < 1.0 )
312 {
313 if( test >= 1.0e-10 )excs += dum*test;
314 }
315 else
316 excs += dum*test;
317 }
318 }
319 }
320 }
321 }
322 if( ran >= excs ) // 3 previous loops continued to the end
323 {
324 quasiElastic = true;
325 return;
326 }
327 np--; nm--; nz--;
328 G4int ncht = std::min( 3, std::max( 1, np-nm+2 ) );
329 switch( ncht )
330 {
331 case 1:
332 if( G4UniformRand() < 0.5 )
333 currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
334 else
335 currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
336 incidentHasChanged = true;
337 break;
338 case 2:
339 if( G4UniformRand() >= 0.5 )
340 {
341 if( G4UniformRand() < 0.5 )
342 currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
343 else
344 currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
345 incidentHasChanged = true;
346 }
347 targetParticle.SetDefinitionAndUpdateE( aNeutron );
348 targetHasChanged = true;
349 break;
350 case 3:
351 targetParticle.SetDefinitionAndUpdateE( aNeutron );
352 targetHasChanged = true;
353 break;
354 }
355 }
356 else // target must be a neutron
357 {
358 counter = -1;
359 for( np=0; np<numSec/3 && ran>=excs; ++np )
360 {
361 for( nm=np; nm<=(np+2) && ran>=excs; ++nm )
362 {
363 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
364 {
365 if( ++counter < numMul )
366 {
367 nt = np+nm+nz;
368 if( (nt>0) && (nt<=numSec) )
369 {
370 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
371 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
372 if( std::fabs(dum) < 1.0 )
373 {
374 if( test >= 1.0e-10 )excs += dum*test;
375 }
376 else
377 excs += dum*test;
378 }
379 }
380 }
381 }
382 }
383 if( ran >= excs ) // 3 previous loops continued to the end
384 {
385 quasiElastic = true;
386 return;
387 }
388 np--; nm--; nz--;
389 G4int ncht = std::min( 3, std::max( 1, np-nm+3 ) );
390 switch( ncht )
391 {
392 case 1:
393 if( G4UniformRand() < 0.5 )
394 currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
395 else
396 currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
397 incidentHasChanged = true;
398 targetParticle.SetDefinitionAndUpdateE( aProton );
399 targetHasChanged = true;
400 break;
401 case 2:
402 if( G4UniformRand() < 0.5 )
403 {
404 if( G4UniformRand() < 0.5 )
405 {
406 currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
407 incidentHasChanged = true;
408 }
409 else
410 {
411 targetParticle.SetDefinitionAndUpdateE( aProton );
412 targetHasChanged = true;
413 }
414 }
415 else
416 {
417 if( G4UniformRand() < 0.5 )
418 {
419 currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
420 incidentHasChanged = true;
421 }
422 else
423 {
424 targetParticle.SetDefinitionAndUpdateE( aProton );
425 targetHasChanged = true;
426 }
427 }
428 break;
429 case 3:
430 break;
431 }
432 }
433 }
434 else // random number <= anhl[iplab]
435 {
436 if( centerofmassEnergy <= aPiPlus->GetPDGMass()/MeV+aKaonPlus->GetPDGMass()/MeV )
437 {
438 quasiElastic = true;
439 return;
440 }
441 G4double n, anpn;
442 GetNormalizationConstant( -centerofmassEnergy, n, anpn );
443 G4double ran = G4UniformRand();
444 G4double dum, excs = 0.0;
445 if( targetParticle.GetDefinition() == aProton )
446 {
447 counter = -1;
448 for( np=1; np<numSec/3 && ran>=excs; ++np )
449 {
450 nm = np;
451 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
452 {
453 if( ++counter < numMulA )
454 {
455 nt = np+nm+nz;
456 if( nt>1 && nt<=numSec )
457 {
458 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
459 dum = (pi/anpn)*nt*protmulA[counter]*protnormA[nt-1]/(2.0*n*n);
460 if( std::fabs(dum) < 1.0 )
461 {
462 if( test >= 1.0e-10 )excs += dum*test;
463 }
464 else
465 excs += dum*test;
466 }
467 }
468 }
469 }
470 if( ran >= excs ) // 3 previous loops continued to the end
471 {
472 quasiElastic = true;
473 return;
474 }
475 np--; nz--;
476 }
477 else // target must be a neutron
478 {
479 counter = -1;
480 for( np=0; np<numSec/3 && ran>=excs; ++np )
481 {
482 nm = np+1;
483 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
484 {
485 if( ++counter < numMulA )
486 {
487 nt = np+nm+nz;
488 if( nt>1 && nt<=numSec )
489 {
490 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
491 dum = (pi/anpn)*nt*neutmulA[counter]*neutnormA[nt-1]/(2.0*n*n);
492 if( std::fabs(dum) < 1.0 )
493 {
494 if( test >= 1.0e-10 )excs += dum*test;
495 }
496 else
497 excs += dum*test;
498 }
499 }
500 }
501 }
502 if( ran >= excs ) // 3 previous loops continued to the end
503 {
504 quasiElastic = true;
505 return;
506 }
507 np--; nz--;
508 }
509 if( nz > 0 )
510 {
511 if( nm > 0 )
512 {
513 if( G4UniformRand() < 0.5 )
514 {
515 vec.Initialize( 1 );
516 G4ReactionProduct *p= new G4ReactionProduct;
517 p->SetDefinition( aKaonMinus );
518 (G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
519 vec.SetElement( vecLen++, p );
520 --nm;
521 }
522 else
523 {
524 vec.Initialize( 1 );
525 G4ReactionProduct *p= new G4ReactionProduct ;
526 p->SetDefinition( aKaonZL );
527 (G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
528 vec.SetElement( vecLen++, p );
529 --nz;
530 }
531 }
532 else // nm == 0
533 {
534 vec.Initialize( 1 );
535 G4ReactionProduct *p = new G4ReactionProduct;
536 p->SetDefinition( aKaonZL );
537 (G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
538 vec.SetElement( vecLen++, p );
539 --nz;
540 }
541 }
542 else // nz == 0
543 {
544 if( nm > 0 )
545 {
546 vec.Initialize( 1 );
547 G4ReactionProduct *p = new G4ReactionProduct;
548 p->SetDefinition( aKaonMinus );
549 (G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
550 vec.SetElement( vecLen++, p );
551 --nm;
552 }
553 }
554 currentParticle.SetMass( 0.0 );
555 targetParticle.SetMass( 0.0 );
556 }
557
558 SetUpPions( np, nm, nz, vec, vecLen );
559 return;
560}
561
562 /* end of file */
563
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