source: trunk/source/processes/hadronic/models/parton_string/diffraction/src/G4DiffractiveExcitation.cc@ 1089

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update processes
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26//
27// $Id: G4DiffractiveExcitation.cc,v 1.7 2008/12/18 13:01:58 gunter Exp $
28// ------------------------------------------------------------
29// GEANT 4 class implemetation file
30//
31// ---------------- G4DiffractiveExcitation --------------
32// by Gunter Folger, October 1998.
33// diffractive Excitation used by strings models
34// Take a projectile and a target
35// excite the projectile and target
36// Essential changed by V. Uzhinsky in November - December 2006
37// in order to put it in a correspondence with original FRITIOF
38// model. Variant of FRITIOF with nucleon de-excitation is implemented.
39// Other changes by V.Uzhinsky in May 2007 were introduced to fit
40// meson-nucleon interactions. Additional changes by V. Uzhinsky
41// were introduced in December 2006. They treat diffraction dissociation
42// processes more exactly.
43// ---------------------------------------------------------------------
44
45
46#include "globals.hh"
47#include "Randomize.hh"
48
49#include "G4DiffractiveExcitation.hh"
50#include "G4LorentzRotation.hh"
51#include "G4ThreeVector.hh"
52#include "G4ParticleDefinition.hh"
53#include "G4VSplitableHadron.hh"
54#include "G4ExcitedString.hh"
55#include "G4FTFParameters.hh" // Uzhi 19.04.08
56//#include "G4ios.hh"
57//#include "UZHI_diffraction.hh"
58
59G4DiffractiveExcitation::G4DiffractiveExcitation()
60{
61}
62
63// ---------------------------------------------------------------------
64G4bool G4DiffractiveExcitation::
65 ExciteParticipants(G4VSplitableHadron *projectile,
66 G4VSplitableHadron *target,
67 G4FTFParameters *theParameters) const
68{
69 G4bool PutOnMassShell=0;
70
71// -------------------- Projectile parameters -----------------------
72
73 G4LorentzVector Pprojectile=projectile->Get4Momentum();
74// G4double M0projectile=projectile->GetDefinition()->GetPDGMass(); // With de-excitation
75 G4double M0projectile = Pprojectile.mag(); // Without de-excitation
76/*
77G4cout<<"ExciteParticipants-------------------"<<G4endl;
78G4cout<<"Mom "<<Pprojectile<<" mass "<<M0projectile<<G4endl;
79*/
80 if(M0projectile < projectile->GetDefinition()->GetPDGMass())
81 {
82 PutOnMassShell=1;
83 M0projectile=projectile->GetDefinition()->GetPDGMass();
84 }
85
86 G4double M0projectile2 = M0projectile * M0projectile;
87
88 G4int PDGcode=projectile->GetDefinition()->GetPDGEncoding();
89 G4int absPDGcode=std::abs(PDGcode);
90
91 G4double ProjectileDiffStateMinMass=theParameters->GetProjMinDiffMass();
92 G4double ProjectileNonDiffStateMinMass=theParameters->GetProjMinNonDiffMass();
93 G4double ProbProjectileDiffraction=theParameters->GetProbabilityOfProjDiff();
94/*
95G4cout<<ProjectileDiffStateMinMass<<" "<<ProjectileNonDiffStateMinMass<<" "<<ProbProjectileDiffraction<<G4endl;
96*/
97// -------------------- Target paraExciteParticipantsmeters -------------------------
98 G4LorentzVector Ptarget=target->Get4Momentum();
99 G4double M0target = Ptarget.mag();
100
101//G4cout<<"Mom "<<Ptarget<<" mass "<<M0target<<G4endl;
102
103 if(M0target < target->GetDefinition()->GetPDGMass())
104 {
105 PutOnMassShell=1;
106 M0target=target->GetDefinition()->GetPDGMass();
107 }
108
109 G4double M0target2 = M0target * M0target; //Ptarget.mag2();
110 // for AA-inter.
