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Rotation matrix in BuildGeometry has been changed to rotx999
[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$Log$
9be6226f 18Revision 1.35 2001/03/09 13:03:40 morsch
19Process_t and Struc_Func_t moved to AliPythia.h
20
f1a48a38 21Revision 1.34 2001/02/14 15:50:40 hristov
22The last particle in event marked using SetHighWaterMark
23
28adac24 24Revision 1.33 2001/01/30 09:23:12 hristov
25Streamers removed (R.Brun)
26
a8a6107b 27Revision 1.32 2001/01/26 19:55:51 hristov
28Major upgrade of AliRoot code
29
2ab0c725 30Revision 1.31 2001/01/17 10:54:31 hristov
31Better protection against FPE
32
0f9e52a3 33Revision 1.30 2000/12/18 08:55:35 morsch
34Make AliPythia dependent generartors work with new scheme of random number generation
35
3356c022 36Revision 1.29 2000/12/04 11:22:03 morsch
37Init of sRandom as in 1.15
38
097ec7c1 39Revision 1.28 2000/12/02 11:41:39 morsch
40Use SetRandom() to initialize random number generator in constructor.
41
1ed25e11 42Revision 1.27 2000/11/30 20:29:02 morsch
43Initialise static variable sRandom in constructor: sRandom = fRandom;
44
ad1df918 45Revision 1.26 2000/11/30 07:12:50 alibrary
46Introducing new Rndm and QA classes
47
65fb704d 48Revision 1.25 2000/10/18 19:11:27 hristov
49Division by zero fixed
50
919c2096 51Revision 1.24 2000/09/18 10:41:35 morsch
52Add possibility to use nuclear structure functions from PDF library V8.
53
811826d8 54Revision 1.23 2000/09/14 14:05:40 morsch
55dito
56
819f84ad 57Revision 1.22 2000/09/14 14:02:22 morsch
58- Correct conversion from mm to cm when passing particle vertex to MC.
59- Correct handling of fForceDecay == all.
60
4451ef92 61Revision 1.21 2000/09/12 14:14:55 morsch
62Call fDecayer->ForceDecay() at the beginning of Generate().
63
00d6ce7d 64Revision 1.20 2000/09/06 14:29:33 morsch
65Use AliPythia for event generation an AliDecayPythia for decays.
66Correct handling of "nodecay" option
67
18edb254 68Revision 1.19 2000/07/11 18:24:56 fca
69Coding convention corrections + few minor bug fixes
70
aee8290b 71Revision 1.18 2000/06/30 12:40:34 morsch
72Pythia takes care of vertex smearing. Correct conversion from Pythia units (mm) to
73Geant units (cm).
74
1512e357 75Revision 1.17 2000/06/09 20:34:07 morsch
76All coding rule violations except RS3 corrected
77
f87cfe57 78Revision 1.16 2000/05/15 15:04:20 morsch
79The full event is written for fNtrack = -1
80Coding rule violations corrected.
81
5ddeb374 82Revision 1.15 2000/04/26 10:14:24 morsch
83Particles array has one entry more than pythia particle list. Upper bound of
84particle loop changed to np-1 (R. Guernane, AM)
85
2a0e6f5b 86Revision 1.14 2000/04/05 08:36:13 morsch
87Check status code of particles in Pythia event
88to avoid double counting as partonic state and final state particle.
