| Geant4 Cross Reference |
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 // $Id: G4ANuElNucleusCcModel.cc 91806 2015-08-06 12:20:45Z gcosmo $
27 //
28 // Geant4 Header : G4ANuElNucleusCcModel
29 //
30 // Author : V.Grichine 12.2.19
31 //
32
33 #include <iostream>
34 #include <fstream>
35 #include <sstream>
36
37 #include "G4ANuElNucleusCcModel.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 "G4Positron.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 G4ANuElNucleusCcModel::numuNucleusModel = G4MUTEX_INITIALIZER;
91 #endif
92
93
94 G4ANuElNucleusCcModel::G4ANuElNucleusCcModel(const G4String& name)
95 : G4NeutrinoNucleusModel(name)
96 {
97 thePositron = G4Positron::Positron();
98 fData = fMaster = false;
99 fMel = electron_mass_c2;
100 InitialiseModel();
101 }
102
103
104 G4ANuElNucleusCcModel::~G4ANuElNucleusCcModel()
105 {}
106
107
108 void G4ANuElNucleusCcModel::ModelDescription(std::ostream& outFile) const
109 {
110
111 outFile << "G4ANuElNucleusCcModel is a neutrino-nucleus (charge current) scattering\n"
112 << "model which uses the standard model \n"
113 << "transfer parameterization. The model is fully relativistic\n";
114
115 }
116
117 /////////////////////////////////////////////////////////
118 //
119 // Read data from G4PARTICLEXSDATA (locally PARTICLEXSDATA)
120
121 void G4ANuElNucleusCcModel::InitialiseModel()
122 {
123 G4String pName = "anti_nu_e";
124
125 G4int nSize(0), i(0), j(0), k(0);
126
127 if(!fData)
128 {
129 #ifdef G4MULTITHREADED
130 G4MUTEXLOCK(&numuNucleusModel);
131 if(!fData)
132 {
133 #endif
134 fMaster = true;
135 #ifdef G4MULTITHREADED
136 }
137 G4MUTEXUNLOCK(&numuNucleusModel);
138 #endif
139 }
140
141 if(fMaster)
142 {
143 const char* path = G4FindDataDir("G4PARTICLEXSDATA");
144 std::ostringstream ost1, ost2, ost3, ost4;
145 ost1 << path << "/" << "neutrino" << "/" << pName << "/xarraycckr";
146
147 std::ifstream filein1( ost1.str().c_str() );
148
149 // filein.open("$PARTICLEXSDATA/");
150
151 filein1>>nSize;
152
153 for( k = 0; k < fNbin; ++k )
154 {
155 for( i = 0; i <= fNbin; ++i )
156 {
157 filein1 >> fNuMuXarrayKR[k][i];
158 // G4cout<< fNuMuXarrayKR[k][i] << " ";
159 }
160 }
161 // G4cout<<G4endl<<G4endl;
162
163 ost2 << path << "/" << "neutrino" << "/" << pName << "/xdistrcckr";
164 std::ifstream filein2( ost2.str().c_str() );
165
166 filein2>>nSize;
167
168 for( k = 0; k < fNbin; ++k )
169 {
170 for( i = 0; i < fNbin; ++i )
171 {
172 filein2 >> fNuMuXdistrKR[k][i];
173 // G4cout<< fNuMuXdistrKR[k][i] << " ";
174 }
175 }
176 // G4cout<<G4endl<<G4endl;
177
178 ost3 << path << "/" << "neutrino" << "/" << pName << "/q2arraycckr";
179 std::ifstream filein3( ost3.str().c_str() );
180
181 filein3>>nSize;
182
183 for( k = 0; k < fNbin; ++k )
184 {
185 for( i = 0; i <= fNbin; ++i )
186 {
187 for( j = 0; j <= fNbin; ++j )
188 {
189 filein3 >> fNuMuQarrayKR[k][i][j];
190 // G4cout<< fNuMuQarrayKR[k][i][j] << " ";
191 }
192 }
193 }
194 // G4cout<<G4endl<<G4endl;
195
196 ost4 << path << "/" << "neutrino" << "/" << pName << "/q2distrcckr";
197 std::ifstream filein4( ost4.str().c_str() );
198
199 filein4>>nSize;
200
201 for( k = 0; k < fNbin; ++k )
202 {
203 for( i = 0; i <= fNbin; ++i )
204 {
205 for( j = 0; j < fNbin; ++j )
206 {
207 filein4 >> fNuMuQdistrKR[k][i][j];
