source: trunk/source/processes/hadronic/models/high_energy/src/G4HEKaonZeroInelastic.cc@ 1201

Last change on this file since 1201 was 1196, checked in by garnier, 16 years ago

update CVS release candidate geant4.9.3.01
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25//
26//
27// $Id: G4HEKaonZeroInelastic.cc,v 1.15 2008/03/17 20:49:17 dennis Exp $
28// GEANT4 tag $Name: geant4-09-03-cand-01 $
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 "G4HEKaonZeroInelastic.hh"
46
47G4HadFinalState * G4HEKaonZeroInelastic::
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 << "GHEKaonZeroInelastic: incident energy < 1 GeV" << G4endl;;
69 }
70 if(verboseLevel > 1)
71 {
72 G4cout << "G4HEKaonZeroInelastic::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 FirstIntInCasKaonZero(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
195G4HEKaonZeroInelastic::FirstIntInCasKaonZero( G4bool &inElastic,
196 const G4double availableEnergy,
197 G4HEVector pv[],
198 G4int &vecLen,
199 G4HEVector incidentParticle,
200 G4HEVector targetParticle,
201 const G4double atomicWeight)
202
203// Kaon0 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] =
257 pmltpc(np,nm,nz,nt,protb,c) ;
258 protnorm[nt-1] += protmul[counter];
259 }
260 }
261 }
262 }
263 }
264 for( i=0; i<numMul; i++ )neutmul[i] = 0.0;
265 for( i=0; i<numSec; i++ )neutnorm[i] = 0.0;
266 counter = -1;
267 for( np=0; np<numSec/3; np++ )
268 {
269 for( nm=np; nm<=(np+2); nm++ )
270 {
271 for( nz=0; nz<numSec/3; nz++ )
272 {
273 if( ++counter < numMul )
274 {
275 nt = np+nm+nz;
276 if( (nt>0) && (nt<=numSec) )
277 {
278 neutmul[counter] =
279 pmltpc(np,nm,nz,nt,neutb,c);
280 neutnorm[nt-1] += neutmul[counter];
281 }
282 }
283 }
284 }
285 }
286 for( i=0; i<numSec; i++ )
287 {
288 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
289 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
290 }
291 } // end of initialization
292
293
294 // initialize the first two places
295 // the same as beam and target
296 pv[0] = incidentParticle;
297 pv[1] = targetParticle;
298 vecLen = 2;
299
300 if( !inElastic )
301 { // quasi-elastic scattering, no pions produced
302 if( targetCode == protonCode )
303 {
304 G4double cech[] = {0.33,0.27,0.29,0.31,0.27,0.18,0.13,0.10,0.09,0.07};
305 G4int iplab = G4int( std::min( 9.0, incidentTotalMomentum*5. ) );
306 if( G4UniformRand() < cech[iplab]/std::pow(atomicWeight,0.42) )
307 { // charge exchange K+ n -> K0 p
308 pv[0] = KaonPlus;
309 pv[1] = Neutron;
310 }
311 }
312 return;
313 }
314 else if (availableEnergy <= PionPlus.getMass())
315 return;
316
317 // inelastic scattering
318
319 np = 0, nm = 0, nz = 0;
320 G4double eab = availableEnergy;
321 G4int ieab = G4int( eab*5.0 );
322
323 G4double supp[] = {0., 0.4, 0.55, 0.65, 0.75, 0.82, 0.86, 0.90, 0.94, 0.98};
324 if( (ieab <= 9) && (G4UniformRand() >= supp[ieab]) )
325 {
326// suppress high multiplicity events at low momentum
327// only one additional pion will be produced
328 G4double w0, wp, wm, wt, ran;
329 if( targetCode == neutronCode ) // target is a neutron
330 {
331 w0 = - sqr(1.+protb)/(2.*c*c);
332 w0 = std::exp(w0);
333 wm = - sqr(-1.+protb)/(2.*c*c);
334 wm = std::exp(wm);
335 w0 = w0/2.;
336 wm = wm*1.5;
337 if( G4UniformRand() < w0/(w0+wm) ) { np = 0; nm = 0; nz = 1; }
338 else
339 { np = 0; nm = 1; nz = 0; }
340 }
341 else
342 { // target is a proton
343 w0 = -sqr(1.+neutb)/(2.*c*c);
344 wp = w0 = std::exp(w0);
345 wm = -sqr(-1.+neutb)/(2.*c*c);
346 wm = std::exp(wm);
347 wt = w0+wp+wm;
348 wp = w0+wp;
349 ran = G4UniformRand();
350 if( ran < w0/wt)
351 { np = 0; nm = 0; nz = 1; }
352 else if( ran < wp/wt)
353 { np = 1; nm = 0; nz = 0; }
354 else
355 { np = 0; nm = 1; nz = 0; }
356 }
357 }
358 else
359 {
360// number of total particles vs. centre of mass Energy - 2*proton mass
361
362 G4double aleab = std::log(availableEnergy);
363 G4double n = 3.62567+aleab*(0.665843+aleab*(0.336514
364 + aleab*(0.117712+0.0136912*aleab))) - 2.0;
365
366// normalization constant for kno-distribution.
