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27 //
28 // -----------------------------------------------------------------------------
29 // GEANT 4 class implementation file
30 //
31 // History: first implementation, Maxim Komogorov, 10-Jul-1998
32 // -----------------------------------------------------------------------------
33 #include "G4QGSMFragmentation.hh"
34 #include "G4PhysicalConstants.hh"
35 #include "G4SystemOfUnits.hh"
36 #include "Randomize.hh"
37 #include "G4ios.hh"
38 #include "G4FragmentingString.hh"
39 #include "G4DiQuarks.hh"
40 #include "G4Quarks.hh"
41 #include "G4HadronicParameters.hh"
42 #include "G4Pow.hh"
43
44 //#define debug_QGSMfragmentation
45
46 // Class G4QGSMFragmentation
47 //****************************************************************************************
48
49 G4QGSMFragmentation::G4QGSMFragmentation()
50 {
51 SigmaQT = 0.45 * GeV;
52
53 MassCut = 0.35*GeV;
54
55 SetStrangenessSuppression((1.0 - 0.16)/2.);
56
57 // Check if charmed and bottom hadrons are enabled: if this is the case, then
58 // set the non-zero probabilities for c-cbar and b-bbar creation from the vacuum,
59 // else set them to 0.0. If these probabilities are/aren't zero then charmed or bottom
60 // hadrons can't/can be created during the string fragmentation of ordinary
61 // (i.e. not heavy) projectile hadron nuclear reactions.
62 if ( G4HadronicParameters::Instance()->EnableBCParticles() ) {
63 SetProbCCbar(0.0002); // According to O.I. Piskunova Yad. Fiz. 56 (1993) 1094; tuned by Uzhi Oct. 2022
64 SetProbBBbar(5.0e-5); // According to O.I. Piskunova Yad. Fiz. 56 (1993) 1094
65 } else {
66 SetProbCCbar(0.0);
67 SetProbBBbar(0.0);
68 }
69
70 SetDiquarkSuppression(0.32);
71 SetDiquarkBreakProbability(0.7);
72
73 SetMinMasses();
74
75 arho = 0.5; // alpha_rho0
76 aphi = 0.0; // alpha_fi
77 aJPs =-2.2; // alpha_J/Psi
78 aUps =-8.0; // alpha_Y ??? O. Piskunova Yad. Phys. 56 (1993) 1094.
79
80 aksi =-1.0;
81 alft = 0.5; // 2 * alpha'_R *<Pt^2>
82
83 an = -0.5 ;
84 ala = -0.75; // an - arho/2 + aphi/2
85 alaC = an - arho/2.0 + aJPs/2.0;
86 alaB = an - arho/2.0 + aUps/2.0;
87 aXi = 0.0; // ??
88 aXiC = 0.0; // ??
89 aXiB = 0.0; // ??
90 aXiCC = 0.0; // ??
91 aXiCB = 0.0; // ??
92 aXiBB = 0.0; // ??
93
94 SetFFq2q();
95 SetFFq2qq();
96 SetFFqq2q();
97 SetFFqq2qq();
98 // d u s c b
99 G4int Index[5][5] = { { 0, 1, 2, 3, 4 }, // d
100 { 1, 5, 6, 7, 8 }, // u
101 { 2, 6, 9, 10, 11 }, // s
102 { 3, 7, 10, 12, 13 }, // c
103 { 4, 8, 11, 13, 14 } }; // b
104 for (G4int i = 0; i < 5; i++ ) {
105 for ( G4int j = 0; j < 5; j++ ) {
106 IndexDiQ[i][j] = Index[i][j];
107 }
108 };
109 }
110
111 G4QGSMFragmentation::~G4QGSMFragmentation()
112 {}
113
114 //----------------------------------------------------------------------------------------------------------
115
116 G4KineticTrackVector* G4QGSMFragmentation::FragmentString(const G4ExcitedString& theString)
117 {
118
119 G4FragmentingString aString(theString);
120 SetMinimalStringMass(&aString);
121
122 #ifdef debug_QGSMfragmentation
123 G4cout<<G4endl<<"QGSM StringFragm: String Mass "
124 <<theString.Get4Momentum().mag()<<" Pz "
125 <<theString.Get4Momentum().pz()
126 <<"------------------------------------"<<G4endl;
127 G4cout<<"String ends Direct "<<theString.GetLeftParton()->GetPDGcode()<<" "
128 <<theString.GetRightParton()->GetPDGcode()<<" "
129 <<theString.GetDirection()<< G4endl;
130 G4cout<<"Left mom "<<theString.GetLeftParton()->Get4Momentum()<<G4endl;
131 G4cout<<"Right mom "<<theString.GetRightParton()->Get4Momentum()<<G4endl;
132 G4cout<<"Check for Fragmentation "<<G4endl;
133 #endif
134
135 // Can no longer modify Parameters for Fragmentation.
136 PastInitPhase=true;
137
138 // Check if string has enough mass to fragment...
