CTEQ5M added (R. Guernane)
[u/mrichter/AliRoot.git] / THerwig / AliGenHerwig.cxx
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618e1dc0 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
7cdba479 16/* $Id$ */
618e1dc0 17
18
19// Generator using Herwig as an external generator
20// The main Herwig options are accessable for the user through this interface.
21// Uses the THerwig implementation of TGenerator.
22
23#include "AliGenHerwig.h"
93831bcf 24#include "AliHerwigRndm.h"
618e1dc0 25#include "AliRun.h"
26
27#include <TParticle.h>
28#include "THerwig6.h"
29
30#include "Riostream.h"
5d12ce38 31#include "AliMC.h"
618e1dc0 32
014a9521 33ClassImp(AliGenHerwig)
618e1dc0 34
7cdba479 35
a1d47d99 36 AliGenHerwig::AliGenHerwig() :
37 AliGenMC(),
38 fAutPDF("GRV"),
39 fModPDF(5),
40 fStrucFunc(kGRVHO),
41 fKeep(0),
42 fDecaysOff(1),
43 fTrigger(0),
44 fSelectAll(0),
45 fFlavor(0),
46 fEnergyCMS(14000),
47 fMomentum1(7000),
48 fMomentum2(7000),
49 fKineBias(1),
50 fTrials(0),
51 fXsection(0),
52 fHerwig(0x0),
53 fProcess(0),
54 fPtHardMin(0),
55 fPtRMS(0),
56 fMaxPr(10),
57 fMaxErrors(1000),
58 fEnSoft(1)
618e1dc0 59{
60// Constructor
61}
62
63AliGenHerwig::AliGenHerwig(Int_t npart)
64 :AliGenMC(npart)
65{
66 SetBeamMomenta();
67 SetTarget();
68 SetProjectile();
69 SetStrucFunc(kGRVLO98);
70 fKeep=0;
71 fTrigger=0;
72 fDecaysOff=1;
73 fSelectAll=0;
74 fFlavor=0;
93831bcf 75 fPtHardMin=0.;
618e1dc0 76 fPtRMS=0.0;
77 fEnSoft=1.0;
93831bcf 78 fMaxPr=10;
618e1dc0 79 fMaxErrors=1000;
93831bcf 80 // Set random number generator
81 AliHerwigRndm::SetHerwigRandom(GetRandom());
618e1dc0 82}
83
84AliGenHerwig::AliGenHerwig(const AliGenHerwig & Herwig)
014a9521 85 :AliGenMC(Herwig)
618e1dc0 86{
014a9521 87// Copy constructor
88 Herwig.Copy(*this);
618e1dc0 89}
90
91
92AliGenHerwig::~AliGenHerwig()
93{
94// Destructor
95}
96
97void AliGenHerwig::Init()
98{
99// Initialisation
100 fTarget.Resize(8);
101 fProjectile.Resize(8);
102 SetMC(new THerwig6());
d274cd60 103 fHerwig=(THerwig6*) fMCEvGen;
618e1dc0 104 // initialize common blocks
105 fHerwig->Initialize(fProjectile, fTarget, fMomentum1, fMomentum2, fProcess);
106 // reset parameters according to user needs
107 InitPDF();
108 fHerwig->SetPTMIN(fPtHardMin);
109 fHerwig->SetPTRMS(fPtRMS);
110 fHerwig->SetMAXPR(fMaxPr);
111 fHerwig->SetMAXER(fMaxErrors);
112 fHerwig->SetENSOF(fEnSoft);
113 // compute parameter dependent constants
114 fHerwig->PrepareRun();
115}
116
117void AliGenHerwig::InitPDF()
118{
119 switch(fStrucFunc)
120 {
121 case kGRVLO:
122 fModPDF=5;
123 fAutPDF="GRV";
124 break;
125 case kGRVHO:
126 fModPDF=6;
127 fAutPDF="GRV";
128 break;
129 case kGRVLO98:
130 fModPDF=12;
131 fAutPDF="GRV";
132 break;
133 case kMRSDminus:
134 fModPDF=31;
135 fAutPDF="MRS";
136 break;
137 case kMRSD0:
138 fModPDF=30;
139 fAutPDF="MRS";
140 break;
141 case kMRSG:
142 fModPDF=41;
143 fAutPDF="MRS";
144 break;
145 case kMRSTcgLO:
146 fModPDF=72;
147 fAutPDF="MRS";
148 break;
149 case kCTEQ4M:
150 fModPDF=34;
151 fAutPDF="CTEQ";
152 break;
153 case kCTEQ5L:
154 fModPDF=46;
155 fAutPDF="CTEQ";
156 break;
157 default:
158 cerr << "This structure function is not inplemented " << fStrucFunc << endl;
159 break;
160 }
161 fAutPDF.Resize(20);
162 fHerwig->SetMODPDF(1,fModPDF);
163 fHerwig->SetMODPDF(2,fModPDF);
164 fHerwig->SetAUTPDF(1,fAutPDF);
165 fHerwig->SetAUTPDF(2,fAutPDF);
166}
167
168void AliGenHerwig::Generate()
169{
170 // Generate one event
171
172 Float_t polar[3] = {0,0,0};
173 Float_t origin[3]= {0,0,0};
174 Float_t origin0[3]= {0,0,0};
175 Float_t p[4], random[6];
176
177 static TClonesArray *particles;
178 // converts from mm/c to s
179 const Float_t kconv=0.001/2.999792458e8;
180 //
181 Int_t nt=0;
182 Int_t jev=0;
183 Int_t j, kf, ks, imo;
184 kf=0;
185
186 if(!particles) particles=new TClonesArray("TParticle",10000);
187
188 fTrials=0;
189 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
190 if(fVertexSmear==kPerEvent) {
