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25 //
26 //
27 // G4LMsdGenerator
28 //
29 //
30
31 #include "G4DynamicParticle.hh"
32 #include "G4LMsdGenerator.hh"
33 #include "G4ReactionProductVector.hh"
34 #include "G4ReactionProduct.hh"
35 #include "G4IonTable.hh"
36 #include "G4NucleiProperties.hh"
37 #include "G4ParticleDefinition.hh"
38 #include "G4HadFinalState.hh"
39 #include "G4KineticTrack.hh"
40 #include "G4DecayKineticTracks.hh"
41 #include "G4KineticTrackVector.hh"
42 #include "G4Log.hh"
43 #include "G4PhysicsModelCatalog.hh"
44
45
46 G4LMsdGenerator::G4LMsdGenerator(const G4String& name)
47 : G4HadronicInteraction(name), secID(-1)
48
49 {
50 fPDGencoding = 0;
51 secID = G4PhysicsModelCatalog::GetModelID( "model_LMsdGenerator" );
52
53 // theParticleChange = new G4HadFinalState;
54 }
55
56 G4LMsdGenerator::~G4LMsdGenerator()
57 {
58 // delete theParticleChange;
59 }
60
61 void G4LMsdGenerator::ModelDescription(std::ostream& outFile) const
62 {
63 outFile << GetModelName() <<" consists of a "
64 << " string model and a stage to de-excite the excited nuclear fragment."
65 << "\n<p>"
66 << "The string model simulates the interaction of\n"
67 << "an incident hadron with a nucleus, forming \n"
68 << "excited strings, decays these strings into hadrons,\n"
69 << "and leaves an excited nucleus. \n"
70 << "<p>The string model:\n";
71 }
72
73 /////////////////////////////////////////////////////////////////
74 //
75 // Particle and kinematical limitation od diffraction dissociation
76
77 G4bool
78 G4LMsdGenerator::IsApplicable( const G4HadProjectile& aTrack,
79 G4Nucleus& targetNucleus )
80 {
81 G4bool applied = false;
82
83 if( ( aTrack.GetDefinition() == G4Proton::Proton() ||
84 aTrack.GetDefinition() == G4Neutron::Neutron() ) &&
85 targetNucleus.GetA_asInt() >= 1 &&
86 // aTrack.GetKineticEnergy() > 1800*CLHEP::MeV
87 aTrack.GetKineticEnergy() > 300*CLHEP::MeV
88 ) // 750*CLHEP::MeV )
89 {
90 applied = true;
91 }
92 else if( ( aTrack.GetDefinition() == G4PionPlus::PionPlus() ||
93 aTrack.GetDefinition() == G4PionMinus::PionMinus() ) &&
94 targetNucleus.GetA_asInt() >= 1 &&
95 aTrack.GetKineticEnergy() > 2340*CLHEP::MeV )
96 {
97 applied = true;
98 }
99 else if( ( aTrack.GetDefinition() == G4KaonPlus::KaonPlus() ||
100 aTrack.GetDefinition() == G4KaonMinus::KaonMinus() ) &&
101 targetNucleus.GetA_asInt() >= 1 &&
102 aTrack.GetKineticEnergy() > 1980*CLHEP::MeV )
103 {
104 applied = true;
105 }
106 return applied;
107 }
108
109 /////////////////////////////////////////////////////////////////
110 //
111 // Return dissociated particle products and recoil nucleus
112
113 G4HadFinalState*
114 G4LMsdGenerator::ApplyYourself( const G4HadProjectile& aTrack,
115 G4Nucleus& targetNucleus )
116 {
117 theParticleChange.Clear();
118
119 const G4HadProjectile* aParticle = &aTrack;
120 G4double eTkin = aParticle->GetKineticEnergy();
121
122 if( eTkin <= 1.*CLHEP::GeV && aTrack.GetDefinition() != G4Proton::Proton())
123 {
124 theParticleChange.SetEnergyChange(eTkin);
