source: trunk/source/processes/hadronic/models/rpg/src/G4RPGTwoCluster.cc@ 819

Last change on this file since 819 was 819, checked in by garnier, 17 years ago

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25//
26// $Id: G4RPGTwoCluster.cc,v 1.2 2007/08/15 20:38:48 dennis Exp $
27// GEANT4 tag $Name: geant4-09-01-patch-02 $
28//
29
30#include "G4RPGTwoCluster.hh"
31#include "Randomize.hh"
32#include "G4Poisson.hh"
33#include <iostream>
34#include "G4HadReentrentException.hh"
35#include <signal.h>
36
37
38G4RPGTwoCluster::G4RPGTwoCluster()
39 : G4RPGReaction() {}
40
41
42G4bool G4RPGTwoCluster::
43ReactionStage(const G4HadProjectile* originalIncident,
44 G4ReactionProduct& modifiedOriginal,
45 G4bool& incidentHasChanged,
46 const G4DynamicParticle* originalTarget,
47 G4ReactionProduct& targetParticle,
48 G4bool& targetHasChanged,
49 const G4Nucleus& targetNucleus,
50 G4ReactionProduct& currentParticle,
51 G4FastVector<G4ReactionProduct,256>& vec,
52 G4int& vecLen,
53 G4bool leadFlag,
54 G4ReactionProduct& leadingStrangeParticle)
55{
56 // Derived from H. Fesefeldt's FORTRAN code TWOCLU
57 //
58 // A simple two cluster model is used to generate x- and pt- values for
59 // incident, target, and all secondary particles.
60 // This should be sufficient for low energy interactions.
61 //
62
63 G4int i;
64 G4ParticleDefinition *aProton = G4Proton::Proton();
65 G4ParticleDefinition *aNeutron = G4Neutron::Neutron();
66 G4ParticleDefinition *aPiPlus = G4PionPlus::PionPlus();
67 G4ParticleDefinition *aPiMinus = G4PionMinus::PionMinus();
68 G4ParticleDefinition *aPiZero = G4PionZero::PionZero();
69 G4bool veryForward = false;
70
71 const G4double protonMass = aProton->GetPDGMass()/MeV;
72 const G4double ekOriginal = modifiedOriginal.GetKineticEnergy()/GeV;
73 const G4double etOriginal = modifiedOriginal.GetTotalEnergy()/GeV;
74 const G4double mOriginal = modifiedOriginal.GetMass()/GeV;
75 const G4double pOriginal = modifiedOriginal.GetMomentum().mag()/GeV;
76 G4double targetMass = targetParticle.GetDefinition()->GetPDGMass()/GeV;
77 G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
78 targetMass*targetMass +
79 2.0*targetMass*etOriginal ); // GeV
80 G4double currentMass = currentParticle.GetMass()/GeV;
81 targetMass = targetParticle.GetMass()/GeV;
82
83 if( currentMass == 0.0 && targetMass == 0.0 )
84 {
85 G4double ek = currentParticle.GetKineticEnergy();
86 G4ThreeVector m = currentParticle.GetMomentum();
87 currentParticle = *vec[0];
88 targetParticle = *vec[1];
89 for( i=0; i<(vecLen-2); ++i )*vec[i] = *vec[i+2];
90 if(vecLen<2)
91 {
92 for(G4int i=0; i<vecLen; i++) delete vec[i];
93 vecLen = 0;
94 throw G4HadReentrentException(__FILE__, __LINE__,
95 "G4RPGTwoCluster::ReactionStage : Negative number of particles");
96 }
97 delete vec[vecLen-1];
98 delete vec[vecLen-2];
99 vecLen -= 2;
100 currentMass = currentParticle.GetMass()/GeV;
101 targetMass = targetParticle.GetMass()/GeV;
102 incidentHasChanged = true;
103 targetHasChanged = true;
104 currentParticle.SetKineticEnergy( ek );
105 currentParticle.SetMomentum( m );
106 veryForward = true;
107 }
108
109 const G4double atomicWeight = targetNucleus.GetN();
110 const G4double atomicNumber = targetNucleus.GetZ();
111 //
112 // particles have been distributed in forward and backward hemispheres
113 // in center of mass system of the hadron nucleon interaction
114 //
115
116 // Incident particle always in forward hemisphere
117
118 G4int forwardCount = 1; // number of particles in forward hemisphere
