1 | // |
---|
2 | // ******************************************************************** |
---|
3 | // * License and Disclaimer * |
---|
4 | // * * |
---|
5 | // * The Geant4 software is copyright of the Copyright Holders of * |
---|
6 | // * the Geant4 Collaboration. It is provided under the terms and * |
---|
7 | // * conditions of the Geant4 Software License, included in the file * |
---|
8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
---|
9 | // * include a list of copyright holders. * |
---|
10 | // * * |
---|
11 | // * Neither the authors of this software system, nor their employing * |
---|
12 | // * institutes,nor the agencies providing financial support for this * |
---|
13 | // * work make any representation or warranty, express or implied, * |
---|
14 | // * regarding this software system or assume any liability for its * |
---|
15 | // * use. Please see the license in the file LICENSE and URL above * |
---|
16 | // * for the full disclaimer and the limitation of liability. * |
---|
17 | // * * |
---|
18 | // * This code implementation is the result of the scientific and * |
---|
19 | // * technical work of the GEANT4 collaboration. * |
---|
20 | // * By using, copying, modifying or distributing the software (or * |
---|
21 | // * any work based on the software) you agree to acknowledge its * |
---|
22 | // * use in resulting scientific publications, and indicate your * |
---|
23 | // * acceptance of all terms of the Geant4 Software license. * |
---|
24 | // ******************************************************************** |
---|
25 | // |
---|
26 | #include "globals.hh" |
---|
27 | #include "G4QGSParticipants.hh" |
---|
28 | #include "G4LorentzVector.hh" |
---|
29 | #include <utility> |
---|
30 | |
---|
31 | // Class G4QGSParticipants |
---|
32 | |
---|
33 | // HPW Feb 1999 |
---|
34 | // Promoting model parameters from local variables class properties |
---|
35 | G4int G4QGSParticipants_NPart = 0; |
---|
36 | |
---|
37 | G4QGSParticipants::G4QGSParticipants() : theDiffExcitaton(), //0.7*GeV, 250*MeV, 250*MeV), |
---|
38 | nCutMax(7),ThersholdParameter(0.45*GeV), |
---|
39 | QGSMThershold(3*GeV),theNucleonRadius(1.5*fermi) |
---|
40 | |
---|
41 | { |
---|
42 | } |
---|
43 | |
---|
44 | G4QGSParticipants::G4QGSParticipants(const G4QGSParticipants &right) |
---|
45 | : G4VParticipants(), nCutMax(right.nCutMax),ThersholdParameter(right.ThersholdParameter), |
---|
46 | QGSMThershold(right.QGSMThershold),theNucleonRadius(right.theNucleonRadius) |
---|
47 | { |
---|
48 | } |
---|
49 | |
---|
50 | |
---|
51 | G4QGSParticipants::~G4QGSParticipants() |
---|
52 | { |
---|
53 | } |
---|
54 | |
---|
55 | void G4QGSParticipants::BuildInteractions(const G4ReactionProduct &thePrimary) |
---|
56 | { |
---|
57 | |
---|
58 | // Find the collisions and collition conditions |
---|
59 | G4VSplitableHadron* aProjectile = SelectInteractions(thePrimary); |
---|
60 | |
---|
61 | // now build the parton pairs. HPW |
---|
62 | SplitHadrons(); |
---|
63 | |
---|
