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Geant4/processes/hadronic/models/parton_string/qgsm/src/G4SingleDiffractiveExcitation.cc

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Diff markup

Differences between /processes/hadronic/models/parton_string/qgsm/src/G4SingleDiffractiveExcitation.cc (Version 11.3.0) and /processes/hadronic/models/parton_string/qgsm/src/G4SingleDiffractiveExcitation.cc (Version 10.7.p1)


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 27 // -------------------------------------------     27 // ------------------------------------------------------------
 28 //      GEANT 4 class implemetation file           28 //      GEANT 4 class implemetation file
 29 //                                                 29 //
 30 //      ---------------- G4SingleDiffractiveEx     30 //      ---------------- G4SingleDiffractiveExcitation --------------
 31 //             by Gunter Folger, October 1998.     31 //             by Gunter Folger, October 1998.
 32 //      diffractive Excitation used by strings     32 //      diffractive Excitation used by strings models
 33 //  Take a projectile and a target                 33 //  Take a projectile and a target
 34 //  excite the projectile and target               34 //  excite the projectile and target
 35 // -------------------------------------------     35 // ------------------------------------------------------------
 36                                                    36 
 37 #include "G4SingleDiffractiveExcitation.hh"        37 #include "G4SingleDiffractiveExcitation.hh"
 38 #include "globals.hh"                              38 #include "globals.hh"
 39 #include "G4PhysicalConstants.hh"                  39 #include "G4PhysicalConstants.hh"
 40 #include "G4SystemOfUnits.hh"                      40 #include "G4SystemOfUnits.hh"
 41 #include "Randomize.hh"                            41 #include "Randomize.hh"
 42 #include "G4LorentzRotation.hh"                    42 #include "G4LorentzRotation.hh"
 43 #include "G4ThreeVector.hh"                        43 #include "G4ThreeVector.hh"
 44 #include "G4ParticleDefinition.hh"                 44 #include "G4ParticleDefinition.hh"
 45 #include "G4VSplitableHadron.hh"                   45 #include "G4VSplitableHadron.hh"
 46 #include "G4ExcitedString.hh"                      46 #include "G4ExcitedString.hh"
 47                                                    47 
 48 #include "G4Log.hh"                                48 #include "G4Log.hh"
 49 #include "G4Pow.hh"                                49 #include "G4Pow.hh"
 50                                                    50 
 51 //#define debugSingleDiffraction                   51 //#define debugSingleDiffraction
 52                                                    52 
 53 G4SingleDiffractiveExcitation::G4SingleDiffrac     53 G4SingleDiffractiveExcitation::G4SingleDiffractiveExcitation(){}
 54                                                    54 
 55 G4SingleDiffractiveExcitation::~G4SingleDiffra     55 G4SingleDiffractiveExcitation::~G4SingleDiffractiveExcitation(){}
 56                                                    56 
 57 G4bool G4SingleDiffractiveExcitation::             57 G4bool G4SingleDiffractiveExcitation::
 58 ExciteParticipants( G4VSplitableHadron *projec     58 ExciteParticipants( G4VSplitableHadron *projectile, G4VSplitableHadron *target, 
 59                     G4bool ProjectileDiffracti     59                     G4bool ProjectileDiffraction ) const
 60 {                                                  60 {
 61   #ifdef debugSingleDiffraction                    61   #ifdef debugSingleDiffraction
 62     G4cout<<G4endl<<"G4SingleDiffractiveExcita     62     G4cout<<G4endl<<"G4SingleDiffractiveExcitation::ExciteParticipants"<<G4endl;
 63   #endif                                           63   #endif
 64                                                    64 
