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Call fGenerator->FinishRun() for final print-outs, cross-section and weight calculations.
[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$Log$
f1a48a38 18Revision 1.34 2001/02/14 15:50:40 hristov
19The last particle in event marked using SetHighWaterMark
20
28adac24 21Revision 1.33 2001/01/30 09:23:12 hristov
22Streamers removed (R.Brun)
23
a8a6107b 24Revision 1.32 2001/01/26 19:55:51 hristov
25Major upgrade of AliRoot code
26
2ab0c725 27Revision 1.31 2001/01/17 10:54:31 hristov
28Better protection against FPE
29
0f9e52a3 30Revision 1.30 2000/12/18 08:55:35 morsch
31Make AliPythia dependent generartors work with new scheme of random number generation
32
3356c022 33Revision 1.29 2000/12/04 11:22:03 morsch
34Init of sRandom as in 1.15
35
097ec7c1 36Revision 1.28 2000/12/02 11:41:39 morsch
37Use SetRandom() to initialize random number generator in constructor.
38
1ed25e11 39Revision 1.27 2000/11/30 20:29:02 morsch
40Initialise static variable sRandom in constructor: sRandom = fRandom;
41
ad1df918 42Revision 1.26 2000/11/30 07:12:50 alibrary
43Introducing new Rndm and QA classes
44
65fb704d 45Revision 1.25 2000/10/18 19:11:27 hristov
46Division by zero fixed
47
919c2096 48Revision 1.24 2000/09/18 10:41:35 morsch
49Add possibility to use nuclear structure functions from PDF library V8.
50
811826d8 51Revision 1.23 2000/09/14 14:05:40 morsch
52dito
53
819f84ad 54Revision 1.22 2000/09/14 14:02:22 morsch
55- Correct conversion from mm to cm when passing particle vertex to MC.
56- Correct handling of fForceDecay == all.
57
4451ef92 58Revision 1.21 2000/09/12 14:14:55 morsch
59Call fDecayer->ForceDecay() at the beginning of Generate().
60
00d6ce7d 61Revision 1.20 2000/09/06 14:29:33 morsch
62Use AliPythia for event generation an AliDecayPythia for decays.
63Correct handling of "nodecay" option
64
18edb254 65Revision 1.19 2000/07/11 18:24:56 fca
66Coding convention corrections + few minor bug fixes
67
aee8290b 68Revision 1.18 2000/06/30 12:40:34 morsch
69Pythia takes care of vertex smearing. Correct conversion from Pythia units (mm) to
70Geant units (cm).
71
1512e357 72Revision 1.17 2000/06/09 20:34:07 morsch
73All coding rule violations except RS3 corrected
74
f87cfe57 75Revision 1.16 2000/05/15 15:04:20 morsch
76The full event is written for fNtrack = -1
77Coding rule violations corrected.
78
5ddeb374 79Revision 1.15 2000/04/26 10:14:24 morsch
80Particles array has one entry more than pythia particle list. Upper bound of
81particle loop changed to np-1 (R. Guernane, AM)
82
2a0e6f5b 83Revision 1.14 2000/04/05 08:36:13 morsch
84Check status code of particles in Pythia event
85to avoid double counting as partonic state and final state particle.