208 // G4cout<< fNuMuQdistrKR[k][i][j] << " ";
209 }
210 }
211 }
212 fData = true;
213 }
214 }
215
216 /////////////////////////////////////////////////////////
217
218 G4bool G4ANuElNucleusCcModel::IsApplicable(const G4HadProjectile & aPart,
219 G4Nucleus & )
220 {
221 G4bool result = false;
222 G4String pName = aPart.GetDefinition()->GetParticleName();
223 G4double energy = aPart.GetTotalEnergy();
224 fMinNuEnergy = GetMinNuElEnergy();
225
226 if( pName == "anti_nu_e"
227 &&
228 energy > fMinNuEnergy )
229 {
230 result = true;
231 }
232
233 return result;
234 }
235
236 /////////////////////////////////////////// ClusterDecay ////////////////////////////////////////////////////////////
237 //
238 //
239
240 G4HadFinalState* G4ANuElNucleusCcModel::ApplyYourself(
241 const G4HadProjectile& aTrack, G4Nucleus& targetNucleus)
242 {
243 theParticleChange.Clear();
244 fProton = f2p2h = fBreak = false;
245 fCascade = fString = false;
246 fLVh = fLVl = fLVt = fLVcpi = G4LorentzVector(0.,0.,0.,0.);
247
248 const G4HadProjectile* aParticle = &aTrack;
249 G4double energy = aParticle->GetTotalEnergy();
250
251 G4String pName = aParticle->GetDefinition()->GetParticleName();
252
253 if( energy < fMinNuEnergy )
254 {
255 theParticleChange.SetEnergyChange(energy);
256 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
257 return &theParticleChange;
258 }
259
260 SampleLVkr( aTrack, targetNucleus);
261
262 if( fBreak == true || fEmu < fMel ) // ~5*10^-6
263 {
264 // G4cout<<"ni, ";
265 theParticleChange.SetEnergyChange(energy);
266 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
267 return &theParticleChange;
268 }
269
270 // LVs of initial state
271
272 G4LorentzVector lvp1 = aParticle->Get4Momentum();
273 G4LorentzVector lvt1( 0., 0., 0., fM1 );
274 G4double mPip = G4ParticleTable::GetParticleTable()->FindParticle(211)->GetPDGMass();
275
276 // 1-pi by fQtransfer && nu-energy
277 G4LorentzVector lvpip1( 0., 0., 0., mPip );
278 G4LorentzVector lvsum, lv2, lvX;
279 G4ThreeVector eP;
280 G4double cost(1.), sint(0.), phi(0.), muMom(0.), massX2(0.), massX(0.), massR(0.), eCut(0.);
281 G4DynamicParticle* aLept = nullptr; // lepton lv
282
283 G4int Z = targetNucleus.GetZ_asInt();
284 G4int A = targetNucleus.GetA_asInt();
285 G4double mTarg = targetNucleus.AtomicMass(A,Z);
286 G4int pdgP(0), qB(0);
287 // G4double mSum = G4ParticleTable::GetParticleTable()->FindParticle(2212)->GetPDGMass() + mPip;
288
289 G4int iPi = GetOnePionIndex(energy);
290 G4double p1pi = GetNuMuOnePionProb( iPi, energy);
291
292 if( p1pi > G4UniformRand() && fCosTheta > 0.9 ) // && fQtransfer < 0.95*GeV ) // mu- & coherent pion + nucleus
293 {
294 // lvsum = lvp1 + lvpip1;
295 lvsum = lvp1 + lvt1;
296 // cost = fCosThetaPi;
297 cost = fCosTheta;
298 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
299 phi = G4UniformRand()*CLHEP::twopi;
300 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
301
302 // muMom = sqrt(fEmuPi*fEmuPi-fMel*fMel);
303 muMom = sqrt(fEmu*fEmu-fMel*fMel);
304
305 eP *= muMom;
306
307 // lv2 = G4LorentzVector( eP, fEmuPi );
308 // lv2 = G4LorentzVector( eP, fEmu );
309 lv2 = fLVl;
310
311 // lvX = lvsum - lv2;
312 lvX = fLVh;
313 massX2 = lvX.m2();
314 massX = lvX.m();
315 massR = fLVt.m();
316
317 if ( massX2 <= 0. ) // vmg: very rarely ~ (1-4)e-6 due to big Q2/x, to be improved
