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>> 27 // $Id: G4QGSDiffractiveExcitation.cc,v 1.1 2007/05/25 07:30:47 gunter Exp $
27 // ------------------------------------------- 28 // ------------------------------------------------------------
28 // GEANT 4 class implemetation file 29 // GEANT 4 class implemetation file
29 // 30 //
30 // ---------------- G4QGSDiffractiveExcit 31 // ---------------- G4QGSDiffractiveExcitation --------------
31 // by Gunter Folger, October 1998. 32 // by Gunter Folger, October 1998.
32 // diffractive Excitation used by stri 33 // diffractive Excitation used by strings models
33 // Take a projectile and a target 34 // Take a projectile and a target
34 // excite the projectile and target 35 // excite the projectile and target
35 // Essential changed by V. Uzhinsky in Novemb 36 // Essential changed by V. Uzhinsky in November - December 2006
36 // in order to put it in a correspondence wit 37 // in order to put it in a correspondence with original FRITIOF
37 // model. Variant of FRITIOF with nucleon de- 38 // model. Variant of FRITIOF with nucleon de-excitation is implemented.
38 // ------------------------------------------- 39 // ---------------------------------------------------------------------
39 40
40 // Modified: 41 // Modified:
41 // 25-05-07 : G.Folger 42 // 25-05-07 : G.Folger
42 // move from management/G4DiffractiveExc 43 // move from management/G4DiffractiveExcitation to to qgsm/G4QGSDiffractiveExcitation
43 // 44 //
44 45
45 #include "globals.hh" 46 #include "globals.hh"
46 #include "G4PhysicalConstants.hh" <<
47 #include "G4SystemOfUnits.hh" <<
48 #include "Randomize.hh" 47 #include "Randomize.hh"
49 48
50 #include "G4QGSDiffractiveExcitation.hh" 49 #include "G4QGSDiffractiveExcitation.hh"
51 #include "G4LorentzRotation.hh" 50 #include "G4LorentzRotation.hh"
52 #include "G4ThreeVector.hh" 51 #include "G4ThreeVector.hh"
53 #include "G4ParticleDefinition.hh" 52 #include "G4ParticleDefinition.hh"
54 #include "G4VSplitableHadron.hh" 53 #include "G4VSplitableHadron.hh"
55 #include "G4ExcitedString.hh" 54 #include "G4ExcitedString.hh"
56 //#include "G4ios.hh" 55 //#include "G4ios.hh"
57 56
58 #include "G4Exp.hh" << 57 G4QGSDiffractiveExcitation::G4QGSDiffractiveExcitation() // Uzhi
59 #include "G4Log.hh" <<
60 #include "G4Pow.hh" <<
61 <<
62 //============================================ <<
63 <<
64 //#define debugDoubleDiffraction <<
65 <<
66 //============================================ <<
67 <<
68 G4QGSDiffractiveExcitation::G4QGSDiffractiveEx <<
69 { 58 {
70 } 59 }
71 60
72 G4QGSDiffractiveExcitation::~G4QGSDiffractiveE << 61 G4bool G4QGSDiffractiveExcitation::
>> 62 ExciteParticipants(G4VSplitableHadron *projectile, G4VSplitableHadron *target) const
73 { 63 {
74 } <<
75 64
>> 65 G4LorentzVector Pprojectile=projectile->Get4Momentum();
76 66
77 G4bool G4QGSDiffractiveExcitation:: << 67 // -------------------- Projectile parameters -----------------------------------
78 ExciteParticipants(G4VSplitableHadron *project << 68 G4bool PutOnMassShell=0;
79 { << 69
80 #ifdef debugDoubleDiffraction << 70 // G4double M0projectile=projectile->GetDefinition()->GetPDGMass(); // With de-excitation
81 G4cout<<G4endl<<"G4QGSDiffractiveExcitatio << 71 G4double M0projectile = Pprojectile.mag(); // Without de-excitation
82 G4cout<<"Proj Targ "<<projectile->GetDefin << 72
83 G4cout<<"Proj 4 Mom "<<projectile->Get4Mom << 73 if(M0projectile < projectile->GetDefinition()->GetPDGMass())
84 G4cout<<"Targ 4 Mom "<<target->Get4Momentu << 74 {
85 #endif << 75 PutOnMassShell=1;
86 << 76 M0projectile=projectile->GetDefinition()->GetPDGMass();