119 currentParticle.SetSide( 1 );
120 G4double forwardMass = currentParticle.GetMass()/GeV;
121 G4double cMass = forwardMass;
122
123 // Target particle always in backward hemisphere
124
125 G4int backwardCount = 1; // number of particles in backward hemisphere
126 targetParticle.SetSide( -1 );
127 G4double backwardMass = targetParticle.GetMass()/GeV;
128 G4double bMass = backwardMass;
129
130 G4int backwardNucleonCount = 1; // number of nucleons in backward hemisphere
131
132 for( i=0; i<vecLen; ++i )
133 {
134 if( vec[i]->GetSide() < 0 )vec[i]->SetSide( -1 ); // to take care of
135 // case where vec has been preprocessed by GenerateXandPt
136 // and some of them have been set to -2 or -3
137 if( vec[i]->GetSide() == -1 )
138 {
139 ++backwardCount;
140 backwardMass += vec[i]->GetMass()/GeV;
141 }
142 else
143 {
144 ++forwardCount;
145 forwardMass += vec[i]->GetMass()/GeV;
146 }
147 }
148
149 //
150 // Add nucleons and some pions from intra-nuclear cascade
151 //
152
153 G4double term1 = std::log(centerofmassEnergy*centerofmassEnergy);
154 if(term1 < 0) term1 = 0.0001; // making sure xtarg<0;
155 const G4double afc = 0.312 + 0.2 * std::log(term1);
156 G4double xtarg;
157 if( centerofmassEnergy < 2.0+G4UniformRand() ) // added +2 below, JLC 4Jul97
158 xtarg = afc * (std::pow(atomicWeight,0.33)-1.0) * (2*backwardCount+vecLen+2)/2.0;
159 else
160 xtarg = afc * (std::pow(atomicWeight,0.33)-1.0) * (2*backwardCount);
161 if( xtarg <= 0.0 )xtarg = 0.01;
162 G4int nuclearExcitationCount = G4Poisson( xtarg );
163
164 if(atomicWeight<1.0001) nuclearExcitationCount = 0;
165 G4int extraNucleonCount = 0;
166 G4double extraMass = 0.0;
167 G4double extraNucleonMass = 0.0;
168 if( nuclearExcitationCount > 0 )
169 {
170 G4int momentumBin = std::min( 4, G4int(pOriginal/3.0) );
171 const G4double nucsup[] = { 1.0, 0.8, 0.6, 0.5, 0.4 };
172 //
173 // NOTE: in TWOCLU, these new particles were given negative codes
174 // here we use NewlyAdded = true instead
175 //
176 for( i=0; i<nuclearExcitationCount; ++i )
177 {
178 G4ReactionProduct* pVec = new G4ReactionProduct();
179 if( G4UniformRand() < nucsup[momentumBin] ) // add proton or neutron
180 {
181 if( G4UniformRand() > 1.0-atomicNumber/atomicWeight )
182 pVec->SetDefinition( aProton );
183 else
184 pVec->SetDefinition( aNeutron );
185 ++backwardNucleonCount;
186 ++extraNucleonCount;
187 extraNucleonMass += pVec->GetMass()/GeV;
188 }
189 else
190 { // add a pion
191 G4double ran = G4UniformRand();
192 if( ran < 0.3181 )
193 pVec->SetDefinition( aPiPlus );
194 else if( ran < 0.6819 )
195 pVec->SetDefinition( aPiZero );
196 else
197 pVec->SetDefinition( aPiMinus );
198 }
199 pVec->SetSide( -2 ); // backside particle
200 extraMass += pVec->GetMass()/GeV;
201 pVec->SetNewlyAdded( true );
202 vec.SetElement( vecLen++, pVec );
203 }
204 }
205
206 // Masses of particles added from cascade not included in energy balance
207 G4double forwardEnergy = (centerofmassEnergy-cMass-bMass)/2.0 +cMass - forwardMass;
208 G4double backwardEnergy = (centerofmassEnergy-cMass-bMass)/2.0 +bMass - backwardMass;
209 G4double eAvailable = centerofmassEnergy - (forwardMass+backwardMass);
210 G4bool secondaryDeleted;
211 G4double pMass;
212
213 while( eAvailable <= 0.0 ) // must eliminate a particle
214 {
215 secondaryDeleted = false;
216 for( i=(vecLen-1); i>=0; --i )
217 {
218 if( vec[i]->GetSide() == 1 && vec[i]->GetMayBeKilled())
219 {
220 pMass = vec[i]->GetMass()/GeV;
