source: trunk/source/processes/hadronic/models/high_energy/src/G4HESigmaMinusInelastic.cc@ 1036

Last change on this file since 1036 was 1007, checked in by garnier, 17 years ago

update to geant4.9.2
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25//
26//
27// $Id: G4HESigmaMinusInelastic.cc,v 1.15 2008/03/17 20:49:17 dennis Exp $
28// GEANT4 tag $Name: geant4-09-02 $
29//
30//
31
32#include "globals.hh"
33#include "G4ios.hh"
34
35//
36// G4 Process: Gheisha High Energy Collision model.
37// This includes the high energy cascading model, the two-body-resonance model
38// and the low energy two-body model. Not included are the low energy stuff like
39// nuclear reactions, nuclear fission without any cascading and all processes for
40// particles at rest.
41// First work done by J.L.Chuma and F.W.Jones, TRIUMF, June 96.
42// H. Fesefeldt, RWTH-Aachen, 23-October-1996
43// Last modified: 29-July-1998
44
45#include "G4HESigmaMinusInelastic.hh"
46
47G4HadFinalState * G4HESigmaMinusInelastic::
48ApplyYourself( const G4HadProjectile &aTrack, G4Nucleus &targetNucleus )
49 {
50 G4HEVector * pv = new G4HEVector[MAXPART];
51 const G4HadProjectile *aParticle = &aTrack;
52// G4DynamicParticle *originalTarget = targetNucleus.ReturnTargetParticle();
53 const G4double A = targetNucleus.GetN();
54 const G4double Z = targetNucleus.GetZ();
55 G4HEVector incidentParticle(aParticle);
56
57 G4double atomicNumber = Z;
58 G4double atomicWeight = A;
59
60 G4int incidentCode = incidentParticle.getCode();
61 G4double incidentMass = incidentParticle.getMass();
62 G4double incidentTotalEnergy = incidentParticle.getEnergy();
63 G4double incidentTotalMomentum = incidentParticle.getTotalMomentum();
64 G4double incidentKineticEnergy = incidentTotalEnergy - incidentMass;
65
66 if(incidentKineticEnergy < 1.)
67 {
68 G4cout << "GHESigmaMinusInelastic: incident energy < 1 GeV" << G4endl;
69 }
70 if(verboseLevel > 1)
71 {
72 G4cout << "G4HESigmaMinusInelastic::ApplyYourself" << G4endl;
73 G4cout << "incident particle " << incidentParticle.getName()
74 << "mass " << incidentMass
75 << "kinetic energy " << incidentKineticEnergy
76 << G4endl;
77 G4cout << "target material with (A,Z) = ("
78 << atomicWeight << "," << atomicNumber << ")" << G4endl;
79 }
80
81 G4double inelasticity = NuclearInelasticity(incidentKineticEnergy,
82 atomicWeight, atomicNumber);
83 if(verboseLevel > 1)
84 G4cout << "nuclear inelasticity = " << inelasticity << G4endl;
85
86 incidentKineticEnergy -= inelasticity;
87
88 G4double excitationEnergyGNP = 0.;
89 G4double excitationEnergyDTA = 0.;
90
91 G4double excitation = NuclearExcitation(incidentKineticEnergy,
92 atomicWeight, atomicNumber,
93 excitationEnergyGNP,
94 excitationEnergyDTA);
95 if(verboseLevel > 1)
96 G4cout << "nuclear excitation = " << excitation << excitationEnergyGNP
97 << excitationEnergyDTA << G4endl;
98
99
100 incidentKineticEnergy -= excitation;
101 incidentTotalEnergy = incidentKineticEnergy + incidentMass;
102 incidentTotalMomentum = std::sqrt( (incidentTotalEnergy-incidentMass)
103 *(incidentTotalEnergy+incidentMass));
104
105
106 G4HEVector targetParticle;
107 if(G4UniformRand() < atomicNumber/atomicWeight)
108 {
109 targetParticle.setDefinition("Proton");
110 }
111 else
112 {
113 targetParticle.setDefinition("Neutron");
114 }
115
116 G4double targetMass = targetParticle.getMass();
117 G4double centerOfMassEnergy = std::sqrt( incidentMass*incidentMass + targetMass*targetMass
118 + 2.0*targetMass*incidentTotalEnergy);
119 G4double availableEnergy = centerOfMassEnergy - targetMass - incidentMass;
120
121 // this was the meaning of inElastic in the
122 // original Gheisha stand-alone version.