367// calculate first the sum of all constants, check for numerical problems.
368 G4double test, dum, anpn = 0.0;
369
370 for (nt=1; nt<=numSec; nt++) {
371 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
372 dum = pi*nt/(2.0*n*n);
373 if (std::fabs(dum) < 1.0) {
374 if( test >= 1.0e-10 )anpn += dum*test;
375 } else {
376 anpn += dum*test;
377 }
378 }
379
380 G4double ran = G4UniformRand();
381 G4double excs = 0.0;
382 if( targetCode == protonCode )
383 {
384 counter = -1;
385 for( np=0; np<numSec/3; np++ )
386 {
387 for( nm=std::max(0,np-1); nm<=(np+1); nm++ )
388 {
389 for (nz=0; nz<numSec/3; nz++) {
390 if (++counter < numMul) {
391 nt = np+nm+nz;
392 if ( (nt>0) && (nt<=numSec) ) {
393 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
394 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
395 if (std::fabs(dum) < 1.0) {
396 if( test >= 1.0e-10 )excs += dum*test;
397 } else {
398 excs += dum*test;
399 }
400 if (ran < excs) goto outOfLoop; //----------------------->
401 }
402 }
403 }
404 }
405 }
406
407 // 3 previous loops continued to the end
408 inElastic = false; // quasi-elastic scattering
409 return;
410 }
411 else
412 { // target must be a neutron
413 counter = -1;
414 for( np=0; np<numSec/3; np++ )
415 {
416 for( nm=np; nm<=(np+2); nm++ )
417 {
418 for (nz=0; nz<numSec/3; nz++) {
419 if (++counter < numMul) {
420 nt = np+nm+nz;
421 if ( (nt>=1) && (nt<=numSec) ) {
422 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
423 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
424 if (std::fabs(dum) < 1.0) {
425 if( test >= 1.0e-10 )excs += dum*test;
426 } else {
427 excs += dum*test;
428 }
429 if (ran < excs) goto outOfLoop; // -------------------------->
430 }
431 }
432 }
433 }
434 }
435 // 3 previous loops continued to the end
436 inElastic = false; // quasi-elastic scattering.
437 return;
438 }
439 }
440 outOfLoop: // <-----------------------------------------------
441
442 if( targetCode == neutronCode)
443 {
444 if( np == nm)
445 {
446 }
447 else if (np == (nm-1))
448 {
449 if( G4UniformRand() < 0.5)
450 {
451 pv[0] = KaonPlus;
452 }
453 else
454 {
455 pv[1] = Proton;
456 }
457 }
458 else
459 {
460 pv[0] = KaonPlus;
461 pv[1] = Proton;
462 }
463 }
464 else
465 {
466 if( np == nm )
467 {
468 if( G4UniformRand() < 0.25)
469 {
470 pv[0] = KaonPlus;
471 pv[1] = Neutron;
472 }
473 else
474 {
475 }
476 }
477 else if ( np == (nm+1))
478 {
479 pv[1] = Neutron;
480 }
481 else
482 {
483 pv[0] = KaonPlus;
484 }
485 }
486
487
488 nt = np + nm + nz;
489 while ( nt > 0)
490 {
491 G4double ran = G4UniformRand();
492 if ( ran < (G4double)np/nt)
493 {
494 if( np > 0 )
495 { pv[vecLen++] = PionPlus;
496 np--;
497 }
498 }
499 else if ( ran < (G4double)(np+nm)/nt)
500 {
501 if( nm > 0 )
502 {
503 pv[vecLen++] = PionMinus;
504 nm--;
505 }
506 }
507 else
508 {
509 if( nz > 0 )
510 {
511 pv[vecLen++] = PionZero;
512 nz--;
513 }
514 }
515 nt = np + nm + nz;
516 }
517 if (verboseLevel > 1)
518 {
519 G4cout << "Particles produced: " ;
520 G4cout << pv[0].getName() << " " ;
521 G4cout << pv[1].getName() << " " ;
522 for (i=2; i < vecLen; i++)
523 {
524 G4cout << pv[i].getName() << " " ;
525 }
526 G4cout << G4endl;
527 }
528 return; }
529
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