source: trunk/source/processes/hadronic/models/low_energy/src/G4LEKaonMinusInelastic.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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27// $Id: G4LEKaonMinusInelastic.cc,v 1.15 2006/06/29 20:44:59 gunter Exp $
28// GEANT4 tag $Name: geant4-09-03-cand-01 $
29//
30 // Hadronic Process: Low Energy KaonMinus Inelastic Process
31 // J.L. Chuma, TRIUMF, 12-Feb-1997
32 // Last modified: 27-Mar-1997
33 // J.P.Wellisch 23-Apr-97: bug-hunting (missing initialization of np,nm,nz fixed)
34 // Modified by J.L.Chuma 30-Apr-97: added originalTarget for CalculateMomenta
35
36#include "G4LEKaonMinusInelastic.hh"
37 #include "Randomize.hh"
38
39 G4HadFinalState *
40 G4LEKaonMinusInelastic::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 G4ReactionProduct targetParticle( originalTarget->GetDefinition() );
56
57 if( verboseLevel > 1 )
58 {
59 const G4Material *targetMaterial = aTrack.GetMaterial();
60 G4cout << "G4LEKaonMinusInelastic::ApplyYourself called" << G4endl;
61 G4cout << "kinetic energy = " << originalIncident->GetKineticEnergy() << "MeV, ";
62 G4cout << "target material = " << targetMaterial->GetName() << ", ";
63 G4cout << "target particle = " << originalTarget->GetDefinition()->GetParticleName()
64 << G4endl;
65 }
66 G4ReactionProduct currentParticle( const_cast<G4ParticleDefinition *>(originalIncident->GetDefinition()) );
67 currentParticle.SetMomentum( originalIncident->Get4Momentum().vect() );
68 currentParticle.SetKineticEnergy( originalIncident->GetKineticEnergy() );
69
70 // Fermi motion and evaporation
71 // As of Geant3, the Fermi energy calculation had not been Done
72
73 G4double ek = originalIncident->GetKineticEnergy();
74 G4double amas = originalIncident->GetDefinition()->GetPDGMass();
75
76 G4double tkin = targetNucleus.Cinema( ek );
77 ek += tkin;
78 currentParticle.SetKineticEnergy( ek );
79 G4double et = ek + amas;
80 G4double p = std::sqrt( std::abs((et-amas)*(et+amas)) );
81 G4double pp = currentParticle.GetMomentum().mag();
82 if( pp > 0.0 )
83 {
84 G4ThreeVector momentum = currentParticle.GetMomentum();
85 currentParticle.SetMomentum( momentum * (p/pp) );
86 }
87
88 // calculate black track energies
89
90 tkin = targetNucleus.EvaporationEffects( ek );
91 ek -= tkin;
92 currentParticle.SetKineticEnergy( ek );
93 et = ek + amas;
94 p = std::sqrt( std::abs((et-amas)*(et+amas)) );
95 pp = currentParticle.GetMomentum().mag();
96 if( pp > 0.0 )
97 {
98 G4ThreeVector momentum = currentParticle.GetMomentum();
99 currentParticle.SetMomentum( momentum * (p/pp) );
100 }
101
102 G4ReactionProduct modifiedOriginal = currentParticle;
103
104 currentParticle.SetSide( 1 ); // incident always goes in forward hemisphere
105 targetParticle.SetSide( -1 ); // target always goes in backward hemisphere
106 G4bool incidentHasChanged = false;
107 G4bool targetHasChanged = false;
108 G4bool quasiElastic = false;
109 G4FastVector<G4ReactionProduct,GHADLISTSIZE> vec; // vec will contain the secondary particles
110 G4int vecLen = 0;
111 vec.Initialize( 0 );
112
113 const G4double cutOff = 0.1*MeV;
114 if( currentParticle.GetKineticEnergy() > cutOff )
115 Cascade( vec, vecLen,
