Merging the VirtualMC branch to the main development branch (HEAD)
[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$Log$
b9d0a01d 18Revision 1.36.6.3 2002/10/10 16:40:08 hristov
19Updating VirtualMC to v3-09-02
20
21Revision 1.39 2002/09/16 08:21:16 morsch
22Use TDatabasePDG::Instance();
23
349be858 24Revision 1.38 2002/05/30 14:59:12 morsch
25Check geometrical acceptance. (G. Martinez)
26
1242532d 27Revision 1.37 2002/04/17 10:20:44 morsch
28Coding Rule violations corrected.
29
6d4dd317 30Revision 1.36 2002/02/08 16:50:50 morsch
31Add name and title in constructor.
32
8b31bfac 33Revision 1.35 2002/01/21 10:02:40 morsch
34ty is Double_t
35Abort if too high rapidity causes numerical paroblem. User has to specify
36meaningful y-range.
37
2d7a47be 38Revision 1.34 2001/11/27 13:13:07 morsch
39Maximum lifetime for long-lived particles to be put on the stack is parameter.
40It can be set via SetMaximumLifetime(..).
41
47fc6bd5 42Revision 1.33 2001/10/21 18:35:56 hristov
43Several pointers were set to zero in the default constructors to avoid memory management problems
44
2685bf00 45Revision 1.32 2001/07/27 17:09:36 morsch
46Use local SetTrack, KeepTrack and SetHighWaterMark methods
47to delegate either to local stack or to stack owned by AliRun.
48(Piotr Skowronski, A.M.)
49
a99cf51f 50Revision 1.31 2001/07/13 10:58:54 morsch
51- Some coded moved to AliGenMC
52- Improved handling of secondary vertices.
53
fff02fee 54Revision 1.30 2001/06/15 07:55:04 morsch
55Put only first generation decay products on the stack.
56
6ba00c52 57Revision 1.29 2001/03/27 10:58:41 morsch
58Initialize decayer before generation. Important if run inside cocktail.
59
771bbe45 60Revision 1.28 2001/03/09 13:01:41 morsch
61- enum constants for paramterisation type (particle family) moved to AliGen*lib.h
62- use AliGenGSIlib::kUpsilon, AliGenPHOSlib::kEtaPrime to access the constants
63
34f60c01 64Revision 1.27 2001/02/02 15:21:10 morsch
65Set high water mark after last particle.
66Use Vertex() method for Vertex.
67
d9ea0e3b 68Revision 1.26 2000/12/21 16:24:06 morsch
69Coding convention clean-up
70
675e9664 71Revision 1.25 2000/11/30 07:12:50 alibrary
72Introducing new Rndm and QA classes
73
65fb704d 74Revision 1.24 2000/10/18 19:11:27 hristov
75Division by zero fixed
76
919c2096 77Revision 1.23 2000/10/02 21:28:06 fca
78Removal of useless dependecies via forward declarations
79
94de3818 80Revision 1.22 2000/09/12 14:14:55 morsch
81Call fDecayer->ForceDecay() at the beginning of Generate().
82
00d6ce7d 83Revision 1.21 2000/09/08 15:39:01 morsch
84Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
85
5ab0acc9 86Revision 1.20 2000/09/06 14:35:44 morsch
87Use AliDecayerPythia for particle decays.
88
fa480368 89Revision 1.19 2000/07/11 18:24:56 fca
90Coding convention corrections + few minor bug fixes
91
aee8290b 92Revision 1.18 2000/06/29 21:08:27 morsch
93All paramatrisation libraries derive from the pure virtual base class AliGenLib.
94This allows to pass a pointer to a library directly to AliGenParam and avoids the
95use of function pointers in Config.C.
96
b22ee262 97Revision 1.17 2000/06/09 20:33:30 morsch
98All coding rule violations except RS3 corrected
99
f87cfe57 100Revision 1.16 2000/05/02 07:51:31 morsch
101- Control precision of pT sampling TF1::SetNpx(..)
