Add pointer to AliGeometry to handle geometrical acceptance. (G. MArtinez)
[u/mrichter/AliRoot.git] / EVGEN / AliGenParam.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$Log$
6d4dd317 18Revision 1.36 2002/02/08 16:50:50 morsch
19Add name and title in constructor.
20
8b31bfac 21Revision 1.35 2002/01/21 10:02:40 morsch
22ty is Double_t
23Abort if too high rapidity causes numerical paroblem. User has to specify
24meaningful y-range.
25
2d7a47be 26Revision 1.34 2001/11/27 13:13:07 morsch
27Maximum lifetime for long-lived particles to be put on the stack is parameter.
28It can be set via SetMaximumLifetime(..).
29
47fc6bd5 30Revision 1.33 2001/10/21 18:35:56 hristov
31Several pointers were set to zero in the default constructors to avoid memory management problems
32
2685bf00 33Revision 1.32 2001/07/27 17:09:36 morsch
34Use local SetTrack, KeepTrack and SetHighWaterMark methods
35to delegate either to local stack or to stack owned by AliRun.
36(Piotr Skowronski, A.M.)
37
a99cf51f 38Revision 1.31 2001/07/13 10:58:54 morsch
39- Some coded moved to AliGenMC
40- Improved handling of secondary vertices.
41
fff02fee 42Revision 1.30 2001/06/15 07:55:04 morsch
43Put only first generation decay products on the stack.
44
6ba00c52 45Revision 1.29 2001/03/27 10:58:41 morsch
46Initialize decayer before generation. Important if run inside cocktail.
47
771bbe45 48Revision 1.28 2001/03/09 13:01:41 morsch
49- enum constants for paramterisation type (particle family) moved to AliGen*lib.h
50- use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
51
34f60c01 52Revision 1.27 2001/02/02 15:21:10 morsch
53Set high water mark after last particle.
54Use Vertex() method for Vertex.
55
d9ea0e3b 56Revision 1.26 2000/12/21 16:24:06 morsch
57Coding convention clean-up
58
675e9664 59Revision 1.25 2000/11/30 07:12:50 alibrary
60Introducing new Rndm and QA classes
61
65fb704d 62Revision 1.24 2000/10/18 19:11:27 hristov
63Division by zero fixed
64
919c2096 65Revision 1.23 2000/10/02 21:28:06 fca
66Removal of useless dependecies via forward declarations
67
94de3818 68Revision 1.22 2000/09/12 14:14:55 morsch
69Call fDecayer->ForceDecay() at the beginning of Generate().
70
00d6ce7d 71Revision 1.21 2000/09/08 15:39:01 morsch
72Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
73
5ab0acc9 74Revision 1.20 2000/09/06 14:35:44 morsch
75Use AliDecayerPythia for particle decays.
76
fa480368 77Revision 1.19 2000/07/11 18:24:56 fca
78Coding convention corrections + few minor bug fixes
79
aee8290b 80Revision 1.18 2000/06/29 21:08:27 morsch
81All paramatrisation libraries derive from the pure virtual base class AliGenLib.
82This allows to pass a pointer to a library directly to AliGenParam and avoids the
83use of function pointers in Config.C.
84
b22ee262 85Revision 1.17 2000/06/09 20:33:30 morsch
86All coding rule violations except RS3 corrected
87
f87cfe57 88Revision 1.16 2000/05/02 07:51:31 morsch
89- Control precision of pT sampling TF1::SetNpx(..)
90- Correct initialisation of child-cuts in all constructors.
91- Most coding rule violations corrected.
92
749070b6 93Revision 1.15 2000/04/03 15:42:12 morsch
94Cuts on primary particles are separated from those on the decay products. Methods
95SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
96
cc5d764c 97Revision 1.14 1999/11/09 07:38:48 fca
98Changes for compatibility with version 2.23 of ROOT
99
084c1b4a 100Revision 1.13 1999/11/04 11:30:31 fca
101Correct the logics for SetForceDecay
102
28337bc1 103Revision 1.12 1999/11/03 17:43:20 fca
104New version from G.Martinez & A.Morsch
105
886b6f73 106Revision 1.11 1999/09/29 09:24:14 fca
107Introduction of the Copyright and cvs Log
108
4c039060 109*/
110
6d4dd317 111
112
113// Class to generate particles from using paramtrized pT and y distributions.
