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26 // $Id: G4ANuMuNucleusCcModel.cc 91806 2015-08-06 12:20:45Z gcosmo $
27 //
28 // Geant4 Header : G4ANuMuNucleusCcModel
29 //
30 // Author : V.Grichine 12.2.19
31 //
32
33 #include <iostream>
34 #include <fstream>
35 #include <sstream>
36
37 #include "G4ANuMuNucleusCcModel.hh"
38 // #include "G4NuMuNuclCcDistrKR.hh"
39
40 // #include "G4NuMuResQX.hh"
41
42 #include "G4SystemOfUnits.hh"
43 #include "G4ParticleTable.hh"
44 #include "G4ParticleDefinition.hh"
45 #include "G4IonTable.hh"
46 #include "Randomize.hh"
47 #include "G4RandomDirection.hh"
48 // #include "G4Threading.hh"
49
50 // #include "G4Integrator.hh"
51 #include "G4DataVector.hh"
52 #include "G4PhysicsTable.hh"
53 /*
54 #include "G4CascadeInterface.hh"
55 // #include "G4BinaryCascade.hh"
56 #include "G4TheoFSGenerator.hh"
57 #include "G4LundStringFragmentation.hh"
58 #include "G4ExcitedStringDecay.hh"
59 #include "G4FTFModel.hh"
60 // #include "G4BinaryCascade.hh"
61 #include "G4HadFinalState.hh"
62 #include "G4HadSecondary.hh"
63 #include "G4HadronicInteractionRegistry.hh"
64 // #include "G4INCLXXInterface.hh"
65 #include "G4QGSModel.hh"
66 #include "G4QGSMFragmentation.hh"
67 #include "G4QGSParticipants.hh"
68 */
69 #include "G4KineticTrack.hh"
70 #include "G4DecayKineticTracks.hh"
71 #include "G4KineticTrackVector.hh"
72 #include "G4Fragment.hh"
73 #include "G4NucleiProperties.hh"
74 #include "G4ReactionProductVector.hh"
75
76 #include "G4GeneratorPrecompoundInterface.hh"
77 #include "G4PreCompoundModel.hh"
78 #include "G4ExcitationHandler.hh"
79
80
81 // #include "G4MuonMinus.hh"
82 #include "G4MuonPlus.hh"
83 #include "G4Nucleus.hh"
84 #include "G4LorentzVector.hh"
85
86 using namespace std;
87 using namespace CLHEP;
88
89 #ifdef G4MULTITHREADED
90 G4Mutex G4ANuMuNucleusCcModel::numuNucleusModel = G4MUTEX_INITIALIZER;
91 #endif
92
93
94 G4ANuMuNucleusCcModel::G4ANuMuNucleusCcModel(const G4String& name)
95 : G4NeutrinoNucleusModel(name)
96 {
97 fData = fMaster = false;
98 InitialiseModel();
99 }
100
101
102 G4ANuMuNucleusCcModel::~G4ANuMuNucleusCcModel()
103 {}
104
105
106 void G4ANuMuNucleusCcModel::ModelDescription(std::ostream& outFile) const
107 {
108
109 outFile << "G4ANuMuNucleusCcModel is a neutrino-nucleus (charge current) scattering\n"
110 << "model which uses the standard model \n"
111 << "transfer parameterization. The model is fully relativistic\n";
112
113 }
114
115 /////////////////////////////////////////////////////////
116 //
117 // Read data from G4PARTICLEXSDATA (locally PARTICLEXSDATA)
118
119 void G4ANuMuNucleusCcModel::InitialiseModel()
120 {
121 G4String pName = "anti_nu_mu";
122
123 G4int nSize(0), i(0), j(0), k(0);
124
125 if(!fData)
126 {
127 #ifdef G4MULTITHREADED
128 G4MUTEXLOCK(&numuNucleusModel);
129 if(!fData)
130 {
131 #endif
132 fMaster = true;
133 #ifdef G4MULTITHREADED
134 }