102- Correct initialisation of child-cuts in all constructors.
103- Most coding rule violations corrected.
104
749070b6 105Revision 1.15 2000/04/03 15:42:12 morsch
106Cuts on primary particles are separated from those on the decay products. Methods
107SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
108
cc5d764c 109Revision 1.14 1999/11/09 07:38:48 fca
110Changes for compatibility with version 2.23 of ROOT
111
084c1b4a 112Revision 1.13 1999/11/04 11:30:31 fca
113Correct the logics for SetForceDecay
114
28337bc1 115Revision 1.12 1999/11/03 17:43:20 fca
116New version from G.Martinez & A.Morsch
117
886b6f73 118Revision 1.11 1999/09/29 09:24:14 fca
119Introduction of the Copyright and cvs Log
120
4c039060 121*/
122
6d4dd317 123
124
125// Class to generate particles from using paramtrized pT and y distributions.
126// Distributions are obtained from pointer to object of type AliGenLib.
127// (For example AliGenMUONlib)
128// Decays are performed using Pythia.
129// andreas.morsch@cern.ch
130
fe4da5cc 131#include "AliGenParam.h"
fa480368 132#include "AliDecayerPythia.h"
fe4da5cc 133#include "AliGenMUONlib.h"
134#include "AliRun.h"
1578254f 135#include <TParticle.h>
fa480368 136#include <TParticlePDG.h>
137#include <TDatabasePDG.h>
138#include <TLorentzVector.h>
139
f87cfe57 140#include <TF1.h>
fe4da5cc 141
142ClassImp(AliGenParam)
143
144//------------------------------------------------------------
145
146 //Begin_Html
147 /*
1439f98e 148 <img src="picts/AliGenParam.gif">
fe4da5cc 149 */
150 //End_Html
151
152//____________________________________________________________
153//____________________________________________________________
154AliGenParam::AliGenParam()
fe4da5cc 155{
b22ee262 156// Deafault constructor
157 fPtPara = 0;
158 fYPara = 0;
34f60c01 159 fParam = 0;
160 fAnalog = kAnalog;
b22ee262 161 SetDeltaPt();
675e9664 162//
163// Set random number generator
164 sRandom = fRandom;
2685bf00 165 fDecayer = 0;
8b31bfac 166
167
b22ee262 168}
169
fff02fee 170AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
b22ee262 171{
172// Constructor using number of particles parameterisation id and library
8b31bfac 173 fName = "Param";
174 fTitle= "Particle Generator using pT and y parameterisation";
b22ee262 175
176 fPtParaFunc = Library->GetPt(param, tname);
177 fYParaFunc = Library->GetY (param, tname);
178 fIpParaFunc = Library->GetIp(param, tname);
179
180 fPtPara = 0;
181 fYPara = 0;
182 fParam = param;
34f60c01 183 fAnalog = kAnalog;
b22ee262 184 SetForceDecay();
b22ee262 185 SetDeltaPt();
675e9664 186//
187// Set random number generator
188 sRandom = fRandom;
fe4da5cc 189}
190
191//____________________________________________________________
886b6f73 192
fff02fee 193AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
fe4da5cc 194{
b22ee262 195// Constructor using parameterisation id and number of particles
8b31bfac 196//
197 fName = "Param";
198 fTitle= "Particle Generator using pT and y parameterisation";
199
675e9664 200 AliGenLib* pLibrary = new AliGenMUONlib();
b22ee262 201
675e9664 202 fPtParaFunc = pLibrary->GetPt(param, tname);
203 fYParaFunc = pLibrary->GetY (param, tname);
204 fIpParaFunc = pLibrary->GetIp(param, tname);
b22ee262 205
206 fPtPara = 0;
207 fYPara = 0;
208 fParam = param;
34f60c01 209 fAnalog = kAnalog;
b22ee262 210 fChildSelect.Set(5);
211 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