191 Rndm(random,6);
192 for (j=0;j<3;j++) {
193 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
194 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
195 }
196 }
197
198 while(1)
199 {
200 fHerwig->GenerateEvent();
201 fTrials++;
202 fHerwig->ImportParticles(particles,"All");
203 Int_t np = particles->GetEntriesFast()-1;
204 if (np == 0 ) continue;
205
206 Int_t nc=0;
207
208 Int_t * newPos = new Int_t[np];
209 for (Int_t i = 0; i<np; i++) *(newPos+i)=-1;
210
211 for (Int_t i = 0; i<np; i++) {
212 TParticle * iparticle = (TParticle *) particles->At(i);
213 imo = iparticle->GetFirstMother();
214 kf = iparticle->GetPdgCode();
215 ks = iparticle->GetStatusCode();
216 if (ks != 3 &&
217 KinematicSelection(iparticle,0))
218 {
219 nc++;
220 p[0]=iparticle->Px();
221 p[1]=iparticle->Py();
222 p[2]=iparticle->Pz();
223 p[3]=iparticle->Energy();
224 origin[0]=origin0[0]+iparticle->Vx()/10;
225 origin[1]=origin0[1]+iparticle->Vy()/10;
226 origin[2]=origin0[2]+iparticle->Vz()/10;
227 Float_t tof = kconv*iparticle->T();
228 Int_t iparent = (imo > -1) ? newPos[imo] : -1;
229 Int_t trackIt = (ks == 1) && fTrackIt;
93831bcf 230 PushTrack(trackIt, iparent, kf,
231 p[0], p[1], p[2], p[3],
232 origin[0], origin[1], origin[2],
233 tof,
234 polar[0], polar[1], polar[2],
235 kPPrimary, nt, 1., ks);
618e1dc0 236 KeepTrack(nt);
237 newPos[i]=nt;
238 } // end of if: selection of particle
239 } // end of for: particle loop
240 if (newPos) delete[] newPos;
618e1dc0 241 // MakeHeader();
618e1dc0 242 if (nc > 0) {
243 jev+=nc;
244 if (jev >= fNpart || fNpart == -1) {
245 fKineBias=Float_t(fNpart)/Float_t(fTrials);
618e1dc0 246 break;
247 }
248 }
249 }
250 SetHighWaterMark(nt);
251// adjust weight due to kinematic selection
252 AdjustWeights();
253// get cross-section
254 fXsection=fHerwig->GetAVWGT();
255}
256
257void AliGenHerwig::AdjustWeights()
258{
259// Adjust the weights after generation of all events
260 TParticle *part;
5d12ce38 261 Int_t ntrack=gAlice->GetMCApp()->GetNtrack();
618e1dc0 262 for (Int_t i=0; i<ntrack; i++) {
5d12ce38 263 part= gAlice->GetMCApp()->Particle(i);
618e1dc0 264 part->SetWeight(part->GetWeight()*fKineBias);
265 }
266}
267
268
269void AliGenHerwig::KeepFullEvent()
270{
271 fKeep=1;
272}
273
274Bool_t AliGenHerwig::DaughtersSelection(TParticle* iparticle, TClonesArray* particles)
275{
276//
277// Looks recursively if one of the daughters has been selected
278//
279// printf("\n Consider daughters %d:",iparticle->GetPdgCode());
280 Int_t imin=-1;
281 Int_t imax=-1;
282 Int_t i;
283 Bool_t hasDaughters= (iparticle->GetFirstDaughter() >=0);
284 Bool_t selected=kFALSE;
285 if (hasDaughters) {
286 imin=iparticle->GetFirstDaughter();
287 imax=iparticle->GetLastDaughter();
288 for (i=imin; i<= imax; i++){
289 TParticle * jparticle = (TParticle *) particles->At(i);
290 Int_t ip=jparticle->GetPdgCode();
291 if (KinematicSelection(jparticle,0)&&SelectFlavor(ip)) {
292 selected=kTRUE; break;
293 }
294 if (DaughtersSelection(jparticle, particles)) {selected=kTRUE; break; }
295 }
296 } else {
297 return kFALSE;
298 }
299
300 return selected;
301}
302
303
304Bool_t AliGenHerwig::SelectFlavor(Int_t pid)
305{
306// Select flavor of particle
307// 0: all
308// 4: charm and beauty
309// 5: beauty
310 if (fFlavor == 0) return kTRUE;
311
312 Int_t ifl=TMath::Abs(pid/100);
313 if (ifl > 10) ifl/=10;
314 return (fFlavor == ifl);
315}
316
317Bool_t AliGenHerwig::Stable(TParticle* particle)
318{
319// Return true for a stable particle
320//
321 Int_t kf = TMath::Abs(particle->GetPdgCode());
322
323 if ( (particle->GetFirstDaughter() < 0 ) || (kf == 1000*fFlavor+122))
324
325 {
326 return kTRUE;
327 } else {
328 return kFALSE;
329 }
330}
331
332void AliGenHerwig::FinishRun()
333{
334 fHerwig->Hwefin();
335}
336
337
338AliGenHerwig& AliGenHerwig::operator=(const AliGenHerwig& rhs)
339{
340// Assignment operator
014a9521 341 rhs.Copy(*this);
342 return (*this);
618e1dc0 343}
344
345