221 for( G4int j=i; j<(vecLen-1); ++j )*vec[j] = *vec[j+1]; // shift up
222 --forwardCount;
223 forwardEnergy += pMass;
224 forwardMass -= pMass;
225 secondaryDeleted = true;
226 break;
227 }
228 else if( vec[i]->GetSide() == -1 && vec[i]->GetMayBeKilled())
229 {
230 pMass = vec[i]->GetMass()/GeV;
231 for( G4int j=i; j<(vecLen-1); ++j )*vec[j] = *vec[j+1]; // shift up
232 --backwardCount;
233 backwardEnergy += pMass;
234 backwardMass -= pMass;
235 secondaryDeleted = true;
236 break;
237 }
238 } // breaks go down to here
239
240 if( secondaryDeleted )
241 {
242 delete vec[vecLen-1];
243 --vecLen;
244 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
245 }
246 else
247 {
248 if( vecLen == 0 ) return false; // all secondaries have been eliminated
249 if( targetParticle.GetSide() == -1 )
250 {
251 pMass = targetParticle.GetMass()/GeV;
252 targetParticle = *vec[0];
253 for( G4int j=0; j<(vecLen-1); ++j )*vec[j] = *vec[j+1]; // shift up
254 --backwardCount;
255 backwardEnergy += pMass;
256 backwardMass -= pMass;
257 secondaryDeleted = true;
258 }
259 else if( targetParticle.GetSide() == 1 )
260 {
261 pMass = targetParticle.GetMass()/GeV;
262 targetParticle = *vec[0];
263 for( G4int j=0; j<(vecLen-1); ++j )*vec[j] = *vec[j+1]; // shift up
264 --forwardCount;
265 forwardEnergy += pMass;
266 forwardMass -= pMass;
267 secondaryDeleted = true;
268 }
269
270 if( secondaryDeleted )
271 {
272 delete vec[vecLen-1];
273 --vecLen;
274 }
275 else
276 {
277 if( currentParticle.GetSide() == -1 )
278 {
279 pMass = currentParticle.GetMass()/GeV;
280 currentParticle = *vec[0];
281 for( G4int j=0; j<(vecLen-1); ++j )*vec[j] = *vec[j+1]; // shift up
282 --backwardCount;
283 backwardEnergy += pMass;
284 backwardMass -= pMass;
285 secondaryDeleted = true;
286 }
287 else if( currentParticle.GetSide() == 1 )
288 {
289 pMass = currentParticle.GetMass()/GeV;
290 currentParticle = *vec[0];
291 for( G4int j=0; j<(vecLen-1); ++j )*vec[j] = *vec[j+1]; // shift up
292 --forwardCount;
293 forwardEnergy += pMass;
294 forwardMass -= pMass;
295 secondaryDeleted = true;
296 }
297 if( secondaryDeleted )
298 {
299 delete vec[vecLen-1];
300 --vecLen;
301 }
302 else break;
303
304 } // secondary not deleted
305 } // secondary not deleted
306
307 eAvailable = centerofmassEnergy - (forwardMass+backwardMass);
308 } // while
309
310 //
311 // This is the start of the TwoCluster function
312 // Choose multi-particle resonance masses by sampling
313 // P(M) = gc[g(M-M0)]**(c-1) *exp[-(g(M-M0))**c]
314 // for M > M0
315 //
316 // Use for the forward and backward clusters, but not
317 // the cascade cluster
318
319 const G4double cpar[] = { 1.60, 1.35, 1.15, 1.10 };
320 const G4double gpar[] = { 2.60, 1.80, 1.30, 1.20 };
321 G4int ntc = 0;
322
323 if (forwardCount < 1 || backwardCount < 1) return false; // array bounds protection
324
325 G4double rmc = forwardMass;
326 if (forwardCount > 1) {
327 ntc = std::min(3,forwardCount-2);
328 rmc += std::pow(-std::log(1.0-G4UniformRand()),1./cpar[ntc])/gpar[ntc];
329 }
330 G4double rmd = backwardMass;
331 if( backwardCount > 1 ) {
332 ntc = std::min(3,backwardCount-2);
333 rmd += std::pow(-std::log(1.0-G4UniformRand()),1./cpar[ntc])/gpar[ntc];
334 }
335
336 while( rmc+rmd > centerofmassEnergy )
337 {
338 if( (rmc <= forwardMass) && (rmd <= backwardMass) )
339 {
340 G4double temp = 0.999*centerofmassEnergy/(rmc+rmd);
341 rmc *= temp;
342 rmd *= temp;
343 }
344 else
345 {
346 rmc = 0.1*forwardMass + 0.9*rmc;
347 rmd = 0.1*backwardMass + 0.9*rmd;