111 G4double TargetDiffStateMinMass=theParameters->GetTarMinDiffMass();
112 G4double TargetNonDiffStateMinMass=theParameters->GetTarMinNonDiffMass();
113 G4double ProbTargetDiffraction=theParameters->GetProbabilityOfTarDiff();
114/*
115G4cout<<TargetDiffStateMinMass<<" "<<TargetNonDiffStateMinMass<<" "<<ProbTargetDiffraction<<G4endl;
116*/
117 G4double AveragePt2=theParameters->GetAveragePt2();
118
119// Kinematical properties of the interactions --------------
120 G4LorentzVector Psum; // 4-momentum in CMS
121 Psum=Pprojectile+Ptarget;
122 G4double S=Psum.mag2();
123
124//G4cout<<" sqrt(s) "<<std::sqrt(S)<<G4endl;
125
126// ------------------------------------------------------------------
127
128//ProbProjectileDiffraction=1.;
129//ProbTargetDiffraction =1.;
130 G4double ProbOfDiffraction=ProbProjectileDiffraction +
131 ProbTargetDiffraction;
132
133 if(ProbOfDiffraction!=0.)
134 {
135 ProbProjectileDiffraction/=ProbOfDiffraction;
136 }
137 else
138 {
139 ProbProjectileDiffraction=0.;
140 }
141// ProbTargetDiffraction /=ProbOfDiffraction;
142
143//G4cout<<"ProbOfDiffraction "<<ProbOfDiffraction<<"ProbProjectileDiffraction "<<ProbProjectileDiffraction<<G4endl; // Vova
144
145 G4double ProjectileDiffStateMinMass2 = ProjectileDiffStateMinMass *
146 ProjectileDiffStateMinMass;
147 G4double ProjectileNonDiffStateMinMass2 = ProjectileNonDiffStateMinMass *
148 ProjectileNonDiffStateMinMass;
149
150 G4double TargetDiffStateMinMass2 = TargetDiffStateMinMass *
151 TargetDiffStateMinMass;
152 G4double TargetNonDiffStateMinMass2 = TargetNonDiffStateMinMass *
153 TargetNonDiffStateMinMass;
154
155// Transform momenta to cms and then rotate parallel to z axis;
156
157// G4LorentzVector Psum;
158// Psum=Pprojectile+Ptarget;
159
160 G4LorentzRotation toCms(-1*Psum.boostVector());
161
162 G4LorentzVector Ptmp=toCms*Pprojectile;
163 if ( Ptmp.pz() <= 0. )
164 {
165 // "String" moving backwards in CMS, abort collision !!
166 //G4cout << " abort Collision!! " << G4endl;
167 return false;
168 }
169
170 toCms.rotateZ(-1*Ptmp.phi());
171 toCms.rotateY(-1*Ptmp.theta());
172
173 G4LorentzRotation toLab(toCms.inverse());
174
175 Pprojectile.transform(toCms);
176 Ptarget.transform(toCms);
177
178 G4double Pt2;
179 G4double ProjMassT2, ProjMassT;
180 G4double TargMassT2, TargMassT;
181 G4double PZcms2, PZcms;
182 G4double PMinusMin, PMinusMax;
183// G4double PPlusMin , PPlusMax;
184 G4double TPlusMin , TPlusMax;
185 G4double PMinusNew, PPlusNew, TPlusNew, TMinusNew;
186
187// G4double S=Psum.mag2();
188 G4double SqrtS=std::sqrt(S);
189
190 if(absPDGcode > 1000 && SqrtS < 2200*MeV)
191 {return false;} // The model cannot work for
192 // p+p-interactions
193 // at Plab < 1.3 GeV/c.
194
195 if(( absPDGcode == 211 || PDGcode == 111) && SqrtS < 1600*MeV)
196 {return false;} // The model cannot work for
197 // Pi+p-interactions
198 // at Plab < 1. GeV/c.
199
200 if(( absPDGcode == 321 || PDGcode == -311) && SqrtS < 1600*MeV)
201 {return false;} // The model cannot work for
202 // K+p-interactions
203 // at Plab < ??? GeV/c. ???
204
205 PZcms2=(S*S+M0projectile2*M0projectile2+M0target2*M0target2-
206 2*S*M0projectile2 - 2*S*M0target2 - 2*M0projectile2*M0target2)
207 /4./S;
208
209 if(PZcms2 < 0)
210 {return false;} // It can be in an interaction with off-shell nuclear nucleon
211
212 PZcms = std::sqrt(PZcms2);
213
214 if(PutOnMassShell)
215 {
216 if(Pprojectile.z() > 0.)