64 | // soft collisions first HPW, ordering is vital |
---|
65 | PerformSoftCollisions(); |
---|
66 | |
---|
67 | // the rest is diffractive HPW |
---|
68 | PerformDiffractiveCollisions(); |
---|
69 | |
---|
70 | // clean-up, if necessary |
---|
71 | std::for_each(theInteractions.begin(), theInteractions.end(), DeleteInteractionContent()); |
---|
72 | theInteractions.clear(); |
---|
73 | std::for_each(theTargets.begin(), theTargets.end(), DeleteSplitableHadron()); |
---|
74 | theTargets.clear(); |
---|
75 | delete aProjectile; |
---|
76 | } |
---|
77 | |
---|
78 | G4VSplitableHadron* G4QGSParticipants::SelectInteractions(const G4ReactionProduct &thePrimary) |
---|
79 | { |
---|
80 | G4VSplitableHadron* aProjectile = new G4QGSMSplitableHadron(thePrimary, TRUE); // @@@ check the TRUE |
---|
81 | G4PomeronCrossSection theProbability(thePrimary.GetDefinition()); // @@@ should be data member |
---|
82 | G4double outerRadius = theNucleus->GetOuterRadius(); |
---|
83 | // Check reaction threshold |
---|
84 | |
---|
85 | theNucleus->StartLoop(); |
---|
86 | G4Nucleon * pNucleon = theNucleus->GetNextNucleon(); |
---|
87 | G4LorentzVector aPrimaryMomentum(thePrimary.GetMomentum(), thePrimary.GetTotalEnergy()); |
---|
88 | //--DEBUG--G4cout << " qgspart- " << aPrimaryMomentum << " # " << aPrimaryMomentum.mag() |
---|
89 | //--DEBUG-- << pNucleon->Get4Momentum() << " # " << (pNucleon->Get4Momentum()).mag()<< G4endl; |
---|
90 | G4double s = (aPrimaryMomentum + pNucleon->Get4Momentum()).mag2(); |
---|
91 | G4double ThresholdMass = thePrimary.GetMass() + pNucleon->GetDefinition()->GetPDGMass(); |
---|
92 | ModelMode = SOFT; |
---|
93 | if (sqr(ThresholdMass + ThersholdParameter) > s) |
---|
94 | { |
---|
95 | throw G4HadronicException(__FILE__, __LINE__, "Initial energy is too low. The 4-vectors of the input are inconsistant with the particle masses."); |
---|
96 | } |
---|
97 | if (sqr(ThresholdMass + QGSMThershold) > s) // thus only diffractive in cascade! |
---|
98 | { |
---|
99 | ModelMode = DIFFRACTIVE; |
---|
100 | } |
---|
101 | |
---|
102 | // first find the collisions HPW |
---|
103 | std::for_each(theInteractions.begin(), theInteractions.end(), DeleteInteractionContent()); |
---|
104 | theInteractions.clear(); |
---|
105 | G4int totalCuts = 0; |
---|
106 | G4double impactUsed = 0; |
---|
107 | |
---|
108 | #ifdef debug_QGS |
---|
109 | G4double eK = thePrimary.GetKineticEnergy()/GeV; |
---|
110 | #endif |
---|
111 | #ifdef debug_G4QGSParticipants |
---|
112 | G4LorentzVector intNuclMom; |
---|
113 | #endif |
---|
114 | while(theInteractions.size() == 0) |
---|
115 | { |
---|
116 | // choose random impact parameter HPW |
---|
117 | std::pair<G4double, G4double> theImpactParameter; |
---|
118 | theImpactParameter = theNucleus->ChooseImpactXandY(outerRadius+theNucleonRadius); |
---|
119 | G4double impactX = theImpactParameter.first; |
---|
120 | G4double impactY = theImpactParameter.second; |
---|
121 | |
---|
122 | // loop over nuclei to find collissions HPW |
---|
123 | theNucleus->StartLoop(); |
---|