 65   G4LorentzVector Pprojectile=projectile->Get4     65   G4LorentzVector Pprojectile=projectile->Get4Momentum();
 66   G4double Mprojectile =    projectile->GetDef     66   G4double Mprojectile =    projectile->GetDefinition()->GetPDGMass();
 67   G4double Mprojectile2=sqr(projectile->GetDef     67   G4double Mprojectile2=sqr(projectile->GetDefinition()->GetPDGMass());
 68                                                    68 
 69   G4LorentzVector Ptarget=target->Get4Momentum     69   G4LorentzVector Ptarget=target->Get4Momentum();
 70   G4double Mtarget =    target->GetDefinition(     70   G4double Mtarget =    target->GetDefinition()->GetPDGMass();
 71   G4double Mtarget2=sqr(target->GetDefinition(     71   G4double Mtarget2=sqr(target->GetDefinition()->GetPDGMass());
 72                                                    72 
 73   #ifdef debugSingleDiffraction                    73   #ifdef debugSingleDiffraction
 74     G4cout<<"Proj Targ "<<projectile->GetDefin     74     G4cout<<"Proj Targ "<<projectile->GetDefinition()->GetPDGEncoding()<<" "<<target->GetDefinition()->GetPDGEncoding()<<G4endl;
 75     G4cout<<"Pr Tr 4-Mom "<<Pprojectile<<" "<<     75     G4cout<<"Pr Tr 4-Mom "<<Pprojectile<<" "<<Pprojectile.mag()<<G4endl
 76           <<"            "<<Ptarget    <<" "<<     76           <<"            "<<Ptarget    <<" "<<Ptarget.mag()   <<G4endl;
 77   #endif                                           77   #endif
 78                                                    78 
 79   G4LorentzVector Psum=Pprojectile+Ptarget;        79   G4LorentzVector Psum=Pprojectile+Ptarget;
 80   G4double SqrtS=Psum.mag();                       80   G4double SqrtS=Psum.mag();
 81   G4double S    =Psum.mag2();                      81   G4double S    =Psum.mag2();
 82                                                    82 
 83   #ifdef debugSingleDiffraction                    83   #ifdef debugSingleDiffraction
 84     G4cout<<"SqrtS-Mprojectile-Mtarget "<<Sqrt     84     G4cout<<"SqrtS-Mprojectile-Mtarget "<<SqrtS<<" "<<Mprojectile<<" "<<Mtarget
 85           <<" "<<SqrtS-Mprojectile-Mtarget<<G4     85           <<" "<<SqrtS-Mprojectile-Mtarget<<G4endl;
 86   #endif                                           86   #endif
 87   if (SqrtS-Mprojectile-Mtarget <= 250.0*MeV)      87   if (SqrtS-Mprojectile-Mtarget <= 250.0*MeV) {
 88     #ifdef debugSingleDiffraction                  88     #ifdef debugSingleDiffraction
 89     G4cerr<<"Projectile: "<<projectile->GetDef     89     G4cerr<<"Projectile: "<<projectile->GetDefinition()->GetPDGEncoding()<<" "
 90           <<Pprojectile<<" "<<Pprojectile.mag(     90           <<Pprojectile<<" "<<Pprojectile.mag()<<G4endl;
 91     G4cerr<<"Target:     "<<target->GetDefinit     91     G4cerr<<"Target:     "<<target->GetDefinition()->GetPDGEncoding()<<" "
 92           <<Ptarget<<" "<<Ptarget.mag()<<G4end     92           <<Ptarget<<" "<<Ptarget.mag()<<G4endl; 
 93     G4cerr<<"sqrt(S) = "<<SqrtS<<" Mp + Mt = "     93     G4cerr<<"sqrt(S) = "<<SqrtS<<" Mp + Mt = "<<Pprojectile.mag()+Ptarget.mag()<<G4endl;
 94     #endif                                         94     #endif
 95     return true;                                   95     return true;
 96   }                                                96   }
 97                                                    97 
 98   G4LorentzRotation toCms(-1*Psum.boostVector(     98   G4LorentzRotation toCms(-1*Psum.boostVector());
 99                                                    99 
100   G4LorentzVector Ptmp=toCms*Pprojectile;         100   G4LorentzVector Ptmp=toCms*Pprojectile;
101                                                   101 
102   if ( Ptmp.pz() <= 0. )                          102   if ( Ptmp.pz() <= 0. )
103   {                                               103   {
104     // "String" moving backwards in  CMS, abor    104     // "String" moving backwards in  CMS, abort collision !!