89
23211d3e 90Revision 1.13 1999/11/09 07:38:48 fca
91Changes for compatibility with version 2.23 of ROOT
92
084c1b4a 93Revision 1.12 1999/11/03 17:43:20 fca
94New version from G.Martinez & A.Morsch
95
886b6f73 96Revision 1.11 1999/09/29 09:24:14 fca
97Introduction of the Copyright and cvs Log
4c039060 98*/
99
fe4da5cc 100#include "AliGenPythia.h"
18edb254 101#include "AliDecayerPythia.h"
fe4da5cc 102#include "AliRun.h"
103#include "AliPythia.h"
18edb254 104#include "AliPDG.h"
1578254f 105#include <TParticle.h>
18edb254 106#include <TSystem.h>
f87cfe57 107
fe4da5cc 108 ClassImp(AliGenPythia)
109
110AliGenPythia::AliGenPythia()
111 :AliGenerator()
112{
18edb254 113// Default Constructor
114 fDecayer = new AliDecayerPythia();
fe4da5cc 115}
116
117AliGenPythia::AliGenPythia(Int_t npart)
118 :AliGenerator(npart)
119{
120// default charm production at 5. 5 TeV
121// semimuonic decay
122// structure function GRVHO
123//
124 fXsection = 0.;
811826d8 125 fNucA1=0;
126 fNucA2=0;
fe4da5cc 127 fParentSelect.Set(5);
128 fChildSelect.Set(5);
129 for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0;
130 SetProcess();
131 SetStrucFunc();
886b6f73 132 SetForceDecay();
fe4da5cc 133 SetPtHard();
134 SetEnergyCMS();
18edb254 135 fDecayer = new AliDecayerPythia();
1ed25e11 136 // Set random number generator
097ec7c1 137 sRandom=fRandom;
fe4da5cc 138}
139
f87cfe57 140AliGenPythia::AliGenPythia(const AliGenPythia & Pythia)
141{
142// copy constructor
143}
144
fe4da5cc 145AliGenPythia::~AliGenPythia()
146{
5ddeb374 147// Destructor
fe4da5cc 148}
149
150void AliGenPythia::Init()
151{
5ddeb374 152// Initialisation
18edb254 153 SetMC(AliPythia::Instance());
fe4da5cc 154 fPythia=(AliPythia*) fgMCEvGen;
155//
156 fParentWeight=1./Float_t(fNpart);
157//
158// Forward Paramters to the AliPythia object
18edb254 159 // gSystem->Exec("ln -s $ALICE_ROOT/data/Decay.table fort.1");
160 // fPythia->Pyupda(2,1);
161 // gSystem->Exec("rm fort.1");
00d6ce7d 162
163 fDecayer->SetForceDecay(fForceDecay);
18edb254 164 fDecayer->Init();
00d6ce7d 165
18edb254 166
fe4da5cc 167 fPythia->SetCKIN(3,fPtHardMin);
168 fPythia->SetCKIN(4,fPtHardMax);
811826d8 169 if (fNucA1 > 0 && fNucA2 > 0) fPythia->SetNuclei(fNucA1, fNucA2);
fe4da5cc 170 fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc);
18edb254 171
172 // fPythia->Pylist(0);
173 // fPythia->Pystat(2);
fe4da5cc 174// Parent and Children Selection
175 switch (fProcess)
176 {
f1a48a38 177 case kPyCharm:
fe4da5cc 178 fParentSelect[0]=411;
179 fParentSelect[1]=421;
180 fParentSelect[2]=431;
181 fParentSelect[3]=4122;
182 break;
f1a48a38 183 case kPyCharmUnforced:
fe4da5cc 184 fParentSelect[0]=411;
185 fParentSelect[1]=421;
186 fParentSelect[2]=431;
187 fParentSelect[3]=4122;
188 break;
f1a48a38 189 case kPyBeauty:
fe4da5cc 190 fParentSelect[0]=511;
191 fParentSelect[1]=521;
192 fParentSelect[2]=531;
193 fParentSelect[3]=5122;
194 break;
f1a48a38 195 case kPyBeautyUnforced:
fe4da5cc 196 fParentSelect[0]=511;
197 fParentSelect[1]=521;
198 fParentSelect[2]=531;
199 fParentSelect[3]=5122;
200 break;
f1a48a38 201 case kPyJpsiChi:
202 case kPyJpsi:
fe4da5cc 203 fParentSelect[0]=443;
204 break;
f1a48a38 205 case kPyMb:
206 case kPyJets:
207 case kPyDirectGamma:
5be1fe76 208 break;
fe4da5cc 209 }
210
211 switch (fForceDecay)
212 {
f1a48a38 213 case kSemiElectronic:
214 case kDiElectron:
215 case kBJpsiDiElectron:
216 case kBPsiPrimeDiElectron:
18edb254 217 fChildSelect[0]=kElectron;
fe4da5cc 218 break;
f1a48a38 219 case kSemiMuonic:
220 case kDiMuon:
221 case kBJpsiDiMuon:
222 case kBPsiPrimeDiMuon:
223 case kPiToMu:
224 case kKaToMu:
18edb254 225 fChildSelect[0]=kMuonMinus;
fe4da5cc 226 break;
f1a48a38 227 case kHadronicD:
18edb254 228 fChildSelect[0]=kPiPlus;
229 fChildSelect[1]=kKPlus;
230 break;
f1a48a38 231 case kAll:
232 case kNoDecay:
18edb254 233 break;
fe4da5cc 234 }
235}
236
237void AliGenPythia::Generate()
238{
5ddeb374 239// Generate one event
00d6ce7d 240 fDecayer->ForceDecay();
fe4da5cc 241
9be6226f 242 Float_t polar[3] = {0,0,0};
243 Float_t origin[3] = {0,0,0};
244 Float_t originP[3] = {0,0,0};
245 Float_t origin0[3] = {0,0,0};
1512e357 246 Float_t p[3], pP[4];
247// Float_t random[6];
09fd3ea2 248 static TClonesArray *particles;
5be1fe76 249// converts from mm/c to s
250 const Float_t kconv=0.001/2.999792458e8;
fe4da5cc 251
252
253//
fe4da5cc 254 Int_t nt=0;
5ddeb374 255 Int_t ntP=0;
fe4da5cc 256 Int_t jev=0;
7921755b 257 Int_t j, kf;
09fd3ea2 258
259 if(!particles) particles=new TClonesArray("TParticle",1000);
fe4da5cc 260
261 fTrials=0;
262 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
aee8290b 263 if(fVertexSmear==kPerEvent) {
1512e357 264 fPythia->SetMSTP(151,1);
fe4da5cc 265 for (j=0;j<3;j++) {
1512e357 266 fPythia->SetPARP(151+j, fOsigma[j]/10.);
fe4da5cc 267 }
aee8290b 268 } else if (fVertexSmear==kPerTrack) {
fe4da5cc 269 fPythia->SetMSTP(151,0);
fe4da5cc 270 }
1512e357 271
fe4da5cc 272 while(1)
273 {
084c1b4a 274 fPythia->Pyevnt();
18edb254 275// fPythia->Pylist(1);
fe4da5cc 276 fTrials++;
f1092809 277 fPythia->ImportParticles(particles,"All");
fe4da5cc 278 Int_t np = particles->GetEntriesFast();
279 printf("\n **************************************************%d\n",np);
280 Int_t nc=0;
281 if (np == 0 ) continue;
f1a48a38 282 if (fProcess != kPyMb && fProcess != kPyJets && fProcess != kPyDirectGamma) {
2a0e6f5b 283 for (Int_t i = 0; i<np-1; i++) {
1578254f 284 TParticle * iparticle = (TParticle *) particles->At(i);
23211d3e 285 Int_t ks = iparticle->GetStatusCode();
a8228d85 286 kf = CheckPDGCode(iparticle->GetPdgCode());
2a0e6f5b 287 if (ks==21) continue;
288
18edb254 289 fChildWeight=(fDecayer->GetPartialBranchingRatio(kf))*fParentWeight;
fe4da5cc 290//
291// Parent
5be1fe76 292 if (ParentSelected(TMath::Abs(kf))) {
293 if (KinematicSelection(iparticle)) {
294 if (nc==0) {
295//
296// Store information concerning the hard scattering process
297//
5ddeb374 298 Float_t massP = fPythia->GetPARI(13);
299 Float_t ptP = fPythia->GetPARI(17);
300 Float_t yP = fPythia->GetPARI(37);
301 Float_t xmtP = sqrt(ptP*ptP+massP*massP);
302 Float_t ty = Float_t(TMath::TanH(yP));
303 pP[0] = ptP;
304 pP[1] = 0;
305 pP[2] = xmtP*ty/sqrt(1.-ty*ty);
306 pP[3] = massP;
5be1fe76 307 gAlice->SetTrack(0,-1,-1,
5ddeb374 308 pP,originP,polar,
65fb704d 309 0,kPPrimary,ntP,fParentWeight);
310// 0,"Hard Scat.",ntP,fParentWeight);
5ddeb374 311 gAlice->KeepTrack(ntP);
5be1fe76 312 }
313 nc++;
fe4da5cc 314//
315// store parent track information
1578254f 316 p[0]=iparticle->Px();
317 p[1]=iparticle->Py();
318 p[2]=iparticle->Pz();
819f84ad 319 origin[0]=origin0[0]+iparticle->Vx()/10.;
320 origin[1]=origin0[1]+iparticle->Vy()/10.;
321 origin[2]=origin0[2]+iparticle->Vz()/10.;
fe4da5cc 322
1578254f 323 Int_t ifch=iparticle->GetFirstDaughter();
324 Int_t ilch=iparticle->GetLastDaughter();
18edb254 325
f1a48a38 326 if ((ifch !=0 && ilch !=0) || fForceDecay == kNoDecay) {
18edb254 327 Int_t trackit=0;
f1a48a38 328 if (fForceDecay == kNoDecay) trackit = 1;
18edb254 329 gAlice->SetTrack(trackit,ntP,kf,
5be1fe76 330 p,origin,polar,
65fb704d 331 0,kPPrimary,nt,fParentWeight);
5be1fe76 332 gAlice->KeepTrack(nt);