116 originalIncident, currentParticle, targetParticle,
117 incidentHasChanged, targetHasChanged, quasiElastic );
118
119 CalculateMomenta( vec, vecLen,
120 originalIncident, originalTarget, modifiedOriginal,
121 targetNucleus, currentParticle, targetParticle,
122 incidentHasChanged, targetHasChanged, quasiElastic );
123
124 SetUpChange( vec, vecLen,
125 currentParticle, targetParticle,
126 incidentHasChanged );
127
128 delete originalTarget;
129 return &theParticleChange;
130 }
131
132 void
133 G4LEKaonMinusInelastic::Cascade(
134 G4FastVector<G4ReactionProduct,GHADLISTSIZE> &vec,
135 G4int& vecLen,
136 const G4HadProjectile *originalIncident,
137 G4ReactionProduct &currentParticle,
138 G4ReactionProduct &targetParticle,
139 G4bool &incidentHasChanged,
140 G4bool &targetHasChanged,
141 G4bool &quasiElastic )
142 {
143 // derived from original FORTRAN code CASKM by H. Fesefeldt (13-Sep-1987)
144 //
145 // K- undergoes interaction with nucleon within a nucleus. Check if it is
146 // energetically possible to produce pions/kaons. In not, assume nuclear excitation
147 // occurs and input particle is degraded in energy. No other particles are produced.
148 // If reaction is possible, find the correct number of pions/protons/neutrons
149 // produced using an interpolation to multiplicity data. Replace some pions or
150 // protons/neutrons by kaons or strange baryons according to the average
151 // multiplicity per Inelastic reaction.
152 //
153 const G4double mOriginal = originalIncident->GetDefinition()->GetPDGMass();
154 const G4double etOriginal = originalIncident->GetTotalEnergy();
155 const G4double pOriginal = originalIncident->GetTotalMomentum();
156 const G4double targetMass = targetParticle.GetMass();
157 G4double centerofmassEnergy = std::sqrt( mOriginal*mOriginal +
158 targetMass*targetMass +
159 2.0*targetMass*etOriginal );
160 G4double availableEnergy = centerofmassEnergy-(targetMass+mOriginal);
161
162 static G4bool first = true;
163 const G4int numMul = 1200;
164 const G4int numSec = 60;
165 static G4double protmul[numMul], protnorm[numSec]; // proton constants
166 static G4double neutmul[numMul], neutnorm[numSec]; // neutron constants
167 // np = number of pi+, nm = number of pi-, nz = number of pi0
168 G4int nt(0), np(0), nm(0), nz(0);
169 const G4double c = 1.25;
170 const G4double b[] = { 0.70, 0.70 };
171 if( first ) // compute normalization constants, this will only be Done once
172 {
173 first = false;
174 G4int i;
175 for( i=0; i<numMul; ++i )protmul[i] = 0.0;
176 for( i=0; i<numSec; ++i )protnorm[i] = 0.0;
177 G4int counter = -1;
178 for( np=0; np<(numSec/3); ++np )
179 {
180 for( nm=std::max(0,np-1); nm<=(np+1); ++nm )
181 {
182 for( nz=0; nz<numSec/3; ++nz )
183 {
184 if( ++counter < numMul )
185 {
186 nt = np+nm+nz;
187 if( (nt>0) && (nt<=numSec) )
188 {
189 protmul[counter] = Pmltpc(np,nm,nz,nt,b[0],c);
190 protnorm[nt-1] += protmul[counter];
191 }
192 }
193 }
194 }
195 }
196 for( i=0; i<numMul; ++i )neutmul[i] = 0.0;
197 for( i=0; i<numSec; ++i )neutnorm[i] = 0.0;
198 counter = -1;
199 for( np=0; np<numSec/3; ++np )
200 {
201 for( nm=np; nm<=(np+2); ++nm )
202 {
203 for( nz=0; nz<numSec/3; ++nz )