348 }
349 }
350
351 G4ReactionProduct pseudoParticle[8];
352 for( i=0; i<8; ++i )pseudoParticle[i].SetZero();
353
354 pseudoParticle[1].SetMass( mOriginal*GeV );
355 pseudoParticle[1].SetTotalEnergy( etOriginal*GeV );
356 pseudoParticle[1].SetMomentum( 0.0, 0.0, pOriginal*GeV );
357
358 pseudoParticle[2].SetMass( protonMass*MeV );
359 pseudoParticle[2].SetTotalEnergy( protonMass*MeV );
360 pseudoParticle[2].SetMomentum( 0.0, 0.0, 0.0 );
361 //
362 // transform into center of mass system
363 //
364 pseudoParticle[0] = pseudoParticle[1] + pseudoParticle[2];
365 pseudoParticle[1].Lorentz( pseudoParticle[1], pseudoParticle[0] );
366 pseudoParticle[2].Lorentz( pseudoParticle[2], pseudoParticle[0] );
367
368 // Calculate cm momentum for forward and backward masses
369 // W = sqrt(pf*pf + rmc*rmc) + sqrt(pf*pf + rmd*rmd)
370 // Solve for pf
371
372 const G4double pfMin = 0.0001;
373 G4double pf = (centerofmassEnergy*centerofmassEnergy+rmd*rmd-rmc*rmc);
374 pf *= pf;
375 pf -= 4*centerofmassEnergy*centerofmassEnergy*rmd*rmd;
376 pf = std::sqrt( std::max(pf,pfMin) )/(2.0*centerofmassEnergy);
377 //
378 // set final state masses and energies in centre of mass system
379 //
380 pseudoParticle[3].SetMass( rmc*GeV );
381 pseudoParticle[3].SetTotalEnergy( std::sqrt(pf*pf+rmc*rmc)*GeV );
382
383 pseudoParticle[4].SetMass( rmd*GeV );
384 pseudoParticle[4].SetTotalEnergy( std::sqrt(pf*pf+rmd*rmd)*GeV );
385
386 //
387 // Get cm scattering angle by sampling t from tmin to tmax
388 //
389 const G4double bMin = 0.01;
390 const G4double b1 = 4.0;
391 const G4double b2 = 1.6;
392 G4double pin = pseudoParticle[1].GetMomentum().mag()/GeV;
393 G4double dtb = 4.0*pin*pf*std::max( bMin, b1+b2*std::log(pOriginal) );
394 G4double factor = 1.0 - std::exp(-dtb);
395 G4double costheta = 1.0 + 2.0*std::log(1.0 - G4UniformRand()*factor) / dtb;
396
397 costheta = std::max(-1.0, std::min(1.0, costheta));
398 G4double sintheta = std::sqrt((1.0-costheta)*(1.0+costheta));
399 G4double phi = G4UniformRand() * twopi;
400 //
401 // calculate final state momenta in centre of mass system
402 //
403 pseudoParticle[3].SetMomentum( pf*sintheta*std::cos(phi)*GeV,
404 pf*sintheta*std::sin(phi)*GeV,
405 pf*costheta*GeV );
406 pseudoParticle[4].SetMomentum( -pseudoParticle[3].GetMomentum());
407
408 // Backward cluster of nucleons and pions from intra-nuclear cascade
409 // Set up in lab system and transform to cms
410
411 G4double pp, pp1;
412 if( nuclearExcitationCount > 0 )
413 {
414 const G4double ga = 1.2;
415 G4double ekit1 = 0.04;
416 G4double ekit2 = 0.6; // Max KE of cascade particle
417 if( ekOriginal <= 5.0 )
418 {
419 ekit1 *= ekOriginal*ekOriginal/25.0;
420 ekit2 *= ekOriginal*ekOriginal/25.0;
421 }
422 G4double scale = std::pow(ekit2/ekit1, 1.0-ga) - 1.0;
423 for( i=0; i<vecLen; ++i )
424 {
425 if( vec[i]->GetSide() == -2 )
426 {
427 G4double kineticE = ekit1*std::pow((1.0 + G4UniformRand()*scale), 1.0/(1.0-ga) );
428 vec[i]->SetKineticEnergy( kineticE*GeV );
429 G4double vMass = vec[i]->GetMass()/MeV;
430 G4double totalE = kineticE*GeV + vMass;
431 pp = std::sqrt( std::abs(totalE*totalE-vMass*vMass) );
432 G4double cost = std::min( 1.0, std::max( -1.0, std::log(2.23*G4UniformRand()+0.383)/0.96 ) );
433 G4double sint = std::sqrt(1.0-cost*cost);
434 phi = twopi*G4UniformRand();
435 vec[i]->SetMomentum( pp*sint*std::cos(phi)*MeV,
436 pp*sint*std::sin(phi)*MeV,
437 pp*cost*MeV );
438 vec[i]->Lorentz( *vec[i], pseudoParticle[0] );
439 }
440 }
441 }