217 {
218 Pprojectile.setPz( PZcms);
219 Ptarget.setPz( -PZcms);
220 }
221 else
222 {
223 Pprojectile.setPz(-PZcms);
224 Ptarget.setPz( PZcms);
225 };
226
227 Pprojectile.setE(std::sqrt(M0projectile2 +
228 Pprojectile.x()*Pprojectile.x()+
229 Pprojectile.y()*Pprojectile.y()+
230 PZcms2));
231 Ptarget.setE(std::sqrt(M0target2 +
232 Ptarget.x()*Ptarget.x()+
233 Ptarget.y()*Ptarget.y()+
234 PZcms2));
235 }
236
237 G4double maxPtSquare; // = PZcms2;
238/*
239G4cout << "Pprojectile aft boost : " << Pprojectile <<" "<<Pprojectile.mag()<< G4endl;
240G4cout << "Ptarget aft boost : " << Ptarget <<" "<<Ptarget.mag()<< G4endl;
241G4cout << "cms aft boost : " << (Pprojectile+ Ptarget) << G4endl;
242G4cout << " Projectile Xplus / Xminus : " <<
243 Pprojectile.plus() << " / " << Pprojectile.minus() << G4endl;
244G4cout << " Target Xplus / Xminus : " << Ptarget.plus() << " / " << Ptarget.minus() << G4endl;
245G4cout<<"maxPtSquare "<<maxPtSquare<<G4endl;
246*/
247 G4LorentzVector Qmomentum;
248 G4double Qminus, Qplus;
249
250 G4int whilecount=0;
251// Choose a process
252
253 if(G4UniformRand() < ProbOfDiffraction)
254 {
255 if(G4UniformRand() < ProbProjectileDiffraction)
256 { //-------- projectile diffraction ---------------
257//G4cout<<" Projectile diffraction"<<G4endl;
258//Uzhi_projectilediffraction++;
259 do {
260// Generate pt
261// if (whilecount++ >= 500 && (whilecount%100)==0)
262// G4cout << "G4DiffractiveExcitation::ExciteParticipants possibly looping"
263// << ", loop count/ maxPtSquare : "
264// << whilecount << " / " << maxPtSquare << G4endl;
265 if (whilecount > 1000 )
266 {
267 Qmomentum=G4LorentzVector(0.,0.,0.,0.);
268 return false; // Ignore this interaction
269 };
270// --------------- Check that the interaction is possible -----------
271 ProjMassT2=ProjectileDiffStateMinMass2;
272 ProjMassT =ProjectileDiffStateMinMass;
273
274 TargMassT2=M0target2;
275 TargMassT =M0target;
276
277 PZcms2=(S*S + ProjMassT2*ProjMassT2 + TargMassT2*TargMassT2-
278 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjMassT2*TargMassT2)
279 /4./S;
280//G4cout<<" Pt2 Mpt Mtt Pz2 "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
281
282if(PZcms2 < 0 )
283{
284/*
285G4cout<<"whilecount "<<whilecount<<" "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
286G4int Uzhi; G4cin>>Uzhi;
287*/
288return false;
289};
290 maxPtSquare=PZcms2;
291
292 Qmomentum=G4LorentzVector(GaussianPt(AveragePt2,maxPtSquare),0);
293 Pt2=G4ThreeVector(Qmomentum.vect()).mag2();
294
295 ProjMassT2=ProjectileDiffStateMinMass2+Pt2;
296 ProjMassT =std::sqrt(ProjMassT2);
297
298 TargMassT2=M0target2+Pt2;
299 TargMassT =std::sqrt(TargMassT2);
300
301 PZcms2=(S*S + ProjMassT2*ProjMassT2 + TargMassT2*TargMassT2-
302 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjMassT2*TargMassT2)
303 /4./S;
304//G4cout<<" Pt2 Mpt Mtt Pz2 "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
305
306// if(PZcms2 < 0 ) {PZcms2=0;};
307 if(PZcms2 < 0 ) continue;
308 PZcms =std::sqrt(PZcms2);
309
310 PMinusMin=std::sqrt(ProjMassT2+PZcms2)-PZcms;
311 PMinusMax=SqrtS-TargMassT;
312//G4cout<<" SqrtS P+mim max "<<SqrtS<<" "<<PMinusMin<<" "<<PMinusMax<<G4endl;
313
314 PMinusNew=ChooseP(PMinusMin, PMinusMax);
315// PMinusNew=1./sqrt(1./PMinusMin-G4UniformRand()*(1./PMinusMin-1./PMinusMax));
316
317 TMinusNew=SqrtS-PMinusNew;
318 Qminus=Ptarget.minus()-TMinusNew;
319 TPlusNew=TargMassT2/TMinusNew;
320 Qplus=Ptarget.plus()-TPlusNew;
321
322 Qmomentum.setPz( (Qplus-Qminus)/2 );
323 Qmomentum.setE( (Qplus+Qminus)/2 );