114// Distributions are obtained from pointer to object of type AliGenLib.
115// (For example AliGenMUONlib)
116// Decays are performed using Pythia.
117// andreas.morsch@cern.ch
118
fe4da5cc 119#include "AliGenParam.h"
fa480368 120#include "AliDecayerPythia.h"
fe4da5cc 121#include "AliGenMUONlib.h"
122#include "AliRun.h"
1578254f 123#include <TParticle.h>
fa480368 124#include <TParticlePDG.h>
125#include <TDatabasePDG.h>
126#include <TLorentzVector.h>
127
f87cfe57 128#include <TF1.h>
fe4da5cc 129
130ClassImp(AliGenParam)
131
132//------------------------------------------------------------
133
134 //Begin_Html
135 /*
1439f98e 136 <img src="picts/AliGenParam.gif">
fe4da5cc 137 */
138 //End_Html
139
140//____________________________________________________________
141//____________________________________________________________
142AliGenParam::AliGenParam()
fe4da5cc 143{
b22ee262 144// Deafault constructor
145 fPtPara = 0;
146 fYPara = 0;
34f60c01 147 fParam = 0;
148 fAnalog = kAnalog;
b22ee262 149 SetDeltaPt();
675e9664 150//
151// Set random number generator
152 sRandom = fRandom;
2685bf00 153 fDecayer = 0;
8b31bfac 154
155
b22ee262 156}
157
fff02fee 158AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
b22ee262 159{
160// Constructor using number of particles parameterisation id and library
8b31bfac 161 fName = "Param";
162 fTitle= "Particle Generator using pT and y parameterisation";
b22ee262 163
164 fPtParaFunc = Library->GetPt(param, tname);
165 fYParaFunc = Library->GetY (param, tname);
166 fIpParaFunc = Library->GetIp(param, tname);
167
168 fPtPara = 0;
169 fYPara = 0;
170 fParam = param;
34f60c01 171 fAnalog = kAnalog;
b22ee262 172 SetForceDecay();
b22ee262 173 SetDeltaPt();
675e9664 174//
175// Set random number generator
176 sRandom = fRandom;
fe4da5cc 177}
178
179//____________________________________________________________
886b6f73 180
fff02fee 181AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
fe4da5cc 182{
b22ee262 183// Constructor using parameterisation id and number of particles
8b31bfac 184//
185 fName = "Param";
186 fTitle= "Particle Generator using pT and y parameterisation";
187
675e9664 188 AliGenLib* pLibrary = new AliGenMUONlib();
b22ee262 189
675e9664 190 fPtParaFunc = pLibrary->GetPt(param, tname);
191 fYParaFunc = pLibrary->GetY (param, tname);
192 fIpParaFunc = pLibrary->GetIp(param, tname);
b22ee262 193
194 fPtPara = 0;
195 fYPara = 0;
196 fParam = param;
34f60c01 197 fAnalog = kAnalog;
b22ee262 198 fChildSelect.Set(5);
199 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
200 SetForceDecay();
201 SetCutOnChild();
202 SetChildMomentumRange();
203 SetChildPtRange();
204 SetChildPhiRange();
205 SetChildThetaRange();
206 SetDeltaPt();
fe4da5cc 207}
208
34f60c01 209AliGenParam::AliGenParam(Int_t npart, Int_t param,
886b6f73 210 Double_t (*PtPara) (Double_t*, Double_t*),
211 Double_t (*YPara ) (Double_t* ,Double_t*),
65fb704d 212 Int_t (*IpPara) (TRandom *))
fff02fee 213 :AliGenMC(npart)