123// G4bool inElastic = InElasticCrossSectionInFirstInt
124// (availableEnergy, incidentCode, incidentTotalMomentum);
125 // by unknown reasons, it has been replaced
126 // to the following code in Geant???
127 G4bool inElastic = true;
128// if (G4UniformRand() < elasticCrossSection/totalCrossSection) inElastic = false;
129
130 vecLength = 0;
131
132 if(verboseLevel > 1)
133 G4cout << "ApplyYourself: CallFirstIntInCascade for particle "
134 << incidentCode << G4endl;
135
136 G4bool successful = false;
137
138 if(inElastic || (!inElastic && atomicWeight < 1.5))
139 {
140 FirstIntInCasSigmaMinus(inElastic, availableEnergy, pv, vecLength,
141 incidentParticle, targetParticle, atomicWeight);
142
143 if(verboseLevel > 1)
144 G4cout << "ApplyYourself::StrangeParticlePairProduction" << G4endl;
145
146
147 if ((vecLength > 0) && (availableEnergy > 1.))
148 StrangeParticlePairProduction( availableEnergy, centerOfMassEnergy,
149 pv, vecLength,
150 incidentParticle, targetParticle);
151 HighEnergyCascading( successful, pv, vecLength,
152 excitationEnergyGNP, excitationEnergyDTA,
153 incidentParticle, targetParticle,
154 atomicWeight, atomicNumber);
155 if (!successful)
156 HighEnergyClusterProduction( successful, pv, vecLength,
157 excitationEnergyGNP, excitationEnergyDTA,
158 incidentParticle, targetParticle,
159 atomicWeight, atomicNumber);
160 if (!successful)
161 MediumEnergyCascading( successful, pv, vecLength,
162 excitationEnergyGNP, excitationEnergyDTA,
163 incidentParticle, targetParticle,
164 atomicWeight, atomicNumber);
165
166 if (!successful)
167 MediumEnergyClusterProduction( successful, pv, vecLength,
168 excitationEnergyGNP, excitationEnergyDTA,
169 incidentParticle, targetParticle,
170 atomicWeight, atomicNumber);
171 if (!successful)
172 QuasiElasticScattering( successful, pv, vecLength,
173 excitationEnergyGNP, excitationEnergyDTA,
174 incidentParticle, targetParticle,
175 atomicWeight, atomicNumber);
176 }
177 if (!successful)
178 {
179 ElasticScattering( successful, pv, vecLength,
180 incidentParticle,
181 atomicWeight, atomicNumber);
182 }
183
184 if (!successful)
185 {
186 G4cout << "GHEInelasticInteraction::ApplyYourself fails to produce final state particles" << G4endl;
187 }
188 FillParticleChange(pv, vecLength);
189 delete [] pv;
190 theParticleChange.SetStatusChange(stopAndKill);
191 return & theParticleChange;
192 }
193
194void
195G4HESigmaMinusInelastic::FirstIntInCasSigmaMinus( G4bool &inElastic,
196 const G4double availableEnergy,
197 G4HEVector pv[],
198 G4int &vecLen,
199 G4HEVector incidentParticle,
200 G4HEVector targetParticle,
201 const G4double atomicWeight)
202
203// Sigma- undergoes interaction with nucleon within a nucleus. Check if it is
204// energetically possible to produce pions/kaons. In not, assume nuclear excitation
205// occurs and input particle is degraded in energy. No other particles are produced.
206// If reaction is possible, find the correct number of pions/protons/neutrons
207// produced using an interpolation to multiplicity data. Replace some pions or
208// protons/neutrons by kaons or strange baryons according to the average
209// multiplicity per inelastic reaction.