87 G4LorentzVector Pprojectile=projectile->Get4 << 77 }
88 << 78
89 // -------------------- Projectile parameter << 79 G4double Mprojectile2 = M0projectile * M0projectile;
90 G4bool PutOnMassShell=0; << 80
91 << 81 G4int PDGcode=projectile->GetDefinition()->GetPDGEncoding();
92 G4double M0projectile = Pprojectile.mag(); << 82 G4int absPDGcode=std::abs(PDGcode);
93 << 83 G4double ProjectileDiffCut;
94 if(M0projectile < projectile->GetDefinition( << 84 G4double AveragePt2;
95 { << 85
96 PutOnMassShell=1; << 86 if( absPDGcode > 1000 ) //------Projectile is baryon --------
97 M0projectile=projectile->GetDefinition()-> << 87 {
98 } << 88 ProjectileDiffCut = 1.1; // GeV
99 << 89 AveragePt2 = 0.3; // GeV^2
100 // -------------------- Target parameters -- << 90 }
101 G4LorentzVector Ptarget=target->Get4Momentum << 91 else if( absPDGcode == 211 || PDGcode == 111) //------Projectile is Pion -----------
102 << 92 {
103 G4double M0target = Ptarget.mag(); << 93 ProjectileDiffCut = 1.0; // GeV
104 << 94 AveragePt2 = 0.3; // GeV^2
105 if(M0target < target->GetDefinition()->GetPD << 95 }
106 { << 96 else if( absPDGcode == 321 || PDGcode == -311) //------Projectile is Kaon -----------
107 PutOnMassShell=1; << 97 {
108 M0target=target->GetDefinition()->GetPDGMa << 98 ProjectileDiffCut = 1.1; // GeV
109 } << 99 AveragePt2 = 0.3; // GeV^2
110 << 100 }
111 G4LorentzVector Psum=Pprojectile+Ptarget; << 101 else //------Projectile is undefined, Nucleon assumed
112 G4double S=Psum.mag2(); << 102 {
113 G4double SqrtS=std::sqrt(S); << 103 ProjectileDiffCut = 1.1; // GeV
114 << 104 AveragePt2 = 0.3; // GeV^2
115 if (SqrtS < M0projectile + M0target) {return << 105 };
116 << 106
117 << 107 ProjectileDiffCut = ProjectileDiffCut * GeV;
118 G4double Mprojectile2 = M0projectile * M0pro << 108 AveragePt2 = AveragePt2 * GeV*GeV;
119 G4double Mtarget2 = M0target * M0tar << 109
120 << 110 // -------------------- Target parameters ----------------------------------------------
121 // Transform momenta to cms and then rotate << 111 G4LorentzVector Ptarget=target->Get4Momentum();
122 << 112
123 G4LorentzRotation toCms(-1*Psum.boostVector( << 113 G4double M0target = Ptarget.mag();
124 << 114
125 G4LorentzVector Ptmp=toCms*Pprojectile; << 115 if(M0target < target->GetDefinition()->GetPDGMass())
126 << 116 {
127 if ( Ptmp.pz() <= 0. ) << 117 PutOnMassShell=1;
128 { << 118 M0target=target->GetDefinition()->GetPDGMass();
129 // "String" moving backwards in CMS, abor << 119 }
130 //G4cout << " abort Collision!! " << G4end << 120
131 return false; << 121 G4double Mtarget2 = M0target * M0target; //Ptarget.mag2(); // for AA-inter.
132 } << 122
133 << 123 G4double NuclearNucleonDiffCut = 1.1*GeV;
134 toCms.rotateZ(-1*Ptmp.phi()); << 124
135 toCms.rotateY(-1*Ptmp.theta()); << 125 G4double ProjectileDiffCut2 = ProjectileDiffCut * ProjectileDiffCut;
136 << 126 G4double NuclearNucleonDiffCut2 = NuclearNucleonDiffCut * NuclearNucleonDiffCut;
137 G4LorentzRotation toLab(toCms.inverse()); << 127
138 << 128 // Transform momenta to cms and then rotate parallel to z axis;
139 Pprojectile.transform(toCms); << 129
140 Ptarget.transform(toCms); << 130 G4LorentzVector Psum;
141 << 131 Psum=Pprojectile+Ptarget;
142 G4double PZcms2=(S*S+Mprojectile2*Mprojectil << 132
143 2*S*Mprojectile2-2*S*Mtarget2-2*Mproj << 133 G4LorentzRotation toCms(-1*Psum.boostVector());
144 << 134
145 if (PZcms2 < 0) {return false;} // It can << 135 G4LorentzVector Ptmp=toCms*Pprojectile;
146 << 136
147 G4double PZcms = std::sqrt(PZcms2); << 137 if ( Ptmp.pz() <= 0. )
148 << 138 {
149 if (PutOnMassShell) << 139 // "String" moving backwards in CMS, abort collision !!