886b6f73 214{
749070b6 215// Constructor
28337bc1 216// Gines Martinez 1/10/99
8b31bfac 217 fName = "Param";
218 fTitle= "Particle Generator using pT and y parameterisation";
219
886b6f73 220 fPtParaFunc = PtPara;
221 fYParaFunc = YPara;
222 fIpParaFunc = IpPara;
28337bc1 223//
886b6f73 224 fPtPara = 0;
225 fYPara = 0;
226 fParam = param;
34f60c01 227 fAnalog = kAnalog;
886b6f73 228 fChildSelect.Set(5);
229 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
230 SetForceDecay();
231 SetCutOnChild();
749070b6 232 SetChildMomentumRange();
233 SetChildPtRange();
234 SetChildPhiRange();
235 SetChildThetaRange();
236 SetDeltaPt();
886b6f73 237}
238
f87cfe57 239
6d4dd317 240AliGenParam::AliGenParam(const AliGenParam & Param)
f87cfe57 241{
242// copy constructor
6d4dd317 243 Param.Copy(*this);
f87cfe57 244}
245
fe4da5cc 246//____________________________________________________________
247AliGenParam::~AliGenParam()
248{
749070b6 249// Destructor
fe4da5cc 250 delete fPtPara;
251 delete fYPara;
252}
253
254//____________________________________________________________
255void AliGenParam::Init()
256{
749070b6 257// Initialisation
fa480368 258
259 fDecayer = new AliDecayerPythia();
fe4da5cc 260 //Begin_Html
261 /*
1439f98e 262 <img src="picts/AliGenParam.gif">
fe4da5cc 263 */
264 //End_Html
265
749070b6 266 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
267// Set representation precision to 10 MeV
268 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
269
270 fPtPara->SetNpx(npx);
271
272 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
273 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
274 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
b7601ac4 275
fe4da5cc 276//
277// dN/dy| y=0
749070b6 278 Double_t y1=0;
279 Double_t y2=0;
280
281 fdNdy0=fYParaFunc(&y1,&y2);
fe4da5cc 282//
283// Integral over generation region
749070b6 284 Float_t intYS = yPara ->Integral(fYMin, fYMax);
285 Float_t intPt0 = ptPara->Integral(0,15);
286 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
287 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
34f60c01 288 if (fAnalog == kAnalog) {
749070b6 289 fYWgt = intYS/fdNdy0;
290 fPtWgt = intPtS/intPt0;
291 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
292 } else {
293 fYWgt = intYS/fdNdy0;
294 fPtWgt = (fPtMax-fPtMin)/intPt0;
295 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
296 }
fe4da5cc 297//
298// particle decay related initialization
00d6ce7d 299 fDecayer->SetForceDecay(fForceDecay);
fa480368 300 fDecayer->Init();
00d6ce7d 301
fe4da5cc 302//
fff02fee 303 AliGenMC::Init();
fe4da5cc 304}
305
306//____________________________________________________________
307void AliGenParam::Generate()
308{
28337bc1 309//
310// Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
311// Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
312// antineutrons in the the desired theta, phi and momentum windows;
313// Gaussian smearing on the vertex is done if selected.