86
23211d3e 87Revision 1.13 1999/11/09 07:38:48 fca
88Changes for compatibility with version 2.23 of ROOT
89
084c1b4a 90Revision 1.12 1999/11/03 17:43:20 fca
91New version from G.Martinez & A.Morsch
92
886b6f73 93Revision 1.11 1999/09/29 09:24:14 fca
94Introduction of the Copyright and cvs Log
4c039060 95*/
96
fe4da5cc 97#include "AliGenPythia.h"
18edb254 98#include "AliDecayerPythia.h"
fe4da5cc 99#include "AliRun.h"
100#include "AliPythia.h"
18edb254 101#include "AliPDG.h"
1578254f 102#include <TParticle.h>
18edb254 103#include <TSystem.h>
f87cfe57 104
fe4da5cc 105 ClassImp(AliGenPythia)
106
107AliGenPythia::AliGenPythia()
108 :AliGenerator()
109{
18edb254 110// Default Constructor
111 fDecayer = new AliDecayerPythia();
fe4da5cc 112}
113
114AliGenPythia::AliGenPythia(Int_t npart)
115 :AliGenerator(npart)
116{
117// default charm production at 5. 5 TeV
118// semimuonic decay
119// structure function GRVHO
120//
121 fXsection = 0.;
811826d8 122 fNucA1=0;
123 fNucA2=0;
fe4da5cc 124 fParentSelect.Set(5);
125 fChildSelect.Set(5);
126 for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0;
127 SetProcess();
128 SetStrucFunc();
886b6f73 129 SetForceDecay();
fe4da5cc 130 SetPtHard();
131 SetEnergyCMS();
18edb254 132 fDecayer = new AliDecayerPythia();
1ed25e11 133 // Set random number generator
097ec7c1 134 sRandom=fRandom;
fe4da5cc 135}
136
f87cfe57 137AliGenPythia::AliGenPythia(const AliGenPythia & Pythia)
138{
139// copy constructor
140}
141
fe4da5cc 142AliGenPythia::~AliGenPythia()
143{
5ddeb374 144// Destructor
fe4da5cc 145}
146
147void AliGenPythia::Init()
148{
5ddeb374 149// Initialisation
18edb254 150 SetMC(AliPythia::Instance());
fe4da5cc 151 fPythia=(AliPythia*) fgMCEvGen;
152//
153 fParentWeight=1./Float_t(fNpart);
154//
155// Forward Paramters to the AliPythia object
18edb254 156 // gSystem->Exec("ln -s $ALICE_ROOT/data/Decay.table fort.1");
157 // fPythia->Pyupda(2,1);
158 // gSystem->Exec("rm fort.1");
00d6ce7d 159
160 fDecayer->SetForceDecay(fForceDecay);
18edb254 161 fDecayer->Init();
00d6ce7d 162
18edb254 163
fe4da5cc 164 fPythia->SetCKIN(3,fPtHardMin);
165 fPythia->SetCKIN(4,fPtHardMax);
811826d8 166 if (fNucA1 > 0 && fNucA2 > 0) fPythia->SetNuclei(fNucA1, fNucA2);
fe4da5cc 167 fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc);
18edb254 168
169 // fPythia->Pylist(0);
170 // fPythia->Pystat(2);
fe4da5cc 171// Parent and Children Selection
172 switch (fProcess)
173 {
f1a48a38 174 case kPyCharm:
fe4da5cc 175 fParentSelect[0]=411;
176 fParentSelect[1]=421;
177 fParentSelect[2]=431;
178 fParentSelect[3]=4122;
179 break;
f1a48a38 180 case kPyCharmUnforced:
fe4da5cc 181 fParentSelect[0]=411;
182 fParentSelect[1]=421;
183 fParentSelect[2]=431;
184 fParentSelect[3]=4122;
185 break;
f1a48a38 186 case kPyBeauty:
fe4da5cc 187 fParentSelect[0]=511;
188 fParentSelect[1]=521;
189 fParentSelect[2]=531;
190 fParentSelect[3]=5122;
191 break;
f1a48a38 192 case kPyBeautyUnforced:
fe4da5cc 193 fParentSelect[0]=511;
194 fParentSelect[1]=521;
195 fParentSelect[2]=531;
196 fParentSelect[3]=5122;
197 break;
f1a48a38 198 case kPyJpsiChi:
199 case kPyJpsi:
fe4da5cc 200 fParentSelect[0]=443;
201 break;
f1a48a38 202 case kPyMb:
203 case kPyJets:
204 case kPyDirectGamma:
5be1fe76 205 break;
fe4da5cc 206 }
207
208 switch (fForceDecay)
209 {
f1a48a38 210 case kSemiElectronic:
211 case kDiElectron:
212 case kBJpsiDiElectron:
213 case kBPsiPrimeDiElectron:
18edb254 214 fChildSelect[0]=kElectron;
fe4da5cc 215 break;
f1a48a38 216 case kSemiMuonic:
217 case kDiMuon:
218 case kBJpsiDiMuon:
219 case kBPsiPrimeDiMuon:
220 case kPiToMu:
221 case kKaToMu:
18edb254 222 fChildSelect[0]=kMuonMinus;
fe4da5cc 223 break;
f1a48a38 224 case kHadronicD:
18edb254 225 fChildSelect[0]=kPiPlus;
226 fChildSelect[1]=kKPlus;
227 break;
f1a48a38 228 case kAll:
229 case kNoDecay:
18edb254 230 break;
fe4da5cc 231 }
232}
233
234void AliGenPythia::Generate()
235{
5ddeb374 236// Generate one event
00d6ce7d 237 fDecayer->ForceDecay();
fe4da5cc 238
5be1fe76 239 Float_t polar[3] = {0,0,0};
240 Float_t origin[3]= {0,0,0};
5ddeb374 241 Float_t originP[3]= {0,0,0};
5be1fe76 242 Float_t origin0[3]= {0,0,0};
1512e357 243 Float_t p[3], pP[4];
244// Float_t random[6];
09fd3ea2 245 static TClonesArray *particles;
5be1fe76 246// converts from mm/c to s
247 const Float_t kconv=0.001/2.999792458e8;
fe4da5cc 248
249
250//
fe4da5cc 251 Int_t nt=0;
5ddeb374 252 Int_t ntP=0;
fe4da5cc 253 Int_t jev=0;
7921755b 254 Int_t j, kf;
09fd3ea2 255
256 if(!particles) particles=new TClonesArray("TParticle",1000);
fe4da5cc 257
258 fTrials=0;
259 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
aee8290b 260 if(fVertexSmear==kPerEvent) {
1512e357 261 fPythia->SetMSTP(151,1);
fe4da5cc 262 for (j=0;j<3;j++) {
1512e357 263 fPythia->SetPARP(151+j, fOsigma[j]/10.);
fe4da5cc 264 }
aee8290b 265 } else if (fVertexSmear==kPerTrack) {
fe4da5cc 266 fPythia->SetMSTP(151,0);
fe4da5cc 267 }
1512e357 268
fe4da5cc 269 while(1)
270 {
084c1b4a 271 fPythia->Pyevnt();
18edb254 272// fPythia->Pylist(1);
fe4da5cc 273 fTrials++;
f1092809 274 fPythia->ImportParticles(particles,"All");
fe4da5cc 275 Int_t np = particles->GetEntriesFast();
276 printf("\n **************************************************%d\n",np);
277 Int_t nc=0;
278 if (np == 0 ) continue;
f1a48a38 279 if (fProcess != kPyMb && fProcess != kPyJets && fProcess != kPyDirectGamma) {
2a0e6f5b 280 for (Int_t i = 0; i<np-1; i++) {
1578254f 281 TParticle * iparticle = (TParticle *) particles->At(i);
23211d3e 282 Int_t ks = iparticle->GetStatusCode();
a8228d85 283 kf = CheckPDGCode(iparticle->GetPdgCode());
2a0e6f5b 284 if (ks==21) continue;
285
18edb254 286 fChildWeight=(fDecayer->GetPartialBranchingRatio(kf))*fParentWeight;
fe4da5cc 287//
288// Parent
5be1fe76 289 if (ParentSelected(TMath::Abs(kf))) {
290 if (KinematicSelection(iparticle)) {
291 if (nc==0) {
292//
293// Store information concerning the hard scattering process
294//
5ddeb374 295 Float_t massP = fPythia->GetPARI(13);
296 Float_t ptP = fPythia->GetPARI(17);
297 Float_t yP = fPythia->GetPARI(37);
298 Float_t xmtP = sqrt(ptP*ptP+massP*massP);
299 Float_t ty = Float_t(TMath::TanH(yP));
300 pP[0] = ptP;
301 pP[1] = 0;
302 pP[2] = xmtP*ty/sqrt(1.-ty*ty);
303 pP[3] = massP;
5be1fe76 304 gAlice->SetTrack(0,-1,-1,
5ddeb374 305 pP,originP,polar,
65fb704d 306 0,kPPrimary,ntP,fParentWeight);
307// 0,"Hard Scat.",ntP,fParentWeight);
5ddeb374 308 gAlice->KeepTrack(ntP);
5be1fe76 309 }
310 nc++;
fe4da5cc 311//
312// store parent track information
1578254f 313 p[0]=iparticle->Px();
314 p[1]=iparticle->Py();
315 p[2]=iparticle->Pz();
819f84ad 316 origin[0]=origin0[0]+iparticle->Vx()/10.;
317 origin[1]=origin0[1]+iparticle->Vy()/10.;
318 origin[2]=origin0[2]+iparticle->Vz()/10.;
fe4da5cc 319
1578254f 320 Int_t ifch=iparticle->GetFirstDaughter();
321 Int_t ilch=iparticle->GetLastDaughter();
18edb254 322
f1a48a38 323 if ((ifch !=0 && ilch !=0) || fForceDecay == kNoDecay) {
18edb254 324 Int_t trackit=0;
f1a48a38 325 if (fForceDecay == kNoDecay) trackit = 1;
18edb254 326 gAlice->SetTrack(trackit,ntP,kf,
5be1fe76 327 p,origin,polar,
65fb704d 328 0,kPPrimary,nt,fParentWeight);
