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G4LEAntiSigmaMinusInelastic.cc

Last change on this file was 1340, checked in by garnier, 14 years ago
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26	//
27	// $Id: G4LEAntiSigmaMinusInelastic.cc,v 1.11 2006/06/29 20:44:49 gunter Exp $
28	// GEANT4 tag $Name: geant4-09-03-ref-09 $
29	//
30	// Hadronic Process: AntiSigmaMinus Inelastic Process
31	// J.L. Chuma, TRIUMF, 19-Feb-1997
32	// Last modified: 27-Mar-1997
33	// J.P. Wellisch: 25.Apr-97: counter errors removed lines 426, 447
34	// Modified by J.L.Chuma 30-Apr-97: added originalTarget for CalculateMomenta
35
36	#include "G4LEAntiSigmaMinusInelastic.hh"
37	#include "Randomize.hh"
38
39	G4HadFinalState *
40	G4LEAntiSigmaMinusInelastic::ApplyYourself( const G4HadProjectile &aTrack,
41	G4Nucleus &targetNucleus )
42	{
43	const G4HadProjectile *originalIncident = &aTrack;
44	if (originalIncident->GetKineticEnergy()<= 0.1*MeV)
45	{
46	theParticleChange.SetStatusChange(isAlive);
47	theParticleChange.SetEnergyChange(aTrack.GetKineticEnergy());
48	theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
49	return &theParticleChange;
50	}
51	//
52	// create the target particle
53	//
54	G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle();
55
56	if( verboseLevel > 1 )
57	{
58	const G4Material *targetMaterial = aTrack.GetMaterial();
59	G4cout << "G4LEAntiSigmaMinusInelastic::ApplyYourself called" << G4endl;
60	G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy()/MeV << "MeV, ";
61	G4cout << "target material = " << targetMaterial->GetName() << ", ";
62	G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName()
63	<< G4endl;
64	}
65	//
66	// Fermi motion and evaporation
67	// As of Geant3, the Fermi energy calculation had not been Done
68	//
69	G4double ek = originalIncident->GetKineticEnergy()/MeV;
70	G4double amas = originalIncident->GetDefinition()->GetPDGMass()/MeV;
71	G4ReactionProduct modifiedOriginal;
72	modifiedOriginal = *originalIncident;
73
74	G4double tkin = targetNucleus.Cinema( ek );
75	ek += tkin;
76	modifiedOriginal.SetKineticEnergy( ek*MeV );
77	G4double et = ek + amas;
78	G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) );
79	G4double pp = modifiedOriginal.GetMomentum().mag()/MeV;
80	if( pp > 0.0 )
81	{
82	G4ThreeVector momentum = modifiedOriginal.GetMomentum();
83	modifiedOriginal.SetMomentum( momentum * (p/pp) );
84	}
85	//
86	// calculate black track energies
87	//
88	tkin = targetNucleus.EvaporationEffects( ek );
89	ek -= tkin;
90	modifiedOriginal.SetKineticEnergy( ek*MeV );
91	et = ek + amas;
92	p = std::sqrt( std::abs((et-amas)*(et+amas)) );
93	pp = modifiedOriginal.GetMomentum().mag()/MeV;
94	if( pp > 0.0 )
95	{
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	const G4double anni = std::min( 1.3*currentParticle.GetTotalMomentum()/GeV, 0.4 );
113	if( (currentParticle.GetKineticEnergy()/MeV > cutOff) \|\| (G4UniformRand() > anni) )
114	Cascade( vec, vecLen,
115	originalIncident, currentParticle, targetParticle,
116	incidentHasChanged, targetHasChanged, quasiElastic );
117
118	CalculateMomenta( vec, vecLen,
119	originalIncident, originalTarget, modifiedOriginal,
120	targetNucleus, currentParticle, targetParticle,
121	incidentHasChanged, targetHasChanged, quasiElastic );
122
123	SetUpChange( vec, vecLen,
124	currentParticle, targetParticle,
125	incidentHasChanged );
126
127	delete originalTarget;
128	return &theParticleChange;
129	}
130
131	void
132	G4LEAntiSigmaMinusInelastic::Cascade(
133	G4FastVector<G4ReactionProduct,GHADLISTSIZE> &vec,
134	G4int& vecLen,
135	const G4HadProjectile *originalIncident,
136	G4ReactionProduct &currentParticle,
137	G4ReactionProduct &targetParticle,
138	G4bool &incidentHasChanged,
139	G4bool &targetHasChanged,
140	G4bool &quasiElastic )
141	{
142	// derived from original FORTRAN code CASASM by H. Fesefeldt (13-Sep-1987)
143	//
144	// AntiSigmaMinus undergoes interaction with nucleon within a nucleus. Check if it is
145	// energetically possible to produce pions/kaons. In not, assume nuclear excitation
146	// occurs and input particle is degraded in energy. No other particles are produced.