150 { << 140 //G4cout << " abort Collision!! " << G4endl;
151 if (Pprojectile.z() > 0.) << 141 return false;
152 { << 142 }
153 Pprojectile.setPz( PZcms); << 143
154 Ptarget.setPz( -PZcms); << 144 toCms.rotateZ(-1*Ptmp.phi());
155 } << 145 toCms.rotateY(-1*Ptmp.theta());
156 else << 146
157 { << 147 G4LorentzRotation toLab(toCms.inverse());
158 Pprojectile.setPz(-PZcms); << 148
159 Ptarget.setPz( PZcms); << 149 Pprojectile.transform(toCms);
160 }; << 150 Ptarget.transform(toCms);
161 << 151
162 Pprojectile.setE(std::sqrt(Mprojectile2+sq << 152 G4double Pt2;
163 Ptarget.setE( std::sqrt( Mtarget2+sq << 153 G4double ProjMassT2, ProjMassT;
164 } << 154 G4double TargMassT2, TargMassT;
165 << 155 G4double PZcms2, PZcms;
166 G4double maxPtSquare = PZcms2; << 156 G4double PMinusNew, TPlusNew;
167 << 157
168 #ifdef debugDoubleDiffraction << 158 G4double S=Psum.mag2();
169 G4cout << "Pprojectile after boost to CMS: << 159 G4double SqrtS=std::sqrt(S);
170 G4cout << "Ptarget after boost to CMS: << 160
171 #endif << 161 if(SqrtS < 2200*MeV) {return false;} // The model cannot work for pp-interactions
172 << 162 // at Plab < 1.3 GeV/c. Uzhi
173 G4int PrPDGcode=projectile->GetDefinition << 163
174 G4int absPrPDGcode=std::abs(PrPDGcode); << 164 PZcms2=(S*S+Mprojectile2*Mprojectile2+Mtarget2*Mtarget2-
175 G4double MinPrDiffMass(0.); << 165 2*S*Mprojectile2-2*S*Mtarget2-2*Mprojectile2*Mtarget2)/4./S;
176 G4double AveragePt2(0.); << 166 if(PZcms2 < 0)
177 << 167 {return false;} // It can be in an interaction with off-shell nuclear nucleon
178 if (M0projectile <= projectile->GetDefinitio << 168
179 { // Normal projectile << 169 PZcms = std::sqrt(PZcms2);
180 if( absPrPDGcode > 1000 ) << 170
181 { << 171 if(PutOnMassShell)
182 if ( absPrPDGcode > 4000 && absPrPDGcode << 172 {
183 { << 173 if(Pprojectile.z() > 0.)
184 MinPrDiffMass = projectile->GetDefinit << 174 {
185 AveragePt2 = 0.3; << 175 Pprojectile.setPz( PZcms);
186 } << 176 Ptarget.setPz( -PZcms);
187 else << 177 }
188 { << 178 else
189 MinPrDiffMass = 1.16; // << 179 {
190 AveragePt2 = 0.3; << 180 Pprojectile.setPz(-PZcms);
191 } << 181 Ptarget.setPz( PZcms);
192 } << 182 };
193 else if( absPrPDGcode == 211 || PrPDGcode << 183
194 { << 184 Pprojectile.setE(std::sqrt(Mprojectile2+
195 MinPrDiffMass = 1.0; << 185 Pprojectile.x()*Pprojectile.x()+
196 AveragePt2 = 0.3; << 186 Pprojectile.y()*Pprojectile.y()+
197 } << 187 PZcms2));
198 else if( absPrPDGcode == 321 || absPrPDGco << 188 Ptarget.setE(std::sqrt( Mtarget2 +
199 { << 189 Ptarget.x()*Ptarget.x()+
200 MinPrDiffMass = 1.1; << 190 Ptarget.y()*Ptarget.y()+
201 AveragePt2 = 0.3; << 191 PZcms2));
202 } << 192 }
203 else if( absPrPDGcode > 400 && absPrPDGcod << 193
204 { << 194 G4double maxPtSquare = PZcms2;
205 MinPrDiffMass = projectile->GetDefinitio << 195
206 AveragePt2 = 0.3; << 196 //G4cout << "Pprojectile aft boost : " << Pprojectile << G4endl;
207 } << 197 //G4cout << "Ptarget aft boost : " << Ptarget << G4endl;
208 else << 198 // G4cout << "cms aft boost : " << (Pprojectile+ Ptarget) << G4endl;
209 { << 199
210 MinPrDiffMass = 1.16; << 200 // G4cout << " Projectile Xplus / Xminus : " <<
211 AveragePt2 = 0.3; << 201 // Pprojectile.plus() << " / " << Pprojectile.minus() << G4endl;