125 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
126 return &theParticleChange;
127 }
128
129 G4int A = targetNucleus.GetA_asInt();
130 G4int Z = targetNucleus.GetZ_asInt();
131
132 G4double plab = aParticle->GetTotalMomentum();
133 G4double plab2 = plab*plab;
134
135 const G4ParticleDefinition* theParticle = aParticle->GetDefinition();
136 G4double partMass = theParticle->GetPDGMass();
137
138 G4double oldE = partMass + eTkin;
139
140 G4double targMass = G4NucleiProperties::GetNuclearMass(A, Z);
141 G4double targMass2 = targMass*targMass;
142
143 G4LorentzVector partLV = aParticle->Get4Momentum();
144
145 G4double sumE = oldE + targMass;
146 G4double sumE2 = sumE*sumE;
147
148 G4ThreeVector p1 = partLV.vect();
149 // G4cout<<"p1 = "<<p1<<G4endl;
150 G4ParticleMomentum p1unit = p1.unit();
151
152 G4double Mx = SampleMx(aParticle); // in GeV
153 G4double t = SampleT( aParticle, Mx); // in GeV
154
155 Mx *= CLHEP::GeV;
156
157 G4double Mx2 = Mx*Mx;
158
159 // equation for q|| based on sum-E-P and new invariant mass
160
161 G4double B = sumE2 + targMass2 - Mx2 - plab2;
162
163 G4double a = 4*(plab2 - sumE2);
164 G4double b = 4*plab*B;
165 G4double c = B*B - 4*sumE2*targMass2;
166 G4double det2 = b*b - 4*a*c;
167 G4double qLong, det, eRetard; // , x2, x3, e2;
168
169 if( det2 >= 0.)
170 {
171 det = std::sqrt(det2);
172 qLong = (-b - det)/2./a;
173 eRetard = std::sqrt((plab-qLong)*(plab-qLong)+Mx2);
174 }
175 else
176 {
177 theParticleChange.SetEnergyChange(eTkin);
178 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
179 return &theParticleChange;
180 }
181 theParticleChange.SetStatusChange(stopAndKill);
182
183 plab -= qLong;
184
185 G4ThreeVector pRetard = plab*p1unit;
186
187 G4ThreeVector pTarg = p1 - pRetard;
188
189 G4double eTarg = std::sqrt( targMass2 + pTarg.mag2()); // std::sqrt( targMass*targMass + pTarg.mag2() );
190
191 G4LorentzVector lvRetard(pRetard, eRetard);
192 G4LorentzVector lvTarg(pTarg, eTarg);
193
194 lvTarg += lvRetard; // sum LV
195
196 G4ThreeVector bst = lvTarg.boostVector();
197
198 lvRetard.boost(-bst); // to CNS
199
200 G4ThreeVector pCMS = lvRetard.vect();
201 G4double momentumCMS = pCMS.mag();
202 G4double tMax = 4.0*momentumCMS*momentumCMS;
203
204 if( t > tMax ) t = tMax*G4UniformRand();
205
206 G4double cost = 1. - 2.0*t/tMax;
207
208
209 G4double phi = G4UniformRand()*CLHEP::twopi;
210 G4double sint;
211
212 if( cost > 1.0 || cost < -1.0 ) //
213 {
214 cost = 1.0;
215 sint = 0.0;
216 }
217 else // normal situation
218 {
219 sint = std::sqrt( (1.0-cost)*(1.0+cost) );
220 }
221 G4ThreeVector v1( sint*std::cos(phi), sint*std::sin(phi), cost);
222
223 v1 *= momentumCMS;
224
225 G4LorentzVector lvRes( v1.x(),v1.y(),v1.z(), std::sqrt( momentumCMS*momentumCMS + Mx2));
226
227 lvRes.boost(bst); // to LS
228
229 lvTarg -= lvRes;
230
231 G4double eRecoil = lvTarg.e() - targMass;
232
233 if( eRecoil > 100.*CLHEP::MeV ) // add recoil nucleus
234 {
235 G4ParticleDefinition * recoilDef = 0;
236
237 if ( Z == 1 && A == 1 ) { recoilDef = G4Proton::Proton(); }
