| Geant4 Cross Reference |
1 // 1 //
2 // ******************************************* 2 // ********************************************************************
3 // * License and Disclaimer 3 // * License and Disclaimer *
4 // * 4 // * *
5 // * The Geant4 software is copyright of th 5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided 6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License 7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/ 8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. 9 // * include a list of copyright holders. *
10 // * 10 // * *
11 // * Neither the authors of this software syst 11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing fin 12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warran 13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assum 14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file 15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitatio 16 // * for the full disclaimer and the limitation of liability. *
17 // * 17 // * *
18 // * This code implementation is the result 18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboratio 19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distri 20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you ag 21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publicati 22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Sof 23 // * acceptance of all terms of the Geant4 Software license. *
24 // ******************************************* 24 // ********************************************************************
25 // 25 //
26 // 26 //
>> 27 // $Id: G4QGSDiffractiveExcitation.cc 100828 2016-11-02 15:25:59Z gcosmo $
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 "G4PhysicalConstants.hh"
47 #include "G4SystemOfUnits.hh" 48 #include "G4SystemOfUnits.hh"
48 #include "Randomize.hh" 49 #include "Randomize.hh"
49 50
50 #include "G4QGSDiffractiveExcitation.hh" 51 #include "G4QGSDiffractiveExcitation.hh"
51 #include "G4LorentzRotation.hh" 52 #include "G4LorentzRotation.hh"
52 #include "G4ThreeVector.hh" 53 #include "G4ThreeVector.hh"
53 #include "G4ParticleDefinition.hh" 54 #include "G4ParticleDefinition.hh"
54 #include "G4VSplitableHadron.hh" 55 #include "G4VSplitableHadron.hh"
55 #include "G4ExcitedString.hh" 56 #include "G4ExcitedString.hh"
56 //#include "G4ios.hh" 57 //#include "G4ios.hh"
57 58
58 #include "G4Exp.hh" 59 #include "G4Exp.hh"
59 #include "G4Log.hh" 60 #include "G4Log.hh"
60 #include "G4Pow.hh" 61 #include "G4Pow.hh"
61 62
62 //============================================ <<
63 <<
64 //#define debugDoubleDiffraction <<
65 <<
66 //============================================ <<
67 63
68 G4QGSDiffractiveExcitation::G4QGSDiffractiveEx 64 G4QGSDiffractiveExcitation::G4QGSDiffractiveExcitation()
69 { 65 {
70 } 66 }
71 67
72 G4QGSDiffractiveExcitation::~G4QGSDiffractiveE 68 G4QGSDiffractiveExcitation::~G4QGSDiffractiveExcitation()
73 { 69 {
74 } 70 }
75 71
76 72
77 G4bool G4QGSDiffractiveExcitation:: 73 G4bool G4QGSDiffractiveExcitation::
78 ExciteParticipants(G4VSplitableHadron *project << 74 ExciteParticipants(G4VSplitableHadron *projectile, G4VSplitableHadron *target) const
79 { 75 {
80 #ifdef debugDoubleDiffraction <<
81 G4cout<<G4endl<<"G4QGSDiffractiveExcitatio <<
82 G4cout<<"Proj Targ "<<projectile->GetDefin <<
83 G4cout<<"Proj 4 Mom "<<projectile->Get4Mom <<
84 G4cout<<"Targ 4 Mom "<<target->Get4Momentu <<
85 #endif <<
86 <<
87 G4LorentzVector Pprojectile=projectile->Get4 76 G4LorentzVector Pprojectile=projectile->Get4Momentum();