147	// If reaction is possible, find the correct number of pions/protons/neutrons
148	// produced using an interpolation to multiplicity data. Replace some pions or
149	// protons/neutrons by kaons or strange baryons according to the average
150	// multiplicity per Inelastic reaction.
151	//
152	const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass()/MeV;
153	const G4double etOriginal = originalIncident->GetTotalEnergy()/MeV;
154	const G4double pOriginal = originalIncident->GetTotalMomentum()/MeV;
155	const G4double targetMass = targetParticle.GetMass()/MeV;
156	G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
157	targetMass*targetMass +
158	2.0targetMassetOriginal );
159	G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal);
160
161	static G4bool first = true;
162	const G4int numMul = 1200;
163	const G4int numMulA = 400;
164	const G4int numSec = 60;
165	static G4double protmul[numMul], protnorm[numSec]; // proton constants
166	static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
167	static G4double protmulA[numMulA], protnormA[numSec]; // proton constants
168	static G4double neutmulA[numMulA], neutnormA[numSec]; // neutron constants
169	// np = number of pi+, nm = number of pi-, nz = number of pi0
170	G4int counter, nt=0, np=0, nm=0, nz=0;
171	G4double test;
172	const G4double c = 1.25;
173	const G4double b[2] = { 0.7, 0.7 };
174	if( first ) // compute normalization constants, this will only be Done once
175	{
176	first = false;
177	G4int i;
178	for( i=0; i<numMul; ++i )protmul[i] = 0.0;
179	for( i=0; i<numSec; ++i )protnorm[i] = 0.0;
180	counter = -1;
181	for( np=0; np<(numSec/3); ++np )
182	{
183	for( nm=std::max(0,np-2); nm<=np; ++nm )
184	{
185	for( nz=0; nz<numSec/3; ++nz )
186	{
187	if( ++counter < numMul )
188	{
189	nt = np+nm+nz;
190	if( nt>0 && nt<=numSec )
191	{
192	protmul[counter] = Pmltpc(np,nm,nz,nt,b[0],c);
193	protnorm[nt-1] += protmul[counter];
194	}
195	}
196	}
197	}
198	}
199	for( i=0; i<numMul; ++i )neutmul[i] = 0.0;
200	for( i=0; i<numSec; ++i )neutnorm[i] = 0.0;
201	counter = -1;
202	for( np=0; np<numSec/3; ++np )
203	{
204	for( nm=std::max(0,np-1); nm<=(np+1); ++nm )
205	{
206	for( nz=0; nz<numSec/3; ++nz )
207	{
208	if( ++counter < numMul )
209	{
210	nt = np+nm+nz;
211	if( nt>0 && nt<=numSec )
212	{
213	neutmul[counter] = Pmltpc(np,nm,nz,nt,b[1],c);
214	neutnorm[nt-1] += neutmul[counter];
215	}
216	}
217	}
218	}
219	}
220	for( i=0; i<numSec; ++i )
221	{
222	if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
223	if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
224	}
225	//
226	// do the same for annihilation channels
227	//
228	for( i=0; i<numMulA; ++i )protmulA[i] = 0.0;
229	for( i=0; i<numSec; ++i )protnormA[i] = 0.0;
230	counter = -1;
231	for( np=2; np<(numSec/3); ++np )
232	{
233	nm = np-2;
234	for( nz=0; nz<numSec/3; ++nz )
235	{