135 G4MUTEXUNLOCK(&numuNucleusModel);
136 #endif
137 }
138
139 if(fMaster)
140 {
141 const char* path = G4FindDataDir("G4PARTICLEXSDATA");
142 std::ostringstream ost1, ost2, ost3, ost4;
143 ost1 << path << "/" << "neutrino" << "/" << pName << "/xarraycckr";
144
145 std::ifstream filein1( ost1.str().c_str() );
146
147 // filein.open("$PARTICLEXSDATA/");
148
149 filein1>>nSize;
150
151 for( k = 0; k < fNbin; ++k )
152 {
153 for( i = 0; i <= fNbin; ++i )
154 {
155 filein1 >> fNuMuXarrayKR[k][i];
156 // G4cout<< fNuMuXarrayKR[k][i] << " ";
157 }
158 }
159 // G4cout<<G4endl<<G4endl;
160
161 ost2 << path << "/" << "neutrino" << "/" << pName << "/xdistrcckr";
162 std::ifstream filein2( ost2.str().c_str() );
163
164 filein2>>nSize;
165
166 for( k = 0; k < fNbin; ++k )
167 {
168 for( i = 0; i < fNbin; ++i )
169 {
170 filein2 >> fNuMuXdistrKR[k][i];
171 // G4cout<< fNuMuXdistrKR[k][i] << " ";
172 }
173 }
174 // G4cout<<G4endl<<G4endl;
175
176 ost3 << path << "/" << "neutrino" << "/" << pName << "/q2arraycckr";
177 std::ifstream filein3( ost3.str().c_str() );
178
179 filein3>>nSize;
180
181 for( k = 0; k < fNbin; ++k )
182 {
183 for( i = 0; i <= fNbin; ++i )
184 {
185 for( j = 0; j <= fNbin; ++j )
186 {
187 filein3 >> fNuMuQarrayKR[k][i][j];
188 // G4cout<< fNuMuQarrayKR[k][i][j] << " ";
189 }
190 }
191 }
192 // G4cout<<G4endl<<G4endl;
193
194 ost4 << path << "/" << "neutrino" << "/" << pName << "/q2distrcckr";
195 std::ifstream filein4( ost4.str().c_str() );
196
197 filein4>>nSize;
198
199 for( k = 0; k < fNbin; ++k )
200 {
201 for( i = 0; i <= fNbin; ++i )
202 {
203 for( j = 0; j < fNbin; ++j )
204 {
205 filein4 >> fNuMuQdistrKR[k][i][j];
206 // G4cout<< fNuMuQdistrKR[k][i][j] << " ";
207 }
208 }
209 }
210 fData = true;
211 }
212 }
213
214 /////////////////////////////////////////////////////////
215
216 G4bool G4ANuMuNucleusCcModel::IsApplicable(const G4HadProjectile & aPart,
217 G4Nucleus & )
218 {
219 G4bool result = false;
220 G4String pName = aPart.GetDefinition()->GetParticleName();
221 G4double energy = aPart.GetTotalEnergy();
222
223 if( pName == "anti_nu_mu"
224 &&
225 energy > fMinNuEnergy )
226 {
227 result = true;
228 }
229
230 return result;
231 }
232
233 /////////////////////////////////////////// ClusterDecay ////////////////////////////////////////////////////////////
234 //
235 //
236
237 G4HadFinalState* G4ANuMuNucleusCcModel::ApplyYourself(
238 const G4HadProjectile& aTrack, G4Nucleus& targetNucleus)
239 {
240 theParticleChange.Clear();
241 fProton = f2p2h = fBreak = false;
242 fCascade = fString = false;
243 fLVh = fLVl = fLVt = fLVcpi = G4LorentzVector(0.,0.,0.,0.);
244
245 const G4HadProjectile* aParticle = &aTrack;
246 G4double energy = aParticle->GetTotalEnergy();
247
248 G4String pName = aParticle->GetDefinition()->GetParticleName();
249
250 if( energy < fMinNuEnergy )
251 {
252 theParticleChange.SetEnergyChange(energy);