139 G4KineticTrackVector * LeftVector=NULL;
140
141 if ( !IsItFragmentable(&aString) ) {
142 LeftVector=ProduceOneHadron(&theString);
143
144 #ifdef debug_QGSMfragmentation
145 if ( LeftVector != 0 ) G4cout<<"Non fragmentable - the string is converted to one hadron "<<G4endl;
146 #endif
147
148 if ( LeftVector == nullptr ) LeftVector = new G4KineticTrackVector;
149 return LeftVector;
150 }
151
152 #ifdef debug_QGSMfragmentation
153 G4cout<<"The string will be fragmented. "<<G4endl;
154 #endif
155
156 LeftVector = new G4KineticTrackVector;
157 G4KineticTrackVector * RightVector=new G4KineticTrackVector;
158
159 G4ExcitedString *theStringInCMS=CopyExcited(theString);
160 G4LorentzRotation toCms=theStringInCMS->TransformToAlignedCms();
161
162 G4bool success=false, inner_sucess=true;
163 G4int attempt=0;
164 while ( !success && attempt++ < StringLoopInterrupt ) /* Loop checking, 07.08.2015, A.Ribon */
165 {
166 #ifdef debug_QGSMfragmentation
167 G4cout<<"Loop_toFrag "<<theStringInCMS->GetLeftParton()->GetPDGcode()<<" "
168 <<theStringInCMS->GetRightParton()->GetPDGcode()<<" "
169 <<theStringInCMS->GetDirection()<< G4endl;
170 #endif
171
172 G4FragmentingString *currentString=new G4FragmentingString(*theStringInCMS);
173
174 std::for_each(LeftVector->begin(), LeftVector->end(), DeleteKineticTrack());
175 LeftVector->clear();
176 std::for_each(RightVector->begin(), RightVector->end(), DeleteKineticTrack());
177 RightVector->clear();
178
179 inner_sucess=true; // set false on failure..
180 const G4int maxNumberOfLoops = 1000;
181 G4int loopCounter = -1;
182 while (! StopFragmenting(currentString) && ++loopCounter < maxNumberOfLoops ) /* Loop checking, 07.08.2015, A.Ribon */
183 { // Split current string into hadron + new string
184
185 #ifdef debug_QGSMfragmentation
186 G4cout<<"The string can fragment. "<<G4endl;;
187 #endif
188 G4FragmentingString *newString=0; // used as output from SplitUp...
189 G4KineticTrack * Hadron=Splitup(currentString,newString);
190
191 if ( Hadron != 0 )
192 {
193 #ifdef debug_QGSMfragmentation
194 G4cout<<"Hadron prod at fragm. "<<Hadron->GetDefinition()->GetParticleName()<<G4endl;
195 #endif
196 // To close the production of hadrons at fragmentation stage
197 if ( currentString->GetDecayDirection() > 0 )
198 LeftVector->push_back(Hadron);
199 else
200 RightVector->push_back(Hadron);
201
202 delete currentString;
203 currentString=newString;
204
205 } else {
206
207 #ifdef debug_QGSMfragmentation
208 G4cout<<"abandon ... start from the beginning ---------------"<<G4endl;
209 #endif
210
211 // Abandon ... start from the beginning
212 if (newString) delete newString;
213 inner_sucess=false;
214 break;
215 }
216 }
217 if ( loopCounter >= maxNumberOfLoops ) {
218 inner_sucess=false;
219 }
220
221 // Split current string into 2 final Hadrons
222 #ifdef debug_QGSMfragmentation
223 if( inner_sucess ) {
224 G4cout<<"Split remaining string into 2 final hadrons."<<G4endl;
225 } else {
226 G4cout<<" New attempt to fragment string"<<G4endl;
227 }
228 #endif
229 // To the close production of hadrons at last string decay
230 if ( inner_sucess &&
231 SplitLast(currentString,LeftVector, RightVector) )
232 {
233 success=true;
234 }
235 delete currentString;
236 }
237
238 delete theStringInCMS;
239
240 if ( ! success )
241 {
242 std::for_each(LeftVector->begin(), LeftVector->end(), DeleteKineticTrack());
243 LeftVector->clear();
244 std::for_each(RightVector->begin(), RightVector->end(), DeleteKineticTrack());
245 delete RightVector;
246 return LeftVector;
247 }
248
249 // Join Left- and RightVector into LeftVector in correct order.