236	if( ++counter < numMulA )
237	{
238	nt = np+nm+nz;
239	if( nt>1 && nt<=numSec )
240	{
241	protmulA[counter] = Pmltpc(np,nm,nz,nt,b[0],c);
242	protnormA[nt-1] += protmulA[counter];
243	}
244	}
245	}
246	}
247	for( i=0; i<numMulA; ++i )neutmulA[i] = 0.0;
248	for( i=0; i<numSec; ++i )neutnormA[i] = 0.0;
249	counter = -1;
250	for( np=1; np<numSec/3; ++np )
251	{
252	nm = np-1;
253	for( nz=0; nz<numSec/3; ++nz )
254	{
255	if( ++counter < numMulA )
256	{
257	nt = np+nm+nz;
258	if( nt>1 && nt<=numSec )
259	{
260	neutmulA[counter] = Pmltpc(np,nm,nz,nt,b[1],c);
261	neutnormA[nt-1] += neutmulA[counter];
262	}
263	}
264	}
265	}
266	for( i=0; i<numSec; ++i )
267	{
268	if( protnormA[i] > 0.0 )protnormA[i] = 1.0/protnormA[i];
269	if( neutnormA[i] > 0.0 )neutnormA[i] = 1.0/neutnormA[i];
270	}
271	} // end of initialization
272	const G4double expxu = 82.; // upper bound for arg. of exp
273	const G4double expxl = -expxu; // lower bound for arg. of exp
274	G4ParticleDefinition *aNeutron = G4Neutron::Neutron();
275	G4ParticleDefinition *aProton = G4Proton::Proton();
276	G4ParticleDefinition *aPiPlus = G4PionPlus::PionPlus();
277	G4ParticleDefinition *aKaonMinus = G4KaonMinus::KaonMinus();
278	G4ParticleDefinition *aKaonZL = G4KaonZeroLong::KaonZeroLong();
279	G4ParticleDefinition *aKaonPlus = G4KaonPlus::KaonPlus();
280	G4ParticleDefinition *anAntiLambda = G4AntiLambda::AntiLambda();
281	G4ParticleDefinition *anAntiSigmaZero = G4AntiSigmaZero::AntiSigmaZero();
282	const G4double anhl[] = {1.00,1.00,1.00,1.00,1.00,1.00,1.00,1.00,0.97,0.88,
283	0.85,0.81,0.75,0.64,0.64,0.55,0.55,0.45,0.47,0.40,
284	0.39,0.36,0.33,0.10,0.01};
285	G4int iplab = G4int( pOriginal/GeV*10.0 );
286	if( iplab > 9 )iplab = G4int( (pOriginal/GeV- 1.0)*5.0 ) + 10;
287	if( iplab > 14 )iplab = G4int( pOriginal/GeV- 2.0 ) + 15;
288	if( iplab > 23 )iplab = G4int( (pOriginal/GeV-10.0)/10.0 ) + 23;
289	if( iplab > 24 )iplab = 24;
290	if( G4UniformRand() > anhl[iplab] )
291	{
292	if( availableEnergy <= aPiPlus->GetPDGMass()/MeV )
293	{
294	quasiElastic = true;
295	return;
296	}
297	G4double n, anpn;
298	GetNormalizationConstant( availableEnergy, n, anpn );
299	G4double ran = G4UniformRand();
300	G4double dum, excs = 0.0;
301	if( targetParticle.GetDefinition() == aProton )
302	{
303	counter = -1;
304	for( np=0; np<numSec/3 && ran>=excs; ++np )
305	{
306	for( nm=std::max(0,np-2); nm<=np && ran>=excs; ++nm )
307	{
308	for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
309	{
310	if( ++counter < numMul )
311	{
312	nt = np+nm+nz;
313	if( nt>0 && nt<=numSec )
314	{
315	test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)(ntnt)/(n*n) ) ) );
316	dum = (pi/anpn)ntprotmul[counter]protnorm[nt-1]/(2.0n*n);
317	if( std::fabs(dum) < 1.0 )
318	{
319	if( test >= 1.0e-10 )excs += dum*test;
320	}
321	else
322	excs += dum*test;
323	}
324	}
325	}
326	}
327	}
