All coding rule violations except RS3 corrected
[u/mrichter/AliRoot.git] / EVGEN / AliGenPythia.cxx
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4c039060 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
16/*
17$Log$
f87cfe57 18Revision 1.16 2000/05/15 15:04:20 morsch
19The full event is written for fNtrack = -1
20Coding rule violations corrected.
21
5ddeb374 22Revision 1.15 2000/04/26 10:14:24 morsch
23Particles array has one entry more than pythia particle list. Upper bound of
24particle loop changed to np-1 (R. Guernane, AM)
25
2a0e6f5b 26Revision 1.14 2000/04/05 08:36:13 morsch
27Check status code of particles in Pythia event
28to avoid double counting as partonic state and final state particle.
29
23211d3e 30Revision 1.13 1999/11/09 07:38:48 fca
31Changes for compatibility with version 2.23 of ROOT
32
084c1b4a 33Revision 1.12 1999/11/03 17:43:20 fca
34New version from G.Martinez & A.Morsch
35
886b6f73 36Revision 1.11 1999/09/29 09:24:14 fca
37Introduction of the Copyright and cvs Log
4c039060 38*/
39
fe4da5cc 40#include "AliGenPythia.h"
fe4da5cc 41#include "AliRun.h"
42#include "AliPythia.h"
1578254f 43#include <TParticle.h>
f87cfe57 44
fe4da5cc 45 ClassImp(AliGenPythia)
46
47AliGenPythia::AliGenPythia()
48 :AliGenerator()
49{
5ddeb374 50// Constructor
fe4da5cc 51}
52
53AliGenPythia::AliGenPythia(Int_t npart)
54 :AliGenerator(npart)
55{
56// default charm production at 5. 5 TeV
57// semimuonic decay
58// structure function GRVHO
59//
60 fXsection = 0.;
61 fParentSelect.Set(5);
62 fChildSelect.Set(5);
63 for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0;
64 SetProcess();
65 SetStrucFunc();
886b6f73 66 SetForceDecay();
fe4da5cc 67 SetPtHard();
68 SetEnergyCMS();
69}
70
f87cfe57 71AliGenPythia::AliGenPythia(const AliGenPythia & Pythia)
72{
73// copy constructor
74}
75
fe4da5cc 76AliGenPythia::~AliGenPythia()
77{
5ddeb374 78// Destructor
fe4da5cc 79}
80
81void AliGenPythia::Init()
82{
5ddeb374 83// Initialisation
fe4da5cc 84 SetMC(new AliPythia());
85 fPythia=(AliPythia*) fgMCEvGen;
86//
87 fParentWeight=1./Float_t(fNpart);
88//
89// Forward Paramters to the AliPythia object
90 fPythia->DefineParticles();
fe4da5cc 91 fPythia->SetCKIN(3,fPtHardMin);
92 fPythia->SetCKIN(4,fPtHardMax);
93 fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc);
5be1fe76 94 fPythia->ForceDecay(fForceDecay);
084c1b4a 95 fPythia->Lulist(0);
96 fPythia->Pystat(2);
fe4da5cc 97// Parent and Children Selection
98 switch (fProcess)
99 {
100 case charm:
101
102 fParentSelect[0]=411;
103 fParentSelect[1]=421;
104 fParentSelect[2]=431;
105 fParentSelect[3]=4122;
106 break;
107 case charm_unforced:
108
109 fParentSelect[0]=411;
110 fParentSelect[1]=421;
111 fParentSelect[2]=431;
112 fParentSelect[3]=4122;
113 break;