238 else if ( Z == 1 && A == 2 ) { recoilDef = G4Deuteron::Deuteron(); }
239 else if ( Z == 1 && A == 3 ) { recoilDef = G4Triton::Triton(); }
240 else if ( Z == 2 && A == 3 ) { recoilDef = G4He3::He3(); }
241 else if ( Z == 2 && A == 4 ) { recoilDef = G4Alpha::Alpha(); }
242 else
243 {
244 recoilDef =
245 G4ParticleTable::GetParticleTable()->GetIonTable()->GetIon( Z, A, 0.0 );
246 }
247 G4DynamicParticle * aSec = new G4DynamicParticle( recoilDef, lvTarg);
248 theParticleChange.AddSecondary(aSec, secID);
249 }
250 else if( eRecoil > 0.0 )
251 {
252 theParticleChange.SetLocalEnergyDeposit( eRecoil );
253 }
254
255 G4ParticleDefinition* ddPart = G4ParticleTable::GetParticleTable()->
256 FindParticle(fPDGencoding);
257
258 // G4cout<<fPDGencoding<<", "<<ddPart->GetParticleName()<<", "<<ddPart->GetPDGMass()<<" MeV; lvRes = "<<lvRes<<G4endl;
259
260 // G4DynamicParticle * aRes = new G4DynamicParticle( ddPart, lvRes);
261 // theParticleChange.AddSecondary(aRes); // simply return resonance
262
263
264
265 // Recursive decay using methods of G4KineticTrack
266
267 G4KineticTrack ddkt( ddPart, 0., G4ThreeVector(0.,0.,0.), lvRes);
268 G4KineticTrackVector* ddktv = ddkt.Decay();
269
270 G4DecayKineticTracks decay( ddktv );
271
272 for( unsigned int i = 0; i < ddktv->size(); i++ ) // add products to partchange
273 {
274 G4DynamicParticle * aNew =
275 new G4DynamicParticle( ddktv->operator[](i)->GetDefinition(),
276 ddktv->operator[](i)->Get4Momentum());
277
278 // G4cout<<" "<<i<<", "<<aNew->GetDefinition()->GetParticleName()<<", "<<aNew->Get4Momentum()<<G4endl;
279
280 theParticleChange.AddSecondary(aNew, secID);
281 delete ddktv->operator[](i);
282 }
283 delete ddktv;
284
285 return &theParticleChange;
286 }
287
288 //////////////////////////////////////
289 //
290 // Sample Mx as Roper resonances, set PDG encoding
291
292 G4double G4LMsdGenerator::SampleMx(const G4HadProjectile* aParticle)
293 {
294 G4double Mx = 0.;
295 G4int i;
296 G4double rand = G4UniformRand();
297
298 for( i = 0; i < 60; i++)
299 {
300 if( rand >= fProbMx[i][1] ) break;
301 }
302 if(i <= 0) Mx = fProbMx[0][0];
303 else if(i >= 59) Mx = fProbMx[59][0];
304 else Mx = fProbMx[i][0];
305
306 fPDGencoding = 0;
307
308 if ( Mx <= 1.45 )
309 {
310 if( aParticle->GetDefinition() == G4Proton::Proton() )
311 {
312 Mx = 1.44;
313 // fPDGencoding = 12212;
314 fPDGencoding = 2214;
315 }
316 else if( aParticle->GetDefinition() == G4Neutron::Neutron() )
317 {
318 Mx = 1.44;
319 fPDGencoding = 12112;
320 }
321 else if( aParticle->GetDefinition() == G4PionPlus::PionPlus() )
322 {
323 // Mx = 1.3;
324 // fPDGencoding = 100211;
325 Mx = 1.26;
326 fPDGencoding = 20213; // a1(1260)+
327 }
328 else if( aParticle->GetDefinition() == G4PionMinus::PionMinus() )
329 {
330 // Mx = 1.3;
331 // fPDGencoding = -100211;
332 Mx = 1.26;
333 fPDGencoding = -20213; // a1(1260)-
334 }
335 else if( aParticle->GetDefinition() == G4KaonPlus::KaonPlus() )
336 {
337 Mx = 1.27;
338 fPDGencoding = 10323;
339 }
340 else if( aParticle->GetDefinition() == G4KaonMinus::KaonMinus() )