212 SetForceDecay();
213 SetCutOnChild();
214 SetChildMomentumRange();
215 SetChildPtRange();
216 SetChildPhiRange();
217 SetChildThetaRange();
218 SetDeltaPt();
fe4da5cc 219}
220
34f60c01 221AliGenParam::AliGenParam(Int_t npart, Int_t param,
886b6f73 222 Double_t (*PtPara) (Double_t*, Double_t*),
223 Double_t (*YPara ) (Double_t* ,Double_t*),
65fb704d 224 Int_t (*IpPara) (TRandom *))
fff02fee 225 :AliGenMC(npart)
886b6f73 226{
749070b6 227// Constructor
28337bc1 228// Gines Martinez 1/10/99
8b31bfac 229 fName = "Param";
230 fTitle= "Particle Generator using pT and y parameterisation";
231
886b6f73 232 fPtParaFunc = PtPara;
233 fYParaFunc = YPara;
234 fIpParaFunc = IpPara;
28337bc1 235//
886b6f73 236 fPtPara = 0;
237 fYPara = 0;
238 fParam = param;
34f60c01 239 fAnalog = kAnalog;
886b6f73 240 fChildSelect.Set(5);
241 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
242 SetForceDecay();
243 SetCutOnChild();
749070b6 244 SetChildMomentumRange();
245 SetChildPtRange();
246 SetChildPhiRange();
247 SetChildThetaRange();
248 SetDeltaPt();
886b6f73 249}
250
f87cfe57 251
6d4dd317 252AliGenParam::AliGenParam(const AliGenParam & Param)
f87cfe57 253{
254// copy constructor
6d4dd317 255 Param.Copy(*this);
f87cfe57 256}
257
fe4da5cc 258//____________________________________________________________
259AliGenParam::~AliGenParam()
260{
749070b6 261// Destructor
fe4da5cc 262 delete fPtPara;
263 delete fYPara;
264}
265
266//____________________________________________________________
267void AliGenParam::Init()
268{
749070b6 269// Initialisation
fa480368 270
271 fDecayer = new AliDecayerPythia();
fe4da5cc 272 //Begin_Html
273 /*
1439f98e 274 <img src="picts/AliGenParam.gif">
fe4da5cc 275 */
276 //End_Html
277
749070b6 278 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
279// Set representation precision to 10 MeV
280 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
281
282 fPtPara->SetNpx(npx);
283
284 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
285 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
286 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
b7601ac4 287
fe4da5cc 288//
289// dN/dy| y=0
749070b6 290 Double_t y1=0;
291 Double_t y2=0;
292
293 fdNdy0=fYParaFunc(&y1,&y2);
fe4da5cc 294//
295// Integral over generation region
749070b6 296 Float_t intYS = yPara ->Integral(fYMin, fYMax);
297 Float_t intPt0 = ptPara->Integral(0,15);
298 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
299 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
34f60c01 300 if (fAnalog == kAnalog) {
749070b6 301 fYWgt = intYS/fdNdy0;
302 fPtWgt = intPtS/intPt0;
303 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
304 } else {
305 fYWgt = intYS/fdNdy0;
306 fPtWgt = (fPtMax-fPtMin)/intPt0;
307 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
308 }
fe4da5cc 309//
310// particle decay related initialization
00d6ce7d 311 fDecayer->SetForceDecay(fForceDecay);
fa480368 312 fDecayer->Init();
00d6ce7d 313
fe4da5cc 314//
fff02fee 315 AliGenMC::Init();
fe4da5cc 316}
317
318//____________________________________________________________
319void AliGenParam::Generate()
320{
28337bc1 321//
322// Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
323// Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
324// antineutrons in the the desired theta, phi and momentum windows;
325// Gaussian smearing on the vertex is done if selected.