324 } while (
325((Pprojectile+Qmomentum).mag2() < ProjectileDiffStateMinMass2) || //No without excitation
326((Ptarget -Qmomentum).mag2() < M0target2 ));
327 }
328 else
329 { // -------------- Target diffraction ----------------
330//G4cout<<" Target difraction"<<G4endl;
331//Uzhi_targetdiffraction++;
332 do {
333// Generate pt
334// if (whilecount++ >= 500 && (whilecount%100)==0)
335// G4cout << "G4DiffractiveExcitation::ExciteParticipants possibly looping"
336// << ", loop count/ maxPtSquare : "
337// << whilecount << " / " << maxPtSquare << G4endl;
338 if (whilecount > 1000 )
339 {
340 Qmomentum=G4LorentzVector(0.,0.,0.,0.);
341 return false; // Ignore this interaction
342 };
343// --------------- Check that the interaction is possible -----------
344 ProjMassT2=M0projectile2;
345 ProjMassT =M0projectile;
346
347 TargMassT2=TargetDiffStateMinMass2;
348 TargMassT =TargetDiffStateMinMass;
349
350 PZcms2=(S*S + ProjMassT2*ProjMassT2 + TargMassT2*TargMassT2-
351 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjMassT2*TargMassT2)
352 /4./S;
353//G4cout<<" Pt2 Mpt Mtt Pz2 "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
354
355if(PZcms2 < 0 )
356{
357/*
358G4cout<<"whilecount "<<whilecount<<" "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
359G4int Uzhi; G4cin>>Uzhi;
360*/
361return false;
362};
363 maxPtSquare=PZcms2;
364
365 Qmomentum=G4LorentzVector(GaussianPt(AveragePt2,maxPtSquare),0);
366 Pt2=G4ThreeVector(Qmomentum.vect()).mag2();
367
368 ProjMassT2=M0projectile2+Pt2;
369 ProjMassT =std::sqrt(ProjMassT2);
370
371 TargMassT2=TargetDiffStateMinMass2+Pt2;
372 TargMassT =std::sqrt(TargMassT2);
373
374 PZcms2=(S*S + ProjMassT2*ProjMassT2 + TargMassT2*TargMassT2-
375 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjMassT2*TargMassT2)
376 /4./S;
377/*
378if(PZcms2 < 0 )
379{
380G4cout<<"whilecount "<<whilecount<<" "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
381G4int Uzhi; G4cin>>Uzhi;
382return false;
383};
384*/
385 if(PZcms2 < 0 ) continue;
386 PZcms =std::sqrt(PZcms2);
387
388 TPlusMin=std::sqrt(TargMassT2+PZcms2)-PZcms;
389 TPlusMax=SqrtS-ProjMassT;
390
391//G4cout<<" Tmin max "<<TPlusMin<<" "<<TPlusMax<<G4endl;
392
393 TPlusNew=ChooseP(TPlusMin, TPlusMax);
394
395//TPlusNew=TPlusMax;
396//G4cout<<"T+new "<<TPlusNew<<G4endl;
397
398 PPlusNew=SqrtS-TPlusNew;
399 Qplus=PPlusNew-Pprojectile.plus();
400 PMinusNew=ProjMassT2/PPlusNew;
401 Qminus=PMinusNew-Pprojectile.minus();
402
403 Qmomentum.setPz( (Qplus-Qminus)/2 );
404 Qmomentum.setE( (Qplus+Qminus)/2 );
405
406 } while (
407 ((Pprojectile+Qmomentum).mag2() < M0projectile2 ) || //No without excitation
408 ((Ptarget -Qmomentum).mag2() < TargetDiffStateMinMass2));
409 }
410 }
411 else //----------- Non-diffraction process ------------
412 {
413//G4cout<<" Non-difraction"<<G4endl;
414 do {
415// Generate pt
416// if (whilecount++ >= 500 && (whilecount%100)==0)
417// G4cout << "G4DiffractiveExcitation::ExciteParticipants possibly looping"
418// << ", loop count/ maxPtSquare : "
419// << whilecount << " / " << maxPtSquare << G4endl;
420 if (whilecount > 1000 )
421 {
422 Qmomentum=G4LorentzVector(0.,0.,0.,0.);
423 return false; // Ignore this interaction
424 };
425// --------------- Check that the interaction is possible -----------
426 ProjMassT2=ProjectileNonDiffStateMinMass2;
427 ProjMassT =ProjectileNonDiffStateMinMass;
428
429 TargMassT2=TargetNonDiffStateMinMass2;
430 TargMassT =TargetNonDiffStateMinMass;
431
432 PZcms2=(S*S + ProjMassT2*ProjMassT2 + TargMassT2*TargMassT2-