253 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
254 return &theParticleChange;
255 }
256
257 SampleLVkr( aTrack, targetNucleus);
258
259 if( fBreak == true || fEmu < fMu ) // ~5*10^-6
260 {
261 // G4cout<<"ni, ";
262 theParticleChange.SetEnergyChange(energy);
263 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
264 return &theParticleChange;
265 }
266
267 // LVs of initial state
268
269 G4LorentzVector lvp1 = aParticle->Get4Momentum();
270 G4LorentzVector lvt1( 0., 0., 0., fM1 );
271 G4double mPip = G4ParticleTable::GetParticleTable()->FindParticle(211)->GetPDGMass();
272
273 // 1-pi by fQtransfer && nu-energy
274 G4LorentzVector lvpip1( 0., 0., 0., mPip );
275 G4LorentzVector lvsum, lv2, lvX;
276 G4ThreeVector eP;
277 G4double cost(1.), sint(0.), phi(0.), muMom(0.), massX2(0.), massX(0.), massR(0.), eCut(0.);
278 G4DynamicParticle* aLept = nullptr; // lepton lv
279
280 G4int Z = targetNucleus.GetZ_asInt();
281 G4int A = targetNucleus.GetA_asInt();
282 G4double mTarg = targetNucleus.AtomicMass(A,Z);
283 G4int pdgP(0), qB(0);
284 // G4double mSum = G4ParticleTable::GetParticleTable()->FindParticle(2212)->GetPDGMass() + mPip;
285
286 G4int iPi = GetOnePionIndex(energy);
287 G4double p1pi = GetNuMuOnePionProb( iPi, energy);
288
289 if( p1pi > G4UniformRand() && fCosTheta > 0.9 ) // && fQtransfer < 0.95*GeV ) // mu- & coherent pion + nucleus
290 {
291 // lvsum = lvp1 + lvpip1;
292 lvsum = lvp1 + lvt1;
293 // cost = fCosThetaPi;
294 cost = fCosTheta;
295 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
296 phi = G4UniformRand()*CLHEP::twopi;
297 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
298
299 // muMom = sqrt(fEmuPi*fEmuPi-fMu*fMu);
300 muMom = sqrt(fEmu*fEmu-fMu*fMu);
301
302 eP *= muMom;
303
304 // lv2 = G4LorentzVector( eP, fEmuPi );
305 // lv2 = G4LorentzVector( eP, fEmu );
306 lv2 = fLVl;
307
308 // lvX = lvsum - lv2;
309 lvX = fLVh;
310 massX2 = lvX.m2();
311 massX = lvX.m();
312 massR = fLVt.m();
313
314 if ( massX2 <= 0. ) // vmg: very rarely ~ (1-4)e-6 due to big Q2/x, to be improved
315 {
316 fCascade = true;
317 theParticleChange.SetEnergyChange(energy);
318 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
319 return &theParticleChange;
320 }
321 fW2 = massX2;
322
323 if( pName == "anti_nu_mu") aLept = new G4DynamicParticle( theMuonPlus, lv2 );
324 else
325 {
326 theParticleChange.SetEnergyChange(energy);
327 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
328 return &theParticleChange;
329 }
330 if( pName == "anti_nu_mu" ) pdgP = -211;
331 // else pdgP = -211;
332 // eCut = fMpi + 0.5*(fMpi*fMpi-massX2)/mTarg; // massX -> fMpi
333
334 if( A > 1 )
335 {
336 eCut = (fMpi + mTarg)*(fMpi + mTarg) - (massX + massR)*(massX + massR);
337 eCut /= 2.*massR;
338 eCut += massX;
339 }
340 else eCut = fM1 + fMpi;
341
342 if ( lvX.e() > eCut ) // && sqrt( GetW2() ) < 1.4*GeV ) //
343 {