124 | G4int nucleonCount = 0; // debug |
---|
125 | G4QGSParticipants_NPart = 0; |
---|
126 | #ifdef debug_G4QGSParticipants |
---|
127 | intNuclMom=aPrimaryMomentum; |
---|
128 | #endif |
---|
129 | while( (pNucleon = theNucleus->GetNextNucleon()) ) |
---|
130 | { |
---|
131 | if(totalCuts>1.5*thePrimary.GetKineticEnergy()/GeV) |
---|
132 | { |
---|
133 | break; |
---|
134 | } |
---|
135 | nucleonCount++; // debug |
---|
136 | // Needs to be moved to Probability class @@@ |
---|
137 | G4double s = (aPrimaryMomentum + pNucleon->Get4Momentum()).mag2(); |
---|
138 | G4double Distance2 = sqr(impactX - pNucleon->GetPosition().x()) + |
---|
139 | sqr(impactY - pNucleon->GetPosition().y()); |
---|
140 | G4double Probability = theProbability.GetInelasticProbability(s, Distance2); |
---|
141 | // test for inelastic collision |
---|
142 | G4double rndNumber = G4UniformRand(); |
---|
143 | // ModelMode = DIFFRACTIVE; |
---|
144 | if (Probability > rndNumber) |
---|
145 | { |
---|
146 | //--DEBUG-- cout << "DEBUG p="<< Probability<<" r="<<rndNumber<<" d="<<std::sqrt(Distance2)<<G4endl; |
---|
147 | //--DEBUG-- G4cout << " qgspart+ " << aPrimaryMomentum << " # " << aPrimaryMomentum.mag() |
---|
148 | //--DEBUG-- << pNucleon->Get4Momentum() << " # " << (pNucleon->Get4Momentum()).mag()<< G4endl; |
---|
149 | |
---|
150 | #ifdef debug_G4QGSParticipants |
---|
151 | intNuclMom += pNucleon->Get4Momentum(); |
---|
152 | #endif |
---|
153 | G4QGSMSplitableHadron* aTarget = new G4QGSMSplitableHadron(*pNucleon); |
---|
154 | G4QGSParticipants_NPart ++; |
---|
155 | theTargets.push_back(aTarget); |
---|
156 | pNucleon->Hit(aTarget); |
---|
157 | if ((theProbability.GetDiffractiveProbability(s, Distance2)/Probability > G4UniformRand() |
---|
158 | &&(ModelMode==SOFT)) || (ModelMode==DIFFRACTIVE )) |
---|
159 | { |
---|
160 | // diffractive interaction occurs |
---|
161 | if(IsSingleDiffractive()) |
---|
162 | { |
---|
163 | theSingleDiffExcitation.ExciteParticipants(aProjectile, aTarget); |
---|
164 | } |
---|
165 | else |
---|
166 | { |
---|
167 | theDiffExcitaton.ExciteParticipants(aProjectile, aTarget); |
---|
168 | } |
---|
169 | G4InteractionContent * aInteraction = new G4InteractionContent(aProjectile); |
---|
170 | aInteraction->SetTarget(aTarget); |
---|
171 | theInteractions.push_back(aInteraction); |
---|
172 | aInteraction->SetNumberOfDiffractiveCollisions(1); |
---|
173 | totalCuts += 1; |
---|
174 | } |
---|
175 | else |
---|
176 | { |
---|
177 | // nondiffractive soft interaction occurs |
---|
178 | // sample nCut+1 (cut Pomerons) pairs of strings can be produced |
---|
179 | G4int nCut; |
---|
180 | G4double * running = new G4double[nCutMax]; |
---|
181 | running[0] = 0; |
---|
182 | for(nCut = 0; nCut < nCutMax; nCut++) |
---|
183 | { |
---|
184 | running[nCut] = theProbability.GetCutPomeronProbability(s, Distance2, nCut + 1); |
---|
185 | if(nCut!=0) running[nCut] += running[nCut-1]; |
---|
186 | } |
---|
187 | G4double random = running[nCutMax-1]*G4UniformRand(); |
---|