cc5d764c 326// The decay of heavy mesons is done using lujet,
327// and the childern particle are tracked by GEANT
328// However, light mesons are directly tracked by GEANT
329// setting fForceDecay = nodecay (SetForceDecay(nodecay))
28337bc1 330//
771bbe45 331//
332// Reinitialize decayer
333 fDecayer->Init();
334//
28337bc1 335 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
336 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
337 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
338 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
339 Float_t p[3], pc[3],
fff02fee 340 och[3]; // Momentum, polarisation and origin of the children particles from lujet
2d7a47be 341 Double_t ty, xmt;
fff02fee 342 Int_t nt, i, j;
fe4da5cc 343 Float_t wgtp, wgtch;
344 Double_t dummy;
09fd3ea2 345 static TClonesArray *particles;
fe4da5cc 346 //
fff02fee 347 if(!particles) particles = new TClonesArray("TParticle",1000);
8b31bfac 348
349be858 349 TDatabasePDG *pDataBase = TDatabasePDG::Instance();
fe4da5cc 350 //
351 Float_t random[6];
28337bc1 352
353// Calculating vertex position per event
fe4da5cc 354 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
aee8290b 355 if(fVertexSmear==kPerEvent) {
d9ea0e3b 356 Vertex();
357 for (j=0;j<3;j++) origin0[j]=fVertex[j];
fe4da5cc 358 }
d9ea0e3b 359
21aaa175 360 Int_t ipa=0;
fff02fee 361
28337bc1 362// Generating fNpart particles
21aaa175 363 while (ipa<fNpart) {
cc5d764c 364 while(1) {
fe4da5cc 365//
366// particle type
65fb704d 367 Int_t iPart = fIpParaFunc(fRandom);
fa480368 368 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
675e9664 369 TParticlePDG *particle = pDataBase->GetParticle(iPart);
fa480368 370 Float_t am = particle->Mass();
8b31bfac 371
65fb704d 372 Rndm(random,2);
fe4da5cc 373//
374// phi
375 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
376//
377// y
2d7a47be 378 ty = TMath::TanH(fYPara->GetRandom());
fe4da5cc 379//
380// pT
34f60c01 381 if (fAnalog == kAnalog) {
fe4da5cc 382 pt=fPtPara->GetRandom();
383 wgtp=fParentWeight;
384 wgtch=fChildWeight;
385 } else {
386 pt=fPtMin+random[1]*(fPtMax-fPtMin);
387 Double_t ptd=pt;
388 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
389 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
390 }
391 xmt=sqrt(pt*pt+am*am);
2d7a47be 392 if (TMath::Abs(ty)==1.) {
393 ty=0.;
394 Fatal("AliGenParam",
395 "Division by 0: Please check you rapidity range !");
396 }
397
fe4da5cc 398 pl=xmt*ty/sqrt(1.-ty*ty);
399 theta=TMath::ATan2(pt,pl);
cc5d764c 400// Cut on theta
fe4da5cc 401 if(theta<fThetaMin || theta>fThetaMax) continue;
402 ptot=TMath::Sqrt(pt*pt+pl*pl);
cc5d764c 403// Cut on momentum
fe4da5cc 404 if(ptot<fPMin || ptot>fPMax) continue;
fff02fee 405//
fe4da5cc 406 p[0]=pt*TMath::Cos(phi);
407 p[1]=pt*TMath::Sin(phi);
408 p[2]=pl;
aee8290b 409 if(fVertexSmear==kPerTrack) {
65fb704d 410 Rndm(random,6);
fe4da5cc 411 for (j=0;j<3;j++) {
412 origin0[j]=
413 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
414 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
415 }
416 }
28337bc1 417
418// Looking at fForceDecay :
cc5d764c 419// if fForceDecay != none Primary particle decays using
420// AliPythia and children are tracked by GEANT
28337bc1 421//