250 while(!RightVector->empty()) /* Loop checking, 07.08.2015, A.Ribon */
251 {
252 LeftVector->push_back(RightVector->back());
253 RightVector->erase(RightVector->end()-1);
254 }
255 delete RightVector;
256
257 CalculateHadronTimePosition(theString.Get4Momentum().mag(), LeftVector);
258
259 G4LorentzRotation toObserverFrame(toCms.inverse());
260
261 for (size_t C1 = 0; C1 < LeftVector->size(); C1++)
262 {
263 G4KineticTrack* Hadron = LeftVector->operator[](C1);
264 G4LorentzVector Momentum = Hadron->Get4Momentum();
265 Momentum = toObserverFrame*Momentum;
266 Hadron->Set4Momentum(Momentum);
267 G4LorentzVector Coordinate(Hadron->GetPosition(), Hadron->GetFormationTime());
268 Momentum = toObserverFrame*Coordinate;
269 Hadron->SetFormationTime(Momentum.e());
270 G4ThreeVector aPosition(Momentum.vect());
271 Hadron->SetPosition(theString.GetPosition()+aPosition);
272 }
273 return LeftVector;
274 }
275
276 //----------------------------------------------------------------------------------------------------------
277
278 G4bool G4QGSMFragmentation::IsItFragmentable(const G4FragmentingString * string)
279 {
280 return sqr( MinimalStringMass + MassCut ) < string->Mass2();
281 }
282
283 //----------------------------------------------------------------------------------------------------------
284
285 G4bool G4QGSMFragmentation::StopFragmenting(const G4FragmentingString * string)
286 {
287 SetMinimalStringMass(string);
288 if ( MinimalStringMass < 0.0 ) return true;
289
290 G4double smass = string->Mass();
291 G4double x = (string->IsAFourQuarkString()) ? 0.005*(smass - MinimalStringMass)
292 : 0.66e-6*(smass - MinimalStringMass)*(smass + MinimalStringMass);
293
294 G4bool res = true;
295 if(x > 0.0) {
296 res = (x < 200.) ? (G4UniformRand() < G4Exp(-x)) : false;
297 }
298 return res;
299 }
300
301 //-----------------------------------------------------------------------------
302
303 G4KineticTrack * G4QGSMFragmentation::Splitup( G4FragmentingString *string,
304 G4FragmentingString *&newString )
305 {
306 #ifdef debug_QGSMfragmentation
307 G4cout<<G4endl;
308 G4cout<<"Start SplitUP (G4VLongitudinalStringDecay) ========================="<<G4endl;
309 G4cout<<"String partons: " <<string->GetLeftParton()->GetPDGEncoding()<<" "
310 <<string->GetRightParton()->GetPDGEncoding()<<" "
311 <<"Direction " <<string->GetDecayDirection()<<G4endl;
312 #endif
313
314 //... random choice of string end to use for creating the hadron (decay)
315 G4int SideOfDecay = (G4UniformRand() < 0.5)? 1: -1;
316 if (SideOfDecay < 0)
317 {
318 string->SetLeftPartonStable();
319 } else
320 {
321 string->SetRightPartonStable();
322 }
323
324 G4ParticleDefinition *newStringEnd;
325 G4ParticleDefinition * HadronDefinition;
326 if (string->DecayIsQuark())
327 {
328 G4double ProbDqADq = GetDiquarkSuppress();
329
330 G4int NumberOfpossibleBaryons = 2;
331
332 if (string->GetLeftParton()->GetParticleSubType() != "quark") NumberOfpossibleBaryons++;
333 if (string->GetRightParton()->GetParticleSubType() != "quark") NumberOfpossibleBaryons++;
334
335 G4double ActualProb = ProbDqADq ;
336 ActualProb *= (1.0-G4Exp(2.0*(1.0 - string->Mass()/(NumberOfpossibleBaryons*1400.0))));
337
338 SetDiquarkSuppression(ActualProb);
339
340 HadronDefinition= QuarkSplitup(string->GetDecayParton(), newStringEnd);
341
342 SetDiquarkSuppression(ProbDqADq);
343 } else {
344 HadronDefinition= DiQuarkSplitup(string->GetDecayParton(), newStringEnd);
345 }
346
347 if ( HadronDefinition == NULL ) return NULL;
348
349 #ifdef debug_QGSMfragmentation
350 G4cout<<"The parton "<<string->GetDecayParton()->GetPDGEncoding()<<" "
351 <<" produces hadron "<<HadronDefinition->GetParticleName()
352 <<" and is transformed to "<<newStringEnd->GetPDGEncoding()<<G4endl;
353 G4cout<<"The side of the string decay Left/Right (1/-1) "<<SideOfDecay<<G4endl;
354 #endif
355 // create new String from old, ie. keep Left and Right order, but replace decay
356
357 newString=new G4FragmentingString(*string,newStringEnd); // To store possible
358 // quark containt of new string
359
360 #ifdef debug_QGSMfragmentation
361 G4cout<<"An attempt to determine its energy (SplitEandP)"<<G4endl;
362 #endif
363 G4LorentzVector* HadronMomentum=SplitEandP(HadronDefinition, string, newString);
364
365 delete newString; newString=0;
366
367 G4KineticTrack * Hadron =0;
368 if ( HadronMomentum != 0 ) {
369
370 #ifdef debug_QGSMfragmentation
371 G4cout<<"The attempt was successful"<<G4endl;
372 #endif
373 G4ThreeVector Pos;
374 Hadron = new G4KineticTrack(HadronDefinition, 0,Pos, *HadronMomentum);
375
376 newString=new G4FragmentingString(*string,newStringEnd,HadronMomentum);
377
378 delete HadronMomentum;
379 }
380 else
381 {
382 #ifdef debug_QGSMfragmentation
383 G4cout<<"The attempt was not successful !!!"<<G4endl;
384 #endif
385 }
386
387 #ifdef debug_VStringDecay
388 G4cout<<"End SplitUP (G4VLongitudinalStringDecay) ====================="<<G4endl;
389 #endif
390
391 return Hadron;
392 }
393
394 //-----------------------------------------------------------------------------
395
396 G4ParticleDefinition *G4QGSMFragmentation::DiQuarkSplitup( G4ParticleDefinition* decay,
397 G4ParticleDefinition *&created )
398 {
399 //... can Diquark break or not?