88 77
89 // -------------------- Projectile parameter 78 // -------------------- Projectile parameters -----------------------------------
90 G4bool PutOnMassShell=0; 79 G4bool PutOnMassShell=0;
91 80
>> 81 //G4double M0projectile=projectile->GetDefinition()->GetPDGMass(); // With de-excitation
92 G4double M0projectile = Pprojectile.mag(); 82 G4double M0projectile = Pprojectile.mag(); // Without de-excitation
93 83
94 if(M0projectile < projectile->GetDefinition( 84 if(M0projectile < projectile->GetDefinition()->GetPDGMass())
95 { 85 {
96 PutOnMassShell=1; 86 PutOnMassShell=1;
97 M0projectile=projectile->GetDefinition()-> 87 M0projectile=projectile->GetDefinition()->GetPDGMass();
98 } 88 }
99 89
>> 90 G4double Mprojectile2 = M0projectile * M0projectile;
>> 91
>> 92 G4int PDGcode=projectile->GetDefinition()->GetPDGEncoding();
>> 93 G4int absPDGcode=std::abs(PDGcode);
>> 94 G4double ProjectileDiffCut;
>> 95 G4double AveragePt2;
>> 96
>> 97 if( absPDGcode > 1000 ) //------Projectile is baryon --------
>> 98 {
>> 99 ProjectileDiffCut = 1.1; // GeV
>> 100 AveragePt2 = 0.3; // GeV^2
>> 101 }
>> 102 else if( absPDGcode == 211 || PDGcode == 111) //------Projectile is Pion -----------
>> 103 {
>> 104 ProjectileDiffCut = 1.0; // GeV
>> 105 AveragePt2 = 0.3; // GeV^2
>> 106 }
>> 107 else if( absPDGcode == 321 || PDGcode == -311) //------Projectile is Kaon -----------
>> 108 {
>> 109 ProjectileDiffCut = 1.1; // GeV
>> 110 AveragePt2 = 0.3; // GeV^2
>> 111 }
>> 112 else //------Projectile is undefined, Nucleon assumed
>> 113 {
>> 114 ProjectileDiffCut = 1.1; // GeV
>> 115 AveragePt2 = 0.3; // GeV^2
>> 116 };
>> 117
>> 118 ProjectileDiffCut = ProjectileDiffCut * GeV;
>> 119 AveragePt2 = AveragePt2 * GeV*GeV;
>> 120
100 // -------------------- Target parameters -- 121 // -------------------- Target parameters ----------------------------------------------
101 G4LorentzVector Ptarget=target->Get4Momentum 122 G4LorentzVector Ptarget=target->Get4Momentum();
102 123
103 G4double M0target = Ptarget.mag(); 124 G4double M0target = Ptarget.mag();
104 125
105 if(M0target < target->GetDefinition()->GetPD 126 if(M0target < target->GetDefinition()->GetPDGMass())
106 { 127 {
107 PutOnMassShell=1; 128 PutOnMassShell=1;
108 M0target=target->GetDefinition()->GetPDGMa 129 M0target=target->GetDefinition()->GetPDGMass();
109 } 130 }
110 131
111 G4LorentzVector Psum=Pprojectile+Ptarget; << 132 G4double Mtarget2 = M0target * M0target; //Ptarget.mag2(); // for AA-inter.
112 G4double S=Psum.mag2(); <<
113 G4double SqrtS=std::sqrt(S); <<
114 133
115 if (SqrtS < M0projectile + M0target) {return << 134 G4double NuclearNucleonDiffCut = 1.1*GeV;
116 <<
117 135
118 G4double Mprojectile2 = M0projectile * M0pro << 136 G4double ProjectileDiffCut2 = ProjectileDiffCut * ProjectileDiffCut;
119 G4double Mtarget2 = M0target * M0tar << 137 G4double NuclearNucleonDiffCut2 = NuclearNucleonDiffCut * NuclearNucleonDiffCut;
120 138
121 // Transform momenta to cms and then rotate 139 // Transform momenta to cms and then rotate parallel to z axis;
122 140
>> 141 G4LorentzVector Psum;
>> 142 Psum=Pprojectile+Ptarget;
>> 143
123 G4LorentzRotation toCms(-1*Psum.boostVector( 144 G4LorentzRotation toCms(-1*Psum.boostVector());
124 145
125 G4LorentzVector Ptmp=toCms*Pprojectile; 146 G4LorentzVector Ptmp=toCms*Pprojectile;
126 147
127 if ( Ptmp.pz() <= 0. ) 148 if ( Ptmp.pz() <= 0. )
128 { 149 {
129 // "String" moving backwards in CMS, abor 150 // "String" moving backwards in CMS, abort collision !!