5be1fe76 329 gAlice->KeepTrack(nt);
330 Int_t iparent = nt;
fe4da5cc 331//
332// Children
f1a48a38 333 if (fForceDecay != kNoDecay) {
18edb254 334 for (j=ifch; j<=ilch; j++)
335 {
336 TParticle * ichild =
1578254f 337 (TParticle *) particles->At(j-1);
18edb254 338 kf = CheckPDGCode(ichild->GetPdgCode());
fe4da5cc 339//
340//
18edb254 341 if (ChildSelected(TMath::Abs(kf))) {
4451ef92 342 origin[0]=origin0[0]+ichild->Vx()/10.;
343 origin[1]=origin0[1]+ichild->Vy()/10.;
344 origin[2]=origin0[2]+ichild->Vz()/10.;
1578254f 345 p[0]=ichild->Px();
346 p[1]=ichild->Py();
347 p[2]=ichild->Pz();
348 Float_t tof=kconv*ichild->T();
349 gAlice->SetTrack(fTrackIt, iparent, kf,
5be1fe76 350 p,origin,polar,
65fb704d 351 tof,kPDecay,nt,fChildWeight);
5be1fe76 352 gAlice->KeepTrack(nt);
18edb254 353 } // select child
354 } // child loop
355 }
5be1fe76 356 }
357 } // kinematic selection
358 } // select particle
359 } // particle loop
360 } else {
2a0e6f5b 361 for (Int_t i = 0; i<np-1; i++) {
1578254f 362 TParticle * iparticle = (TParticle *) particles->At(i);
a8228d85 363 kf = CheckPDGCode(iparticle->GetPdgCode());
1578254f 364 Int_t ks = iparticle->GetStatusCode();
2a0e6f5b 365
1578254f 366 if (ks==1 && kf!=0 && KinematicSelection(iparticle)) {
5be1fe76 367 nc++;
368//
369// store track information
1578254f 370 p[0]=iparticle->Px();
371 p[1]=iparticle->Py();
372 p[2]=iparticle->Pz();
4451ef92 373 origin[0]=origin0[0]+iparticle->Vx()/10.;
374 origin[1]=origin0[1]+iparticle->Vy()/10.;
375 origin[2]=origin0[2]+iparticle->Vz()/10.;
1578254f 376 Float_t tof=kconv*iparticle->T();
377 gAlice->SetTrack(fTrackIt,-1,kf,p,origin,polar,
65fb704d 378 tof,kPPrimary,nt);
28adac24 379 gAlice->KeepTrack(nt);
5be1fe76 380 } // select particle
381 } // particle loop
382 printf("\n I've put %i particles on the stack \n",nc);
383 } // mb ?
fe4da5cc 384 if (nc > 0) {
5be1fe76 385 jev+=nc;
5ddeb374 386 if (jev >= fNpart || fNpart == -1) {
fe4da5cc 387 fKineBias=Float_t(fNpart)/Float_t(fTrials);
23211d3e 388 printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
811826d8 389// Print x-section summary
390 fPythia->Pystat(1);
fe4da5cc 391 break;
392 }
393 }
394 } // event loop
28adac24 395 gAlice->SetHighWaterMark(nt);
fe4da5cc 396// adjust weight due to kinematic selection
397 AdjustWeights();
398// get cross-section
399 fXsection=fPythia->GetPARI(1);
400}
401
402Bool_t AliGenPythia::ParentSelected(Int_t ip)
403{
5ddeb374 404// True if particle is in list of parent particles to be selected
fe4da5cc 405 for (Int_t i=0; i<5; i++)
406 {
407 if (fParentSelect[i]==ip) return kTRUE;
408 }
409 return kFALSE;
410}
411
412Bool_t AliGenPythia::ChildSelected(Int_t ip)
413{
5ddeb374 414// True if particle is in list of decay products to be selected
f1a48a38 415 if (fForceDecay == kAll) return kTRUE;
4451ef92 416
fe4da5cc 417 for (Int_t i=0; i<5; i++)
418 {
419 if (fChildSelect[i]==ip) return kTRUE;
420 }
421 return kFALSE;
422}
423
1578254f 424Bool_t AliGenPythia::KinematicSelection(TParticle *particle)
fe4da5cc 425{
5ddeb374 426// Perform kinematic selection
1578254f 427 Float_t px=particle->Px();
428 Float_t py=particle->Py();
429 Float_t pz=particle->Pz();
430 Float_t e=particle->Energy();
fe4da5cc 431
432//
433// transverse momentum cut
434 Float_t pt=TMath::Sqrt(px*px+py*py);
435 if (pt > fPtMax || pt < fPtMin)
436 {
437// printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
438 return kFALSE;
439 }
440//
441// momentum cut
442 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
443 if (p > fPMax || p < fPMin)