114 case beauty:
115 fParentSelect[0]=511;
116 fParentSelect[1]=521;
117 fParentSelect[2]=531;
118 fParentSelect[3]=5122;
119 break;
120 case beauty_unforced:
121 fParentSelect[0]=511;
122 fParentSelect[1]=521;
123 fParentSelect[2]=531;
124 fParentSelect[3]=5122;
125 break;
126 case jpsi_chi:
127 case jpsi:
128 fParentSelect[0]=443;
129 break;
5be1fe76 130 case mb:
131 break;
fe4da5cc 132 }
133
134 switch (fForceDecay)
135 {
136 case semielectronic:
137 case dielectron:
138 case b_jpsi_dielectron:
139 case b_psip_dielectron:
140 fChildSelect[0]=11;
141 break;
142 case semimuonic:
143 case dimuon:
144 case b_jpsi_dimuon:
145 case b_psip_dimuon:
5be1fe76 146 case pitomu:
147 case katomu:
fe4da5cc 148 fChildSelect[0]=13;
149 break;
886b6f73 150 case all:
151 case nodecay:
152 break;
fe4da5cc 153 }
154}
155
156void AliGenPythia::Generate()
157{
5ddeb374 158// Generate one event
fe4da5cc 159
5be1fe76 160 Float_t polar[3] = {0,0,0};
161 Float_t origin[3]= {0,0,0};
5ddeb374 162 Float_t originP[3]= {0,0,0};
5be1fe76 163 Float_t origin0[3]= {0,0,0};
5ddeb374 164 Float_t p[3], pP[4], random[6];
09fd3ea2 165 static TClonesArray *particles;
5be1fe76 166// converts from mm/c to s
167 const Float_t kconv=0.001/2.999792458e8;
fe4da5cc 168
169
170//
fe4da5cc 171 Int_t nt=0;
5ddeb374 172 Int_t ntP=0;
fe4da5cc 173 Int_t jev=0;
7921755b 174 Int_t j, kf;
09fd3ea2 175
176 if(!particles) particles=new TClonesArray("TParticle",1000);
fe4da5cc 177
178 fTrials=0;
179 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
180 if(fVertexSmear==perEvent) {
cfce8870 181 gMC->Rndm(random,6);
fe4da5cc 182 for (j=0;j<3;j++) {
183 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
184 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
185 fPythia->SetMSTP(151,0);
186 }
187 } else if (fVertexSmear==perTrack) {
188 fPythia->SetMSTP(151,0);
189 for (j=0;j<3;j++) {
190 fPythia->SetPARP(151+j, fOsigma[j]*10.);
191 }
192 }
fe4da5cc 193 while(1)
194 {
084c1b4a 195 fPythia->Pyevnt();
f87cfe57 196// fPythia->Lulist(1);
fe4da5cc 197 fTrials++;
f1092809 198 fPythia->ImportParticles(particles,"All");
fe4da5cc 199 Int_t np = particles->GetEntriesFast();
200 printf("\n **************************************************%d\n",np);
201 Int_t nc=0;
202 if (np == 0 ) continue;
5be1fe76 203 if (fProcess != mb) {
2a0e6f5b 204 for (Int_t i = 0; i<np-1; i++) {
1578254f 205 TParticle * iparticle = (TParticle *) particles->At(i);
23211d3e 206 Int_t ks = iparticle->GetStatusCode();
a8228d85 207 kf = CheckPDGCode(iparticle->GetPdgCode());
2a0e6f5b 208 if (ks==21) continue;
209
5be1fe76 210 fChildWeight=(fPythia->GetBraPart(kf))*fParentWeight;
fe4da5cc 211//
212// Parent
5be1fe76 213 if (ParentSelected(TMath::Abs(kf))) {
214 if (KinematicSelection(iparticle)) {