344 CoherentPion( lvX, pdgP, targetNucleus);
345 }
346 else
347 {
348 fCascade = true;
349 theParticleChange.SetEnergyChange(energy);
350 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
351 return &theParticleChange;
352 }
353 theParticleChange.AddSecondary( aLept, fSecID );
354
355 return &theParticleChange;
356 }
357 else // lepton part in lab
358 {
359 lvsum = lvp1 + lvt1;
360 cost = fCosTheta;
361 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
362 phi = G4UniformRand()*CLHEP::twopi;
363 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
364
365 muMom = sqrt(fEmu*fEmu-fMu*fMu);
366
367 eP *= muMom;
368
369 lv2 = G4LorentzVector( eP, fEmu );
370 lv2 = fLVl;
371 lvX = lvsum - lv2;
372 lvX = fLVh;
373 massX2 = lvX.m2();
374
375 if ( massX2 <= 0. ) // vmg: very rarely ~ (1-4)e-6 due to big Q2/x, to be improved
376 {
377 fCascade = true;
378 theParticleChange.SetEnergyChange(energy);
379 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
380 return &theParticleChange;
381 }
382 fW2 = massX2;
383
384 if( pName == "anti_nu_mu") aLept = new G4DynamicParticle( theMuonPlus, lv2 );
385 else
386 {
387 theParticleChange.SetEnergyChange(energy);
388 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
389 return &theParticleChange;
390 }
391 theParticleChange.AddSecondary( aLept, fSecID );
392 }
393
394 // hadron part
395
396 fRecoil = nullptr;
397
398 if( A == 1 )
399 {
400 if( pName == "anti_nu_mu" ) qB = 2;
401 // else qB = 0;
402
403 // if( G4UniformRand() > 0.1 ) // > 0.9999 ) // > 0.0001 ) //
404 {
405 ClusterDecay( lvX, qB );
406 }
407 return &theParticleChange;
408 }
409 /*
410 // else
411 {
412 if( pName == "nu_mu" ) pdgP = 211;
413 else pdgP = -211;
414
415
416 if ( fQtransfer < 0.95*GeV ) // < 0.35*GeV ) //
417 {
418 if( lvX.m() > mSum ) CoherentPion( lvX, pdgP, targetNucleus);
419 }
420 }
421 return &theParticleChange;
422 }
423 */
424 G4Nucleus recoil;
425 G4double ratio = G4double(Z)/G4double(A);
426
427 if( ratio > G4UniformRand() ) // proton is excited
428 {
429 fProton = true;
430 recoil = G4Nucleus(A-1,Z-1);
431 fRecoil = &recoil;
432 if( pName == "anti_nu_mu" ) // (0) state -> p + pi-
433 {
434 fMt = G4ParticleTable::GetParticleTable()->FindParticle(2212)->GetPDGMass()
435 + G4ParticleTable::GetParticleTable()->FindParticle(211)->GetPDGMass();
436 }
437 else // (0) state -> p + pi-, n + pi0
438 {
439 // fMt = G4ParticleTable::GetParticleTable()->FindParticle(2212)->GetPDGMass()
440 // + G4ParticleTable::GetParticleTable()->FindParticle(-211)->GetPDGMass();
441 }
442 }
443 else // excited neutron
444 {
445 fProton = false;
446 recoil = G4Nucleus(A-1,Z);
447 fRecoil = &recoil;
448 if( pName == "anti_nu_mu" ) // (+) state -> n + pi+
449 {
450 fMt = G4ParticleTable::GetParticleTable()->FindParticle(2112)->GetPDGMass()
451 + G4ParticleTable::GetParticleTable()->FindParticle(211)->GetPDGMass();
452 }
453 else // (-) state -> n + pi-, // n + pi0