318 {
319 fCascade = true;
320 theParticleChange.SetEnergyChange(energy);
321 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
322 return &theParticleChange;
323 }
324 fW2 = massX2;
325
326 if( pName == "anti_nu_e" ) aLept = new G4DynamicParticle( thePositron, lv2 );
327 else
328 {
329 theParticleChange.SetEnergyChange(energy);
330 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
331 return &theParticleChange;
332 }
333 if( pName == "anti_nu_e" ) pdgP = 211;
334 // else pdgP = -211;
335 // eCut = fMpi + 0.5*(fMpi*fMpi-massX2)/mTarg; // massX -> fMpi
336
337 if( A > 1 )
338 {
339 eCut = (fMpi + mTarg)*(fMpi + mTarg) - (massX + massR)*(massX + massR);
340 eCut /= 2.*massR;
341 eCut += massX;
342 }
343 else eCut = fM1 + fMpi;
344
345 if ( lvX.e() > eCut ) // && sqrt( GetW2() ) < 1.4*GeV ) //
346 {
347 CoherentPion( lvX, pdgP, targetNucleus);
348 }
349 else
350 {
351 fCascade = true;
352 theParticleChange.SetEnergyChange(energy);
353 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
354 return &theParticleChange;
355 }
356 theParticleChange.AddSecondary( aLept, fSecID );
357
358 return &theParticleChange;
359 }
360 else // lepton part in lab
361 {
362 lvsum = lvp1 + lvt1;
363 cost = fCosTheta;
364 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
365 phi = G4UniformRand()*CLHEP::twopi;
366 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
367
368 muMom = sqrt(fEmu*fEmu-fMel*fMel);
369
370 eP *= muMom;
371
372 lv2 = G4LorentzVector( eP, fEmu );
373 lv2 = fLVl;
374 lvX = lvsum - lv2;
375 lvX = fLVh;
376 massX2 = lvX.m2();
377
378 if ( massX2 <= 0. ) // vmg: very rarely ~ (1-4)e-6 due to big Q2/x, to be improved
379 {
380 fCascade = true;
381 theParticleChange.SetEnergyChange(energy);
382 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
383 return &theParticleChange;
384 }
385 fW2 = massX2;
386
387 if( pName == "anti_nu_e" ) aLept = new G4DynamicParticle( thePositron, lv2 );
388 else
389 {
390 theParticleChange.SetEnergyChange(energy);
391 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
392 return &theParticleChange;
393 }
394 theParticleChange.AddSecondary( aLept, fSecID );
395 }
396
397 // hadron part
398
399 fRecoil = nullptr;
400
401 if( A == 1 )
402 {
403 if( pName == "anti_nu_e" ) qB = 2;
404 // else qB = 0;
405
406 // if( G4UniformRand() > 0.1 ) // > 0.9999 ) // > 0.0001 ) //
407 {
408 ClusterDecay( lvX, qB );
409 }
410 return &theParticleChange;
411 }
412 /*
413 // else
414 {
415 if( pName == "nu_mu" ) pdgP = 211;
416 else pdgP = -211;
417
418
419 if ( fQtransfer < 0.95*GeV ) // < 0.35*GeV ) //
420 {
421 if( lvX.m() > mSum ) CoherentPion( lvX, pdgP, targetNucleus);
422 }
423 }
424 return &theParticleChange;
425 }
426 */
427 G4Nucleus recoil;
428 G4double ratio = G4double(Z)/G4double(A);
429
430 if( ratio > G4UniformRand() ) // proton is excited
431 {
432 fProton = true;
433 recoil = G4Nucleus(A-1,Z-1);
434 fRecoil = &recoil;
435 if( pName == "anti_nu_e" ) // (++) state -> p + pi+
436 {
437 fMt = G4ParticleTable::GetParticleTable()->FindParticle(2212)->GetPDGMass()
438 + G4ParticleTable::GetParticleTable()->FindParticle(211)->GetPDGMass();
439 }
440 else // (0) state -> p + pi-, n + pi0
441 {
442 // fMt = G4ParticleTable::GetParticleTable()->FindParticle(2212)->GetPDGMass()