442
443 //
444 // Fragmentation of forward and backward clusters
445 //
446
447 currentParticle.SetMomentum( pseudoParticle[3].GetMomentum() );
448 currentParticle.SetTotalEnergy( pseudoParticle[3].GetTotalEnergy() );
449
450 targetParticle.SetMomentum( pseudoParticle[4].GetMomentum() );
451 targetParticle.SetTotalEnergy( pseudoParticle[4].GetTotalEnergy() );
452
453 pseudoParticle[5].SetMomentum( pseudoParticle[3].GetMomentum() * (-1.0) );
454 pseudoParticle[5].SetMass( pseudoParticle[3].GetMass() );
455 pseudoParticle[5].SetTotalEnergy( pseudoParticle[3].GetTotalEnergy() );
456
457 pseudoParticle[6].SetMomentum( pseudoParticle[4].GetMomentum() * (-1.0) );
458 pseudoParticle[6].SetMass( pseudoParticle[4].GetMass() );
459 pseudoParticle[6].SetTotalEnergy( pseudoParticle[4].GetTotalEnergy() );
460
461 G4double wgt;
462 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
463 if( forwardCount > 1 ) // tempV will contain the forward particles
464 {
465 G4FastVector<G4ReactionProduct,256> tempV;
466 tempV.Initialize( forwardCount );
467 G4bool constantCrossSection = true;
468 G4int tempLen = 0;
469 if( currentParticle.GetSide() == 1 )
470 tempV.SetElement( tempLen++, &currentParticle );
471 if( targetParticle.GetSide() == 1 )
472 tempV.SetElement( tempLen++, &targetParticle );
473 for( i=0; i<vecLen; ++i )
474 {
475 if( vec[i]->GetSide() == 1 )
476 {
477 if( tempLen < 18 )
478 tempV.SetElement( tempLen++, vec[i] );
479 else
480 {
481 vec[i]->SetSide( -1 );
482 continue;
483 }
484 }
485 }
486 if( tempLen >= 2 )
487 {
488 wgt = GenerateNBodyEvent( pseudoParticle[3].GetMass()/MeV,
489 constantCrossSection, tempV, tempLen );
490 if( currentParticle.GetSide() == 1 )
491 currentParticle.Lorentz( currentParticle, pseudoParticle[5] );
492 if( targetParticle.GetSide() == 1 )
493 targetParticle.Lorentz( targetParticle, pseudoParticle[5] );
494 for( i=0; i<vecLen; ++i )
495 {
496 if( vec[i]->GetSide() == 1 )vec[i]->Lorentz( *vec[i], pseudoParticle[5] );
497 }
498 }
499 }
500 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
501 if( backwardCount > 1 ) // tempV will contain the backward particles,
502 { // but not those created from the intranuclear cascade
503 G4FastVector<G4ReactionProduct,256> tempV;
504 tempV.Initialize( backwardCount );
505 G4bool constantCrossSection = true;
506 G4int tempLen = 0;
507 if( currentParticle.GetSide() == -1 )
508 tempV.SetElement( tempLen++, &currentParticle );
509 if( targetParticle.GetSide() == -1 )
510 tempV.SetElement( tempLen++, &targetParticle );
511 for( i=0; i<vecLen; ++i )
512 {
513 if( vec[i]->GetSide() == -1 )
514 {
515 if( tempLen < 18 )
516 tempV.SetElement( tempLen++, vec[i] );
517 else
518 {
519 vec[i]->SetSide( -2 );
520 vec[i]->SetKineticEnergy( 0.0 );
521 vec[i]->SetMomentum( 0.0, 0.0, 0.0 );
522 continue;
523 }
524 }
525 }
526 if( tempLen >= 2 )
527 {
528 wgt = GenerateNBodyEvent( pseudoParticle[4].GetMass()/MeV,
529 constantCrossSection, tempV, tempLen );
530 if( currentParticle.GetSide() == -1 )
531 currentParticle.Lorentz( currentParticle, pseudoParticle[6] );
532 if( targetParticle.GetSide() == -1 )
533 targetParticle.Lorentz( targetParticle, pseudoParticle[6] );
534 for( i=0; i<vecLen; ++i )
535 {
536 if( vec[i]->GetSide() == -1 )vec[i]->Lorentz( *vec[i], pseudoParticle[6] );
537 }
538 }
539 }
540
541 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
542 //
543 // Lorentz transformation in lab system
544 //
545 currentParticle.Lorentz( currentParticle, pseudoParticle[2] );