333 Int_t iparent = nt;
fe4da5cc 334//
335// Children
f1a48a38 336 if (fForceDecay != kNoDecay) {
18edb254 337 for (j=ifch; j<=ilch; j++)
338 {
339 TParticle * ichild =
1578254f 340 (TParticle *) particles->At(j-1);
18edb254 341 kf = CheckPDGCode(ichild->GetPdgCode());
fe4da5cc 342//
343//
18edb254 344 if (ChildSelected(TMath::Abs(kf))) {
4451ef92 345 origin[0]=origin0[0]+ichild->Vx()/10.;
346 origin[1]=origin0[1]+ichild->Vy()/10.;
347 origin[2]=origin0[2]+ichild->Vz()/10.;
1578254f 348 p[0]=ichild->Px();
349 p[1]=ichild->Py();
350 p[2]=ichild->Pz();
9be6226f 351 Float_t tof=kconv*ichild->T();
352 gAlice->SetTrack(fTrackIt, iparent, kf,
353 p,origin,polar,
354 tof,kPDecay,nt,fChildWeight);
355 gAlice->KeepTrack(nt);
356 } // select child
357 } // child loop
358 }
359 }
360 } // kinematic selection
361 } // select particle
362 } // particle loop
363 } else {
364 for (Int_t i = 0; i<np-1; i++) {
365 TParticle * iparticle = (TParticle *) particles->At(i);
366 kf = CheckPDGCode(iparticle->GetPdgCode());
367 Int_t ks = iparticle->GetStatusCode();
368 Int_t km = iparticle->GetFirstMother();
369 // printf("\n process %d %d\n", ks,km);
370
371 if ((ks==1 && kf!=0 && KinematicSelection(iparticle)) ||
372 (fProcess == kPyJets && ks == 21 && km == 0 && i>1)) {
373 nc++;
5be1fe76 374//
375// store track information
9be6226f 376 p[0]=iparticle->Px();
377 p[1]=iparticle->Py();
378 p[2]=iparticle->Pz();
379 origin[0]=origin0[0]+iparticle->Vx()/10.;
380 origin[1]=origin0[1]+iparticle->Vy()/10.;
381 origin[2]=origin0[2]+iparticle->Vz()/10.;
382 Float_t tof=kconv*iparticle->T();
383 gAlice->SetTrack(fTrackIt,-1,kf,p,origin,polar,
384 tof,kPPrimary,nt);
385 gAlice->KeepTrack(nt);
5be1fe76 386 } // select particle
387 } // particle loop
388 printf("\n I've put %i particles on the stack \n",nc);
389 } // mb ?
fe4da5cc 390 if (nc > 0) {
5be1fe76 391 jev+=nc;
5ddeb374 392 if (jev >= fNpart || fNpart == -1) {
fe4da5cc 393 fKineBias=Float_t(fNpart)/Float_t(fTrials);
23211d3e 394 printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
fe4da5cc 395 break;
396 }
397 }
398 } // event loop
28adac24 399 gAlice->SetHighWaterMark(nt);
fe4da5cc 400// adjust weight due to kinematic selection
401 AdjustWeights();
402// get cross-section
403 fXsection=fPythia->GetPARI(1);
404}
405
9be6226f 406void AliGenPythia::FinishRun()
407{
408// Print x-section summary
409 fPythia->Pystat(1);
410}
411
fe4da5cc 412Bool_t AliGenPythia::ParentSelected(Int_t ip)
413{
5ddeb374 414// True if particle is in list of parent particles to be selected
fe4da5cc 415 for (Int_t i=0; i<5; i++)
416 {
417 if (fParentSelect[i]==ip) return kTRUE;
418 }
419 return kFALSE;
420}
421
422Bool_t AliGenPythia::ChildSelected(Int_t ip)
423{
5ddeb374 424// True if particle is in list of decay products to be selected
f1a48a38 425 if (fForceDecay == kAll) return kTRUE;
4451ef92 426
fe4da5cc 427 for (Int_t i=0; i<5; i++)
428 {
429 if (fChildSelect[i]==ip) return kTRUE;
430 }
431 return kFALSE;
432}
433
1578254f 434Bool_t AliGenPythia::KinematicSelection(TParticle *particle)
fe4da5cc 435{
5ddeb374 436// Perform kinematic selection
1578254f 437 Float_t px=particle->Px();
438 Float_t py=particle->Py();
439 Float_t pz=particle->Pz();
440 Float_t e=particle->Energy();
fe4da5cc 441
442//
443// transverse momentum cut
444 Float_t pt=TMath::Sqrt(px*px+py*py);
445 if (pt > fPtMax || pt < fPtMin)
446 {
447// printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
448 return kFALSE;
449 }
450//
451// momentum cut
452 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
453 if (p > fPMax || p < fPMin)