130 //G4cout << " abort Collision!! " << G4end 151 //G4cout << " abort Collision!! " << G4endl;
131 return false; 152 return false;
132 } 153 }
133 154
134 toCms.rotateZ(-1*Ptmp.phi()); 155 toCms.rotateZ(-1*Ptmp.phi());
135 toCms.rotateY(-1*Ptmp.theta()); 156 toCms.rotateY(-1*Ptmp.theta());
136 157
137 G4LorentzRotation toLab(toCms.inverse()); 158 G4LorentzRotation toLab(toCms.inverse());
138 159
139 Pprojectile.transform(toCms); 160 Pprojectile.transform(toCms);
140 Ptarget.transform(toCms); 161 Ptarget.transform(toCms);
141 162
142 G4double PZcms2=(S*S+Mprojectile2*Mprojectil << 163 G4double Pt2;
143 2*S*Mprojectile2-2*S*Mtarget2-2*Mproj << 164 G4double ProjMassT2, ProjMassT;
>> 165 G4double TargMassT2, TargMassT;
>> 166 G4double PZcms2, PZcms;
>> 167 G4double PMinusNew, TPlusNew;
144 168
145 if (PZcms2 < 0) {return false;} // It can << 169 G4double S=Psum.mag2();
>> 170 G4double SqrtS=std::sqrt(S);
146 171
147 G4double PZcms = std::sqrt(PZcms2); << 172 if(SqrtS < 2200*MeV) {return false;} // The model cannot work for pp-interactions
>> 173 // at Plab < 1.3 GeV/c. Uzhi
148 174
149 if (PutOnMassShell) << 175 PZcms2=(S*S+Mprojectile2*Mprojectile2+Mtarget2*Mtarget2-
>> 176 2*S*Mprojectile2-2*S*Mtarget2-2*Mprojectile2*Mtarget2)/4./S;
>> 177 if(PZcms2 < 0)
>> 178 {return false;} // It can be in an interaction with off-shell nuclear nucleon
>> 179
>> 180 PZcms = std::sqrt(PZcms2);
>> 181
>> 182 if(PutOnMassShell)
150 { 183 {
151 if (Pprojectile.z() > 0.) << 184 if(Pprojectile.z() > 0.)
152 { 185 {
153 Pprojectile.setPz( PZcms); 186 Pprojectile.setPz( PZcms);
154 Ptarget.setPz( -PZcms); 187 Ptarget.setPz( -PZcms);
155 } << 188 } else
156 else <<
157 { 189 {
158 Pprojectile.setPz(-PZcms); 190 Pprojectile.setPz(-PZcms);
159 Ptarget.setPz( PZcms); 191 Ptarget.setPz( PZcms);
160 }; 192 };
161 193
162 Pprojectile.setE(std::sqrt(Mprojectile2+sq << 194 Pprojectile.setE(std::sqrt(Mprojectile2+
163 Ptarget.setE( std::sqrt( Mtarget2+sq << 195 Pprojectile.x()*Pprojectile.x()+
>> 196 Pprojectile.y()*Pprojectile.y()+
>> 197 PZcms2));
>> 198 Ptarget.setE(std::sqrt( Mtarget2 +
>> 199 Ptarget.x()*Ptarget.x()+
>> 200 Ptarget.y()*Ptarget.y()+
>> 201 PZcms2));
164 } 202 }
165 203
166 G4double maxPtSquare = PZcms2; 204 G4double maxPtSquare = PZcms2;
167 205
168 #ifdef debugDoubleDiffraction << 206 //G4cout << "Pprojectile aft boost : " << Pprojectile << G4endl;
169 G4cout << "Pprojectile after boost to CMS: << 207 //G4cout << "Ptarget aft boost : " << Ptarget << G4endl;
170 G4cout << "Ptarget after boost to CMS: << 208 // G4cout << "cms aft boost : " << (Pprojectile+ Ptarget) << G4endl;
171 #endif << 209 // G4cout << " Projectile Xplus / Xminus : " <<
172 << 210 // Pprojectile.plus() << " / " << Pprojectile.minus() << G4endl;
173 G4int PrPDGcode=projectile->GetDefinition << 211 // G4cout << " Target Xplus / Xminus : " <<
174 G4int absPrPDGcode=std::abs(PrPDGcode); << 212 // Ptarget.plus() << " / " << Ptarget.minus() << G4endl;
175 G4double MinPrDiffMass(0.); <<