105     //         G4cout << " abort Collision!! "    105     //         G4cout << " abort Collision!! " << G4endl;
106     return false;                                 106     return false;
107   }                                               107   }
108                                                   108 
109   toCms.rotateZ(-1*Ptmp.phi());                   109   toCms.rotateZ(-1*Ptmp.phi());
110   toCms.rotateY(-1*Ptmp.theta());                 110   toCms.rotateY(-1*Ptmp.theta());
111                                                   111 
112   G4LorentzRotation toLab(toCms.inverse());       112   G4LorentzRotation toLab(toCms.inverse());
113                                                   113 
114   Pprojectile.transform(toCms);                   114   Pprojectile.transform(toCms);
115   Ptarget.transform(toCms);                       115   Ptarget.transform(toCms);
116   #ifdef debugSingleDiffraction                   116   #ifdef debugSingleDiffraction
117     G4cout << "Pprojectile  in CMS " << Pproje    117     G4cout << "Pprojectile  in CMS " << Pprojectile << G4endl;
118     G4cout << "Ptarget      in CMS " << Ptarge    118     G4cout << "Ptarget      in CMS " << Ptarget     << G4endl;
119   #endif                                          119   #endif
120   G4double maxPtSquare=sqr(Ptarget.pz());         120   G4double maxPtSquare=sqr(Ptarget.pz());
121                                                   121 
122   G4double ProjectileMinDiffrMass(0.), TargetM    122   G4double ProjectileMinDiffrMass(0.), TargetMinDiffrMass(0.);
123   G4double AveragePt2(0.);                        123   G4double AveragePt2(0.);
124   G4int absPDGcode=std::abs(projectile->GetDef    124   G4int absPDGcode=std::abs(projectile->GetDefinition()->GetPDGEncoding()); 
125                                                   125 
126   if ( ProjectileDiffraction ) {                  126   if ( ProjectileDiffraction ) {
127     if ( absPDGcode > 1000 )                      127     if ( absPDGcode > 1000 )                            //------Projectile is baryon --------
128     {                                             128     {
129       if ( absPDGcode > 4000 && absPDGcode < 6    129       if ( absPDGcode > 4000 && absPDGcode < 6000 )  // Projectile is a charm or bottom baryon
130       {                                           130       {
131         ProjectileMinDiffrMass = projectile->G    131         ProjectileMinDiffrMass = projectile->GetDefinition()->GetPDGMass()/CLHEP::GeV + 0.25;  // GeV
132         AveragePt2 = 0.3;                         132         AveragePt2 = 0.3;                                                                      // GeV^2
133       }                                           133       }
134       else                                        134       else
135       {                                           135       {
136         ProjectileMinDiffrMass = 1.16;            136         ProjectileMinDiffrMass = 1.16;              // GeV
137         AveragePt2 = 0.3;                         137         AveragePt2 = 0.3;                           // GeV^2
138       }                                           138       }
139     }                                             139     }
140     else if( absPDGcode == 211 || absPDGcode =    140     else if( absPDGcode == 211 || absPDGcode ==  111) //------Projectile is Pion -----------
141     {                                             141     {
142       ProjectileMinDiffrMass = 1.0;               142       ProjectileMinDiffrMass = 1.0;               // GeV
143       AveragePt2 = 0.3;                           143       AveragePt2 = 0.3;                           // GeV^2
144     }                                             144     }
145     else if( absPDGcode == 321 || absPDGcode =    145     else if( absPDGcode == 321 || absPDGcode == 130 || absPDGcode == 310) //Projectile is Kaon
146     {                                             146     {
147       ProjectileMinDiffrMass = 1.1;               147       ProjectileMinDiffrMass = 1.1;               // GeV
148       AveragePt2 = 0.3;                           148       AveragePt2 = 0.3;                           // GeV^2
149     }                                             149     }
150     else if( absPDGcode == 22)                    150     else if( absPDGcode == 22)                        //------Projectile is Gamma -----------
151     {                                             151     {
152       ProjectileMinDiffrMass = 0.25;              152       ProjectileMinDiffrMass = 0.25;             // GeV
153       AveragePt2 = 0.36;                          153       AveragePt2 = 0.36;                         // GeV^2
154     }                                             154     }
155     else if( absPDGcode > 400 && absPDGcode <     155     else if( absPDGcode > 400 && absPDGcode < 600)  // Projectile is a charm or bottom meson
156     {                                             156     {
157       ProjectileMinDiffrMass = projectile->Get    157       ProjectileMinDiffrMass = projectile->GetDefinition()->GetPDGMass()/CLHEP::GeV + 0.25;  // GeV
158       AveragePt2 = 0.3;                           158       AveragePt2 = 0.3;                                                                      // GeV^2
159     }                                             159     }