212 } << 202 // G4cout << " Target Xplus / Xminus : " <<
213 } << 203 // Ptarget.plus() << " / " << Ptarget.minus() << G4endl;
214 else << 204
215 { // Excited projectile << 205 G4LorentzVector Qmomentum;
216 MinPrDiffMass = M0projectile + 220.0*MeV; << 206 G4double Qminus, Qplus;
217 AveragePt2 = 0.3; << 207
218 } << 208 // /* Vova
219 << 209 G4int whilecount=0;
220 MinPrDiffMass = MinPrDiffMass * GeV; << 210 do {
221 AveragePt2 = AveragePt2 * GeV*GeV; << 211 // Generate pt
222 //------------------------------------------ << 212
223 G4double MinTrDiffMass = 1.16*GeV; << 213 if (whilecount++ >= 500 && (whilecount%100)==0)
224 << 214 // G4cout << "G4QGSDiffractiveExcitation::ExciteParticipants possibly looping"
225 if (SqrtS < MinPrDiffMass + MinTrDiffMass) { << 215 // << ", loop count/ maxPtSquare : "
226 << 216 // << whilecount << " / " << maxPtSquare << G4endl;
227 G4double MinPrDiffMass2 = MinPrDiffMass * Mi << 217 if (whilecount > 1000 )
228 G4double MinTrDiffMass2 = MinTrDiffMass * Mi << 218 {
229 << 219 Qmomentum=G4LorentzVector(0.,0.,0.,0.);
230 G4double Pt2; << 220 return false; // Ignore this interaction
231 G4double ProjMassT2, ProjMassT; << 221 }
232 G4double TargMassT2, TargMassT; << 222
233 G4double PMinusNew, TPlusNew; << 223 Qmomentum=G4LorentzVector(GaussianPt(AveragePt2,maxPtSquare),0);
234 << 224
235 G4LorentzVector Qmomentum; << 225 //G4cout << "generated Pt " << Qmomentum << G4endl;
236 G4double Qminus, Qplus; << 226 //G4cout << "Pprojectile with pt : " << Pprojectile+Qmomentum << G4endl;
237 << 227 //G4cout << "Ptarget with pt : " << Ptarget-Qmomentum << G4endl;
238 G4int whilecount=0; << 228
239 do { << 229 // Momentum transfer
240 if (whilecount++ >= 500 && (whilecount%100 << 230 /* // Uzhi
241 if (whilecount > 1000 ) { << 231 G4double Xmin = minmass / ( Pprojectile.e() + Ptarget.e() );
242 Qmomentum=G4LorentzVector(0.,0.,0.,0.); << 232 G4double Xmax=1.;
243 return false; // Ignore this interactio << 233 G4double Xplus =ChooseX(Xmin,Xmax);
244 } << 234 G4double Xminus=ChooseX(Xmin,Xmax);
245 << 235
246 // Generate pt << 236 // G4cout << " X-plus " << Xplus << G4endl;
247 Qmomentum=G4LorentzVector(GaussianPt(Avera << 237 // G4cout << " X-minus " << Xminus << G4endl;
248 << 238
249 Pt2=G4ThreeVector(Qmomentum.vect()).mag2() << 239 G4double pt2=G4ThreeVector(Qmomentum.vect()).mag2();
250 ProjMassT2=MinPrDiffMass2+Pt2; << 240 G4double Qplus =-1 * pt2 / Xminus/Ptarget.minus();
251 ProjMassT =std::sqrt(ProjMassT2); << 241 G4double Qminus= pt2 / Xplus /Pprojectile.plus();
252 << 242 */ // Uzhi *
253 TargMassT2=MinTrDiffMass2+Pt2; << 243
254 TargMassT =std::sqrt(TargMassT2); << 244 Pt2=G4ThreeVector(Qmomentum.vect()).mag2();
255 << 245 ProjMassT2=Mprojectile2+Pt2;
256 if (SqrtS < ProjMassT + TargMassT) continu << 246 ProjMassT =std::sqrt(ProjMassT2);
257 << 247
258 PZcms2=(S*S+ProjMassT2*ProjMassT2+TargMass << 248 TargMassT2=Mtarget2+Pt2;
259 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjM << 249 TargMassT =std::sqrt(TargMassT2);
260 if (PZcms2 < 0 ) {PZcms2=0;}; << 250
261 PZcms =std::sqrt(PZcms2); << 251 PZcms2=(S*S+ProjMassT2*ProjMassT2+
262 << 252 TargMassT2*TargMassT2-