176 G4double AveragePt2(0.); <<
177 <<
178 if (M0projectile <= projectile->GetDefinitio <<
179 { // Normal projectile <<
180 if( absPrPDGcode > 1000 ) <<
181 { <<
182 if ( absPrPDGcode > 4000 && absPrPDGcode <<
183 { <<
184 MinPrDiffMass = projectile->GetDefinit <<
185 AveragePt2 = 0.3; <<
186 } <<
187 else <<
188 { <<
189 MinPrDiffMass = 1.16; // <<
190 AveragePt2 = 0.3; <<
191 } <<
192 } <<
193 else if( absPrPDGcode == 211 || PrPDGcode <<
194 { <<
195 MinPrDiffMass = 1.0; <<
196 AveragePt2 = 0.3; <<
197 } <<
198 else if( absPrPDGcode == 321 || absPrPDGco <<
199 { <<
200 MinPrDiffMass = 1.1; <<
201 AveragePt2 = 0.3; <<
202 } <<
203 else if( absPrPDGcode > 400 && absPrPDGcod <<
204 { <<
205 MinPrDiffMass = projectile->GetDefinitio <<
206 AveragePt2 = 0.3; <<
207 } <<
208 else <<
209 { <<
210 MinPrDiffMass = 1.16; <<
211 AveragePt2 = 0.3; <<
212 } <<
213 } <<
214 else <<
215 { // Excited projectile <<
216 MinPrDiffMass = M0projectile + 220.0*MeV; <<
217 AveragePt2 = 0.3; <<
218 } <<
219 <<
220 MinPrDiffMass = MinPrDiffMass * GeV; <<
221 AveragePt2 = AveragePt2 * GeV*GeV; <<
222 //------------------------------------------ <<
223 G4double MinTrDiffMass = 1.16*GeV; <<
224 <<
225 if (SqrtS < MinPrDiffMass + MinTrDiffMass) { <<
226 <<
227 G4double MinPrDiffMass2 = MinPrDiffMass * Mi <<
228 G4double MinTrDiffMass2 = MinTrDiffMass * Mi <<
229 <<
230 G4double Pt2; <<
231 G4double ProjMassT2, ProjMassT; <<
232 G4double TargMassT2, TargMassT; <<
233 G4double PMinusNew, TPlusNew; <<
234 213
235 G4LorentzVector Qmomentum; 214 G4LorentzVector Qmomentum;
236 G4double Qminus, Qplus; 215 G4double Qminus, Qplus;
237 216
238 G4int whilecount=0; 217 G4int whilecount=0;
239 do { 218 do {
>> 219 // Generate pt
>> 220
240 if (whilecount++ >= 500 && (whilecount%100 221 if (whilecount++ >= 500 && (whilecount%100)==0)
241 if (whilecount > 1000 ) { << 222 //G4cout << "G4QGSDiffractiveExcitation::ExciteParticipants possibly looping"
242 Qmomentum=G4LorentzVector(0.,0.,0.,0.); << 223 // << ", loop count/ maxPtSquare : "
243 return false; // Ignore this interactio << 224 // << whilecount << " / " << maxPtSquare << G4endl;
244 } << 225
>> 226 if (whilecount > 1000 )
>> 227 {
>> 228 Qmomentum=G4LorentzVector(0.,0.,0.,0.);
>> 229 return false; // Ignore this interaction
>> 230 }
245 231
246 // Generate pt <<
247 Qmomentum=G4LorentzVector(GaussianPt(Avera 232 Qmomentum=G4LorentzVector(GaussianPt(AveragePt2,maxPtSquare),0);
248 233
>> 234 //G4cout << "generated Pt " << Qmomentum << G4endl;
>> 235 //G4cout << "Pprojectile with pt : " << Pprojectile+Qmomentum << G4endl;
>> 236 //G4cout << "Ptarget with pt : " << Ptarget-Qmomentum << G4endl;
>> 237
>> 238 // Momentum transfer
>> 239 /*
>> 240 G4double Xmin = minmass / ( Pprojectile.e() + Ptarget.e() );
>> 241 G4double Xmax=1.;
>> 242 G4double Xplus =ChooseX(Xmin,Xmax);
>> 243 G4double Xminus=ChooseX(Xmin,Xmax);
>> 244
>> 245 //G4cout << " X-plus " << Xplus << G4endl;
>> 246 //G4cout << " X-minus " << Xminus << G4endl;
>> 247