204 {
205 if( ++counter < numMul )
206 {
207 nt = np+nm+nz;
208 if( (nt>0) && (nt<=numSec) )
209 {
210 neutmul[counter] = Pmltpc(np,nm,nz,nt,b[1],c);
211 neutnorm[nt-1] += neutmul[counter];
212 }
213 }
214 }
215 }
216 }
217 for( i=0; i<numSec; ++i )
218 {
219 if( protnorm[i] > 0.0 )protnorm[i] = 1.0/protnorm[i];
220 if( neutnorm[i] > 0.0 )neutnorm[i] = 1.0/neutnorm[i];
221 }
222 } // end of initialization
223
224 const G4double expxu = 82.; // upper bound for arg. of exp
225 const G4double expxl = -expxu; // lower bound for arg. of exp
226 G4ParticleDefinition *aKaonMinus = G4KaonMinus::KaonMinus();
227 G4ParticleDefinition *aKaonZS = G4KaonZeroShort::KaonZeroShort();
228 G4ParticleDefinition *aKaonZL = G4KaonZeroLong::KaonZeroLong();
229 G4ParticleDefinition *aNeutron = G4Neutron::Neutron();
230 G4ParticleDefinition *aProton = G4Proton::Proton();
231 G4ParticleDefinition *aPiPlus = G4PionPlus::PionPlus();
232 G4ParticleDefinition *aPiMinus = G4PionMinus::PionMinus();
233 G4ParticleDefinition *aPiZero = G4PionZero::PionZero();
234 G4ParticleDefinition *aLambda = G4Lambda::Lambda();
235 G4ParticleDefinition *aSigmaPlus = G4SigmaPlus::SigmaPlus();
236 G4ParticleDefinition *aSigmaMinus = G4SigmaMinus::SigmaMinus();
237 G4ParticleDefinition *aSigmaZero = G4SigmaZero::SigmaZero();
238 const G4double cech[] = {1.,1.,1.,0.70,0.60,0.55,0.35,0.25,0.18,0.15};
239 G4int iplab = G4int(std::min( 9.0, pOriginal/GeV*5.0 ));
240 if( (pOriginal <= 2.0*GeV) && (G4UniformRand() < cech[iplab]) )
241 {
242 np = nm = nz = nt = 0;
243 iplab = G4int(std::min( 19.0, pOriginal/GeV*10.0 ));
244 const G4double cnk0[] = {0.17,0.18,0.17,0.24,0.26,0.20,0.22,0.21,0.34,0.45,
245 0.58,0.55,0.36,0.29,0.29,0.32,0.32,0.33,0.33,0.33};
246 if( G4UniformRand() <= cnk0[iplab] )
247 {
248 quasiElastic = true;
249 if( targetParticle.GetDefinition() == aProton )
250 {
251 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
252 incidentHasChanged = true;
253 targetParticle.SetDefinitionAndUpdateE( aNeutron );
254 targetHasChanged = true;
255 }
256 }
257 else // random number > cnk0[iplab]
258 {
259 G4double ran = G4UniformRand();
260 if( ran < 0.25 ) // k- p --> pi- s+
261 {
262 if( targetParticle.GetDefinition() == aProton )
263 {
264 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
265 targetParticle.SetDefinitionAndUpdateE( aSigmaPlus );
266 incidentHasChanged = true;
267 targetHasChanged = true;
268 }
269 }
270 else if( ran < 0.50 ) // k- p --> pi0 s0 or k- n --> pi- s0
271 {
272 if( targetParticle.GetDefinition() == aNeutron )
273 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
274 else
275 currentParticle.SetDefinitionAndUpdateE( aPiZero );
276 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
277 incidentHasChanged = true;
278 targetHasChanged = true;
279 }
280 else if( ran < 0.75 ) // k- p --> pi+ s- or k- n --> pi0 s-
281 {
282 if( targetParticle.GetDefinition() == aNeutron )
283 currentParticle.SetDefinitionAndUpdateE( aPiZero );
284 else
285 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
286 targetParticle.SetDefinitionAndUpdateE( aSigmaMinus );
287 incidentHasChanged = true;
288 targetHasChanged = true;
289 }