433 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjMassT2*TargMassT2)
434 /4./S;
435//G4cout<<" Pt2 Mpt Mtt Pz2 "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
436
437if(PZcms2 < 0 )
438{
439/*
440G4cout<<"whilecount "<<whilecount<<" "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<PZcms2<<G4endl;
441G4int Uzhi; G4cin>>Uzhi;
442*/
443return false;
444};
445 maxPtSquare=PZcms2;
446 Qmomentum=G4LorentzVector(GaussianPt(AveragePt2,maxPtSquare),0);
447 Pt2=G4ThreeVector(Qmomentum.vect()).mag2();
448
449 ProjMassT2=ProjectileNonDiffStateMinMass2+Pt2;
450 ProjMassT =std::sqrt(ProjMassT2);
451
452 TargMassT2=TargetNonDiffStateMinMass2+Pt2;
453 TargMassT =std::sqrt(TargMassT2);
454
455 PZcms2=(S*S + ProjMassT2*ProjMassT2 + TargMassT2*TargMassT2-
456 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjMassT2*TargMassT2)
457 /4./S;
458/*
459G4cout<<"ProjectileNonDiffStateMinMass2 "<<ProjectileNonDiffStateMinMass2<<G4endl;
460G4cout<<"TargetNonDiffStateMinMass2 "<<TargetNonDiffStateMinMass2<<G4endl;
461G4cout<<"Mt "<<ProjMassT<<" "<<TargMassT<<" "<<Pt2<<" "<<PZcms2<<G4endl<<G4endl;
462*/
463// if(PZcms2 < 0 ) {PZcms2=0;};
464 if(PZcms2 < 0 ) continue;
465 PZcms =std::sqrt(PZcms2);
466
467 PMinusMin=std::sqrt(ProjMassT2+PZcms2)-PZcms;
468 PMinusMax=SqrtS-TargMassT;
469
470 PMinusNew=ChooseP(PMinusMin, PMinusMax);
471// PMinusNew=1./sqrt(1./PMinusMin-G4UniformRand()*(1./PMinusMin-1./PMinusMax));
472
473//G4cout<<"Proj "<<PMinusMin<<" "<<PMinusMax<<" "<<PMinusNew<<G4endl;
474
475//PMinusNew=PMinusMax; //+++++++++++++++++++++++++++++++++++ Vova
476
477 Qminus=PMinusNew-Pprojectile.minus();
478
479 TPlusMin=std::sqrt(TargMassT2+PZcms2)-PZcms;
480// TPlusMax=SqrtS-PMinusNew; // Vova
481 TPlusMax=SqrtS-ProjMassT; // Vova
482
483 TPlusNew=ChooseP(TPlusMin, TPlusMax);
484
485//G4cout<<"Targ "<<TPlusMin<<" "<<TPlusMax<<" "<<TPlusNew<<G4endl;
486//G4cout<<PMinusNew<<" "<<TPlusNew<<G4endl;
487
488 Qplus=-(TPlusNew-Ptarget.plus());
489
490 Qmomentum.setPz( (Qplus-Qminus)/2 );
491 Qmomentum.setE( (Qplus+Qminus)/2 );
492/*
493G4cout << "Qplus / Qminus " << Qplus << " / " << Qminus<<G4endl;
494G4cout << "pt2" << pt2 << G4endl;
495G4cout << "Qmomentum " << Qmomentum << G4endl;
496G4cout << " Masses (P/T) : " << (Pprojectile+Qmomentum).mag() <<
497 " / " << (Ptarget-Qmomentum).mag() << G4endl; // mag()
498G4cout<<"Mprojectile "<<std::sqrt(M0projectile2)<<G4endl;
499G4cout<<"Mtarget "<<std::sqrt(M0target2 )<<G4endl;
500G4cout<<"ProjectileDiffStateMinMass "<<std::sqrt(ProjectileDiffStateMinMass2)<<G4endl;
501G4cout<<"TargetDiffStateMinMass "<<std::sqrt(TargetDiffStateMinMass2)<<G4endl;
502*/
503 } while (
504 ((Pprojectile+Qmomentum).mag2() < ProjectileNonDiffStateMinMass2) || //No double Diffraction
505 ((Ptarget -Qmomentum).mag2() < TargetNonDiffStateMinMass2 ));
506 }
507
508//G4int Uzhiinp; G4cin>>Uzhiinp; // Vova
509
510 Pprojectile += Qmomentum;
511 Ptarget -= Qmomentum;
512/*
513G4cout << "Pprojectile with Q : " << Pprojectile << G4endl;
514G4cout << "Ptarget with Q : " << Ptarget << G4endl;
515G4cout << "Target mass " << Ptarget.mag() << G4endl;
516G4cout << "Projectile mass " << Pprojectile.mag() << G4endl;
517//
518//G4cout << "Projectile back: " << toLab * Pprojectile << G4endl;
519//G4cout << "Target back: " << toLab * Ptarget << G4endl;
520*/
521//-------------- Flip if projectale moves in backward direction ------------
522//G4bool Flip=Pprojectile.pz()< 0.;
523
524
525// Transform back and update SplitableHadron Participant.