>> 248 G4double pt2=G4ThreeVector(Qmomentum.vect()).mag2();
>> 249 G4double Qplus =-1 * pt2 / Xminus/Ptarget.minus();
>> 250 G4double Qminus= pt2 / Xplus /Pprojectile.plus();
>> 251 */
>> 252
249 Pt2=G4ThreeVector(Qmomentum.vect()).mag2() 253 Pt2=G4ThreeVector(Qmomentum.vect()).mag2();
250 ProjMassT2=MinPrDiffMass2+Pt2; << 254 ProjMassT2=Mprojectile2+Pt2;
251 ProjMassT =std::sqrt(ProjMassT2); 255 ProjMassT =std::sqrt(ProjMassT2);
252 256
253 TargMassT2=MinTrDiffMass2+Pt2; << 257 TargMassT2=Mtarget2+Pt2;
254 TargMassT =std::sqrt(TargMassT2); 258 TargMassT =std::sqrt(TargMassT2);
255 259
256 if (SqrtS < ProjMassT + TargMassT) continu << 260 PZcms2=(S*S+ProjMassT2*ProjMassT2+
257 << 261 TargMassT2*TargMassT2-
258 PZcms2=(S*S+ProjMassT2*ProjMassT2+TargMass << 262 2.*S*ProjMassT2-2.*S*TargMassT2-
259 2.*S*ProjMassT2-2.*S*TargMassT2-2.*ProjM << 263 2.*ProjMassT2*TargMassT2)/4./S;
260 if (PZcms2 < 0 ) {PZcms2=0;}; << 264 if(PZcms2 < 0 ) {PZcms2=0;};
261 PZcms =std::sqrt(PZcms2); 265 PZcms =std::sqrt(PZcms2);
262 266
263 G4double PMinusMin=std::sqrt(ProjMassT2+PZ 267 G4double PMinusMin=std::sqrt(ProjMassT2+PZcms2)-PZcms;
264 G4double PMinusMax=SqrtS-TargMassT; 268 G4double PMinusMax=SqrtS-TargMassT;
265 269
266 PMinusNew=ChooseP(PMinusMin,PMinusMax); 270 PMinusNew=ChooseP(PMinusMin,PMinusMax);
267 Qminus=PMinusNew-Pprojectile.minus(); 271 Qminus=PMinusNew-Pprojectile.minus();
268 272
269 G4double TPlusMin=std::sqrt(TargMassT2+PZc 273 G4double TPlusMin=std::sqrt(TargMassT2+PZcms2)-PZcms;
270 G4double TPlusMax=SqrtS-ProjMassT; 274 G4double TPlusMax=SqrtS-ProjMassT;
271 275
272 TPlusNew=ChooseP(TPlusMin, TPlusMax); 276 TPlusNew=ChooseP(TPlusMin, TPlusMax);
273 Qplus=-(TPlusNew-Ptarget.plus()); 277 Qplus=-(TPlusNew-Ptarget.plus());
274 278
275 Qmomentum.setPz( (Qplus-Qminus)/2 ); 279 Qmomentum.setPz( (Qplus-Qminus)/2 );
276 Qmomentum.setE( (Qplus+Qminus)/2 ); 280 Qmomentum.setE( (Qplus+Qminus)/2 );
277 281
278 } while ( (Pprojectile+Qmomentum).mag2() < << 282 //G4cout << "Qplus / Qminus " << Qplus << " / " << Qminus<<G4endl;
279 (Ptarget -Qmomentum).mag2() < MinTrD << 283 //G4cout << "pt2" << pt2 << G4endl;
>> 284 //G4cout << "Qmomentum " << Qmomentum << G4endl;
>> 285 //G4cout << " Masses (P/T) : " << (Pprojectile+Qmomentum).mag() <<
>> 286 // " / " << (Ptarget-Qmomentum).mag() << G4endl;
>> 287 /*
>> 288 } while ( (Pprojectile+Qmomentum).mag2() <= Mprojectile2 ||
>> 289 (Ptarget-Qmomentum).mag2() <= Mtarget2 );
>> 290 */
>> 291 } while ( /* Loop checking, 26.10.2015, A.Ribon */
>> 292 ( (Pprojectile+Qmomentum).mag2() < Mprojectile2 || // No without excitation
>> 293 (Ptarget -Qmomentum).mag2() < Mtarget2 ) ||
>> 294 ( (Pprojectile+Qmomentum).mag2() < ProjectileDiffCut2 && // No double Diffraction
>> 295 (Ptarget -Qmomentum).mag2() < NuclearNucleonDiffCut2) );
>> 296
>> 297 if((Ptarget-Qmomentum).mag2() < NuclearNucleonDiffCut2) // Uzhi Projectile diffraction
>> 298 {
>> 299 G4double TMinusNew=SqrtS-PMinusNew;
>> 300 Qminus=Ptarget.minus()-TMinusNew;
>> 301 TPlusNew=TargMassT2/TMinusNew;