290 else // k- p --> pi0 L or k- n --> pi- L
291 {
292 if( targetParticle.GetDefinition() == aNeutron )
293 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
294 else
295 currentParticle.SetDefinitionAndUpdateE( aPiZero );
296 targetParticle.SetDefinitionAndUpdateE( aLambda );
297 incidentHasChanged = true;
298 targetHasChanged = true;
299 }
300 }
301 }
302 else // (pOriginal > 2.0*GeV) || (random number >= cech[iplab])
303 {
304 if( availableEnergy < aPiPlus->GetPDGMass() )
305 { // not energetically possible to produce pion(s)
306 quasiElastic = true;
307 return;
308 }
309 G4double n, anpn;
310 GetNormalizationConstant( availableEnergy, n, anpn );
311 G4double ran = G4UniformRand();
312 G4double dum, test, excs = 0.0;
313 if( targetParticle.GetDefinition() == aProton )
314 {
315 G4int counter = -1;
316 for( np=0; np<numSec/3 && ran>=excs; ++np )
317 {
318 for( nm=std::max(0,np-1); nm<=(np+1) && ran>=excs; ++nm )
319 {
320 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
321 {
322 if( ++counter < numMul )
323 {
324 nt = np+nm+nz;
325 if( nt > 0 )
326 {
327 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
328 dum = (pi/anpn)*nt*protmul[counter]*protnorm[nt-1]/(2.0*n*n);
329 if( std::fabs(dum) < 1.0 )
330 {
331 if( test >= 1.0e-10 )excs += dum*test;
332 }
333 else
334 excs += dum*test;
335 }
336 }
337 }
338 }
339 }
340 if( ran >= excs ) // 3 previous loops continued to the end
341 {
342 quasiElastic = true;
343 return;
344 }
345 np--; nm--; nz--;
346 if( np == nm )
347 {
348 if( G4UniformRand() >= 0.75 )
349 {
350 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
351 targetParticle.SetDefinitionAndUpdateE( aNeutron );
352 incidentHasChanged = true;
353 targetHasChanged = true;
354 }
355 }
356 else if( np == nm+1 )
357 {
358 targetParticle.SetDefinitionAndUpdateE( aNeutron );
359 targetHasChanged = true;
360 }
361 else
362 {
363 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
364 incidentHasChanged = true;
365 }
366 }
367 else // target must be a neutron
368 {
369 G4int counter = -1;
370 for( np=0; np<numSec/3 && ran>=excs; ++np )
371 {
372 for( nm=np; nm<=(np+2) && ran>=excs; ++nm )
373 {
374 for( nz=0; nz<numSec/3 && ran>=excs; ++nz )
375 {
376 if( ++counter < numMul )
377 {
378 nt = np+nm+nz;
379 if( (nt>=1) && (nt<=numSec) )
380 {
381 test = std::exp( std::min( expxu, std::max( expxl, -(pi/4.0)*(nt*nt)/(n*n) ) ) );
382 dum = (pi/anpn)*nt*neutmul[counter]*neutnorm[nt-1]/(2.0*n*n);
383 if( std::fabs(dum) < 1.0 )
384 {
385 if( test >= 1.0e-10 )excs += dum*test;
386 }
387 else
388 excs += dum*test;
389 }
390 }
391 }
392 }
393 }
394 if( ran >= excs ) // 3 previous loops continued to the end
395 {
396 quasiElastic = true;
397 return;
398 }
399 np--; nm--; nz--;
400 if( np == nm-1 )
401 {
402 if( G4UniformRand() < 0.5 )
403 {
404 targetParticle.SetDefinitionAndUpdateE( aProton );
405 targetHasChanged = true;
406 }
407 else
408 {
409 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
410 incidentHasChanged = true;
411 }
412 }
413 else if( np != nm )
414 {
415 currentParticle.SetDefinitionAndUpdateE( aKaonZL );
416 incidentHasChanged = true;
417 }
418 }
419 if( G4UniformRand() >= 0.5 )
420 {