400 if (G4UniformRand() < DiquarkBreakProb ) //... Diquark break
401 {
402 G4int stableQuarkEncoding = decay->GetPDGEncoding()/1000;
403 G4int decayQuarkEncoding = (decay->GetPDGEncoding()/100)%10;
404
405 if (G4UniformRand() < 0.5)
406 {
407 G4int Swap = stableQuarkEncoding;
408 stableQuarkEncoding = decayQuarkEncoding;
409 decayQuarkEncoding = Swap;
410 }
411
412 G4int IsParticle=(decayQuarkEncoding>0) ? -1 : +1; // if we have a quark, we need antiquark
413
414 G4double StrSup=GetStrangeSuppress();
415 SetStrangenessSuppression((1.0 - 0.07)/2.); // Prob qq->K qq' 0.07
416 pDefPair QuarkPair = CreatePartonPair(IsParticle,false); // no diquarks wanted
417 SetStrangenessSuppression(StrSup);
418
419 //... Build new Diquark
420 G4int QuarkEncoding=QuarkPair.second->GetPDGEncoding();
421 G4int i10 = std::max(std::abs(QuarkEncoding), std::abs(stableQuarkEncoding));
422 G4int i20 = std::min(std::abs(QuarkEncoding), std::abs(stableQuarkEncoding));
423 G4int spin = (i10 != i20 && G4UniformRand() <= 0.5)? 1 : 3;
424 G4int NewDecayEncoding = -1*IsParticle*(i10 * 1000 + i20 * 100 + spin);
425
426 created = FindParticle(NewDecayEncoding);
427 G4ParticleDefinition * decayQuark=FindParticle(decayQuarkEncoding);
428 G4ParticleDefinition * had=hadronizer->Build(QuarkPair.first, decayQuark);
429
430 DecayQuark = decay->GetPDGEncoding();
431 NewQuark = NewDecayEncoding;
432
433 return had;
434
435 } else { //... Diquark does not break
436
437 G4int IsParticle=(decay->GetPDGEncoding()>0) ? +1 : -1; // if we have a diquark, we need quark)
438 G4double StrSup=GetStrangeSuppress(); // for changing s-sbar production
439 SetStrangenessSuppression((1.0 - 0.07)/2.);
440 pDefPair QuarkPair = CreatePartonPair(IsParticle,false); // no diquarks wanted
441 SetStrangenessSuppression(StrSup);
442
443 created = QuarkPair.second;
444
445 DecayQuark = decay->GetPDGEncoding();
446 NewQuark = created->GetPDGEncoding();
447
448 G4ParticleDefinition * had=hadronizer->Build(QuarkPair.first, decay);
449 return had;
450 }
451 }
452
453 //-----------------------------------------------------------------------------------------
454
455 G4LorentzVector * G4QGSMFragmentation::SplitEandP(G4ParticleDefinition * pHadron,
456 G4FragmentingString * string,
457 G4FragmentingString * NewString)
458 {
459 G4double HadronMass = pHadron->GetPDGMass();
460
461 SetMinimalStringMass(NewString);
462
463 if ( MinimalStringMass < 0.0 ) return nullptr;
464
465 #ifdef debug_QGSMfragmentation
466 G4cout<<"G4QGSMFragmentation::SplitEandP "<<pHadron->GetParticleName()<<G4endl;
467 G4cout<<"String 4 mom, String M "<<string->Get4Momentum()<<" "<<string->Mass()<<G4endl;
468 G4cout<<"HadM MinimalStringMassLeft StringM hM+sM "<<HadronMass<<" "<<MinimalStringMass<<" "
469 <<string->Mass()<<" "<<HadronMass+MinimalStringMass<<G4endl;
470 #endif
471
472 if (HadronMass + MinimalStringMass > string->Mass())
473 {
474 #ifdef debug_QGSMfragmentation
475 G4cout<<"Mass of the string is not sufficient to produce the hadron!"<<G4endl;
476 #endif
477 return 0;
478 } // have to start all over!
479
480 // calculate and assign hadron transverse momentum component HadronPx andHadronPy
481 G4double StringMT2 = string->MassT2();
482 G4double StringMT = std::sqrt(StringMT2);
483
484 G4LorentzVector String4Momentum = string->Get4Momentum();
485 String4Momentum.setPz(0.);
486 G4ThreeVector StringPt = String4Momentum.vect();
487
488 G4ThreeVector HadronPt , RemSysPt;
489 G4double HadronMassT2, ResidualMassT2;
490
491 // Mt distribution is implemented
492 G4double HadronMt, Pt, Pt2, phi;
493
494 //... sample Pt of the hadron
495 G4int attempt=0;
496 do
497 {
498 attempt++; if (attempt > StringLoopInterrupt) return 0;
499
500 HadronMt = HadronMass - 200.0*G4Log(G4UniformRand()); // 200.0 must be tuned
501 Pt2 = sqr(HadronMt)-sqr(HadronMass); Pt=std::sqrt(Pt2);
502 phi = 2.*pi*G4UniformRand();
503 G4ThreeVector SampleQuarkPtw= G4ThreeVector(Pt*std::cos(phi), Pt*std::sin(phi), 0);
504 HadronPt =SampleQuarkPtw + string->DecayPt();
505 HadronPt.setZ(0);
506 RemSysPt = StringPt - HadronPt;
507
508 HadronMassT2 = sqr(HadronMass) + HadronPt.mag2();
509 ResidualMassT2=sqr(MinimalStringMass) + RemSysPt.mag2();
510
511 } while (std::sqrt(HadronMassT2) + std::sqrt(ResidualMassT2) > StringMT); /* Loop checking, 07.08.2015, A.Ribon */
512
513 //... sample z to define hadron longitudinal momentum and energy
514 //... but first check the available phase space
515
516 G4double Pz2 = (sqr(StringMT2 - HadronMassT2 - ResidualMassT2) -
517 4*HadronMassT2 * ResidualMassT2)/4./StringMT2;
518
519 if ( Pz2 < 0 ) {return 0;} // have to start all over!