188 | for(nCut = 0; nCut < nCutMax; nCut++) |
---|
189 | { |
---|
190 | if(running[nCut] > random) break; |
---|
191 | } |
---|
192 | delete [] running; |
---|
193 | nCut = 0; |
---|
194 | aTarget->IncrementCollisionCount(nCut+1); |
---|
195 | aProjectile->IncrementCollisionCount(nCut+1); |
---|
196 | G4InteractionContent * aInteraction = new G4InteractionContent(aProjectile); |
---|
197 | aInteraction->SetTarget(aTarget); |
---|
198 | aInteraction->SetNumberOfSoftCollisions(nCut+1); |
---|
199 | theInteractions.push_back(aInteraction); |
---|
200 | totalCuts += nCut+1; |
---|
201 | impactUsed=Distance2; |
---|
202 | } |
---|
203 | } |
---|
204 | } |
---|
205 | //--DEBUG-- g4cout << G4endl<<"NUCLEONCOUNT "<<nucleonCount<<G4endl; |
---|
206 | //--DEBUG-- G4cout << " Interact 4-Vect " << intNuclMom << G4endl; |
---|
207 | } |
---|
208 | //--DEBUG-- cout << G4endl<<"CUTDEBUG "<< totalCuts <<G4endl; |
---|
209 | //--DEBUG-- cout << "Impact Parameter used = "<<impactUsed<<G4endl; |
---|
210 | return aProjectile; |
---|
211 | } |
---|
212 | |
---|
213 | void G4QGSParticipants::PerformDiffractiveCollisions() |
---|
214 | { |
---|
215 | // remove the "G4PartonPair::PROJECTILE", etc., which are not necessary. @@@ |
---|
216 | unsigned int i; |
---|
217 | for(i = 0; i < theInteractions.size(); i++) |
---|
218 | { |
---|
219 | G4InteractionContent* anIniteraction = theInteractions[i]; |
---|
220 | G4VSplitableHadron* aProjectile = anIniteraction->GetProjectile(); |
---|
221 | G4Parton* aParton = aProjectile->GetNextParton(); |
---|
222 | G4PartonPair * aPartonPair; |
---|
223 | // projectile first HPW |
---|
224 | if (aParton) |
---|
225 | { |
---|
226 | aPartonPair = new G4PartonPair(aParton, aProjectile->GetNextAntiParton(), |
---|
227 | G4PartonPair::DIFFRACTIVE, |
---|
228 | G4PartonPair::PROJECTILE); |
---|
229 | #ifdef debug_G4QGSPart_PDiffColl |
---|
230 | G4cout << "DiffPair Pro " << aPartonPair->GetParton1()->GetPDGcode() << " " |
---|
231 | << aPartonPair->GetParton1()->Get4Momentum() << " " |
---|
232 | << aPartonPair->GetParton1()->GetX() << " " << G4endl; |
---|
233 | G4cout << " " << aPartonPair->GetParton2()->GetPDGcode() << " " |
---|
234 | << aPartonPair->GetParton2()->Get4Momentum() << " " |
---|
235 | << aPartonPair->GetParton2()->GetX() << " " << G4endl; |
---|
236 | #endif |
---|
237 | thePartonPairs.push_back(aPartonPair); |
---|
238 | } |
---|
239 | // then target HPW |
---|
240 | G4VSplitableHadron* aTarget = anIniteraction->GetTarget(); |
---|
241 | aParton = aTarget->GetNextParton(); |
---|
242 | if (aParton) |
---|
243 | { |
---|
244 | aPartonPair = new G4PartonPair(aParton, aTarget->GetNextAntiParton(), |
---|
245 | G4PartonPair::DIFFRACTIVE, |
---|
246 | G4PartonPair::TARGET); |
---|
247 | #ifdef debug_G4QGSPart_PDiffColl |
---|
248 | G4cout << "DiffPair Tgt " << aPartonPair->GetParton1()->GetPDGcode() << " " |
---|
249 | << aPartonPair->GetParton1()->Get4Momentum() << " " |
---|
250 | << aPartonPair->GetParton1()->GetX() << " " << G4endl; |
---|
251 | G4cout << " " << aPartonPair->GetParton2()->GetPDGcode() << " " |