526 Pprojectile.transform(toLab);
527 Ptarget.transform(toLab);
528
529//G4cout << "Pprojectile with Q M: " << Pprojectile<<" "<< Pprojectile.mag() << G4endl;
530//G4cout << "Ptarget with Q M: " << Ptarget <<" "<< Ptarget.mag() << G4endl;
531//G4cout << "Target mass " << Ptarget.mag() << G4endl;
532//G4cout << "Projectile mass " << Pprojectile.mag() << G4endl;
533
534/*
535if(!Flip){
536 projectile->Set4Momentum(Pprojectile);
537 target->Set4Momentum(Ptarget);
538 }
539else {
540 G4ParticleDefinition * t_Definition=projectile->GetDefinition();
541 projectile->SetDefinition(target->GetDefinition());
542 projectile->Set4Momentum(Ptarget);
543 target->SetDefinition(t_Definition);
544 target->Set4Momentum(Pprojectile);
545 }
546*/
547//
548/*
549if(G4UniformRand() < 1.) {
550 G4ParticleDefinition * t_Definition=projectile->GetDefinition();
551 projectile->SetDefinition(target->GetDefinition());
552 target->SetDefinition(t_Definition);
553}
554*/ // For flip, for HARP
555
556 G4double ZcoordinateOfCurrentInteraction = target->GetPosition().z();
557// It is assumed that nucleon z-coordinates are ordered on increasing -----------
558
559 G4double betta_z=projectile->Get4Momentum().pz()/projectile->Get4Momentum().e();
560
561 G4double ZcoordinateOfPreviousCollision=projectile->GetPosition().z();
562 if(projectile->GetSoftCollisionCount()==0) {
563 projectile->SetTimeOfCreation(0.);
564 target->SetTimeOfCreation(0.);
565 ZcoordinateOfPreviousCollision=ZcoordinateOfCurrentInteraction;
566 }
567
568 G4ThreeVector thePosition(projectile->GetPosition().x(),
569 projectile->GetPosition().y(),
570 ZcoordinateOfCurrentInteraction);
571 projectile->SetPosition(thePosition);
572
573 G4double TimeOfPreviousCollision=projectile->GetTimeOfCreation();
574 G4double TimeOfCurrentCollision=TimeOfPreviousCollision+
575 (ZcoordinateOfCurrentInteraction-ZcoordinateOfPreviousCollision)/betta_z;
576
577 projectile->SetTimeOfCreation(TimeOfCurrentCollision);
578 target->SetTimeOfCreation(TimeOfCurrentCollision);
579
580 projectile->Set4Momentum(Pprojectile);
581 target->Set4Momentum(Ptarget);
582
583 projectile->IncrementCollisionCount(1);
584 target->IncrementCollisionCount(1);
585
586//
587//G4cout<<"Out of Excitation --------------------"<<G4endl;
588//G4int Uzhiinp; G4cin>>Uzhiinp; // Vova
589
590 return true;
591}
592
593// ---------------------------------------------------------------------
594G4ExcitedString * G4DiffractiveExcitation::
595 String(G4VSplitableHadron * hadron, G4bool isProjectile) const
596{
597
598//G4cout<<"G4DiffractiveExcitation::String isProj"<<isProjectile<<G4endl;
599
600 hadron->SplitUp();
601 G4Parton *start= hadron->GetNextParton();
602 if ( start==NULL)
603 { G4cout << " G4FTFModel::String() Error:No start parton found"<< G4endl;
604 return NULL;
605 }
606 G4Parton *end = hadron->GetNextParton();
607 if ( end==NULL)
608 { G4cout << " G4FTFModel::String() Error:No end parton found"<< G4endl;
609 return NULL;
610 }
611
612 G4ExcitedString * string;
613 if ( isProjectile )
614 {
615 string= new G4ExcitedString(end,start, +1);
616 } else {
617 string= new G4ExcitedString(start,end, -1);