443 // + G4ParticleTable::GetParticleTable()->FindParticle(-211)->GetPDGMass();
444 }
445 }
446 else // excited neutron
447 {
448 fProton = false;
449 recoil = G4Nucleus(A-1,Z);
450 fRecoil = &recoil;
451 if( pName == "anti_nu_e" ) // (+) state -> n + pi+
452 {
453 fMt = G4ParticleTable::GetParticleTable()->FindParticle(2112)->GetPDGMass()
454 + G4ParticleTable::GetParticleTable()->FindParticle(211)->GetPDGMass();
455 }
456 else // (-) state -> n + pi-, // n + pi0
457 {
458 // fMt = G4ParticleTable::GetParticleTable()->FindParticle(2112)->GetPDGMass()
459 // + G4ParticleTable::GetParticleTable()->FindParticle(-211)->GetPDGMass();
460 }
461 }
462 // G4int index = GetEnergyIndex(energy);
463 G4int nepdg = aParticle->GetDefinition()->GetPDGEncoding();
464
465 G4double qeTotRat; // = GetNuMuQeTotRat(index, energy);
466 qeTotRat = CalculateQEratioA( Z, A, energy, nepdg);
467
468 G4ThreeVector dX = (lvX.vect()).unit();
469 G4double eX = lvX.e(); // excited nucleon
470 G4double mX = sqrt(massX2);
471 // G4double pX = sqrt( eX*eX - mX*mX );
472 // G4double sumE = eX + rM;
473
474 if( qeTotRat > G4UniformRand() || mX <= fMt ) // || eX <= 1232.*MeV) // QE
475 {
476 fString = false;
477
478 G4double rM;
479 if( fProton )
480 {
481 fPDGencoding = 2212;
482 fMr = proton_mass_c2;
483 recoil = G4Nucleus(A-1,Z-1);
484 fRecoil = &recoil;
485 rM = recoil.AtomicMass(A-1,Z-1);
486 }
487 else
488 {
489 fPDGencoding = 2112;
490 fMr = G4ParticleTable::GetParticleTable()->
491 FindParticle(fPDGencoding)->GetPDGMass(); // 939.5654133*MeV;
492 recoil = G4Nucleus(A-1,Z);
493 fRecoil = &recoil;
494 rM = recoil.AtomicMass(A-1,Z);
495 }
496 // sumE = eX + rM;
497 G4double eTh = fMr + 0.5*(fMr*fMr - mX*mX)/rM;
498
499 if( eX <= eTh ) // vmg, very rarely out of kinematics
500 {
501 fString = true;
502 theParticleChange.SetEnergyChange(energy);
503 theParticleChange.SetMomentumChange(aTrack.Get4Momentum().vect().unit());
504 return &theParticleChange;
505 }
506 // FinalBarion( fLVh, 0, fPDGencoding ); // p(n)+deexcited recoil
507 FinalBarion( lvX, 0, fPDGencoding ); // p(n)+deexcited recoil
508 }
509 else // if ( eX < 9500000.*GeV ) // < 25.*GeV) // < 95.*GeV ) // < 2.5*GeV ) //cluster decay
510 {
511 if ( fProton && pName == "anti_nu_e" ) qB = 2;
512 else if( !fProton && pName == "anti_nu_e" ) qB = 1;
513
514 ClusterDecay( lvX, qB );
515 }
516 return &theParticleChange;
517 }
518
519
520 /////////////////////////////////////////////////////////////////////
521 ////////////////////////////////////////////////////////////////////
522 ///////////////////////////////////////////////////////////////////
523
524 /////////////////////////////////////////////////
525 //
526 // sample x, then Q2
527
528 void G4ANuElNucleusCcModel::SampleLVkr(const G4HadProjectile & aTrack, G4Nucleus& targetNucleus)
529 {
530 fBreak = false;
531 G4int A = targetNucleus.GetA_asInt(), iTer(0), iTerMax(100);
532 G4int Z = targetNucleus.GetZ_asInt();
533 G4double e3(0.), pMu2(0.), pX2(0.), nMom(0.), rM(0.), hM(0.), tM = targetNucleus.AtomicMass(A,Z);
534 G4double Ex(0.), ei(0.), nm2(0.);
535 G4double cost(1.), sint(0.), phi(0.), muMom(0.);
536 G4ThreeVector eP, bst;
537 const G4HadProjectile* aParticle = &aTrack;
538 G4LorentzVector lvp1 = aParticle->Get4Momentum();
539
540 if( A == 1 ) // hydrogen, no Fermi motion ???