520
521 //... then compute allowed z region z_min <= z <= z_max
522
523 G4double Pz = std::sqrt(Pz2);
524 G4double zMin = (std::sqrt(HadronMassT2+Pz2) - Pz)/std::sqrt(StringMT2);
525 G4double zMax = (std::sqrt(HadronMassT2+Pz2) + Pz)/std::sqrt(StringMT2);
526
527 if (zMin >= zMax) return 0; // have to start all over!
528
529 G4double z = GetLightConeZ(zMin, zMax,
530 string->GetDecayParton()->GetPDGEncoding(), pHadron,
531 HadronPt.x(), HadronPt.y());
532
533 //... now compute hadron longitudinal momentum and energy
534 // longitudinal hadron momentum component HadronPz
535
536 HadronPt.setZ( 0.5* string->GetDecayDirection() *
537 (z * string->LightConeDecay() -
538 HadronMassT2/(z * string->LightConeDecay())) );
539 G4double HadronE = 0.5* (z * string->LightConeDecay() +
540 HadronMassT2/(z * string->LightConeDecay()) );
541
542 G4LorentzVector * a4Momentum= new G4LorentzVector(HadronPt,HadronE);
543
544 #ifdef debug_QGSMfragmentation
545 G4cout<<"string->GetDecayDirection() string->LightConeDecay() "
546 <<string->GetDecayDirection()<<" "<<string->LightConeDecay()<<G4endl;
547 G4cout<<"HadronPt,HadronE "<<HadronPt<<" "<<HadronE<<G4endl;
548 G4cout<<"Out of QGSM SplitEandP "<<G4endl;
549 #endif
550
551 return a4Momentum;
552 }
553
554 //----------------------------------------------------------------------------------------------------------
555
556 G4double G4QGSMFragmentation::GetLightConeZ(G4double zmin, G4double zmax, G4int /* PartonEncoding */ ,
557 G4ParticleDefinition* /* pHadron */, G4double ptx , G4double pty)
558 {
559 G4double lambda = 2.0*(sqr(ptx)+sqr(pty))/sqr(GeV);
560
561 #ifdef debug_QGSMfragmentation
562 G4cout<<"GetLightConeZ zmin zmax Parton pHadron "<<zmin<<" "<<zmax<<" "/*<< PartonEncoding */
563 <<" "/*<< pHadron->GetParticleName() */ <<G4endl;
564 #endif
565
566 G4double z(0.);
567 G4int DiQold(0), DiQnew(0);
568 G4double d1(-1.0), d2(0.);
569 G4double invD1(0.),invD2(0.), r1(0.),r2(0.),r12(0.);
570
571 G4int absDecayQuarkCode = std::abs( DecayQuark );
572 G4int absNewQuarkCode = std::abs( NewQuark );
573
574 G4int q1(0), q2(0);
575 // q1 = absDecayQuarkCode/1000; q2 = (absDecayQuarkCode % 1000)/100;
576
577 G4int qA(0), qB(0);
578 // qA = absNewQuarkCode/1000; qB = (absNewQuarkCode % 1000)/100;
579
580 if ( (absDecayQuarkCode < 6) && (absNewQuarkCode < 6) ) {
581 d1 = FFq2q[absDecayQuarkCode-1][absNewQuarkCode-1][0]; d2 = FFq2q[absDecayQuarkCode-1][absNewQuarkCode-1][1];
582 }
583
584 if ( (absDecayQuarkCode < 6) && (absNewQuarkCode > 6) ) {
585 qA = absNewQuarkCode/1000; qB = (absNewQuarkCode % 1000)/100; DiQnew = IndexDiQ[qA-1][qB-1];
586 d1 = FFq2qq[absDecayQuarkCode-1][DiQnew][0]; d2 = FFq2q[absDecayQuarkCode-1][DiQnew][1];
587 }
588
589 if ( (absDecayQuarkCode > 6) && (absNewQuarkCode < 6) ) {
590 q1 = absDecayQuarkCode/1000; q2 = (absDecayQuarkCode % 1000)/100; DiQold = IndexDiQ[q1-1][q2-1];
591 d1 = FFqq2q[DiQold][absNewQuarkCode-1][0]; d2 = FFqq2q[DiQold][absNewQuarkCode-1][1];
592 }
593
594 if ( d1 < 0. ) {
595 q1 = absDecayQuarkCode/1000; q2 = (absDecayQuarkCode % 1000)/100; DiQold = IndexDiQ[q1-1][q2-1];
596 qA = absNewQuarkCode/1000; qB = (absNewQuarkCode % 1000)/100; DiQnew = IndexDiQ[qA-1][qB-1];
597 d1 = FFqq2qq[DiQold][DiQnew][0]; d2 = FFqq2qq[DiQold][DiQnew][1];
598 }
599
600 d2 +=lambda;
601 d1+=1.0; d2+=1.0;
602
603 invD1=1./d1; invD2=1./d2;
604
605 const G4int maxNumberOfLoops = 10000;
606 G4int loopCounter = 0;
607 do // Jong's algorithm
608 {
609 r1=G4Pow::GetInstance()->powA(G4UniformRand(),invD1);
610 r2=G4Pow::GetInstance()->powA(G4UniformRand(),invD2);
611 r12=r1+r2;
612 z=r1/r12;
613 } while ( ( (r12 > 1.0) || !((zmin <= z)&&(z <= zmax))) &&
614 ++loopCounter < maxNumberOfLoops ); /* Loop checking, 07.08.2015, A.Ribon */
615
616 if ( loopCounter >= maxNumberOfLoops ) {
617 z = 0.5*(zmin + zmax); // Just a value between zmin and zmax, no physics considerations at all!