328	if( ran >= excs ) // 3 previous loops continued to the end
329	{
330	quasiElastic = true;
331	return;
332	}
333	np--; nm--; nz--;
334	G4int ncht = std::min( 3, std::max( 1, np-nm+1 ) );
335	switch( ncht )
336	{
337	case 1:
338	break;
339	case 2:
340	if( G4UniformRand() < 0.5 )
341	{
342	targetParticle.SetDefinitionAndUpdateE( aNeutron );
343	targetHasChanged = true;
344	}
345	else
346	{
347	if( G4UniformRand() < 0.5 )
348	currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
349	else
350	currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
351	incidentHasChanged = true;
352	}
353	break;
354	case 3:
355	if( G4UniformRand() < 0.5 )
356	currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
357	else
358	currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
359	incidentHasChanged = true;
360	targetParticle.SetDefinitionAndUpdateE( aNeutron );
361	targetHasChanged = true;
362	break;
363	}
364	}
365	else // target must be a neutron
366	{
367	counter = -1;
368	for( np=0; np<numSec/3 && ran>=excs; ++np )
369	{
370	for( nm=std::max(0,np-1); nm<=(np+1) && ran>=excs; ++nm )
371	{
372	for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
373	{
374	if( ++counter < numMul )
375	{
376	nt = np+nm+nz;
377	if( nt>0 && nt<=numSec )
378	{
379	test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)(ntnt)/(n*n) ) ) );
380	dum = (pi/anpn)ntneutmul[counter]neutnorm[nt-1]/(2.0n*n);
381	if( std::fabs(dum) < 1.0 )
382	{
383	if( test >= 1.0e-10 )excs += dum*test;
384	}
385	else
386	excs += dum*test;
387	}
388	}
389	}
390	}
391	}
392	if( ran >= excs ) // 3 previous loops continued to the end
393	{
394	quasiElastic = true;
395	return;
396	}
397	np--; nm--; nz--;
398	G4int ncht = std::min( 3, std::max( 1, np-nm+2 ) );
399	switch( ncht )
400	{
401	case 1:
402	{
403	targetParticle.SetDefinitionAndUpdateE( aProton );
404	targetHasChanged = true;
405	}
406	break;
407	case 2:
408	if( G4UniformRand() < 0.5 )
409	{
410	if( G4UniformRand() < 0.5 )
411	{
412	currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
413	incidentHasChanged = true;
414	targetParticle.SetDefinitionAndUpdateE( aProton );
415	targetHasChanged = true;
416	}
417	}
418	else
419	{
420	if( G4UniformRand() < 0.5 )
421	{
422	currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
423	incidentHasChanged = true;
424	targetParticle.SetDefinitionAndUpdateE( aProton );
425	targetHasChanged = true;
426	}
427	}
428	break;
429	case 3:
430	if( G4UniformRand() < 0.5 )
431	currentParticle.SetDefinitionAndUpdateE( anAntiLambda );
432	else
433	currentParticle.SetDefinitionAndUpdateE( anAntiSigmaZero );
434	incidentHasChanged = true;
435	break;
436	}
437	}
438	}
439	else // random number <= anhl[iplab]
440	{
441	if( centerofmassEnergy <= aPiPlus->GetPDGMass()/MeV+aKaonPlus->GetPDGMass()/MeV )
442	{
443	quasiElastic = true;
444	return;
445	}
446	G4double n, anpn;