263 G4double PMinusMin=std::sqrt(ProjMassT2+PZ << 253 2.*S*ProjMassT2-2.*S*TargMassT2-
264 G4double PMinusMax=SqrtS-TargMassT; << 254 2.*ProjMassT2*TargMassT2)/4./S;
265 << 255 if(PZcms2 < 0 ) {PZcms2=0;};
266 PMinusNew=ChooseP(PMinusMin,PMinusMax); << 256 PZcms =std::sqrt(PZcms2);
267 Qminus=PMinusNew-Pprojectile.minus(); << 257
268 << 258 G4double PMinusMin=std::sqrt(ProjMassT2+PZcms2)-PZcms;
269 G4double TPlusMin=std::sqrt(TargMassT2+PZc << 259 G4double PMinusMax=SqrtS-TargMassT;
270 G4double TPlusMax=SqrtS-ProjMassT; << 260
271 << 261 PMinusNew=ChooseP(PMinusMin,PMinusMax);
272 TPlusNew=ChooseP(TPlusMin, TPlusMax); << 262 Qminus=PMinusNew-Pprojectile.minus();
273 Qplus=-(TPlusNew-Ptarget.plus()); << 263
274 << 264 G4double TPlusMin=std::sqrt(TargMassT2+PZcms2)-PZcms;
275 Qmomentum.setPz( (Qplus-Qminus)/2 ); << 265 G4double TPlusMax=SqrtS-ProjMassT;
276 Qmomentum.setE( (Qplus+Qminus)/2 ); << 266
277 << 267 TPlusNew=ChooseP(TPlusMin, TPlusMax);
278 } while ( (Pprojectile+Qmomentum).mag2() < << 268 Qplus=-(TPlusNew-Ptarget.plus());
279 (Ptarget -Qmomentum).mag2() < MinTrD << 269
280 << 270 Qmomentum.setPz( (Qplus-Qminus)/2 );
281 Pprojectile += Qmomentum; << 271 Qmomentum.setE( (Qplus+Qminus)/2 );
282 Ptarget -= Qmomentum; << 272
283 << 273 //G4cout << "Qplus / Qminus " << Qplus << " / " << Qminus<<G4endl;
284 // Transform back and update SplitableHadron << 274 // G4cout << "pt2" << pt2 << G4endl;
285 Pprojectile.transform(toLab); << 275 // G4cout << "Qmomentum " << Qmomentum << G4endl;
286 Ptarget.transform(toLab); << 276 // G4cout << " Masses (P/T) : " << (Pprojectile+Qmomentum).mag() <<
287 << 277 // " / " << (Ptarget-Qmomentum).mag() << G4endl;
288 #ifdef debugDoubleDiffraction << 278 /* // Uzhi
289 G4cout << "Pprojectile after boost to Lab: << 279 } while ( (Pprojectile+Qmomentum).mag2() <= Mprojectile2 ||
290 G4cout << "Ptarget after boost to Lab: << 280 (Ptarget-Qmomentum).mag2() <= Mtarget2 );
291 #endif << 281 */ // Uzhi *
>> 282
>> 283
>> 284 } while (( (Pprojectile+Qmomentum).mag2() < Mprojectile2 || // Uzhi No without excitation
>> 285 (Ptarget -Qmomentum).mag2() < Mtarget2 ) || // Uzhi
>> 286 ( (Pprojectile+Qmomentum).mag2() < ProjectileDiffCut2 && // Uzhi No double Diffraction
>> 287 (Ptarget -Qmomentum).mag2() < NuclearNucleonDiffCut2) );// Uzhi
>> 288
>> 289 if((Ptarget-Qmomentum).mag2() < NuclearNucleonDiffCut2) // Uzhi Projectile diffraction
>> 290 {
>> 291 G4double TMinusNew=SqrtS-PMinusNew;
>> 292 Qminus=Ptarget.minus()-TMinusNew;
>> 293 TPlusNew=TargMassT2/TMinusNew;
>> 294 Qplus=Ptarget.plus()-TPlusNew;
>> 295
>> 296 Qmomentum.setPz( (Qplus-Qminus)/2 );
>> 297 Qmomentum.setE( (Qplus+Qminus)/2 );
>> 298 }
>> 299 else if((Pprojectile+Qmomentum).mag2() < ProjectileDiffCut2) // Uzhi Target diffraction
>> 300 {
>> 301 G4double PPlusNew=SqrtS-TPlusNew;
>> 302 Qplus=PPlusNew-Pprojectile.plus();
>> 303 PMinusNew=ProjMassT2/PPlusNew;
>> 304 Qminus=PMinusNew-Pprojectile.minus();
>> 305
>> 306 Qmomentum.setPz( (Qplus-Qminus)/2 );
>> 307 Qmomentum.setE( (Qplus+Qminus)/2 );
>> 308 };
>> 309
>> 310 Pprojectile += Qmomentum;
>> 311 Ptarget -= Qmomentum;
>> 312
>> 313 // Vova
>> 314
>> 315 /*
>> 316 Pprojectile.setPz(0.);
>> 317 Pprojectile.setE(SqrtS-M0target);
>> 318
>> 319 Ptarget.setPz(0.);