618 }
619
620 return z;
621 }
622
623 //-----------------------------------------------------------------------------------------
624
625 G4bool G4QGSMFragmentation::SplitLast(G4FragmentingString * string,
626 G4KineticTrackVector * LeftVector,
627 G4KineticTrackVector * RightVector)
628 {
629 //... perform last cluster decay
630
631 G4ThreeVector ClusterVel =string->Get4Momentum().boostVector();
632 G4double ResidualMass =string->Mass();
633
634 #ifdef debug_QGSMfragmentation
635 G4cout<<"Split last-----------------------------------------"<<G4endl;
636 G4cout<<"StrMass "<<ResidualMass<<" q's "
637 <<string->GetLeftParton()->GetParticleName()<<" "
638 <<string->GetRightParton()->GetParticleName()<<G4endl;
639 #endif
640
641 G4int cClusterInterrupt = 0;
642 G4ParticleDefinition *LeftHadron = nullptr;
643 G4ParticleDefinition *RightHadron = nullptr;
644 const G4int maxNumberOfLoops = 1000;
645 G4int loopCounter = 0;
646
647 G4double LeftHadronMass(0.); G4double RightHadronMass(0.);
648 do
649 {
650 if (cClusterInterrupt++ >= ClusterLoopInterrupt) return false;
651 LeftHadronMass = -MaxMass; RightHadronMass = -MaxMass;
652
653 G4ParticleDefinition * quark = nullptr;
654 string->SetLeftPartonStable(); // to query quark contents..
655
656 if (string->DecayIsQuark() && string->StableIsQuark() )
657 {
658 //... there are quarks on cluster ends
659
660 G4int IsParticle=(string->GetLeftParton()->GetPDGEncoding()>0) ? -1 : +1;
661 // if we have a quark, we need antiquark or diquark
662
663 pDefPair QuarkPair = CreatePartonPair(IsParticle);
664 quark = QuarkPair.second;
665
666 LeftHadron= hadronizer->Build(QuarkPair.first, string->GetLeftParton());
667 if ( LeftHadron == NULL ) continue;
668 RightHadron = hadronizer->Build(string->GetRightParton(), quark);
669 if ( RightHadron == NULL ) continue;
670 } else if( (!string->DecayIsQuark() && string->StableIsQuark() ) ||
671 ( string->DecayIsQuark() && !string->StableIsQuark() ) ) {
672 //... there is a Diquark on one of cluster ends
673 G4int IsParticle;
674 if ( string->StableIsQuark() ) {
675 IsParticle=(string->GetLeftParton()->GetPDGEncoding()>0) ? -1 : +1;
676 } else {
677 IsParticle=(string->GetLeftParton()->GetPDGEncoding()>0) ? +1 : -1;
678 }
679
680 //G4double ProbSaS = 1.0 - 2.0 * GetStrangeSuppress();
681 //G4double ActualProb = ProbSaS * 1.4;
682 //SetStrangenessSuppression((1.0-ActualProb)/2.0);
683
684 pDefPair QuarkPair = CreatePartonPair(IsParticle,false); // no diquarks wanted
685 //SetStrangenessSuppression((1.0-ProbSaS)/2.0);
686 quark = QuarkPair.second;
687 LeftHadron=hadronizer->Build(QuarkPair.first, string->GetLeftParton());
688 if ( LeftHadron == NULL ) continue;
689 RightHadron = hadronizer->Build(string->GetRightParton(), quark);
690 if ( RightHadron == NULL ) continue;
691 } else { // Diquark and anti-diquark are on the string ends
692 if (cClusterInterrupt++ >= ClusterLoopInterrupt) return false;
693 G4int LeftQuark1= string->GetLeftParton()->GetPDGEncoding()/1000;
694 G4int LeftQuark2=(string->GetLeftParton()->GetPDGEncoding()/100)%10;
695 G4int RightQuark1= string->GetRightParton()->GetPDGEncoding()/1000;
696 G4int RightQuark2=(string->GetRightParton()->GetPDGEncoding()/100)%10;
697 if (G4UniformRand()<0.5) {