447	GetNormalizationConstant( -centerofmassEnergy, n, anpn );
448	G4double ran = G4UniformRand();
449	G4double dum, excs = 0.0;
450	if( targetParticle.GetDefinition() == aProton )
451	{
452	counter = -1;
453	for( np=2; np<numSec/3 && ran>=excs; ++np )
454	{
455	nm=np-2;
456	for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
457	{
458	if( ++counter < numMulA )
459	{
460	nt = np+nm+nz;
461	if( nt>1 && nt<=numSec )
462	{
463	test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)(ntnt)/(n*n) ) ) );
464	dum = (pi/anpn)ntprotmulA[counter]protnormA[nt-1]/(2.0n*n);
465	if( std::fabs(dum) < 1.0 )
466	{
467	if( test >= 1.0e-10 )excs += dum*test;
468	}
469	else
470	excs += dum*test;
471	}
472	}
473	}
474	}
475	if( ran >= excs ) // 3 previous loops continued to the end
476	{
477	quasiElastic = true;
478	return;
479	}
480	np--; nz--;
481	}
482	else // target must be a neutron
483	{
484	counter = -1;
485	for( np=1; np<numSec/3 && ran>=excs; ++np )
486	{
487	nm = np-1;
488	for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
489	{
490	if( ++counter < numMulA )
491	{
492	nt = np+nm+nz;
493	if( nt>1 && nt<=numSec )
494	{
495	test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)(ntnt)/(n*n) ) ) );
496	dum = (pi/anpn)ntneutmulA[counter]neutnormA[nt-1]/(2.0n*n);
497	if( std::fabs(dum) < 1.0 )
498	{
499	if( test >= 1.0e-10 )excs += dum*test;
500	}
501	else
502	excs += dum*test;
503	}
504	}
505	}
506	}
507	if( ran >= excs ) // 3 previous loops continued to the end
508	{
509	quasiElastic = true;
510	return;
511	}
512	np--; nz--;
513	}
514	if( nz > 0 )
515	{
516	if( nm > 0 )
517	{
518	if( G4UniformRand() < 0.5 )
519	{
520	vec.Initialize( 1 );
521	G4ReactionProduct *p = new G4ReactionProduct;
522	p->SetDefinition( aKaonMinus );
523	(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
524	vec.SetElement( vecLen++, p );
525	--nm;
526	}
527	else // random number >= 0.5
528	{
529	vec.Initialize( 1 );
530	G4ReactionProduct *p = new G4ReactionProduct;
531	p->SetDefinition( aKaonZL );
532	(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
533	vec.SetElement( vecLen++, p );
534	--nz;
535	}
536	}
537	else // nm == 0
538	{
539	vec.Initialize( 1 );
540	G4ReactionProduct *p = new G4ReactionProduct;
541	p->SetDefinition( aKaonZL );
542	(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
543	vec.SetElement( vecLen++, p );
544	--nz;
545	}
546	}
547	else // nz == 0
548	{
549	if( nm > 0 )
550	{
551	vec.Initialize( 1 );
552	G4ReactionProduct *p = new G4ReactionProduct;
553	p->SetDefinition( aKaonMinus );
554	(G4UniformRand() < 0.5) ? p->SetSide( -1 ) : p->SetSide( 1 );
555	vec.SetElement( vecLen++, p );
556	--nm;
557	}
558	}
559	currentParticle.SetMass( 0.0 );
560	targetParticle.SetMass( 0.0 );
561	}
562	SetUpPions( np, nm, nz, vec, vecLen );
563	return;
564	}
565
566	/* end of file */
567

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