---|
252 | << aPartonPair->GetParton2()->Get4Momentum() << " " |
---|
253 | << aPartonPair->GetParton2()->GetX() << " " << G4endl; |
---|
254 | #endif |
---|
255 | thePartonPairs.push_back(aPartonPair); |
---|
256 | } |
---|
257 | } |
---|
258 | } |
---|
259 | |
---|
260 | void G4QGSParticipants::PerformSoftCollisions() |
---|
261 | { |
---|
262 | std::vector<G4InteractionContent*>::iterator i; |
---|
263 | G4LorentzVector str4Mom; |
---|
264 | i = theInteractions.begin(); |
---|
265 | while ( i != theInteractions.end() ) |
---|
266 | { |
---|
267 | G4InteractionContent* anIniteraction = *i; |
---|
268 | G4PartonPair * aPair = NULL; |
---|
269 | if (anIniteraction->GetNumberOfSoftCollisions()) |
---|
270 | { |
---|
271 | G4VSplitableHadron* pProjectile = anIniteraction->GetProjectile(); |
---|
272 | G4VSplitableHadron* pTarget = anIniteraction->GetTarget(); |
---|
273 | for (G4int j = 0; j < anIniteraction->GetNumberOfSoftCollisions(); j++) |
---|
274 | { |
---|
275 | aPair = new G4PartonPair(pTarget->GetNextParton(), pProjectile->GetNextAntiParton(), |
---|
276 | G4PartonPair::SOFT, G4PartonPair::TARGET); |
---|
277 | #ifdef debug_G4QGSPart_PSoftColl |
---|
278 | G4cout << "SoftPair " << aPair->GetParton1()->GetPDGcode() << " " |
---|
279 | << aPair->GetParton1()->Get4Momentum() << " " |
---|
280 | << aPair->GetParton1()->GetX() << " " << G4endl; |
---|
281 | G4cout << " " << aPair->GetParton2()->GetPDGcode() << " " |
---|
282 | << aPair->GetParton2()->Get4Momentum() << " " |
---|
283 | << aPair->GetParton2()->GetX() << " " << G4endl; |
---|
284 | #endif |
---|
285 | #ifdef debug_G4QGSParticipants |
---|
286 | str4Mom += aPair->GetParton1()->Get4Momentum(); |
---|
287 | str4Mom += aPair->GetParton2()->Get4Momentum(); |
---|
288 | #endif |
---|
289 | thePartonPairs.push_back(aPair); |
---|
290 | aPair = new G4PartonPair(pProjectile->GetNextParton(), pTarget->GetNextAntiParton(), |
---|
291 | G4PartonPair::SOFT, G4PartonPair::PROJECTILE); |
---|
292 | #ifdef debug_G4QGSPart_PSoftColl |
---|
293 | G4cout << "SoftPair " << aPair->GetParton1()->GetPDGcode() << " " |
---|
294 | << aPair->GetParton1()->Get4Momentum() << " " |
---|
295 | << aPair->GetParton1()->GetX() << " " << G4endl; |
---|
296 | G4cout << " " << aPair->GetParton2()->GetPDGcode() << " " |
---|
297 | << aPair->GetParton2()->Get4Momentum() << " " |
---|
298 | << aPair->GetParton2()->GetX() << " " << G4endl; |
---|
299 | #endif |
---|
300 | #ifdef debug_G4QGSParticipants |
---|
301 | str4Mom += aPair->GetParton1()->Get4Momentum(); |
---|
302 | str4Mom += aPair->GetParton2()->Get4Momentum(); |
---|
303 | #endif |
---|
304 | thePartonPairs.push_back(aPair); |
---|
305 | } |
---|
306 | delete *i; |
---|
307 | i=theInteractions.erase(i); // i now points to the next interaction |
---|
308 | } else { |
---|
309 | i++; |
---|
310 | } |
---|
311 | } |
---|
312 | #ifdef debug_G4QGSPart_PSoftColl |
---|
313 | G4cout << " string 4 mom " << str4Mom << G4endl; |
---|
314 | #endif |
---|
315 | } |
---|