698 LeftHadron =hadronizer->Build(FindParticle( LeftQuark1), FindParticle(RightQuark1));
699 RightHadron =hadronizer->Build(FindParticle( LeftQuark2), FindParticle(RightQuark2));
700 } else {
701 LeftHadron =hadronizer->Build(FindParticle( LeftQuark1), FindParticle(RightQuark2));
702 RightHadron =hadronizer->Build(FindParticle( LeftQuark2), FindParticle(RightQuark1));
703 }
704 if ( (LeftHadron == NULL) || (RightHadron == NULL) ) continue;
705 }
706 LeftHadronMass = LeftHadron->GetPDGMass();
707 RightHadronMass = RightHadron->GetPDGMass();
708 //... repeat procedure, if mass of cluster is too low to produce hadrons
709 } while ( ( ResidualMass <= LeftHadronMass + RightHadronMass )
710 && ++loopCounter < maxNumberOfLoops ); /* Loop checking, 07.08.2015, A.Ribon */
711
712 if ( loopCounter >= maxNumberOfLoops ) {
713 return false;
714 }
715
716 //... compute hadron momenta and energies
717 G4LorentzVector LeftMom, RightMom;
718 G4ThreeVector Pos;
719 Sample4Momentum(&LeftMom , LeftHadron->GetPDGMass() ,
720 &RightMom, RightHadron->GetPDGMass(), ResidualMass);
721 LeftMom.boost(ClusterVel);
722 RightMom.boost(ClusterVel);
723
724 #ifdef debug_QGSMfragmentation
725 G4cout<<LeftHadron->GetParticleName()<<" "<<RightHadron->GetParticleName()<<G4endl;
726 G4cout<<"Left Hadrom P M "<<LeftMom<<" "<<LeftMom.mag()<<G4endl;
727 G4cout<<"Right Hadrom P M "<<RightMom<<" "<<RightMom.mag()<<G4endl;
728 #endif
729
730 LeftVector->push_back(new G4KineticTrack(LeftHadron, 0, Pos, LeftMom));
731 RightVector->push_back(new G4KineticTrack(RightHadron, 0, Pos, RightMom));
732
733 return true;
734 }
735
736 //----------------------------------------------------------------------------------------------------------
737
738 void G4QGSMFragmentation::Sample4Momentum(G4LorentzVector* Mom , G4double Mass ,
739 G4LorentzVector* AntiMom, G4double AntiMass, G4double InitialMass)
740 {
741 #ifdef debug_QGSMfragmentation
742 G4cout<<"Sample4Momentum Last-----------------------------------------"<<G4endl;
743 G4cout<<" StrMass "<<InitialMass<<" Mass1 "<<Mass<<" Mass2 "<<AntiMass<<G4endl;
744 G4cout<<" SumMass "<<Mass+AntiMass<<G4endl;
745 #endif
746
747 G4double r_val = sqr(InitialMass*InitialMass - Mass*Mass - AntiMass*AntiMass) - sqr(2.*Mass*AntiMass);
748 G4double Pabs = (r_val > 0.)? std::sqrt(r_val)/(2.*InitialMass) : 0;
749
750 //... sample unit vector
751 G4double pz = 1. - 2.*G4UniformRand();
752 G4double st = std::sqrt(1. - pz * pz)*Pabs;
753 G4double phi = 2.*pi*G4UniformRand();
754 G4double px = st*std::cos(phi);
755 G4double py = st*std::sin(phi);
756 pz *= Pabs;
757
758 Mom->setPx(px); Mom->setPy(py); Mom->setPz(pz);
759 Mom->setE(std::sqrt(Pabs*Pabs + Mass*Mass));
760
761 AntiMom->setPx(-px); AntiMom->setPy(-py); AntiMom->setPz(-pz);
762 AntiMom->setE (std::sqrt(Pabs*Pabs + AntiMass*AntiMass));
763 }
764
765 //----------------------------------------------------------------------------------------------------------
766
767 void G4QGSMFragmentation::SetFFq2q() // q-> q' + Meson (q anti q')
768 {
769 for (G4int i=0; i < 5; i++) {
770 FFq2q[i][0][0] = 2.0 ; FFq2q[i][0][1] = -arho + alft; // q->d + (q dbar) Pi0, Eta, Eta', Rho0, omega
771 FFq2q[i][1][0] = 2.0 ; FFq2q[i][1][1] = -arho + alft; // q->u + (q ubar) Pi-, Rho-
772 FFq2q[i][2][0] = 1.0 ; FFq2q[i][2][1] = -aphi + alft; // q->s + (q sbar) K0, K*0