541 {
542 fNuEnergy = aParticle->GetTotalEnergy();
543 iTer = 0;
544
545 do
546 {
547 fXsample = SampleXkr(fNuEnergy);
548 fQtransfer = SampleQkr(fNuEnergy, fXsample);
549 fQ2 = fQtransfer*fQtransfer;
550
551 if( fXsample > 0. )
552 {
553 fW2 = fM1*fM1 - fQ2 + fQ2/fXsample; // sample excited hadron mass
554 fEmu = fNuEnergy - fQ2/2./fM1/fXsample;
555 }
556 else
557 {
558 fW2 = fM1*fM1;
559 fEmu = fNuEnergy;
560 }
561 e3 = fNuEnergy + fM1 - fEmu;
562
563 if( e3 < sqrt(fW2) ) G4cout<<"energyX = "<<e3/GeV<<", fW = "<<sqrt(fW2)/GeV<<G4endl;
564
565 pMu2 = fEmu*fEmu - fMel*fMel;
566
567 if(pMu2 < 0.) { fBreak = true; return; }
568
569 pX2 = e3*e3 - fW2;
570
571 fCosTheta = fNuEnergy*fNuEnergy + pMu2 - pX2;
572 fCosTheta /= 2.*fNuEnergy*sqrt(pMu2);
573 iTer++;
574 }
575 while( ( abs(fCosTheta) > 1. || fEmu < fMel ) && iTer < iTerMax );
576
577 if( iTer >= iTerMax ) { fBreak = true; return; }
578
579 if( abs(fCosTheta) > 1.) // vmg: due to big Q2/x values. To be improved ...
580 {
581 G4cout<<"H2: fCosTheta = "<<fCosTheta<<", fEmu = "<<fEmu<<G4endl;
582 // fCosTheta = -1. + 2.*G4UniformRand();
583 if(fCosTheta < -1.) fCosTheta = -1.;
584 if(fCosTheta > 1.) fCosTheta = 1.;
585 }
586 // LVs
587
588 G4LorentzVector lvt1 = G4LorentzVector( 0., 0., 0., fM1 );
589 G4LorentzVector lvsum = lvp1 + lvt1;
590
591 cost = fCosTheta;
592 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
593 phi = G4UniformRand()*CLHEP::twopi;
594 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
595 muMom = sqrt(fEmu*fEmu-fMel*fMel);
596 eP *= muMom;
597 fLVl = G4LorentzVector( eP, fEmu );
598
599 fLVh = lvsum - fLVl;
600 fLVt = G4LorentzVector( 0., 0., 0., 0. ); // no recoil
601 }
602 else // Fermi motion, Q2 in nucleon rest frame
603 {
604 G4Nucleus recoil1( A-1, Z );
605 rM = recoil1.AtomicMass(A-1,Z);
606 do
607 {
608 // nMom = NucleonMomentumBR( targetNucleus ); // BR
609 nMom = GgSampleNM( targetNucleus ); // Gg
610 Ex = GetEx(A-1, fProton);
611 ei = tM - sqrt( (rM + Ex)*(rM + Ex) + nMom*nMom );
612 // ei = 0.5*( tM - s2M - 2*eX );
613
614 nm2 = ei*ei - nMom*nMom;
615 iTer++;
616 }
617 while( nm2 < 0. && iTer < iTerMax );
618
619 if( iTer >= iTerMax ) { fBreak = true; return; }
620
621 G4ThreeVector nMomDir = nMom*G4RandomDirection();
622
623 if( !f2p2h || A < 3 ) // 1p1h
624 {
625 // hM = tM - rM;
626
627 fLVt = G4LorentzVector( -nMomDir, sqrt( (rM + Ex)*(rM + Ex) + nMom*nMom ) ); // rM ); //
628 fLVh = G4LorentzVector( nMomDir, ei ); // hM); //
629 }
630 else // 2p2h
631 {
632 G4Nucleus recoil(A-2,Z-1);
633 rM = recoil.AtomicMass(A-2,Z-1)+sqrt(nMom*nMom+fM1*fM1);
634 hM = tM - rM;
635
636 fLVt = G4LorentzVector( nMomDir, sqrt( rM*rM+nMom*nMom ) );
637 fLVh = G4LorentzVector(-nMomDir, sqrt( hM*hM+nMom*nMom ) );
638 }
639 // G4cout<<hM<<", ";
640 // bst = fLVh.boostVector();
641
642 // lvp1.boost(-bst); // -> nucleon rest system, where Q2 transfer is ???