>> 302 Qplus=Ptarget.plus()-TPlusNew;
>> 303
>> 304 Qmomentum.setPz( (Qplus-Qminus)/2 );
>> 305 Qmomentum.setE( (Qplus+Qminus)/2 );
>> 306 }
>> 307 else if((Pprojectile+Qmomentum).mag2() < ProjectileDiffCut2) // Uzhi Target diffraction
>> 308 {
>> 309 G4double PPlusNew=SqrtS-TPlusNew;
>> 310 Qplus=PPlusNew-Pprojectile.plus();
>> 311 PMinusNew=ProjMassT2/PPlusNew;
>> 312 Qminus=PMinusNew-Pprojectile.minus();
>> 313
>> 314 Qmomentum.setPz( (Qplus-Qminus)/2 );
>> 315 Qmomentum.setE( (Qplus+Qminus)/2 );
>> 316 };
280 317
281 Pprojectile += Qmomentum; 318 Pprojectile += Qmomentum;
282 Ptarget -= Qmomentum; 319 Ptarget -= Qmomentum;
283 320
>> 321 // Vova
>> 322
>> 323 /*
>> 324 Pprojectile.setPz(0.);
>> 325 Pprojectile.setE(SqrtS-M0target);
>> 326 Ptarget.setPz(0.);
>> 327 Ptarget.setE(M0target);
>> 328 */
>> 329
>> 330 //G4cout << "Pprojectile with Q : " << Pprojectile << G4endl;
>> 331 //G4cout << "Ptarget with Q : " << Ptarget << G4endl;
>> 332 //G4cout << "Projectile back: " << toLab * Pprojectile << G4endl;
>> 333 //G4cout << "Target back: " << toLab * Ptarget << G4endl;
>> 334
284 // Transform back and update SplitableHadron 335 // Transform back and update SplitableHadron Participant.
285 Pprojectile.transform(toLab); 336 Pprojectile.transform(toLab);
286 Ptarget.transform(toLab); 337 Ptarget.transform(toLab);
287 338
288 #ifdef debugDoubleDiffraction << 339 //G4cout << "Pprojectile with Q M: " << Pprojectile<<" "<< Pprojectile.mag() << G4endl;
289 G4cout << "Pprojectile after boost to Lab: << 340 //G4cout << "Ptarget with Q M: " << Ptarget <<" "<< Ptarget.mag() << G4endl;
290 G4cout << "Ptarget after boost to Lab: << 341 //G4cout << "Target mass " << Ptarget.mag() << G4endl;
291 #endif <<
292 342
293 target->Set4Momentum(Ptarget); 343 target->Set4Momentum(Ptarget);
>> 344
>> 345 //G4cout << "Projectile mass " << Pprojectile.mag() << G4endl;
>> 346
294 projectile->Set4Momentum(Pprojectile); 347 projectile->Set4Momentum(Pprojectile);
295 348
296 return true; 349 return true;
297 } 350 }
298 351
299 352
300 G4ExcitedString * G4QGSDiffractiveExcitation:: 353 G4ExcitedString * G4QGSDiffractiveExcitation::
301 String(G4VSplitableHadron * hadron, G4bool isP 354 String(G4VSplitableHadron * hadron, G4bool isProjectile) const
302 { 355 {
303 hadron->SplitUp(); 356 hadron->SplitUp();
304 G4Parton *start= hadron->GetNextParton(); 357 G4Parton *start= hadron->GetNextParton();
305 if ( start==NULL) << 358 if ( start==NULL) {
306 { G4cout << " G4QGSDiffractiveExcitation::St << 359 G4cout << " G4FTFModel::String() Error:No start parton found"<< G4endl;
307 return NULL; 360 return NULL;
308 } 361 }
309 G4Parton *end = hadron->GetNextParton(); 362 G4Parton *end = hadron->GetNextParton();
310 if ( end==NULL) << 363 if ( end==NULL) {
311 { G4cout << " G4QGSDiffractiveExcitation::St << 364 G4cout << " G4FTFModel::String() Error:No end parton found"<< G4endl;
312 return NULL; 365 return NULL;
313 } 366 }
314 367
315 G4ExcitedString * string; 368 G4ExcitedString * string;