421 if( (currentParticle.GetDefinition() == aKaonMinus &&
422 targetParticle.GetDefinition() == aNeutron ) ||
423 (currentParticle.GetDefinition() == aKaonZL &&
424 targetParticle.GetDefinition() == aProton ) )
425 {
426 ran = G4UniformRand();
427 if( ran < 0.68 )
428 {
429 if( targetParticle.GetDefinition() == aProton )
430 {
431 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
432 targetParticle.SetDefinitionAndUpdateE( aLambda );
433 incidentHasChanged = true;
434 targetHasChanged = true;
435 }
436 else
437 {
438 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
439 targetParticle.SetDefinitionAndUpdateE( aLambda );
440 incidentHasChanged = true;
441 targetHasChanged = true;
442 }
443 }
444 else if( ran < 0.84 )
445 {
446 if( targetParticle.GetDefinition() == aProton )
447 {
448 currentParticle.SetDefinitionAndUpdateE( aPiZero );
449 targetParticle.SetDefinitionAndUpdateE( aSigmaPlus );
450 incidentHasChanged = true;
451 targetHasChanged = true;
452 }
453 else
454 {
455 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
456 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
457 incidentHasChanged = true;
458 targetHasChanged = true;
459 }
460 }
461 else
462 {
463 if( targetParticle.GetDefinition() == aProton )
464 {
465 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
466 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
467 incidentHasChanged = true;
468 targetHasChanged = true;
469 }
470 else
471 {
472 currentParticle.SetDefinitionAndUpdateE( aPiZero );
473 targetParticle.SetDefinitionAndUpdateE( aSigmaMinus );
474 incidentHasChanged = true;
475 targetHasChanged = true;
476 }
477 }
478 }
479 else // ( current != aKaonMinus || target != aNeutron ) &&
480 // ( current != aKaonZL || target != aProton )
481 {
482 ran = G4UniformRand();
483 if( ran < 0.67 )
484 {
485 currentParticle.SetDefinitionAndUpdateE( aPiZero );
486 targetParticle.SetDefinitionAndUpdateE( aLambda );
487 incidentHasChanged = true;
488 targetHasChanged = true;
489 }
490 else if( ran < 0.78 )
491 {
492 currentParticle.SetDefinitionAndUpdateE( aPiMinus );
493 targetParticle.SetDefinitionAndUpdateE( aSigmaPlus );
494 incidentHasChanged = true;
495 targetHasChanged = true;
496 }
497 else if( ran < 0.89 )
498 {
499 currentParticle.SetDefinitionAndUpdateE( aPiZero );
500 targetParticle.SetDefinitionAndUpdateE( aSigmaZero );
501 incidentHasChanged = true;
502 targetHasChanged = true;
503 }
504 else
505 {
506 currentParticle.SetDefinitionAndUpdateE( aPiPlus );
507 targetParticle.SetDefinitionAndUpdateE( aSigmaMinus );
508 incidentHasChanged = true;
509 targetHasChanged = true;
510 }
511 }
512 }
513 }
514 if( currentParticle.GetDefinition() == aKaonZL )
515 {
516 if( G4UniformRand() >= 0.5 )
517 {
518 currentParticle.SetDefinitionAndUpdateE( aKaonZS );
519 incidentHasChanged = true;
520 }
521 }
522 if( targetParticle.GetDefinition() == aKaonZL )
523 {
524 if( G4UniformRand() >= 0.5 )
525 {
526 targetParticle.SetDefinitionAndUpdateE( aKaonZS );
527 targetHasChanged = true;
528 }
529 }
530 SetUpPions( np, nm, nz, vec, vecLen );
531 return;
532 }
533
534 /* end of file */
535
536
537
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