cc5d764c 314// The decay of heavy mesons is done using lujet,
315// and the childern particle are tracked by GEANT
316// However, light mesons are directly tracked by GEANT
317// setting fForceDecay = nodecay (SetForceDecay(nodecay))
28337bc1 318//
771bbe45 319//
320// Reinitialize decayer
321 fDecayer->Init();
322//
28337bc1 323 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
324 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
325 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
326 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
327 Float_t p[3], pc[3],
fff02fee 328 och[3]; // Momentum, polarisation and origin of the children particles from lujet
2d7a47be 329 Double_t ty, xmt;
fff02fee 330 Int_t nt, i, j;
fe4da5cc 331 Float_t wgtp, wgtch;
332 Double_t dummy;
09fd3ea2 333 static TClonesArray *particles;
fe4da5cc 334 //
fff02fee 335 if(!particles) particles = new TClonesArray("TParticle",1000);
8b31bfac 336
675e9664 337 static TDatabasePDG *pDataBase = new TDatabasePDG();
338 if(!pDataBase) pDataBase = new TDatabasePDG();
fe4da5cc 339 //
340 Float_t random[6];
28337bc1 341
342// Calculating vertex position per event
fe4da5cc 343 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
aee8290b 344 if(fVertexSmear==kPerEvent) {
d9ea0e3b 345 Vertex();
346 for (j=0;j<3;j++) origin0[j]=fVertex[j];
fe4da5cc 347 }
d9ea0e3b 348
21aaa175 349 Int_t ipa=0;
fff02fee 350
28337bc1 351// Generating fNpart particles
21aaa175 352 while (ipa<fNpart) {
cc5d764c 353 while(1) {
fe4da5cc 354//
355// particle type
65fb704d 356 Int_t iPart = fIpParaFunc(fRandom);
fa480368 357 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
675e9664 358 TParticlePDG *particle = pDataBase->GetParticle(iPart);
fa480368 359 Float_t am = particle->Mass();
8b31bfac 360
65fb704d 361 Rndm(random,2);
fe4da5cc 362//
363// phi
364 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
365//
366// y
2d7a47be 367 ty = TMath::TanH(fYPara->GetRandom());
fe4da5cc 368//
369// pT
34f60c01 370 if (fAnalog == kAnalog) {
fe4da5cc 371 pt=fPtPara->GetRandom();
372 wgtp=fParentWeight;
373 wgtch=fChildWeight;
374 } else {
375 pt=fPtMin+random[1]*(fPtMax-fPtMin);
376 Double_t ptd=pt;
377 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
378 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
379 }
380 xmt=sqrt(pt*pt+am*am);
2d7a47be 381 if (TMath::Abs(ty)==1.) {
382 ty=0.;
383 Fatal("AliGenParam",
384 "Division by 0: Please check you rapidity range !");
385 }
386
fe4da5cc 387 pl=xmt*ty/sqrt(1.-ty*ty);
388 theta=TMath::ATan2(pt,pl);
cc5d764c 389// Cut on theta
fe4da5cc 390 if(theta<fThetaMin || theta>fThetaMax) continue;
391 ptot=TMath::Sqrt(pt*pt+pl*pl);
cc5d764c 392// Cut on momentum
fe4da5cc 393 if(ptot<fPMin || ptot>fPMax) continue;
fff02fee 394//
fe4da5cc 395 p[0]=pt*TMath::Cos(phi);
396 p[1]=pt*TMath::Sin(phi);
397 p[2]=pl;
aee8290b 398 if(fVertexSmear==kPerTrack) {
65fb704d 399 Rndm(random,6);
fe4da5cc 400 for (j=0;j<3;j++) {
401 origin0[j]=
402 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
403 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
404 }
405 }
28337bc1 406
407// Looking at fForceDecay :
cc5d764c 408// if fForceDecay != none Primary particle decays using
409// AliPythia and children are tracked by GEANT
28337bc1 410//
cc5d764c 411// if fForceDecay == none Primary particle is tracked by GEANT
412// (In the latest, make sure that GEANT actually does all the decays you want)
fe4da5cc 413//
fff02fee 414
34f60c01 415 if (fForceDecay != kNoDecay) {
28337bc1 416// Using lujet to decay particle
886b6f73 417 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
fa480368 418 TLorentzVector pmom(p[0], p[1], p[2], energy);
419 fDecayer->Decay(iPart,&pmom);
fe4da5cc 420//
cc5d764c 421// select decay particles
fa480368 422 Int_t np=fDecayer->ImportParticles(particles);
886b6f73 423 Int_t ncsel=0;
fff02fee 424 Int_t* pFlag = new Int_t[np];
425 Int_t* pParent = new Int_t[np];
426 Int_t* pSelected = new Int_t[np];
427 Int_t* trackIt = new Int_t[np];
428
429 for (i=0; i<np; i++) {
430 pFlag[i] = 0;
431 pSelected[i] = 0;
432 pParent[i] = -1;
433 }
434
6ba00c52 435 if (np >1) {
436 TParticle* iparticle = (TParticle *) particles->At(0);
fff02fee 437 Int_t ipF, ipL;
438 for (i = 1; i<np ; i++) {
439 trackIt[i] = 1;
6ba00c52 440 iparticle = (TParticle *) particles->At(i);
441 Int_t kf = iparticle->GetPdgCode();
fff02fee 442 Int_t ks = iparticle->GetStatusCode();
443// flagged particle
444
445 if (pFlag[i] == 1) {
fff02fee 446 ipF = iparticle->GetFirstDaughter();
447 ipL = iparticle->GetLastDaughter();
448 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
449 continue;
450 }
451
452// flag decay products of particles with long life-time (c tau > .3 mum)
453
454 if (ks != 1) {
2d7a47be 455// TParticlePDG *particle = pDataBase->GetParticle(kf);
fff02fee 456
457 Double_t lifeTime = fDecayer->GetLifetime(kf);
2d7a47be 458// Double_t mass = particle->Mass();
459// Double_t width = particle->Width();
47fc6bd5 460 if (lifeTime > (Double_t) fMaxLifeTime) {
fff02fee 461 ipF = iparticle->GetFirstDaughter();
462 ipL = iparticle->GetLastDaughter();
463 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
464 } else{
465 trackIt[i] = 0;
466 pSelected[i] = 1;
467 }
468 } // ks==1 ?