316 if ( isProjectile ) << 369 if ( isProjectile ) {
317 { <<
318 string= new G4ExcitedString(end,start, +1) 370 string= new G4ExcitedString(end,start, +1);
319 } else { 371 } else {
320 string= new G4ExcitedString(start,end, -1) 372 string= new G4ExcitedString(start,end, -1);
321 } 373 }
322 374
323 string->SetPosition(hadron->GetPosition()); 375 string->SetPosition(hadron->GetPosition());
324 376
325 // momenta of string ends 377 // momenta of string ends
>> 378 G4double ptSquared= hadron->Get4Momentum().perp2();
>> 379 G4double transverseMassSquared= hadron->Get4Momentum().plus()
>> 380 * hadron->Get4Momentum().minus();
326 381
327 G4double maxAvailMomentumSquared=sqr(hadron- << 382 G4double maxAvailMomentumSquared=
>> 383 sqr( std::sqrt(transverseMassSquared) - std::sqrt(ptSquared) );
328 384
329 G4double widthOfPtSquare = 0.5*sqr(GeV); << 385 G4double widthOfPtSquare = 0.25; // Uzhi <Pt^2>=0.25 ???
330 G4ThreeVector pt=GaussianPt(widthOfPtSquare, 386 G4ThreeVector pt=GaussianPt(widthOfPtSquare,maxAvailMomentumSquared);
331 387
332 G4LorentzVector Pstart(G4LorentzVector(pt,0. 388 G4LorentzVector Pstart(G4LorentzVector(pt,0.));
333 G4LorentzVector Pend; 389 G4LorentzVector Pend;
334 Pend.setPx(hadron->Get4Momentum().px() - pt. 390 Pend.setPx(hadron->Get4Momentum().px() - pt.x());
335 Pend.setPy(hadron->Get4Momentum().py() - pt. 391 Pend.setPy(hadron->Get4Momentum().py() - pt.y());
336 392
337 G4double tm1=hadron->Get4Momentum().minus() 393 G4double tm1=hadron->Get4Momentum().minus() +
338 ( Pend.perp2()-Pstart.perp2() ) / had 394 ( Pend.perp2()-Pstart.perp2() ) / hadron->Get4Momentum().plus();
339 395
340 G4double tm2= std::sqrt( std::max(0., sqr(tm 396 G4double tm2= std::sqrt( std::max(0., sqr(tm1) -
341 4. * Pend.perp2() * hadron->Get4Momen 397 4. * Pend.perp2() * hadron->Get4Momentum().minus()
342 / hadron->Get4Momentum().plus() )); 398 / hadron->Get4Momentum().plus() ));
343 399
344 G4int Sign= isProjectile ? -1 : 1; 400 G4int Sign= isProjectile ? -1 : 1;
345 401
346 G4double endMinus = 0.5 * (tm1 + Sign*tm2); 402 G4double endMinus = 0.5 * (tm1 + Sign*tm2);
347 G4double startMinus= hadron->Get4Momentum(). 403 G4double startMinus= hadron->Get4Momentum().minus() - endMinus;
348 404
349 G4double startPlus= Pstart.perp2() / startM 405 G4double startPlus= Pstart.perp2() / startMinus;
350 G4double endPlus = hadron->Get4Momentum().p 406 G4double endPlus = hadron->Get4Momentum().plus() - startPlus;
351 407
352 Pstart.setPz(0.5*(startPlus - startMinus)); 408 Pstart.setPz(0.5*(startPlus - startMinus));
353 Pstart.setE(0.5*(startPlus + startMinus)); 409 Pstart.setE(0.5*(startPlus + startMinus));
354 410
355 Pend.setPz(0.5*(endPlus - endMinus)); 411 Pend.setPz(0.5*(endPlus - endMinus));
356 Pend.setE(0.5*(endPlus + endMinus)); 412 Pend.setE(0.5*(endPlus + endMinus));
357 413
358 start->Set4Momentum(Pstart); 414 start->Set4Momentum(Pstart);
359 end->Set4Momentum(Pend); 415 end->Set4Momentum(Pend);
360 416
361 #ifdef debugQGSdiffExictation << 417 #ifdef G4_FTFDEBUG