618 }
619// Uzhi
620//G4cout<<"G4ExcitedString * G4DiffractiveExcitation::String"<<G4endl;
621//G4cout<<hadron->GetTimeOfCreation()<<" "<<hadron->GetPosition()/fermi<<G4endl;
622
623 string->SetTimeOfCreation(hadron->GetTimeOfCreation());
624 string->SetPosition(hadron->GetPosition());
625
626// momenta of string ends
627//
628 G4double Momentum=hadron->Get4Momentum().vect().mag();
629 G4double Plus=hadron->Get4Momentum().e() + Momentum;
630 G4double Minus=hadron->Get4Momentum().e() - Momentum;
631
632 G4ThreeVector tmp;
633 if(Momentum > 0.)
634 {
635 tmp.set(hadron->Get4Momentum().px(),
636 hadron->Get4Momentum().py(),
637 hadron->Get4Momentum().pz());
638 tmp/=Momentum;
639 }
640 else
641 {
642 tmp.set(0.,0.,1.);
643 };
644
645 G4LorentzVector Pstart(tmp,0.);
646 G4LorentzVector Pend(tmp,0.);
647
648 if(isProjectile)
649 {
650 Pstart*=(-1.)*Minus/2.;
651 Pend *=(+1.)*Plus /2.;
652 }
653 else
654 {
655 Pstart*=(+1.)*Plus/2.;
656 Pend *=(-1.)*Minus/2.;
657 };
658
659 Momentum=-Pstart.mag();
660 Pstart.setT(Momentum); // It is assumed that quark has m=0.
661
662 Momentum=-Pend.mag();
663 Pend.setT(Momentum); // It is assumed that di-quark has m=0.
664//
665/* Uzhi
666 G4double ptSquared= hadron->Get4Momentum().perp2();
667 G4double transverseMassSquared= hadron->Get4Momentum().plus()
668 * hadron->Get4Momentum().minus();
669
670
671 G4double maxAvailMomentumSquared=
672 sqr( std::sqrt(transverseMassSquared) - std::sqrt(ptSquared) );
673
674 G4double widthOfPtSquare = 0.25*GeV*GeV; // Uzhi 11.07 <Pt^2>=0.25 ??????????????????
675 G4ThreeVector pt=GaussianPt(widthOfPtSquare,maxAvailMomentumSquared);
676
677 G4LorentzVector Pstart(G4LorentzVector(pt,0.));
678 G4LorentzVector Pend;
679 Pend.setPx(hadron->Get4Momentum().px() - pt.x());
680 Pend.setPy(hadron->Get4Momentum().py() - pt.y());
681
682 G4double tm1=hadron->Get4Momentum().minus() +
683 ( Pend.perp2()-Pstart.perp2() ) / hadron->Get4Momentum().plus();
684
685 G4double tm2= std::sqrt( std::max(0., sqr(tm1) -
686 4. * Pend.perp2() * hadron->Get4Momentum().minus()
687 / hadron->Get4Momentum().plus() ));
688
689 G4int Sign= isProjectile ? -1 : 1;
690
691 G4double endMinus = 0.5 * (tm1 + Sign*tm2);
692 G4double startMinus= hadron->Get4Momentum().minus() - endMinus;
693
694 G4double startPlus= Pstart.perp2() / startMinus;
695 G4double endPlus = hadron->Get4Momentum().plus() - startPlus;
696
697 Pstart.setPz(0.5*(startPlus - startMinus));
698 Pstart.setE(0.5*(startPlus + startMinus));
699
700 Pend.setPz(0.5*(endPlus - endMinus));
701 Pend.setE(0.5*(endPlus + endMinus));
702*/ // Uzhi
703 start->Set4Momentum(Pstart);
704 end->Set4Momentum(Pend);
705/*
706G4cout<<"G4DiffractiveExcitation::String hadro"<<hadron->Get4Momentum()<<" "<<hadron->Get4Momentum().mag2()<<G4endl;
707
708G4cout<<"G4DiffractiveExcitation::String start"<<start->Get4Momentum()<<" "<<start->GetPDGcode()<<G4endl;
709
710G4cout<<"G4DiffractiveExcitation::String end "<< end->Get4Momentum()<<" "<< end->GetPDGcode()<<G4endl;
711G4int Uzhi; G4cin>>Uzhi;
712*/
713#ifdef G4_FTFDEBUG
714 G4cout << " generated string flavors "
715 << start->GetPDGcode() << " / "