546 targetParticle.Lorentz( targetParticle, pseudoParticle[2] );
547 for( i=0; i<vecLen; ++i ) vec[i]->Lorentz( *vec[i], pseudoParticle[2] );
548
549 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
550 //
551 // sometimes the leading strange particle is lost, set it back
552 //
553 G4bool dum = true;
554 if( leadFlag )
555 {
556 // leadFlag will be true
557 // iff original particle is strange AND if incident particle is strange
558 // leadFlag is set to the incident particle
559 // or
560 // target particle is strange leadFlag is set to the target particle
561
562 if( currentParticle.GetDefinition() == leadingStrangeParticle.GetDefinition() )
563 dum = false;
564 else if( targetParticle.GetDefinition() == leadingStrangeParticle.GetDefinition() )
565 dum = false;
566 else
567 {
568 for( i=0; i<vecLen; ++i )
569 {
570 if( vec[i]->GetDefinition() == leadingStrangeParticle.GetDefinition() )
571 {
572 dum = false;
573 break;
574 }
575 }
576 }
577 if( dum )
578 {
579 G4double leadMass = leadingStrangeParticle.GetMass()/MeV;
580 G4double ekin;
581 if( ((leadMass < protonMass) && (targetParticle.GetMass()/MeV < protonMass)) ||
582 ((leadMass >= protonMass) && (targetParticle.GetMass()/MeV >= protonMass)) )
583 {
584 ekin = targetParticle.GetKineticEnergy()/GeV;
585 pp1 = targetParticle.GetMomentum().mag()/MeV; // old momentum
586 targetParticle.SetDefinition( leadingStrangeParticle.GetDefinition() );
587 targetParticle.SetKineticEnergy( ekin*GeV );
588 pp = targetParticle.GetTotalMomentum()/MeV; // new momentum
589 if( pp1 < 1.0e-3 ) {
590 G4ThreeVector iso = Isotropic(pp);
591 targetParticle.SetMomentum( iso.x(), iso.y(), iso.z() );
592 } else {
593 targetParticle.SetMomentum( targetParticle.GetMomentum() * (pp/pp1) );
594 }
595 targetHasChanged = true;
596 }
597 else
598 {
599 ekin = currentParticle.GetKineticEnergy()/GeV;
600 pp1 = currentParticle.GetMomentum().mag()/MeV;
601 currentParticle.SetDefinition( leadingStrangeParticle.GetDefinition() );
602 currentParticle.SetKineticEnergy( ekin*GeV );
603 pp = currentParticle.GetTotalMomentum()/MeV;
604 if( pp1 < 1.0e-3 ) {
605 G4ThreeVector iso = Isotropic(pp);
606 currentParticle.SetMomentum( iso.x(), iso.y(), iso.z() );
607 } else {
608 currentParticle.SetMomentum( currentParticle.GetMomentum() * (pp/pp1) );
609 }
610 incidentHasChanged = true;
611 }
612 }
613 } // end of if( leadFlag )
614
615 // Get number of final state nucleons and nucleons remaining in
616 // target nucleus
617
618 std::pair<G4int, G4int> finalStateNucleons =
619 GetFinalStateNucleons(originalTarget, vec, vecLen);
620
621 G4int protonsInFinalState = finalStateNucleons.first;
622 G4int neutronsInFinalState = finalStateNucleons.second;
623
624 G4int numberofFinalStateNucleons =
625 protonsInFinalState + neutronsInFinalState;
626
627 if (currentParticle.GetDefinition()->GetBaryonNumber() == 1 &&
628 targetParticle.GetDefinition()->GetBaryonNumber() == 1 &&
629 originalIncident->GetDefinition()->GetPDGMass() <
630 G4Lambda::Lambda()->GetPDGMass())
631 numberofFinalStateNucleons++;
632
633 numberofFinalStateNucleons = std::max(1, numberofFinalStateNucleons);
634
635 G4int PinNucleus = std::max(0,
636 G4int(targetNucleus.GetZ()) - protonsInFinalState);
637 G4int NinNucleus = std::max(0,
638 G4int(targetNucleus.GetN()-targetNucleus.GetZ()) - neutronsInFinalState);
639 //
640 // for various reasons, the energy balance is not sufficient,
641 // check that, energy balance, angle of final system, etc.