362 G4cout << " generated string flavors << 418 G4cout << " generated string flavors " << start->GetPDGcode() << " / " << end->GetPDGcode() << G4endl;
363 G4cout << " generated string momenta: qu << 419 G4cout << " generated string momenta: quark " << start->Get4Momentum() << "mass : " <<start->Get4Momentum().mag()<< G4endl;
364 G4cout << " generated string momenta: Diqu << 420 G4cout << " generated string momenta: Diquark " << end ->Get4Momentum() << "mass : " <<end->Get4Momentum().mag()<< G4endl;
365 G4cout << " sum of ends << 421 G4cout << " sum of ends " << Pstart+Pend << G4endl;
366 G4cout << " Original << 422 G4cout << " Original " << hadron->Get4Momentum() << G4endl;
367 #endif 423 #endif
368 424
369 return string; 425 return string;
370 } 426 }
371 427
372 428
373 // --------- private methods ----------------- 429 // --------- private methods ----------------------
374 430
375 G4double G4QGSDiffractiveExcitation::ChooseP(G 431 G4double G4QGSDiffractiveExcitation::ChooseP(G4double Pmin, G4double Pmax) const
376 { 432 {
377 // choose an x between Xmin and Xmax with P( 433 // choose an x between Xmin and Xmax with P(x) ~ 1/x
378 // to be improved... 434 // to be improved...
379 435
380 G4double range=Pmax-Pmin; 436 G4double range=Pmax-Pmin;
381 437
382 if ( Pmin <= 0. || range <=0. ) 438 if ( Pmin <= 0. || range <=0. )
383 { 439 {
384 G4cout << " Pmin, range : " << Pmin << " , 440 G4cout << " Pmin, range : " << Pmin << " , " << range << G4endl;
385 throw G4HadronicException(__FILE__, __LINE 441 throw G4HadronicException(__FILE__, __LINE__, "G4QGSDiffractiveExcitation::ChooseP : Invalid arguments ");
386 } 442 }
387 443
388 G4double P; 444 G4double P;
>> 445 /*
>> 446 do {
>> 447 x=Xmin + G4UniformRand() * range;
>> 448 } while ( Xmin/x < G4UniformRand() );
>> 449 */
>> 450
389 P=Pmin * G4Pow::GetInstance()->powA(Pmax/Pmi 451 P=Pmin * G4Pow::GetInstance()->powA(Pmax/Pmin,G4UniformRand());
>> 452
390 //debug-hpw cout << "DiffractiveX "<<x<<G4en 453 //debug-hpw cout << "DiffractiveX "<<x<<G4endl;
391 return P; 454 return P;
392 } 455 }
393 456
394 <<
395 G4ThreeVector G4QGSDiffractiveExcitation::Gaus 457 G4ThreeVector G4QGSDiffractiveExcitation::GaussianPt(G4double AveragePt2, G4double maxPtSquare) const
396 { // @@ this method is used in FTF 458 { // @@ this method is used in FTFModel as well. Should go somewhere common!
>> 459
397 G4double Pt2; 460 G4double Pt2;
>> 461 /*
>> 462 do {
>> 463 pt2=widthSquare * G4Log( G4UniformRand() );
>> 464 } while ( pt2 > maxPtSquare);
>> 465 */
398 466
399 Pt2 = -AveragePt2 * G4Log(1. + G4UniformRand 467 Pt2 = -AveragePt2 * G4Log(1. + G4UniformRand() * (G4Exp(-maxPtSquare/AveragePt2)-1.));
400 468
401 G4double Pt=std::sqrt(Pt2); 469 G4double Pt=std::sqrt(Pt2);
402 470
403 G4double phi=G4UniformRand() * twopi; 471 G4double phi=G4UniformRand() * twopi;
404 472
405 return G4ThreeVector (Pt*std::cos(phi), Pt*s 473 return G4ThreeVector (Pt*std::cos(phi), Pt*std::sin(phi), 0.);
406 } 474 }
>> 475
407 476