454 {
455 // fMt = G4ParticleTable::GetParticleTable()->FindParticle(2112)->GetPDGMass()
456 // + G4ParticleTable::GetParticleTable()->FindParticle(-211)->GetPDGMass();
457 }
458 }
459 // G4int index = GetEnergyIndex(energy);
460 G4int nepdg = aParticle->GetDefinition()->GetPDGEncoding();
461
462 G4double qeTotRat; // = GetNuMuQeTotRat(index, energy);
463 qeTotRat = CalculateQEratioA( Z, A, energy, nepdg);
464
465 G4ThreeVector dX = (lvX.vect()).unit();
466 G4double eX = lvX.e(); // excited nucleon
467 G4double mX = sqrt(massX2);
468 // G4double pX = sqrt( eX*eX - mX*mX );
469 // G4double sumE = eX + rM;
470
471 if( qeTotRat > G4UniformRand() || mX <= fMt ) // || eX <= 1232.*MeV) // QE
472 {
473 fString = false;
474
475 G4double rM;
476 if( fProton )
477 {
478 fPDGencoding = 2212;
479 fMr = proton_mass_c2;
480 recoil = G4Nucleus(A-1,Z-1);
481 fRecoil = &recoil;
482 rM = recoil.AtomicMass(A-1,Z-1);
483 }
484 else // if( pName == "anti_nu_mu" )
485 {
486 fPDGencoding = 2112;
487 fMr = G4ParticleTable::GetParticleTable()->
488 FindParticle(fPDGencoding)->GetPDGMass(); // 939.5654133*MeV;
489 recoil = G4Nucleus(A-1,Z);
490 fRecoil = &recoil;
491 rM = recoil.AtomicMass(A-1,Z);
492 }
493 // sumE = eX + rM;
494 G4double eTh = fMr + 0.5*(fMr*fMr - mX*mX)/rM;
495
496 if( eX <= eTh ) // vmg, very rarely out of kinematics
497 {
498 fString = true;
499 theParticleChange.SetEnergyChange(energy);
500 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
501 return &theParticleChange;
502 }
503 // FinalBarion( fLVh, 0, fPDGencoding ); // p(n)+deexcited recoil
504 FinalBarion( lvX, 0, fPDGencoding ); // p(n)+deexcited recoil
505 }
506 else // if ( eX < 9500000.*GeV ) // < 25.*GeV) // < 95.*GeV ) // < 2.5*GeV ) //cluster decay
507 {
508 if ( fProton && pName == "anti_nu_mu" ) qB = 0;
509 else if( !fProton && pName == "anti_nu_mu" ) qB = -1;
510
511 ClusterDecay( lvX, qB );
512 }
513 return &theParticleChange;
514 }
515
516
517 /////////////////////////////////////////////////////////////////////
518 ////////////////////////////////////////////////////////////////////
519 ///////////////////////////////////////////////////////////////////
520
521 /////////////////////////////////////////////////
522 //
523 // sample x, then Q2
524
525 void G4ANuMuNucleusCcModel::SampleLVkr(const G4HadProjectile & aTrack, G4Nucleus& targetNucleus)
526 {
527 fBreak = false;
528 G4int A = targetNucleus.GetA_asInt(), iTer(0), iTerMax(100);
529 G4int Z = targetNucleus.GetZ_asInt();
530 G4double e3(0.), pMu2(0.), pX2(0.), nMom(0.), rM(0.), hM(0.), tM = targetNucleus.AtomicMass(A,Z);
531 G4double Ex(0.), ei(0.), nm2(0.);
532 G4double cost(1.), sint(0.), phi(0.), muMom(0.);
533 G4ThreeVector eP, bst;
534 const G4HadProjectile* aParticle = &aTrack;
535 G4LorentzVector lvp1 = aParticle->Get4Momentum();
536
537 if( A == 1 ) // hydrogen, no Fermi motion ???