454 {
455// printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
456 return kFALSE;
457 }
458
459//
460// theta cut
5be1fe76 461 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz)));
fe4da5cc 462 if (theta > fThetaMax || theta < fThetaMin)
463 {
464// printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
465 return kFALSE;
466 }
467
468//
469// rapidity cut
0f9e52a3 470 if ( (e-pz)<=0 || (e+pz)<=0 ) {
919c2096 471 return kFALSE;
472 }
473 else {
474 Float_t y = 0.5*TMath::Log((e+pz)/(e-pz));
475 if (y > fYMax || y < fYMin)
476 {
fe4da5cc 477// printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
919c2096 478 return kFALSE;
479 }
fe4da5cc 480 }
481
482//
483// phi cut
f87cfe57 484 Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)));
fe4da5cc 485 if (phi > fPhiMax || phi < fPhiMin)
486 {
487// printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
488 return kFALSE;
489 }
490
491 return kTRUE;
492}
493void AliGenPythia::AdjustWeights()
494{
5ddeb374 495// Adjust the weights after generation of all events
496//
5ddeb374 497 TParticle *part;
fe4da5cc 498 Int_t ntrack=gAlice->GetNtrack();
499 for (Int_t i=0; i<ntrack; i++) {
2ab0c725 500 part= gAlice->Particle(i);
5ddeb374 501 part->SetWeight(part->GetWeight()*fKineBias);
fe4da5cc 502 }
503}
504
a8228d85 505Int_t AliGenPythia::CheckPDGCode(Int_t pdgcode)
506{
507//
23211d3e 508// If the particle is in a diffractive state, then take action accordingly
a8228d85 509 switch (pdgcode) {
18edb254 510 case 91:
511 return 92;
a8228d85 512 case 110:
513 //rho_diff0 -- difficult to translate, return rho0
514 return 113;
515 case 210:
516 //pi_diffr+ -- change to pi+
517 return 211;
518 case 220:
519 //omega_di0 -- change to omega0
520 return 223;
521 case 330:
522 //phi_diff0 -- return phi0
523 return 333;
524 case 440:
525 //J/psi_di0 -- return J/psi
526 return 443;
527 case 2110:
528 //n_diffr -- return neutron
529 return 2112;
530 case 2210:
531 //p_diffr+ -- return proton
532 return 2212;
533 }
534 //non diffractive state -- return code unchanged
535 return pdgcode;
536}
811826d8 537
538
539void AliGenPythia::SetNuclei(Int_t a1, Int_t a2)
540{
541// Treat protons as inside nuclei with mass numbers a1 and a2
542 fNucA1 = a1;
543 fNucA2 = a2;
544}
545
546
f87cfe57 547AliGenPythia& AliGenPythia::operator=(const AliGenPythia& rhs)
548{
549// Assignment operator
550 return *this;
551}
fe4da5cc 552
553
811826d8 554
a8a6107b 555#ifdef never
18edb254 556void AliGenPythia::Streamer(TBuffer &R__b)
557{
558 // Stream an object of class AliGenPythia.
559
560 if (R__b.IsReading()) {
561 Version_t R__v = R__b.ReadVersion(); if (R__v) { }
562 AliGenerator::Streamer(R__b);
563 R__b >> (Int_t&)fProcess;
564 R__b >> (Int_t&)fStrucFunc;
565 R__b >> (Int_t&)fForceDecay;
566 R__b >> fEnergyCMS;
567 R__b >> fKineBias;
568 R__b >> fTrials;
569 fParentSelect.Streamer(R__b);
570 fChildSelect.Streamer(R__b);
571 R__b >> fXsection;
572// (AliPythia::Instance())->Streamer(R__b);
573 R__b >> fPtHardMin;
574 R__b >> fPtHardMax;
575// if (fDecayer) fDecayer->Streamer(R__b);
576 } else {
577 R__b.WriteVersion(AliGenPythia::IsA());
578 AliGenerator::Streamer(R__b);
579 R__b << (Int_t)fProcess;
580 R__b << (Int_t)fStrucFunc;
581 R__b << (Int_t)fForceDecay;
582 R__b << fEnergyCMS;
583 R__b << fKineBias;
584 R__b << fTrials;
585 fParentSelect.Streamer(R__b);
586 fChildSelect.Streamer(R__b);
587 R__b << fXsection;
588// R__b << fPythia;
589 R__b << fPtHardMin;
590 R__b << fPtHardMax;
591 // fDecayer->Streamer(R__b);
592 }
593}
a8a6107b 594#endif
18edb254 595