642 //
643 pseudoParticle[4].SetMass( mOriginal*GeV );
644 pseudoParticle[4].SetTotalEnergy( etOriginal*GeV );
645 pseudoParticle[4].SetMomentum( 0.0, 0.0, pOriginal*GeV );
646
647 G4ParticleDefinition * aOrgDef = modifiedOriginal.GetDefinition();
648 G4int diff = 0;
649 if(aOrgDef == G4Proton::Proton() || aOrgDef == G4Neutron::Neutron() ) diff = 1;
650 if(numberofFinalStateNucleons == 1) diff = 0;
651 pseudoParticle[5].SetMomentum( 0.0, 0.0, 0.0 );
652 pseudoParticle[5].SetMass( protonMass*(numberofFinalStateNucleons-diff)*MeV);
653 pseudoParticle[5].SetTotalEnergy( protonMass*(numberofFinalStateNucleons-diff)*MeV);
654
655 G4double theoreticalKinetic =
656 pseudoParticle[4].GetTotalEnergy()/GeV + pseudoParticle[5].GetTotalEnergy()/GeV;
657
658 pseudoParticle[6] = pseudoParticle[4] + pseudoParticle[5];
659 pseudoParticle[4].Lorentz( pseudoParticle[4], pseudoParticle[6] );
660 pseudoParticle[5].Lorentz( pseudoParticle[5], pseudoParticle[6] );
661
662 if( vecLen < 16 )
663 {
664 G4ReactionProduct tempR[130];
665 tempR[0] = currentParticle;
666 tempR[1] = targetParticle;
667 for( i=0; i<vecLen; ++i )tempR[i+2] = *vec[i];
668
669 G4FastVector<G4ReactionProduct,256> tempV;
670 tempV.Initialize( vecLen+2 );
671 G4bool constantCrossSection = true;
672 G4int tempLen = 0;
673 for( i=0; i<vecLen+2; ++i )tempV.SetElement( tempLen++, &tempR[i] );
674
675 if( tempLen >= 2 )
676 {
677 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
678 wgt = GenerateNBodyEvent( pseudoParticle[4].GetTotalEnergy()/MeV +
679 pseudoParticle[5].GetTotalEnergy()/MeV,
680 constantCrossSection, tempV, tempLen );
681 if (wgt == -1) {
682 G4double Qvalue = 0;
683 for (i = 0; i < tempLen; i++) Qvalue += tempV[i]->GetMass();
684 wgt = GenerateNBodyEvent( Qvalue/MeV,
685 constantCrossSection, tempV, tempLen );
686 }
687 theoreticalKinetic = 0.0;
688 for( i=0; i<vecLen+2; ++i )
689 {
690 pseudoParticle[7].SetMomentum( tempV[i]->GetMomentum() );
691 pseudoParticle[7].SetMass( tempV[i]->GetMass() );
692 pseudoParticle[7].SetTotalEnergy( tempV[i]->GetTotalEnergy() );
693 pseudoParticle[7].Lorentz( pseudoParticle[7], pseudoParticle[5] );
694 theoreticalKinetic += pseudoParticle[7].GetKineticEnergy()/GeV;
695 }
696 }
697 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
698 }
699 else
700 {
701 theoreticalKinetic -=
702 ( currentParticle.GetMass()/GeV + targetParticle.GetMass()/GeV );
703 for( i=0; i<vecLen; ++i )theoreticalKinetic -= vec[i]->GetMass()/GeV;
704 }
705 G4double simulatedKinetic =
706 currentParticle.GetKineticEnergy()/GeV + targetParticle.GetKineticEnergy()/GeV;
707 for( i=0; i<vecLen; ++i )simulatedKinetic += vec[i]->GetKineticEnergy()/GeV;
708
709 // make sure that kinetic energies are correct
710 // the backward nucleon cluster is not produced within proper kinematics!!!