160     else                                          160     else                                             //------Projectile is undefined, Nucleon assumed
161     {                                             161     {
162       ProjectileMinDiffrMass = 1.1;               162       ProjectileMinDiffrMass = 1.1;              // GeV
163       AveragePt2 = 0.3;                           163       AveragePt2 = 0.3;                          // GeV^2
164     };                                            164     };
165                                                   165 
166     ProjectileMinDiffrMass = ProjectileMinDiff    166     ProjectileMinDiffrMass = ProjectileMinDiffrMass * GeV;
167     Mprojectile2=sqr(ProjectileMinDiffrMass);     167     Mprojectile2=sqr(ProjectileMinDiffrMass);
168   }                                               168   }
169   else                                            169   else
170   {                                               170   {
171     TargetMinDiffrMass = 1.16*GeV;                171     TargetMinDiffrMass = 1.16*GeV;                     // For target nucleon
172     Mtarget2 = sqr( TargetMinDiffrMass) ;         172     Mtarget2 = sqr( TargetMinDiffrMass) ;
173     AveragePt2 = 0.3;                             173     AveragePt2 = 0.3;                                  // GeV^2
174   }   // end of if ( ProjectileDiffraction )      174   }   // end of if ( ProjectileDiffraction )
175                                                   175 
176   AveragePt2 = AveragePt2 * GeV*GeV;              176   AveragePt2 = AveragePt2 * GeV*GeV;
177                                                   177 
178   G4double Pt2, PZcms, PZcms2;                    178   G4double Pt2, PZcms, PZcms2;
179   G4double ProjMassT2, ProjMassT;                 179   G4double ProjMassT2, ProjMassT;
180   G4double TargMassT2, TargMassT;                 180   G4double TargMassT2, TargMassT;
181   G4double PMinusMin, PMinusMax;                  181   G4double PMinusMin, PMinusMax;
182   G4double TPlusMin, TPlusMax;                    182   G4double TPlusMin, TPlusMax;
183   G4double PMinusNew, PPlusNew, TPlusNew, TMin    183   G4double PMinusNew, PPlusNew, TPlusNew, TMinusNew;
184                                                   184 
185   G4LorentzVector Qmomentum;                      185   G4LorentzVector Qmomentum;
186   G4double Qminus, Qplus;                         186   G4double Qminus, Qplus;
187                                                   187 
188   G4int whilecount=0;                             188   G4int whilecount=0;
189   do {                                            189   do {
190     whilecount++;                                 190     whilecount++;
191                                                   191 
192     if (whilecount > 1000 )                       192     if (whilecount > 1000 )
193     {                                             193     {
194       Qmomentum=G4LorentzVector(0.,0.,0.,0.);     194       Qmomentum=G4LorentzVector(0.,0.,0.,0.);
195       return false;     //  Ignore this intera    195       return false;     //  Ignore this interaction
196     }                                             196     }
197                                                   197     
198     //  Generate pt                               198     //  Generate pt
199     Qmomentum=G4LorentzVector(GaussianPt(Avera    199     Qmomentum=G4LorentzVector(GaussianPt(AveragePt2,maxPtSquare),0);
200                                                   200 
201     Pt2 = G4ThreeVector( Qmomentum.vect() ).ma    201     Pt2 = G4ThreeVector( Qmomentum.vect() ).mag2();
202                                                   202 
203     ProjMassT2 = Mprojectile2 + Pt2;              203     ProjMassT2 = Mprojectile2 + Pt2;
204     ProjMassT = std::sqrt( ProjMassT2 );          204     ProjMassT = std::sqrt( ProjMassT2 );
205     TargMassT2 = Mtarget2 + Pt2;                  205     TargMassT2 = Mtarget2 + Pt2;
206     TargMassT = std::sqrt( TargMassT2 );          206     TargMassT = std::sqrt( TargMassT2 );
207                                                   207 
208     #ifdef debugSingleDiffraction                 208     #ifdef debugSingleDiffraction
209       G4cout<<whilecount<<" "<<Pt2<<" "<<ProjM    209       G4cout<<whilecount<<" "<<Pt2<<" "<<ProjMassT<<" "<<TargMassT<<" "<<SqrtS<<" "<<S<<" "<<ProjectileDiffraction<<G4endl;
210     #endif                                        210     #endif
211     if ( SqrtS < ProjMassT + TargMassT ) conti    211     if ( SqrtS < ProjMassT + TargMassT ) continue;
212                                                   212 
213     PZcms2 = ( S*S + ProjMassT2*ProjMassT2 + T    213     PZcms2 = ( S*S + ProjMassT2*ProjMassT2 + TargMassT2*TargMassT2
214               - 2.0*S*ProjMassT2 - 2.0*S*TargM    214               - 2.0*S*ProjMassT2 - 2.0*S*TargMassT2 - 2.0*ProjMassT2*TargMassT2 ) / 4.0 / S;
215                                                   215 
216     if ( PZcms2 < 0 ) continue;                   216     if ( PZcms2 < 0 ) continue;
217                                                   217 
218     PZcms = std::sqrt( PZcms2 );                  218     PZcms = std::sqrt( PZcms2 );
219                                                   219 
220     if ( ProjectileDiffraction )                  220     if ( ProjectileDiffraction )
221     {       // The projectile will fragment, t    221     {       // The projectile will fragment, the target will saved.