215 if (nc==0) {
216//
217// Store information concerning the hard scattering process
218//
5ddeb374 219 Float_t massP = fPythia->GetPARI(13);
220 Float_t ptP = fPythia->GetPARI(17);
221 Float_t yP = fPythia->GetPARI(37);
222 Float_t xmtP = sqrt(ptP*ptP+massP*massP);
223 Float_t ty = Float_t(TMath::TanH(yP));
224 pP[0] = ptP;
225 pP[1] = 0;
226 pP[2] = xmtP*ty/sqrt(1.-ty*ty);
227 pP[3] = massP;
5be1fe76 228 gAlice->SetTrack(0,-1,-1,
5ddeb374 229 pP,originP,polar,
230 0,"Hard Scat.",ntP,fParentWeight);
231 gAlice->KeepTrack(ntP);
5be1fe76 232 }
233 nc++;
fe4da5cc 234//
235// store parent track information
1578254f 236 p[0]=iparticle->Px();
237 p[1]=iparticle->Py();
238 p[2]=iparticle->Pz();
239 origin[0]=origin0[0]+iparticle->Vx()/10;
240 origin[1]=origin0[1]+iparticle->Vy()/10;
241 origin[2]=origin0[2]+iparticle->Vz()/10;
fe4da5cc 242
1578254f 243 Int_t ifch=iparticle->GetFirstDaughter();
244 Int_t ilch=iparticle->GetLastDaughter();
5be1fe76 245 if (ifch !=0 && ilch !=0) {
5ddeb374 246 gAlice->SetTrack(0,ntP,kf,
5be1fe76 247 p,origin,polar,
248 0,"Primary",nt,fParentWeight);
249 gAlice->KeepTrack(nt);
250 Int_t iparent = nt;
fe4da5cc 251//
252// Children
253
7921755b 254 for (j=ifch; j<=ilch; j++)
5be1fe76 255 {
1578254f 256 TParticle * ichild =
257 (TParticle *) particles->At(j-1);
a8228d85 258 kf = CheckPDGCode(ichild->GetPdgCode());
fe4da5cc 259//
260//
5be1fe76 261 if (ChildSelected(TMath::Abs(kf))) {
1578254f 262 origin[0]=ichild->Vx();
263 origin[1]=ichild->Vy();
264 origin[2]=ichild->Vz();
265 p[0]=ichild->Px();
266 p[1]=ichild->Py();
267 p[2]=ichild->Pz();
268 Float_t tof=kconv*ichild->T();
269 gAlice->SetTrack(fTrackIt, iparent, kf,
5be1fe76 270 p,origin,polar,
271 tof,"Decay",nt,fChildWeight);
272 gAlice->KeepTrack(nt);
273 } // select child
274 } // child loop
275 }
276 } // kinematic selection
277 } // select particle
278 } // particle loop
279 } else {
2a0e6f5b 280 for (Int_t i = 0; i<np-1; i++) {
1578254f 281 TParticle * iparticle = (TParticle *) particles->At(i);
a8228d85 282 kf = CheckPDGCode(iparticle->GetPdgCode());
1578254f 283 Int_t ks = iparticle->GetStatusCode();
2a0e6f5b 284
1578254f 285 if (ks==1 && kf!=0 && KinematicSelection(iparticle)) {
5be1fe76 286 nc++;
287//
288// store track information
1578254f 289 p[0]=iparticle->Px();
290 p[1]=iparticle->Py();
291 p[2]=iparticle->Pz();
292 origin[0]=origin0[0]+iparticle->Vx()/10;
293 origin[1]=origin0[1]+iparticle->Vy()/10;
294 origin[2]=origin0[2]+iparticle->Vz()/10;
295 Float_t tof=kconv*iparticle->T();
296 gAlice->SetTrack(fTrackIt,-1,kf,p,origin,polar,
5be1fe76 297 tof,"Primary",nt);
298 gAlice->KeepTrack(nt);
299 } // select particle
300 } // particle loop
301 printf("\n I've put %i particles on the stack \n",nc);
302 } // mb ?