>> 320 Ptarget.setE(M0target);
>> 321 */
>> 322
>> 323 //G4cout << "Pprojectile with Q : " << Pprojectile << G4endl;
>> 324 //G4cout << "Ptarget with Q : " << Ptarget << G4endl;
>> 325
>> 326 // G4cout << "Projectile back: " << toLab * Pprojectile << G4endl;
>> 327 // G4cout << "Target back: " << toLab * Ptarget << G4endl;
>> 328
>> 329 // Transform back and update SplitableHadron Participant.
>> 330 Pprojectile.transform(toLab);
>> 331 Ptarget.transform(toLab);
>> 332
>> 333 //G4cout << "Pprojectile with Q M: " << Pprojectile<<" "<< Pprojectile.mag() << G4endl;
>> 334 //G4cout << "Ptarget with Q M: " << Ptarget <<" "<< Ptarget.mag() << G4endl;
>> 335
>> 336 //G4cout << "Target mass " << Ptarget.mag() << G4endl;
>> 337
>> 338 target->Set4Momentum(Ptarget);
>> 339
>> 340 //G4cout << "Projectile mass " << Pprojectile.mag() << G4endl;
292 341
293 target->Set4Momentum(Ptarget); << 342 projectile->Set4Momentum(Pprojectile);
294 projectile->Set4Momentum(Pprojectile); <<
295 343
296 return true; << 344 return true;
297 } 345 }
298 346
299 347
300 G4ExcitedString * G4QGSDiffractiveExcitation:: 348 G4ExcitedString * G4QGSDiffractiveExcitation::
301 String(G4VSplitableHadron * hadron, G4bool isP << 349 String(G4VSplitableHadron * hadron, G4bool isProjectile) const
302 { 350 {
303 hadron->SplitUp(); << 351 hadron->SplitUp();
304 G4Parton *start= hadron->GetNextParton(); << 352 G4Parton *start= hadron->GetNextParton();
305 if ( start==NULL) << 353 if ( start==NULL)
306 { G4cout << " G4QGSDiffractiveExcitation::St << 354 { G4cout << " G4FTFModel::String() Error:No start parton found"<< G4endl;
307 return NULL; << 355 return NULL;
308 } << 356 }
309 G4Parton *end = hadron->GetNextParton(); << 357 G4Parton *end = hadron->GetNextParton();
310 if ( end==NULL) << 358 if ( end==NULL)
311 { G4cout << " G4QGSDiffractiveExcitation::St << 359 { G4cout << " G4FTFModel::String() Error:No end parton found"<< G4endl;
312 return NULL; << 360 return NULL;
313 } << 361 }
314 << 362
315 G4ExcitedString * string; << 363 G4ExcitedString * string;
316 if ( isProjectile ) << 364 if ( isProjectile )
317 { << 365 {
318 string= new G4ExcitedString(end,start, +1) << 366 string= new G4ExcitedString(end,start, +1);
319 } else { << 367 } else {
320 string= new G4ExcitedString(start,end, -1) << 368 string= new G4ExcitedString(start,end, -1);
321 } << 369 }
322 << 370
323 string->SetPosition(hadron->GetPosition()); << 371 string->SetPosition(hadron->GetPosition());
324 << 372
325 // momenta of string ends << 373 // momenta of string ends
326 << 374 G4double ptSquared= hadron->Get4Momentum().perp2();
327 G4double maxAvailMomentumSquared=sqr(hadron- << 375 G4double transverseMassSquared= hadron->Get4Momentum().plus()
328 << 376 * hadron->Get4Momentum().minus();
329 G4double widthOfPtSquare = 0.5*sqr(GeV); << 377
330 G4ThreeVector pt=GaussianPt(widthOfPtSquare, << 378
331 << 379 G4double maxAvailMomentumSquared=
332 G4LorentzVector Pstart(G4LorentzVector(pt,0. << 380 sqr( std::sqrt(transverseMassSquared) - std::sqrt(ptSquared) );
333 G4LorentzVector Pend; << 381
334 Pend.setPx(hadron->Get4Momentum().px() - pt. << 382 G4double widthOfPtSquare = 0.25; // Uzhi <Pt^2>=0.25 ??????????????????