210
211 {
212 static const G4double expxu = std::log(MAXFLOAT); // upper bound for arg. of exp
213 static const G4double expxl = -expxu; // lower bound for arg. of exp
214
215 static const G4double protb = 0.7;
216 static const G4double neutb = 0.7;
217 static const G4double c = 1.25;
218
219 static const G4int numMul = 1200;
220 static const G4int numSec = 60;
221
222 G4int neutronCode = Neutron.getCode();
223 G4int protonCode = Proton.getCode();
224
225 G4int targetCode = targetParticle.getCode();
226// G4double incidentMass = incidentParticle.getMass();
227// G4double incidentEnergy = incidentParticle.getEnergy();
228 G4double incidentTotalMomentum = incidentParticle.getTotalMomentum();
229
230 static G4bool first = true;
231 static G4double protmul[numMul], protnorm[numSec]; // proton constants
232 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
233
234 // misc. local variables
235 // np = number of pi+, nm = number of pi-, nz = number of pi0
236
237 G4int i, counter, nt, np, nm, nz;
238
239 if( first )
240 { // compute normalization constants, this will only be done once
241 first = false;
242 for( i=0; i<numMul; i++ )protmul[i] = 0.0;
243 for( i=0; i<numSec; i++ )protnorm[i] = 0.0;
244 counter = -1;
245 for( np=0; np<(numSec/3); np++ )
246 {
247 for( nm=std::max(0,np-1); nm<=(np+1); nm++ )
248 {
249 for( nz=0; nz<numSec/3; nz++ )
250 {
251 if( ++counter < numMul )
252 {
253 nt = np+nm+nz;
254 if( (nt>0) && (nt<=numSec) )
255 {
256 protmul[counter] = pmltpc(np,nm,nz,nt,protb,c);
257 protnorm[nt-1] += protmul[counter];
258 }
259 }
260 }
261 }
262 }
263 for( i=0; i<numMul; i++ )neutmul[i] = 0.0;
264 for( i=0; i<numSec; i++ )neutnorm[i] = 0.0;
265 counter = -1;
266 for( np=0; np<numSec/3; np++ )
267 {
268 for( nm=np; nm<=(np+2); nm++ )
269 {
270 for( nz=0; nz<numSec/3; nz++ )
271 {
272 if( ++counter < numMul )
273 {
274 nt = np+nm+nz;
275 if( (nt>0) && (nt<=numSec) )
276 {
277 neutmul[counter] = pmltpc(np,nm,nz,nt,neutb,c);
278 neutnorm[nt-1] += neutmul[counter];
279 }
280 }
281 }
282 }
283 }
284 for( i=0; i<numSec; i++ )
285 {
286 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
287 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
288 }
289 } // end of initialization
290
291
292 // initialize the first two places
293 // the same as beam and target
294 pv[0] = incidentParticle;
295 pv[1] = targetParticle;
296 vecLen = 2;
297
298 if( !inElastic )
299 { // quasi-elastic scattering, no pions produced
300 G4double cech[] = {0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.06, 0.04, 0.005, 0.};
301 G4int iplab = G4int( std::min( 9.0, incidentTotalMomentum*2.5 ) );
302 if( G4UniformRand() < cech[iplab]/std::pow(atomicWeight,0.42) )
303 {
304 G4double ran = G4UniformRand();
305 if( targetCode == neutronCode)
306 {
307 pv[0] = Neutron;
308 pv[1] = SigmaMinus;
309 }
310 else
311 {
312 if(ran < 0.2)
313 {
314 pv[0] = SigmaZero;
315 pv[1] = Neutron;
316 }
317 else if(ran < 0.4)
318 {
319 pv[0] = Lambda;
320 pv[1] = Neutron;
321 }
322 else if(ran < 0.6)
323 {
324 pv[0] = Proton;
325 pv[1] = SigmaMinus;
326 }
327 else if(ran < 0.8)
328 {
329 pv[0] = Neutron;
330 pv[1] = SigmaZero;
331 }
332 else
333 {
334 pv[0] = Neutron;
335 pv[1] = Lambda;
336 }
337 }
338 }
339 return;
340 }
341 else if (availableEnergy <= PionPlus.getMass())
342 return;
343
344 // inelastic scattering
345
346 np = 0, nm = 0, nz = 0;
347
348 // number of total particles vs. centre of mass Energy - 2*proton mass
349
350 G4double aleab = std::log(availableEnergy);
351 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
352 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
353
354 // normalization constant for kno-distribution.
355 // calculate first the sum of all constants, check for numerical problems.