fe4da5cc 303 if (nc > 0) {
5be1fe76 304 jev+=nc;
5ddeb374 305 if (jev >= fNpart || fNpart == -1) {
fe4da5cc 306 fKineBias=Float_t(fNpart)/Float_t(fTrials);
23211d3e 307 printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
fe4da5cc 308 break;
309 }
310 }
311 } // event loop
312// adjust weight due to kinematic selection
313 AdjustWeights();
314// get cross-section
315 fXsection=fPythia->GetPARI(1);
316}
317
318Bool_t AliGenPythia::ParentSelected(Int_t ip)
319{
5ddeb374 320// True if particle is in list of parent particles to be selected
fe4da5cc 321 for (Int_t i=0; i<5; i++)
322 {
323 if (fParentSelect[i]==ip) return kTRUE;
324 }
325 return kFALSE;
326}
327
328Bool_t AliGenPythia::ChildSelected(Int_t ip)
329{
5ddeb374 330// True if particle is in list of decay products to be selected
fe4da5cc 331 for (Int_t i=0; i<5; i++)
332 {
333 if (fChildSelect[i]==ip) return kTRUE;
334 }
335 return kFALSE;
336}
337
1578254f 338Bool_t AliGenPythia::KinematicSelection(TParticle *particle)
fe4da5cc 339{
5ddeb374 340// Perform kinematic selection
1578254f 341 Float_t px=particle->Px();
342 Float_t py=particle->Py();
343 Float_t pz=particle->Pz();
344 Float_t e=particle->Energy();
fe4da5cc 345
346//
347// transverse momentum cut
348 Float_t pt=TMath::Sqrt(px*px+py*py);
349 if (pt > fPtMax || pt < fPtMin)
350 {
351// printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
352 return kFALSE;
353 }
354//
355// momentum cut
356 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
357 if (p > fPMax || p < fPMin)
358 {
359// printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
360 return kFALSE;
361 }
362
363//
364// theta cut
5be1fe76 365 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz)));
fe4da5cc 366 if (theta > fThetaMax || theta < fThetaMin)
367 {
368// printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
369 return kFALSE;
370 }
371
372//
373// rapidity cut
374 Float_t y = 0.5*TMath::Log((e+pz)/(e-pz));
375 if (y > fYMax || y < fYMin)
376 {
377// printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
378 return kFALSE;
379 }
380
381//
382// phi cut
f87cfe57 383 Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)));
fe4da5cc 384 if (phi > fPhiMax || phi < fPhiMin)
385 {
386// printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
387 return kFALSE;
388 }
389
390 return kTRUE;
391}
392void AliGenPythia::AdjustWeights()
393{
5ddeb374 394// Adjust the weights after generation of all events
395//
396 TClonesArray *partArray = gAlice->Particles();
397 TParticle *part;
fe4da5cc 398 Int_t ntrack=gAlice->GetNtrack();
399 for (Int_t i=0; i<ntrack; i++) {
5ddeb374 400 part= (TParticle*) partArray->UncheckedAt(i);
401 part->SetWeight(part->GetWeight()*fKineBias);
fe4da5cc 402 }
403}
404
a8228d85 405Int_t AliGenPythia::CheckPDGCode(Int_t pdgcode)
406{
407//
23211d3e 408// If the particle is in a diffractive state, then take action accordingly
a8228d85 409 switch (pdgcode) {
410 case 110:
411 //rho_diff0 -- difficult to translate, return rho0
412 return 113;
413 case 210:
414 //pi_diffr+ -- change to pi+
415 return 211;
416 case 220:
417 //omega_di0 -- change to omega0
418 return 223;
419 case 330:
420 //phi_diff0 -- return phi0
421 return 333;
422 case 440:
423 //J/psi_di0 -- return J/psi
424 return 443;
425 case 2110:
426 //n_diffr -- return neutron
427 return 2112;
428 case 2210:
429 //p_diffr+ -- return proton
430 return 2212;
431 }
432 //non diffractive state -- return code unchanged
433 return pdgcode;
434}
435
f87cfe57 436AliGenPythia& AliGenPythia::operator=(const AliGenPythia& rhs)
437{
438// Assignment operator
439 return *this;
440}
fe4da5cc 441
442
443
5be1fe76 444
445
446
447