335 Pend.setPy(hadron->Get4Momentum().py() - pt. << 383 G4ThreeVector pt=GaussianPt(widthOfPtSquare,maxAvailMomentumSquared);
336 << 384
337 G4double tm1=hadron->Get4Momentum().minus() << 385 G4LorentzVector Pstart(G4LorentzVector(pt,0.));
338 ( Pend.perp2()-Pstart.perp2() ) / had << 386 G4LorentzVector Pend;
339 << 387 Pend.setPx(hadron->Get4Momentum().px() - pt.x());
340 G4double tm2= std::sqrt( std::max(0., sqr(tm << 388 Pend.setPy(hadron->Get4Momentum().py() - pt.y());
341 4. * Pend.perp2() * hadron->Get4Momen << 389
342 / hadron->Get4Momentum().plus() )); << 390 G4double tm1=hadron->Get4Momentum().minus() +
343 << 391 ( Pend.perp2()-Pstart.perp2() ) / hadron->Get4Momentum().plus();
344 G4int Sign= isProjectile ? -1 : 1; << 392
345 << 393 G4double tm2= std::sqrt( std::max(0., sqr(tm1) -
346 G4double endMinus = 0.5 * (tm1 + Sign*tm2); << 394 4. * Pend.perp2() * hadron->Get4Momentum().minus()
347 G4double startMinus= hadron->Get4Momentum(). << 395 / hadron->Get4Momentum().plus() ));
348 << 396
349 G4double startPlus= Pstart.perp2() / startM << 397 G4int Sign= isProjectile ? -1 : 1;
350 G4double endPlus = hadron->Get4Momentum().p << 398
351 << 399 G4double endMinus = 0.5 * (tm1 + Sign*tm2);
352 Pstart.setPz(0.5*(startPlus - startMinus)); << 400 G4double startMinus= hadron->Get4Momentum().minus() - endMinus;
353 Pstart.setE(0.5*(startPlus + startMinus)); << 401
354 << 402 G4double startPlus= Pstart.perp2() / startMinus;
355 Pend.setPz(0.5*(endPlus - endMinus)); << 403 G4double endPlus = hadron->Get4Momentum().plus() - startPlus;
356 Pend.setE(0.5*(endPlus + endMinus)); << 404
357 << 405 Pstart.setPz(0.5*(startPlus - startMinus));
358 start->Set4Momentum(Pstart); << 406 Pstart.setE(0.5*(startPlus + startMinus));
359 end->Set4Momentum(Pend); << 407
360 << 408 Pend.setPz(0.5*(endPlus - endMinus));
361 #ifdef debugQGSdiffExictation << 409 Pend.setE(0.5*(endPlus + endMinus));
362 G4cout << " generated string flavors << 410
363 G4cout << " generated string momenta: qu << 411 start->Set4Momentum(Pstart);
364 G4cout << " generated string momenta: Diqu << 412 end->Set4Momentum(Pend);
365 G4cout << " sum of ends << 413
366 G4cout << " Original << 414 #ifdef G4_FTFDEBUG
367 #endif << 415 G4cout << " generated string flavors " << start->GetPDGcode() << " / " << end->GetPDGcode() << G4endl;
368 << 416 G4cout << " generated string momenta: quark " << start->Get4Momentum() << "mass : " <<start->Get4Momentum().mag()<< G4endl;
369 return string; << 417 G4cout << " generated string momenta: Diquark " << end ->Get4Momentum() << "mass : " <<end->Get4Momentum().mag()<< G4endl;
>> 418 G4cout << " sum of ends " << Pstart+Pend << G4endl;
>> 419 G4cout << " Original " << hadron->Get4Momentum() << G4endl;
>> 420 #endif
>> 421
>> 422 return string;
370 } 423 }
371 424
372 425
373 // --------- private methods ----------------- 426 // --------- private methods ----------------------
374 427
375 G4double G4QGSDiffractiveExcitation::ChooseP(G << 428 G4double G4QGSDiffractiveExcitation::ChooseP(G4double Pmin, G4double Pmax) const // Uzhi
376 { 429 {
377 // choose an x between Xmin and Xmax with P( << 430 // choose an x between Xmin and Xmax with P(x) ~ 1/x