341 {
342 Mx = 1.27;
343 fPDGencoding = -10323;
344 }
345 }
346 else if ( Mx <= 1.55 )
347 {
348 if( aParticle->GetDefinition() == G4Proton::Proton() )
349 {
350 Mx = 1.52;
351 // fPDGencoding = 2124;
352 fPDGencoding = 2214;
353 }
354 else if( aParticle->GetDefinition() == G4Neutron::Neutron() )
355 {
356 Mx = 1.52;
357 fPDGencoding = 1214;
358 }
359 else if( aParticle->GetDefinition() == G4PionPlus::PionPlus() )
360 {
361 // Mx = 1.45;
362 // fPDGencoding = 10211;
363 Mx = 1.32;
364 fPDGencoding = 215; // a2(1320)+
365 }
366 else if( aParticle->GetDefinition() == G4PionMinus::PionMinus() )
367 {
368 // Mx = 1.45;
369 // fPDGencoding = -10211;
370 Mx = 1.32;
371 fPDGencoding = -215; // a2(1320)-
372 }
373 else if( aParticle->GetDefinition() == G4KaonPlus::KaonPlus() )
374 {
375 Mx = 1.46;
376 fPDGencoding = 100321;
377 }
378 else if( aParticle->GetDefinition() == G4KaonMinus::KaonMinus() )
379 {
380 Mx = 1.46;
381 fPDGencoding = -100321;
382 }
383 }
384 else
385 {
386 if( aParticle->GetDefinition() == G4Proton::Proton() )
387 {
388 Mx = 1.68;
389 // fPDGencoding = 12216;
390 fPDGencoding = 2214;
391 }
392 else if( aParticle->GetDefinition() == G4Neutron::Neutron() )
393 {
394 Mx = 1.68;
395 fPDGencoding = 12116;
396 }
397 else if( aParticle->GetDefinition() == G4PionPlus::PionPlus() )
398 {
399 Mx = 1.67;
400 fPDGencoding = 10215; // pi2(1670)+
401 // Mx = 1.45;
402 // fPDGencoding = 10211;
403 }
404 else if( aParticle->GetDefinition() == G4PionMinus::PionMinus() )
405 {
406 Mx = 1.67; // f0 problems->4pi vmg 20.11.14
407 fPDGencoding = -10215; // pi2(1670)-
408 // Mx = 1.45;
409 // fPDGencoding = -10211;
410 }
411 else if( aParticle->GetDefinition() == G4KaonPlus::KaonPlus() )
412 {
413 Mx = 1.68;
414 fPDGencoding = 30323;
415 }
416 else if( aParticle->GetDefinition() == G4KaonMinus::KaonMinus() )
417 {
418 Mx = 1.68;
419 fPDGencoding = -30323;
420 }
421 }
422 if(fPDGencoding == 0)
423 {
424 Mx = 1.44;
425 // fPDGencoding = 12212;
426 fPDGencoding = 2214;
427 }
428 G4ParticleDefinition* myResonance =
429 G4ParticleTable::GetParticleTable()->FindParticle( fPDGencoding );
430
431 if ( myResonance ) Mx = myResonance->GetPDGMass();
432
433 // G4cout<<"PDG-ID = "<<fPDGencoding<<"; with mass = "<<Mx/CLHEP::GeV<<" GeV"<<G4endl;
434
435 return Mx/CLHEP::GeV;
436 }
437
438 //////////////////////////////////////
439 //
440 // Sample t with kinematic limitations of Mx and Tkin
441
442 G4double G4LMsdGenerator::SampleT( const G4HadProjectile* aParticle,
443 G4double Mx)
444 {
445 G4double t=0., b=0., rTkin = 50.*CLHEP::GeV, eTkin = aParticle->GetKineticEnergy();
446 G4int i;
447
448 for( i = 0; i < 23; ++i)
449 {
450 if( Mx <= fMxBdata[i][0] ) break;
451 }
452 if( i <= 0 ) b = fMxBdata[0][1];
453 else if( i >= 22 ) b = fMxBdata[22][1];
454 else b = fMxBdata[i][1];
455
456 if( eTkin > rTkin ) b *= 1. + G4Log(eTkin/rTkin);
457
458 G4double rand = G4UniformRand();
459
460 t = -G4Log(rand)/b;
461
462 t *= (CLHEP::GeV*CLHEP::GeV); // in G4 internal units
463
464 return t;
465 }
466
467