773 FFq2q[i][3][0] = 1.0 ; FFq2q[i][3][1] = -aJPs + alft; // q->c + (q+cbar) D-, D*-
774 FFq2q[i][4][0] = 1.0 ; FFq2q[i][4][1] = -aUps + alft; // q->b + (q bbar) EtaB, Upsilon
775 }
776 }
777
778 //----------------------------------------------------------------------------------------------------------
779
780 void G4QGSMFragmentation::SetFFq2qq() // q-> anti (q1'q2') + Baryon (q + q1 + q2)
781 {
782 for (G4int i=0; i < 5; i++) {
783 FFq2qq[i][ 0][0] = 0.0 ; FFq2qq[i][ 0][1] = arho - 2.0*an + alft; // q->dd bar + (q dd)
784 FFq2qq[i][ 1][0] = 0.0 ; FFq2qq[i][ 1][1] = arho - 2.0*an + alft; // q->ud bar + (q ud)
785 FFq2qq[i][ 2][0] = 0.0 ; FFq2qq[i][ 2][1] = arho - 2.0*ala + alft; // q->sd bar + (q sd)
786 FFq2qq[i][ 3][0] = 0.0 ; FFq2qq[i][ 3][1] = arho - 2.0*alaC + alft; // q->cd bar + (q cd)
787 FFq2qq[i][ 4][0] = 0.0 ; FFq2qq[i][ 4][1] = arho - 2.0*alaB + alft; // q->bd bar + (q bd)
788 FFq2qq[i][ 5][0] = 0.0 ; FFq2qq[i][ 5][1] = arho - 2.0*an + alft; // q->uu bar + (q uu)
789 FFq2qq[i][ 6][0] = 0.0 ; FFq2qq[i][ 6][1] = arho - 2.0*ala + alft; // q->su bar + (q su)
790 FFq2qq[i][ 7][0] = 0.0 ; FFq2qq[i][ 7][1] = arho - 2.0*alaC + alft; // q->cu bar + (q cu)
791 FFq2qq[i][ 8][0] = 0.0 ; FFq2qq[i][ 8][1] = arho - 2.0*alaB + alft; // q->bu bar + (q bu)
792 FFq2qq[i][ 9][0] = 0.0 ; FFq2qq[i][ 9][1] = arho - 2.0*aXi + alft; // q->ss bar + (q ss)
793 FFq2qq[i][10][0] = 0.0 ; FFq2qq[i][10][1] = arho - 2.0*aXiC + alft; // q->cs bar + (q cs)
794 FFq2qq[i][11][0] = 0.0 ; FFq2qq[i][11][1] = arho - 2.0*aXiB + alft; // q->bs bar + (q bc)
795 FFq2qq[i][12][0] = 0.0 ; FFq2qq[i][12][1] = arho - 2.0*aXiCC + alft; // q->cc bar + (q cc)
796 FFq2qq[i][13][0] = 0.0 ; FFq2qq[i][13][1] = arho - 2.0*aXiCB + alft; // q->bc bar + (q bc)
797 FFq2qq[i][14][0] = 0.0 ; FFq2qq[i][14][1] = arho - 2.0*aXiBB + alft; // q->bb bar + (q bb)
798 }
799 }
800
801 //----------------------------------------------------------------------------------------------------------
802
803 void G4QGSMFragmentation::SetFFqq2q() // q1q2-> anti(q') + Baryon (q1 + q2 + q')
804 {
805 for (G4int i=0; i < 15; i++) {
806 FFqq2q[i][0][0] = 2.0*(arho - an); FFqq2q[i][0][1] = -arho + alft;
807 FFqq2q[i][1][0] = 2.0*(arho - an); FFqq2q[i][1][1] = -arho + alft;
808 FFqq2q[i][2][0] = 2.0*(arho - an); FFqq2q[i][2][1] = -aphi + alft;
809 FFqq2q[i][3][0] = 2.0*(arho - an); FFqq2q[i][3][1] = -aJPs + alft;
810 FFqq2q[i][4][0] = 2.0*(arho - an); FFqq2q[i][4][1] = -aUps + alft;
811 }
812 }
813
814 //----------------------------------------------------------------------------------------------------------
815
816 void G4QGSMFragmentation::SetFFqq2qq() // q1(q2)-> q'(q2) + Meson(q1 anti q')
817 {
818 for (G4int i=0; i < 15; i++) {
819 FFqq2qq[i][0][0] = 0. ; FFqq2qq[i][0][1] = 2.0*arho - 2.0*an -arho + alft; // dd -> dd + Pi0 (d d bar)
820 FFqq2qq[i][1][0] = 0. ; FFqq2qq[i][1][1] = 2.0*arho - 2.0*an -arho + alft; // dd -> ud + Pi- (d u bar)
821 FFqq2qq[i][2][0] = 0. ; FFqq2qq[i][2][1] = 2.0*arho - 2.0*an -aphi + alft; // dd -> sd + K0 (d s bar)
822 FFqq2qq[i][3][0] = 0. ; FFqq2qq[i][3][1] = 2.0*arho - 2.0*an -aJPs + alft; // dd -> cd + D- (d c bar)
823 FFqq2qq[i][4][0] = 0. ; FFqq2qq[i][4][1] = 2.0*arho - 2.0*an -aUps + alft; // dd -> bd + B0 (d b bar)
824 }
825 }
826
827