538 {
539 fNuEnergy = aParticle->GetTotalEnergy();
540 iTer = 0;
541
542 do
543 {
544 fXsample = SampleXkr(fNuEnergy);
545 fQtransfer = SampleQkr(fNuEnergy, fXsample);
546 fQ2 = fQtransfer*fQtransfer;
547
548 if( fXsample > 0. )
549 {
550 fW2 = fM1*fM1 - fQ2 + fQ2/fXsample; // sample excited hadron mass
551 fEmu = fNuEnergy - fQ2/2./fM1/fXsample;
552 }
553 else
554 {
555 fW2 = fM1*fM1;
556 fEmu = fNuEnergy;
557 }
558 e3 = fNuEnergy + fM1 - fEmu;
559
560 if( e3 < sqrt(fW2) ) G4cout<<"energyX = "<<e3/GeV<<", fW = "<<sqrt(fW2)/GeV<<G4endl;
561
562 pMu2 = fEmu*fEmu - fMu*fMu;
563
564 if(pMu2 < 0.) { fBreak = true; return; }
565
566 pX2 = e3*e3 - fW2;
567
568 fCosTheta = fNuEnergy*fNuEnergy + pMu2 - pX2;
569 fCosTheta /= 2.*fNuEnergy*sqrt(pMu2);
570 iTer++;
571 }
572 while( ( abs(fCosTheta) > 1. || fEmu < fMu ) && iTer < iTerMax );
573
574 if( iTer >= iTerMax ) { fBreak = true; return; }
575
576 if( abs(fCosTheta) > 1.) // vmg: due to big Q2/x values. To be improved ...
577 {
578 G4cout<<"H2: fCosTheta = "<<fCosTheta<<", fEmu = "<<fEmu<<G4endl;
579 // fCosTheta = -1. + 2.*G4UniformRand();
580 if(fCosTheta < -1.) fCosTheta = -1.;
581 if(fCosTheta > 1.) fCosTheta = 1.;
582 }
583 // LVs
584
585 G4LorentzVector lvt1 = G4LorentzVector( 0., 0., 0., fM1 );
586 G4LorentzVector lvsum = lvp1 + lvt1;
587
588 cost = fCosTheta;
589 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
590 phi = G4UniformRand()*CLHEP::twopi;
591 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
592 muMom = sqrt(fEmu*fEmu-fMu*fMu);
593 eP *= muMom;
594 fLVl = G4LorentzVector( eP, fEmu );
595
596 fLVh = lvsum - fLVl;
597 fLVt = G4LorentzVector( 0., 0., 0., 0. ); // no recoil
598 }
599 else // Fermi motion, Q2 in nucleon rest frame
600 {
601 G4Nucleus recoil1( A-1, Z );
602 rM = recoil1.AtomicMass(A-1,Z);
603 do
604 {
605 // nMom = NucleonMomentumBR( targetNucleus ); // BR
606 nMom = GgSampleNM( targetNucleus ); // Gg
607 Ex = GetEx(A-1, fProton);
608 ei = tM - sqrt( (rM + Ex)*(rM + Ex) + nMom*nMom );
609 // ei = 0.5*( tM - s2M - 2*eX );
610
611 nm2 = ei*ei - nMom*nMom;
612 iTer++;
613 }
614 while( nm2 < 0. && iTer < iTerMax );
615
616 if( iTer >= iTerMax ) { fBreak = true; return; }
617
618 G4ThreeVector nMomDir = nMom*G4RandomDirection();
619
620 if( !f2p2h || A < 3 ) // 1p1h
621 {
622 // hM = tM - rM;
623
624 fLVt = G4LorentzVector( -nMomDir, sqrt( (rM + Ex)*(rM + Ex) + nMom*nMom ) ); // rM ); //
625 fLVh = G4LorentzVector( nMomDir, ei ); // hM); //
626 }
627 else // 2p2h
628 {
629 G4Nucleus recoil(A-2,Z-1);
630 rM = recoil.AtomicMass(A-2,Z-1)+sqrt(nMom*nMom+fM1*fM1);
631 hM = tM - rM;
632
633 fLVt = G4LorentzVector( nMomDir, sqrt( rM*rM+nMom*nMom ) );
634 fLVh = G4LorentzVector(-nMomDir, sqrt( hM*hM+nMom*nMom ) );
635 }
636 // G4cout<<hM<<", ";
637 // bst = fLVh.boostVector();
638
639 // lvp1.boost(-bst); // -> nucleon rest system, where Q2 transfer is ???