378 // to be improved... <<
379 431
380 G4double range=Pmax-Pmin; << 432 // to be improved...
381 433
382 if ( Pmin <= 0. || range <=0. ) << 434 G4double range=Pmax-Pmin; // Uzhi
383 { << 435
384 G4cout << " Pmin, range : " << Pmin << " , << 436 if ( Pmin <= 0. || range <=0. )
385 throw G4HadronicException(__FILE__, __LINE << 437 {
386 } << 438 G4cout << " Pmin, range : " << Pmin << " , " << range << G4endl;
387 << 439 throw G4HadronicException(__FILE__, __LINE__, "G4QGSDiffractiveExcitation::ChooseP : Invalid arguments ");
388 G4double P; << 440 }
389 P=Pmin * G4Pow::GetInstance()->powA(Pmax/Pmi << 441
390 //debug-hpw cout << "DiffractiveX "<<x<<G4en << 442 G4double P;
391 return P; << 443 /* // Uzhi
392 } << 444 do {
>> 445 x=Xmin + G4UniformRand() * range;
>> 446 } while ( Xmin/x < G4UniformRand() );
>> 447 */ // Uzhi
393 448
>> 449 P=Pmin * std::pow(Pmax/Pmin,G4UniformRand()); // Uzhi
>> 450
>> 451 //debug-hpw cout << "DiffractiveX "<<x<<G4endl;
>> 452 return P;
>> 453 }
394 454
395 G4ThreeVector G4QGSDiffractiveExcitation::Gaus << 455 G4ThreeVector G4QGSDiffractiveExcitation::GaussianPt(G4double AveragePt2, G4double maxPtSquare) const // Uzhi
396 { // @@ this method is used in FTF 456 { // @@ this method is used in FTFModel as well. Should go somewhere common!
397 G4double Pt2; << 457
>> 458 G4double Pt2;
>> 459 /* // Uzhi
>> 460 do {
>> 461 pt2=widthSquare * std::log( G4UniformRand() );
>> 462 } while ( pt2 > maxPtSquare);
>> 463 */ // Uzhi
>> 464
>> 465 Pt2 = -AveragePt2 * std::log(1. + G4UniformRand() * (std::exp(-maxPtSquare/AveragePt2)-1.));// Uzhi
>> 466
>> 467 G4double Pt=std::sqrt(Pt2);
>> 468
>> 469 G4double phi=G4UniformRand() * twopi;
>> 470
>> 471 return G4ThreeVector (Pt*std::cos(phi), Pt*std::sin(phi), 0.);
>> 472 }
>> 473
>> 474 G4QGSDiffractiveExcitation::G4QGSDiffractiveExcitation(const G4QGSDiffractiveExcitation &)
>> 475 {
>> 476 throw G4HadronicException(__FILE__, __LINE__, "G4QGSDiffractiveExcitation copy contructor not meant to be called");
>> 477 }
398 478
399 Pt2 = -AveragePt2 * G4Log(1. + G4UniformRand <<
400 479
401 G4double Pt=std::sqrt(Pt2); << 480 G4QGSDiffractiveExcitation::~G4QGSDiffractiveExcitation()
>> 481 {
>> 482 }
402 483
403 G4double phi=G4UniformRand() * twopi; <<
404 484
405 return G4ThreeVector (Pt*std::cos(phi), Pt*s << 485 const G4QGSDiffractiveExcitation & G4QGSDiffractiveExcitation::operator=(const G4QGSDiffractiveExcitation &)
>> 486 {
>> 487 throw G4HadronicException(__FILE__, __LINE__, "G4QGSDiffractiveExcitation = operator meant to be called");
>> 488 return *this;
>> 489 }
>> 490
>> 491
>> 492 int G4QGSDiffractiveExcitation::operator==(const G4QGSDiffractiveExcitation &) const
>> 493 {
>> 494 throw G4HadronicException(__FILE__, __LINE__, "G4QGSDiffractiveExcitation == operator meant to be called");
>> 495 return false;
>> 496 }
>> 497
>> 498 int G4QGSDiffractiveExcitation::operator!=(const G4QGSDiffractiveExcitation &) const
>> 499 {
>> 500 throw G4HadronicException(__FILE__, __LINE__, "G4QGSDiffractiveExcitation != operator meant to be called");
>> 501 return true;
406 } 502 }
407 503