356 G4double test, dum, anpn = 0.0;
357
358 for (nt=1; nt<=numSec; nt++) {
359 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
360 dum = pi*nt/(2.0*n*n);
361 if (std::fabs(dum) < 1.0) {
362 if (test >= 1.0e-10) anpn += dum*test;
363 } else {
364 anpn += dum*test;
365 }
366 }
367
368 G4double ran = G4UniformRand();
369 G4double excs = 0.0;
370 if( targetCode == protonCode )
371 {
372 counter = -1;
373 for (np=0; np<numSec/3; np++) {
374 for (nm=std::max(0,np-1); nm<=(np+1); nm++) {
375 for (nz=0; nz<numSec/3; nz++) {
376 if (++counter < numMul) {
377 nt = np+nm+nz;
378 if ( (nt>0) && (nt<=numSec) ) {
379 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
380 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
381 if (std::fabs(dum) < 1.0) {
382 if( test >= 1.0e-10 )excs += dum*test;
383 } else {
384 excs += dum*test;
385 }
386 if (ran < excs) goto outOfLoop; //----------------------->
387 }
388 }
389 }
390 }
391 }
392
393 // 3 previous loops continued to the end
394 inElastic = false; // quasi-elastic scattering
395 return;
396 }
397 else
398 { // target must be a neutron
399 counter = -1;
400 for (np=0; np<numSec/3; np++) {
401 for (nm=np; nm<=(np+2); nm++) {
402 for (nz=0; nz<numSec/3; nz++) {
403 if (++counter < numMul) {
404 nt = np+nm+nz;
405 if ( (nt>=1) && (nt<=numSec) ) {
406 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
407 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
408 if (std::fabs(dum) < 1.0) {
409 if( test >= 1.0e-10 )excs += dum*test;
410 } else {
411 excs += dum*test;
412 }
413 if (ran < excs) goto outOfLoop; // -------------------->
414 }
415 }
416 }
417 }
418 }
419 // 3 previous loops continued to the end
420 inElastic = false; // quasi-elastic scattering.
421 return;
422 }
423
424 outOfLoop: // <-------------------------------------------
425
426 ran = G4UniformRand();
427 if( targetCode == neutronCode)
428 {
429 if( np == nm)
430 {
431 }
432 else if (np == (nm-1))
433 {
434 if( ran < 0.25)
435 {
436 pv[0] = SigmaZero;
437 }
438 else if (ran < 0.5)
439 {
440 pv[0] = Lambda;
441 }
442 else
443 {
444 pv[1] = Proton;
445 }
446 }
447 else
448 {
449 if(ran < 0.5)
450 {
451 pv[0] = SigmaZero;
452 pv[1] = Proton;
453 }
454 else
455 {
456 pv[0] = Lambda;
457 pv[1] = Proton;
458 }
459 }
460 }
461 else
462 {
463 if (np == nm)
464 {
465 if (ran < 0.5)
466 {
467 }
468 else if (ran < 0.75)
469 {
470 pv[0] = SigmaZero;
471 pv[1] = Neutron;
472 }
473 else
474 {
475 pv[0] = Lambda;
476 pv[1] = Neutron;
477 }
478 }
479 else if (np == (nm+1))
480 {
481 pv[1] = Neutron;
482 }
483 else
484 {
485 if (ran < 0.5)
486 {
487 pv[0] = SigmaZero;
488 }
489 else
490 {
491 pv[0] = Lambda;
492 }
493 }
494 }
495
496
497 nt = np + nm + nz;
498 while ( nt > 0)
499 {
500 G4double ran = G4UniformRand();
501 if ( ran < (G4double)np/nt)
502 {
503 if( np > 0 )
504 { pv[vecLen++] = PionPlus;
505 np--;
506 }
507 }
508 else if ( ran < (G4double)(np+nm)/nt)
509 {
510 if( nm > 0 )
511 {
512 pv[vecLen++] = PionMinus;
513 nm--;
514 }
515 }
516 else
517 {
518 if( nz > 0 )
519 {
520 pv[vecLen++] = PionZero;
521 nz--;
522 }
523 }
524 nt = np + nm + nz;
525 }
526 if (verboseLevel > 1)
527 {
528 G4cout << "Particles produced: " ;
529 G4cout << pv[0].getCode() << " " ;
530 G4cout << pv[1].getCode() << " " ;
531 for (i=2; i < vecLen; i++)
532 {
533 G4cout << pv[i].getCode() << " " ;
534 }
535 G4cout << G4endl;
536 }
537 return;
538 }
539
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