444 {
445// printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
446 return kFALSE;
447 }
448
449//
450// theta cut
5be1fe76 451 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz)));
fe4da5cc 452 if (theta > fThetaMax || theta < fThetaMin)
453 {
454// printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
455 return kFALSE;
456 }
457
458//
459// rapidity cut
0f9e52a3 460 if ( (e-pz)<=0 || (e+pz)<=0 ) {
919c2096 461 return kFALSE;
462 }
463 else {
464 Float_t y = 0.5*TMath::Log((e+pz)/(e-pz));
465 if (y > fYMax || y < fYMin)
466 {
fe4da5cc 467// printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
919c2096 468 return kFALSE;
469 }
fe4da5cc 470 }
471
472//
473// phi cut
f87cfe57 474 Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)));
fe4da5cc 475 if (phi > fPhiMax || phi < fPhiMin)
476 {
477// printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
478 return kFALSE;
479 }
480
481 return kTRUE;
482}
483void AliGenPythia::AdjustWeights()
484{
5ddeb374 485// Adjust the weights after generation of all events
486//
5ddeb374 487 TParticle *part;
fe4da5cc 488 Int_t ntrack=gAlice->GetNtrack();
489 for (Int_t i=0; i<ntrack; i++) {
2ab0c725 490 part= gAlice->Particle(i);
5ddeb374 491 part->SetWeight(part->GetWeight()*fKineBias);
fe4da5cc 492 }
493}
494
a8228d85 495Int_t AliGenPythia::CheckPDGCode(Int_t pdgcode)
496{
497//
23211d3e 498// If the particle is in a diffractive state, then take action accordingly
a8228d85 499 switch (pdgcode) {
18edb254 500 case 91:
501 return 92;
a8228d85 502 case 110:
503 //rho_diff0 -- difficult to translate, return rho0
504 return 113;
505 case 210:
506 //pi_diffr+ -- change to pi+
507 return 211;
508 case 220:
509 //omega_di0 -- change to omega0
510 return 223;
511 case 330:
512 //phi_diff0 -- return phi0
513 return 333;
514 case 440:
515 //J/psi_di0 -- return J/psi
516 return 443;
517 case 2110:
518 //n_diffr -- return neutron
519 return 2112;
520 case 2210:
521 //p_diffr+ -- return proton
522 return 2212;
523 }
524 //non diffractive state -- return code unchanged
525 return pdgcode;
526}
811826d8 527
528
529void AliGenPythia::SetNuclei(Int_t a1, Int_t a2)
530{
531// Treat protons as inside nuclei with mass numbers a1 and a2
532 fNucA1 = a1;
533 fNucA2 = a2;
534}
535
536
f87cfe57 537AliGenPythia& AliGenPythia::operator=(const AliGenPythia& rhs)
538{
539// Assignment operator
540 return *this;
541}
fe4da5cc 542
543
811826d8 544
a8a6107b 545#ifdef never
18edb254 546void AliGenPythia::Streamer(TBuffer &R__b)
547{
548 // Stream an object of class AliGenPythia.
549
550 if (R__b.IsReading()) {
551 Version_t R__v = R__b.ReadVersion(); if (R__v) { }
552 AliGenerator::Streamer(R__b);
553 R__b >> (Int_t&)fProcess;
554 R__b >> (Int_t&)fStrucFunc;
555 R__b >> (Int_t&)fForceDecay;
556 R__b >> fEnergyCMS;
557 R__b >> fKineBias;
558 R__b >> fTrials;
559 fParentSelect.Streamer(R__b);
560 fChildSelect.Streamer(R__b);
561 R__b >> fXsection;
562// (AliPythia::Instance())->Streamer(R__b);
563 R__b >> fPtHardMin;
564 R__b >> fPtHardMax;
565// if (fDecayer) fDecayer->Streamer(R__b);
566 } else {
567 R__b.WriteVersion(AliGenPythia::IsA());
568 AliGenerator::Streamer(R__b);
569 R__b << (Int_t)fProcess;
570 R__b << (Int_t)fStrucFunc;
571 R__b << (Int_t)fForceDecay;
572 R__b << fEnergyCMS;
573 R__b << fKineBias;
574 R__b << fTrials;
575 fParentSelect.Streamer(R__b);
576 fChildSelect.Streamer(R__b);
577 R__b << fXsection;
578// R__b << fPythia;
579 R__b << fPtHardMin;
580 R__b << fPtHardMax;
581 // fDecayer->Streamer(R__b);
582 }
583}
a8a6107b 584#endif
18edb254 585