716 << end->GetPDGcode() << G4endl;
717 G4cout << " generated string momenta: quark "
718 << start->Get4Momentum() << "mass : "
719 <<start->Get4Momentum().mag() << G4endl;
720 G4cout << " generated string momenta: Diquark "
721 << end ->Get4Momentum()
722 << "mass : " <<end->Get4Momentum().mag()<< G4endl;
723 G4cout << " sum of ends " << Pstart+Pend << G4endl;
724 G4cout << " Original " << hadron->Get4Momentum() << G4endl;
725#endif
726
727 return string;
728}
729
730
731// --------- private methods ----------------------
732
733// ---------------------------------------------------------------------
734G4double G4DiffractiveExcitation::ChooseP(G4double Pmin, G4double Pmax) const // Uzhi
735{
736// choose an x between Xmin and Xmax with P(x) ~ 1/x
737// to be improved...
738
739 G4double range=Pmax-Pmin; // Uzhi
740
741 if ( Pmin <= 0. || range <=0. )
742 {
743 G4cout << " Pmin, range : " << Pmin << " , " << range << G4endl;
744 throw G4HadronicException(__FILE__, __LINE__, "G4DiffractiveExcitation::ChooseP : Invalid arguments ");
745 }
746
747 G4double P;
748/* // Uzhi
749 do {
750 x=Xmin + G4UniformRand() * range;
751 } while ( Xmin/x < G4UniformRand() );
752*/ // Uzhi
753
754 P=Pmin * std::pow(Pmax/Pmin,G4UniformRand()); // Uzhi
755
756//debug-hpw cout << "DiffractiveX "<<x<<G4endl;
757 return P;
758}
759
760// ---------------------------------------------------------------------
761G4ThreeVector G4DiffractiveExcitation::GaussianPt(G4double AveragePt2,
762 G4double maxPtSquare) const // Uzhi
763{ // @@ this method is used in FTFModel as well. Should go somewhere common!
764
765 G4double Pt2;
766/* // Uzhi
767 do {
768 pt2=widthSquare * std::log( G4UniformRand() );
769 } while ( pt2 > maxPtSquare);
770*/ // Uzhi
771
772 Pt2 = -AveragePt2 * std::log(1. + G4UniformRand() *
773 (std::exp(-maxPtSquare/AveragePt2)-1.));// Uzhi
774
775 G4double Pt=std::sqrt(Pt2);
776
777 G4double phi=G4UniformRand() * twopi;
778
779 return G4ThreeVector (Pt*std::cos(phi), Pt*std::sin(phi), 0.);
780}
781
782// ---------------------------------------------------------------------
783G4DiffractiveExcitation::G4DiffractiveExcitation(const G4DiffractiveExcitation &)
784{
785 throw G4HadronicException(__FILE__, __LINE__, "G4DiffractiveExcitation copy contructor not meant to be called");
786}
787
788
789G4DiffractiveExcitation::~G4DiffractiveExcitation()
790{
791}
792
793
794const G4DiffractiveExcitation & G4DiffractiveExcitation::operator=(const G4DiffractiveExcitation &)
795{
796 throw G4HadronicException(__FILE__, __LINE__, "G4DiffractiveExcitation = operator meant to be called");
797 return *this;
798}
799
800
801int G4DiffractiveExcitation::operator==(const G4DiffractiveExcitation &) const
802{
803 throw G4HadronicException(__FILE__, __LINE__, "G4DiffractiveExcitation == operator meant to be called");
804 return false;
805}
806
807int G4DiffractiveExcitation::operator!=(const G4DiffractiveExcitation &) const
808{
809 throw G4HadronicException(__FILE__, __LINE__, "G4DiffractiveExcitation != operator meant to be called");
810 return true;
811}
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