643
644 fNuEnergy = lvp1.e();
645 // G4double mN = fLVh.m(); // better mN = fM1 !? vmg
646 iTer = 0;
647
648 do // no FM!?, 5.4.20 vmg
649 {
650 fXsample = SampleXkr(fNuEnergy);
651 fQtransfer = SampleQkr(fNuEnergy, fXsample);
652 fQ2 = fQtransfer*fQtransfer;
653
654 // G4double mR = mN + fM1*(A-1.)*std::exp(-2.0*fQtransfer/mN); // recoil mass in+el
655
656 if( fXsample > 0. )
657 {
658 fW2 = fM1*fM1 - fQ2 + fQ2/fXsample; // sample excited hadron mass
659
660 // fW2 = mN*mN - fQ2 + fQ2/fXsample; // sample excited hadron mass
661 // fEmu = fNuEnergy - fQ2/2./mR/fXsample; // fM1->mN
662
663 fEmu = fNuEnergy - fQ2/2./fM1/fXsample; // fM1->mN
664 }
665 else
666 {
667 // fW2 = mN*mN;
668
669 fW2 = fM1*fM1;
670 fEmu = fNuEnergy;
671 }
672 // if(fEmu < 0.) G4cout<<"fEmu = "<<fEmu<<" hM = "<<hM<<G4endl;
673 // e3 = fNuEnergy + mR - fEmu;
674
675 e3 = fNuEnergy + fM1 - fEmu;
676
677 // if( e3 < sqrt(fW2) ) G4cout<<"energyX = "<<e3/GeV<<", fW = "<<sqrt(fW2)/GeV<<G4endl;
678
679 pMu2 = fEmu*fEmu - fMel*fMel;
680 pX2 = e3*e3 - fW2;
681
682 if(pMu2 < 0.) { fBreak = true; return; }
683
684 fCosTheta = fNuEnergy*fNuEnergy + pMu2 - pX2;
685 fCosTheta /= 2.*fNuEnergy*sqrt(pMu2);
686 iTer++;
687 }
688 while( ( abs(fCosTheta) > 1. || fEmu < fMel ) && iTer < iTerMax );
689
690 if( iTer >= iTerMax ) { fBreak = true; return; }
691
692 if( abs(fCosTheta) > 1.) // vmg: due to big Q2/x values. To be improved ...
693 {
694 G4cout<<"FM: fCosTheta = "<<fCosTheta<<", fEmu = "<<fEmu<<G4endl;
695 // fCosTheta = -1. + 2.*G4UniformRand();
696 if( fCosTheta < -1.) fCosTheta = -1.;
697 if( fCosTheta > 1.) fCosTheta = 1.;
698 }
699 // LVs
700 // G4LorentzVector lvt1 = G4LorentzVector( 0., 0., 0., mN ); // fM1 );
701
702 G4LorentzVector lvt1 = G4LorentzVector( 0., 0., 0., fM1 ); // fM1 );
703 G4LorentzVector lvsum = lvp1 + lvt1;
704
705 cost = fCosTheta;
706 sint = std::sqrt( (1.0 - cost)*(1.0 + cost) );
707 phi = G4UniformRand()*CLHEP::twopi;
708 eP = G4ThreeVector( sint*std::cos(phi), sint*std::sin(phi), cost );
709 muMom = sqrt(fEmu*fEmu-fMel*fMel);
710 eP *= muMom;
711 fLVl = G4LorentzVector( eP, fEmu );
712 fLVh = lvsum - fLVl;
713
714 // if( fLVh.e() < mN || fLVh.m2() < 0.) { fBreak = true; return; }
715
716 if( fLVh.e() < fM1 || fLVh.m2() < 0.) { fBreak = true; return; }
717
718 // back to lab system
719
720 // fLVl.boost(bst);
721 // fLVh.boost(bst);
722 }
723 //G4cout<<iTer<<", "<<fBreak<<"; ";
724 }
725
726 //
727 //
728 ///////////////////////////
729