222       PMinusMin = std::sqrt( ProjMassT2 + PZcm    222       PMinusMin = std::sqrt( ProjMassT2 + PZcms2 ) - PZcms;
223       PMinusMax = SqrtS - TargMassT;              223       PMinusMax = SqrtS - TargMassT;
224                                                   224 
225       PMinusNew = ChooseX( PMinusMin, PMinusMa    225       PMinusNew = ChooseX( PMinusMin, PMinusMax );
226       TMinusNew = SqrtS - PMinusNew;              226       TMinusNew = SqrtS - PMinusNew;
227                                                   227 
228       Qminus = Ptarget.minus() - TMinusNew;       228       Qminus = Ptarget.minus() - TMinusNew;
229       TPlusNew = TargMassT2 / TMinusNew;          229       TPlusNew = TargMassT2 / TMinusNew;
230       Qplus = Ptarget.plus() - TPlusNew;          230       Qplus = Ptarget.plus() - TPlusNew;
231                                                   231 
232     } else {  // The target will fragment, the    232     } else {  // The target will fragment, the projectile will saved.
233       TPlusMin = std::sqrt( TargMassT2 + PZcms    233       TPlusMin = std::sqrt( TargMassT2 + PZcms2 ) - PZcms;
234       TPlusMax = SqrtS - ProjMassT;               234       TPlusMax = SqrtS - ProjMassT;
235                                                   235   
236       TPlusNew = ChooseX( TPlusMin, TPlusMax )    236       TPlusNew = ChooseX( TPlusMin, TPlusMax );
237       PPlusNew = SqrtS - TPlusNew;                237       PPlusNew = SqrtS - TPlusNew;
238                                                   238 
239       Qplus = PPlusNew - Pprojectile.plus();      239       Qplus = PPlusNew - Pprojectile.plus();
240       PMinusNew = ProjMassT2 / PPlusNew;          240       PMinusNew = ProjMassT2 / PPlusNew;
241       Qminus = PMinusNew - Pprojectile.minus()    241       Qminus = PMinusNew - Pprojectile.minus();
242     }                                             242     }
243                                                   243   
244     Qmomentum.setPz( (Qplus - Qminus)/2 );        244     Qmomentum.setPz( (Qplus - Qminus)/2 );
245     Qmomentum.setE(  (Qplus + Qminus)/2 );        245     Qmomentum.setE(  (Qplus + Qminus)/2 );
246                                                   246 
247     #ifdef debugSingleDiffraction                 247     #ifdef debugSingleDiffraction
248       G4cout<<ProjectileDiffraction<<" "<<( Pp    248       G4cout<<ProjectileDiffraction<<" "<<( Pprojectile + Qmomentum ).mag2()<<" "<< Mprojectile2<<G4endl;
249       G4cout<<!ProjectileDiffraction<<" "<<( P    249       G4cout<<!ProjectileDiffraction<<" "<<( Ptarget    - Qmomentum ).mag2()<<" "<< Mtarget2<<G4endl;
250     #endif                                        250     #endif
251                                                   251 
252   } while ( ( ProjectileDiffraction&&( Pprojec    252   } while ( ( ProjectileDiffraction&&( Pprojectile + Qmomentum ).mag2() <  Mprojectile2 ) ||
253             (!ProjectileDiffraction&&( Ptarget    253             (!ProjectileDiffraction&&( Ptarget     - Qmomentum ).mag2() <  Mtarget2       )   ); 
254     // Repeat the sampling because there was n    254     // Repeat the sampling because there was not any excitation
255                                                   255 
256   Pprojectile += Qmomentum;                       256   Pprojectile += Qmomentum;
257                                                   257 
258   Ptarget     -= Qmomentum;                       258   Ptarget     -= Qmomentum;
259                                                   259 
260   // Transform back and update SplitableHadron    260   // Transform back and update SplitableHadron Participant.