711
712 if( simulatedKinetic != 0.0 )
713 {
714 wgt = (theoreticalKinetic)/simulatedKinetic;
715 currentParticle.SetKineticEnergy( wgt*currentParticle.GetKineticEnergy() );
716 pp = currentParticle.GetTotalMomentum()/MeV;
717 pp1 = currentParticle.GetMomentum().mag()/MeV;
718 if( pp1 < 0.001*MeV ) {
719 G4ThreeVector iso = Isotropic(pp);
720 currentParticle.SetMomentum( iso.x(), iso.y(), iso.z() );
721 } else {
722 currentParticle.SetMomentum( currentParticle.GetMomentum() * (pp/pp1) );
723 }
724
725 targetParticle.SetKineticEnergy( wgt*targetParticle.GetKineticEnergy() );
726 pp = targetParticle.GetTotalMomentum()/MeV;
727 pp1 = targetParticle.GetMomentum().mag()/MeV;
728 if( pp1 < 0.001*MeV ) {
729 G4ThreeVector iso = Isotropic(pp);
730 targetParticle.SetMomentum( iso.x(), iso.y(), iso.z() );
731 } else {
732 targetParticle.SetMomentum( targetParticle.GetMomentum() * (pp/pp1) );
733 }
734
735 for( i=0; i<vecLen; ++i )
736 {
737 vec[i]->SetKineticEnergy( wgt*vec[i]->GetKineticEnergy() );
738 pp = vec[i]->GetTotalMomentum()/MeV;
739 pp1 = vec[i]->GetMomentum().mag()/MeV;
740 if( pp1 < 0.001 ) {
741 G4ThreeVector iso = Isotropic(pp);
742 vec[i]->SetMomentum( iso.x(), iso.y(), iso.z() );
743 } else {
744 vec[i]->SetMomentum( vec[i]->GetMomentum() * (pp/pp1) );
745 }
746 }
747 }
748 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
749
750 Rotate( numberofFinalStateNucleons, pseudoParticle[4].GetMomentum(),
751 modifiedOriginal, originalIncident, targetNucleus,
752 currentParticle, targetParticle, vec, vecLen );
753
754 // Add black track particles
755 // the total number of particles produced is restricted to 198
756 // this may have influence on very high energies
757
758 if( atomicWeight >= 1.5 )
759 {
760 // npnb is number of proton/neutron black track particles
761 // ndta is the number of deuterons, tritons, and alphas produced
762 // epnb is the kinetic energy available for proton/neutron black track
763 // particles
764 // edta is the kinetic energy available for deuteron/triton/alpha
765 // particles
766
767 G4int npnb = 0;
768 G4int ndta = 0;
769
770 G4double epnb, edta;
771 if (veryForward) {
772 epnb = targetNucleus.GetAnnihilationPNBlackTrackEnergy();
773 edta = targetNucleus.GetAnnihilationDTABlackTrackEnergy();
774 } else {
775 epnb = targetNucleus.GetPNBlackTrackEnergy();
776 edta = targetNucleus.GetDTABlackTrackEnergy();
777 }
778
779 const G4double pnCutOff = 0.001; // GeV
780 const G4double dtaCutOff = 0.001; // GeV
781 const G4double kineticMinimum = 1.e-6;
782 const G4double kineticFactor = -0.005;
783
784 G4double sprob = 0.0; // sprob = probability of self-absorption in
785 // heavy molecules
786 const G4double ekIncident = originalIncident->GetKineticEnergy()/GeV;
787 if( ekIncident >= 5.0 )sprob = std::min( 1.0, 0.6*std::log(ekIncident-4.0) );
788
789 if( epnb >= pnCutOff )
790 {
791 npnb = G4Poisson((1.5+1.25*numberofFinalStateNucleons)*epnb/(epnb+edta));
792 if( numberofFinalStateNucleons + npnb > atomicWeight )
793 npnb = G4int(atomicWeight - numberofFinalStateNucleons);
794 npnb = std::min( npnb, 127-vecLen );
795 }
796 if( edta >= dtaCutOff )
797 {
798 ndta = G4Poisson( (1.5+1.25*numberofFinalStateNucleons)*edta/(epnb+edta) );
799 ndta = std::min( ndta, 127-vecLen );
800 }
801 if (npnb == 0 && ndta == 0) npnb = 1;
802
803 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
804
805 AddBlackTrackParticles(epnb, npnb, edta, ndta, sprob, kineticMinimum,
806 kineticFactor, modifiedOriginal,
807 PinNucleus, NinNucleus, targetNucleus,
808 vec, vecLen );
809 // DEBUGGING --> DumpFrames::DumpFrame(vec, vecLen);
810 }
811
812 //if( centerofmassEnergy <= (4.0+G4UniformRand()) )
813 // MomentumCheck( modifiedOriginal, currentParticle, targetParticle, vec, vecLen );
814 //
815 // calculate time delay for nuclear reactions
816 //
817 if( (atomicWeight >= 1.5) && (atomicWeight <= 230.0) && (ekOriginal <= 0.2) )
818 currentParticle.SetTOF( 1.0-500.0*std::exp(-ekOriginal/0.04)*std::log(G4UniformRand()) );
819 else
820 currentParticle.SetTOF( 1.0 );
821
822 return true;
823}
824
825 /* end of file */
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