fe4da5cc 469//
470// children
47fc6bd5 471
fff02fee 472 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
6ba00c52 473 {
6ba00c52 474 if (fCutOnChild) {
fff02fee 475 pc[0]=iparticle->Px();
476 pc[1]=iparticle->Py();
477 pc[2]=iparticle->Pz();
478 Bool_t childok = KinematicSelection(iparticle, 1);
479 if(childok) {
480 pSelected[i] = 1;
6ba00c52 481 ncsel++;
482 } else {
483 ncsel=-1;
484 break;
485 } // child kine cuts
486 } else {
fff02fee 487 pSelected[i] = 1;
886b6f73 488 ncsel++;
6ba00c52 489 } // if child selection
490 } // select muon
491 } // decay particle loop
492 } // if decay products
493
886b6f73 494 Int_t iparent;
495 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
496 ipa++;
21aaa175 497//
fff02fee 498// Parent
a99cf51f 499 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
fff02fee 500 pParent[0] = nt;
a99cf51f 501 KeepTrack(nt);
fff02fee 502//
503// Decay Products
504//
505 for (i = 1; i < np; i++) {
506 if (pSelected[i]) {
507 TParticle* iparticle = (TParticle *) particles->At(i);
508 Int_t kf = iparticle->GetPdgCode();
509 Int_t ipa = iparticle->GetFirstMother()-1;
510
511 och[0] = origin0[0]+iparticle->Vx()/10;
512 och[1] = origin0[1]+iparticle->Vy()/10;
513 och[2] = origin0[2]+iparticle->Vz()/10;
514 pc[0] = iparticle->Px();
515 pc[1] = iparticle->Py();
516 pc[2] = iparticle->Pz();
517
518 if (ipa > -1) {
519 iparent = pParent[ipa];
520 } else {
521 iparent = -1;
522 }
a99cf51f 523 SetTrack(fTrackIt*trackIt[i], iparent, kf,
fff02fee 524 pc, och, polar,
525 0, kPDecay, nt, wgtch);
526 pParent[i] = nt;
a99cf51f 527 KeepTrack(nt);
8b31bfac 528 } // Selected
529 } // Particle loop
28337bc1 530 } // Decays by Lujet
8b31bfac 531 particles->Clear();
fff02fee 532 if (pFlag) delete[] pFlag;
533 if (pParent) delete[] pParent;
534 if (pSelected) delete[] pSelected;
8b31bfac 535 if (trackIt) delete[] trackIt;
21aaa175 536 } // kinematic selection
28337bc1 537 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
538 {
539 gAlice->
65fb704d 540 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
28337bc1 541 ipa++;
542 }
fe4da5cc 543 break;
21aaa175 544 } // while
fe4da5cc 545 } // event loop
a99cf51f 546 SetHighWaterMark(nt);
fe4da5cc 547}
548
f87cfe57 549AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
550{
551// Assignment operator
552 return *this;
553}
554
fe4da5cc 555
556