261   Pprojectile.transform(toLab);                   261   Pprojectile.transform(toLab);
262   Ptarget.transform(toLab);                       262   Ptarget.transform(toLab);
263                                                   263 
264   #ifdef debugSingleDiffraction                   264   #ifdef debugSingleDiffraction
265     G4cout << "Pprojectile  in Lab. " << Pproj    265     G4cout << "Pprojectile  in Lab. " << Pprojectile << G4endl;
266     G4cout << "Ptarget      in Lab. " << Ptarg    266     G4cout << "Ptarget      in Lab. " << Ptarget     << G4endl;
267     G4cout << "G4SingleDiffractiveExcitation-     267     G4cout << "G4SingleDiffractiveExcitation- Projectile mass  " <<  Pprojectile.mag() << G4endl;
268     G4cout << "G4SingleDiffractiveExcitation-     268     G4cout << "G4SingleDiffractiveExcitation- Target mass      " <<  Ptarget.mag() << G4endl;
269   #endif                                          269   #endif
270                                                   270 
271   target->Set4Momentum(Ptarget);                  271   target->Set4Momentum(Ptarget);
272   projectile->Set4Momentum(Pprojectile);          272   projectile->Set4Momentum(Pprojectile);
273                                                   273 
274   return true;                                    274   return true;
275 }                                                 275 }
276                                                   276 
277 // --------- private methods -----------------    277 // --------- private methods ----------------------
278                                                   278 
279 G4double G4SingleDiffractiveExcitation::Choose    279 G4double G4SingleDiffractiveExcitation::ChooseX(G4double Xmin, G4double Xmax) const
280 {                                                 280 {
281   // choose an x between Xmin and Xmax with P(    281   // choose an x between Xmin and Xmax with P(x) ~ 1/x
282   G4double range=Xmax-Xmin;                       282   G4double range=Xmax-Xmin;
283                                                   283 
284   if ( Xmin <= 0. || range <=0. )                 284   if ( Xmin <= 0. || range <=0. ) 
285   {                                               285   {
286     G4cout << " Xmin, range : " << Xmin << " ,    286     G4cout << " Xmin, range : " << Xmin << " , " << range << G4endl;
287     throw G4HadronicException(__FILE__, __LINE    287     throw G4HadronicException(__FILE__, __LINE__, "G4SingleDiffractiveExcitation::ChooseX : Invalid arguments ");
288   }                                               288   }
289                                                   289 
290   G4double x = Xmin*G4Pow::GetInstance()->powA    290   G4double x = Xmin*G4Pow::GetInstance()->powA(Xmax/Xmin, G4UniformRand() );
291   // G4double x = 1.0/sqr(1.0/std::sqrt(Xmin)     291   // G4double x = 1.0/sqr(1.0/std::sqrt(Xmin) - G4UniformRand() * (1.0/std::sqrt(Xmin) - 1.0/std::sqrt(Xmax)));
292   return x;                                       292   return x;
293 }                                                 293 }
294                                                   294 
295                                                   295 
296 G4ThreeVector G4SingleDiffractiveExcitation::G    296 G4ThreeVector G4SingleDiffractiveExcitation::GaussianPt(G4double widthSquare, G4double maxPtSquare) const
297 {            //  @@ this method is used in FTF    297 {            //  @@ this method is used in FTFModel as well. Should go somewhere common!
298                                                   298 
299   G4double pt2;                                   299   G4double pt2;
300                                                   300 
301   const G4int maxNumberOfLoops = 1000;            301   const G4int maxNumberOfLoops = 1000;
302   G4int loopCounter = 0;                          302   G4int loopCounter = 0;
303   do {                                            303   do {
304     pt2=-widthSquare * G4Log( G4UniformRand()     304     pt2=-widthSquare * G4Log( G4UniformRand() );
305   } while ( ( pt2 > maxPtSquare) && ++loopCoun    305   } while ( ( pt2 > maxPtSquare) && ++loopCounter < maxNumberOfLoops );  /* Loop checking, 07.08.2015, A.Ribon */
306   if ( loopCounter >= maxNumberOfLoops ) {        306   if ( loopCounter >= maxNumberOfLoops ) {
307     pt2 = 0.99*maxPtSquare;  // Just an accept    307     pt2 = 0.99*maxPtSquare;  // Just an acceptable value, without any physics consideration. 
308   }                                               308   }
309                                                   309 
310   pt2=std::sqrt(pt2);                             310   pt2=std::sqrt(pt2);
311                                                   311 
312   G4double phi=G4UniformRand() * twopi;           312   G4double phi=G4UniformRand() * twopi;
313                                                   313 
314   return G4ThreeVector (pt2*std::cos(phi), pt2    314   return G4ThreeVector (pt2*std::cos(phi), pt2*std::sin(phi), 0.);    
315 }                                                 315 }
316                                                   316 
317                                                   317