468 ////////////////////////////////////////////////
469 //
470 // Integral spectrum of Mx (GeV)
471
472 const G4double G4LMsdGenerator::fProbMx[60][2] =
473 {
474 {1.000000e+00, 1.000000e+00},
475 {1.025000e+00, 1.000000e+00},
476 {1.050000e+00, 1.000000e+00},
477 {1.075000e+00, 1.000000e+00},
478 {1.100000e+00, 9.975067e-01},
479 {1.125000e+00, 9.934020e-01},
480 {1.150000e+00, 9.878333e-01},
481 {1.175000e+00, 9.805002e-01},
482 {1.200000e+00, 9.716846e-01},
483 {1.225000e+00, 9.604761e-01},
484 {1.250000e+00, 9.452960e-01},
485 {1.275000e+00, 9.265278e-01},
486 {1.300000e+00, 9.053632e-01},
487 {1.325000e+00, 8.775566e-01},
488 {1.350000e+00, 8.441969e-01},
489 {1.375000e+00, 8.076336e-01},
490 {1.400000e+00, 7.682520e-01},
491 {1.425000e+00, 7.238306e-01},
492 {1.450000e+00, 6.769306e-01},
493 {1.475000e+00, 6.303898e-01},
494 {1.500000e+00, 5.824632e-01},
495 {1.525000e+00, 5.340696e-01},
496 {1.550000e+00, 4.873736e-01},
497 {1.575000e+00, 4.422901e-01},
498 {1.600000e+00, 3.988443e-01},
499 {1.625000e+00, 3.583727e-01},
500 {1.650000e+00, 3.205405e-01},
501 {1.675000e+00, 2.856655e-01},
502 {1.700000e+00, 2.537508e-01},
503 {1.725000e+00, 2.247863e-01},
504 {1.750000e+00, 1.985798e-01},
505 {1.775000e+00, 1.750252e-01},
506 {1.800000e+00, 1.539777e-01},
507 {1.825000e+00, 1.352741e-01},
508 {1.850000e+00, 1.187157e-01},
509 {1.875000e+00, 1.040918e-01},
510 {1.900000e+00, 9.118422e-02},
511 {1.925000e+00, 7.980909e-02},
512 {1.950000e+00, 6.979378e-02},
513 {1.975000e+00, 6.097771e-02},
514 {2.000000e+00, 5.322122e-02},
515 {2.025000e+00, 4.639628e-02},
516 {2.050000e+00, 4.039012e-02},
517 {2.075000e+00, 3.510275e-02},
518 {2.100000e+00, 3.044533e-02},
519 {2.125000e+00, 2.633929e-02},
520 {2.150000e+00, 2.271542e-02},
521 {2.175000e+00, 1.951295e-02},
522 {2.200000e+00, 1.667873e-02},
523 {2.225000e+00, 1.416633e-02},
524 {2.250000e+00, 1.193533e-02},
525 {2.275000e+00, 9.950570e-03},
526 {2.300000e+00, 8.181515e-03},
527 {2.325000e+00, 6.601664e-03},
528 {2.350000e+00, 5.188025e-03},
529 {2.375000e+00, 3.920655e-03},
530 {2.400000e+00, 2.782246e-03},
531 {2.425000e+00, 1.757765e-03},
532 {2.450000e+00, 8.341435e-04},
533 {2.475000e+00, 0.000000e+00}
534 };
535
536 //////////////////////////////////////////////
537 //
538 // Slope b (1/GeV/GeV) vs Mx (GeV) for t-sampling over exp(-b*t)
539
540 const G4double G4LMsdGenerator::fMxBdata[23][2] =
541 {
542 {1.09014, 17.8620},
543 {1.12590, 19.2831},
544 {1.18549, 17.6907},
545 {1.21693, 16.4760},
546 {1.25194, 15.3867},
547 {1.26932, 14.4236},
548 {1.29019, 13.2931},
549 {1.30755, 12.2882},
550 {1.31790, 11.4509},
551 {1.33888, 10.6969},
552 {1.34911, 9.44130},
553 {1.37711, 8.56148},
554 {1.39101, 7.76593},
555 {1.42608, 6.88582},
556 {1.48593, 6.13019},
557 {1.53179, 5.87723},
558 {1.58111, 5.37308},
559 {1.64105, 4.95217},
560 {1.69037, 4.44803},
561 {1.81742, 3.89879},
562 {1.88096, 3.68693},
563 {1.95509, 3.43278},
564 {2.02219, 3.30445}
565 };
566
567
568
569 //
570 //
571 /////////////////////////////////////////////
572