640
641 fNuEnergy = lvp1.e();
642 // G4double mN = fLVh.m(); // better mN = fM1 !? vmg
643 iTer = 0;
644
645 do // no FM!?, 5.4.20 vmg
646 {
647 fXsample = SampleXkr(fNuEnergy);
648 fQtransfer = SampleQkr(fNuEnergy, fXsample);
649 fQ2 = fQtransfer*fQtransfer;
650
651 // G4double mR = mN + fM1*(A-1.)*std::exp(-2.0*fQtransfer/mN); // recoil mass in+el
652
653 if( fXsample > 0. )
654 {
655 fW2 = fM1*fM1 - fQ2 + fQ2/fXsample; // sample excited hadron mass
656
657 // fW2 = mN*mN - fQ2 + fQ2/fXsample; // sample excited hadron mass
658 // fEmu = fNuEnergy - fQ2/2./mR/fXsample; // fM1->mN
659
660 fEmu = fNuEnergy - fQ2/2./fM1/fXsample; // fM1->mN
661 }
662 else
663 {
664 // fW2 = mN*mN;
665
666 fW2 = fM1*fM1;
667 fEmu = fNuEnergy;
668 }
669 // if(fEmu < 0.) G4cout<<"fEmu = "<<fEmu<<" hM = "<<hM<<G4endl;
670 // e3 = fNuEnergy + mR - fEmu;
671
672 e3 = fNuEnergy + fM1 - fEmu;
673
674 // if( e3 < sqrt(fW2) ) G4cout<<"energyX = "<<e3/GeV<<", fW = "<<sqrt(fW2)/GeV<<G4endl;
675
676 pMu2 = fEmu*fEmu - fMu*fMu;
677 pX2 = e3*e3 - fW2;
678
679 if(pMu2 < 0.) { fBreak = true; return; }
680
681 fCosTheta = fNuEnergy*fNuEnergy + pMu2 - pX2;
682 fCosTheta /= 2.*fNuEnergy*sqrt(pMu2);
683 iTer++;
684 }
685 while( ( abs(fCosTheta) > 1. || fEmu < fMu ) && iTer < iTerMax );
686
687 if( iTer >= iTerMax ) { fBreak = true; return; }
688
689 if( abs(fCosTheta) > 1.) // vmg: due to big Q2/x values. To be improved ...
690 {
691 G4cout<<"FM: fCosTheta = "<<fCosTheta<<", fEmu = "<<fEmu<<G4endl;
692 // fCosTheta = -1. + 2.*G4UniformRand();
693 if( fCosTheta < -1.) fCosTheta = -1.;
694 if( fCosTheta > 1.) fCosTheta = 1.;
695 }
696 // LVs
697 // G4LorentzVector lvt1 = G4LorentzVector( 0., 0., 0., mN ); // fM1 );
698
699 G4LorentzVector lvt1 = G4LorentzVector( 0., 0., 0., fM1 ); // fM1 );
700 G4LorentzVector lvsum = lvp1 + lvt1;
701
702 cost = fCosTheta;
703 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
704 phi = G4UniformRand()*CLHEP::twopi;
705 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
706 muMom = sqrt(fEmu*fEmu-fMu*fMu);
707 eP *= muMom;
708 fLVl = G4LorentzVector( eP, fEmu );
709 fLVh = lvsum - fLVl;
710
711 // if( fLVh.e() < mN || fLVh.m2() < 0.) { fBreak = true; return; }
712
713 if( fLVh.e() < fM1 || fLVh.m2() < 0.) { fBreak = true; return; }
714
715 // back to lab system
716
717 // fLVl.boost(bst);
718 // fLVh.boost(bst);
719 }
720 //G4cout<<iTer<<", "<<fBreak<<"; ";
721 }
722
723 //
724 //
725 ///////////////////////////
726