cc5d764c 422// if fForceDecay == none Primary particle is tracked by GEANT
423// (In the latest, make sure that GEANT actually does all the decays you want)
fe4da5cc 424//
fff02fee 425
34f60c01 426 if (fForceDecay != kNoDecay) {
28337bc1 427// Using lujet to decay particle
886b6f73 428 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
fa480368 429 TLorentzVector pmom(p[0], p[1], p[2], energy);
430 fDecayer->Decay(iPart,&pmom);
fe4da5cc 431//
cc5d764c 432// select decay particles
fa480368 433 Int_t np=fDecayer->ImportParticles(particles);
1242532d 434
435 // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
436 if (fGeometryAcceptance)
437 if (!CheckAcceptanceGeometry(np,particles)) continue;
886b6f73 438 Int_t ncsel=0;
fff02fee 439 Int_t* pFlag = new Int_t[np];
440 Int_t* pParent = new Int_t[np];
441 Int_t* pSelected = new Int_t[np];
442 Int_t* trackIt = new Int_t[np];
443
444 for (i=0; i<np; i++) {
445 pFlag[i] = 0;
446 pSelected[i] = 0;
447 pParent[i] = -1;
448 }
449
6ba00c52 450 if (np >1) {
451 TParticle* iparticle = (TParticle *) particles->At(0);
fff02fee 452 Int_t ipF, ipL;
453 for (i = 1; i<np ; i++) {
454 trackIt[i] = 1;
6ba00c52 455 iparticle = (TParticle *) particles->At(i);
456 Int_t kf = iparticle->GetPdgCode();
fff02fee 457 Int_t ks = iparticle->GetStatusCode();
458// flagged particle
459
460 if (pFlag[i] == 1) {
fff02fee 461 ipF = iparticle->GetFirstDaughter();
462 ipL = iparticle->GetLastDaughter();
463 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
464 continue;
465 }
466
467// flag decay products of particles with long life-time (c tau > .3 mum)
468
469 if (ks != 1) {
2d7a47be 470// TParticlePDG *particle = pDataBase->GetParticle(kf);
fff02fee 471
472 Double_t lifeTime = fDecayer->GetLifetime(kf);
2d7a47be 473// Double_t mass = particle->Mass();
474// Double_t width = particle->Width();
47fc6bd5 475 if (lifeTime > (Double_t) fMaxLifeTime) {
fff02fee 476 ipF = iparticle->GetFirstDaughter();
477 ipL = iparticle->GetLastDaughter();
478 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
479 } else{
480 trackIt[i] = 0;
481 pSelected[i] = 1;
482 }
483 } // ks==1 ?
fe4da5cc 484//
485// children
47fc6bd5 486
fff02fee 487 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
6ba00c52 488 {
6ba00c52 489 if (fCutOnChild) {
fff02fee 490 pc[0]=iparticle->Px();
491 pc[1]=iparticle->Py();
492 pc[2]=iparticle->Pz();
493 Bool_t childok = KinematicSelection(iparticle, 1);
494 if(childok) {
495 pSelected[i] = 1;
6ba00c52 496 ncsel++;
497 } else {
498 ncsel=-1;
499 break;
500 } // child kine cuts
501 } else {
fff02fee 502 pSelected[i] = 1;
886b6f73 503 ncsel++;
6ba00c52 504 } // if child selection
505 } // select muon
506 } // decay particle loop
507 } // if decay products
508
886b6f73 509 Int_t iparent;
510 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
511 ipa++;
21aaa175 512//
fff02fee 513// Parent
a99cf51f 514 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
fff02fee 515 pParent[0] = nt;
a99cf51f 516 KeepTrack(nt);
fff02fee 517//
518// Decay Products
519//
520 for (i = 1; i < np; i++) {
521 if (pSelected[i]) {
522 TParticle* iparticle = (TParticle *) particles->At(i);
523 Int_t kf = iparticle->GetPdgCode();
524 Int_t ipa = iparticle->GetFirstMother()-1;
525
526 och[0] = origin0[0]+iparticle->Vx()/10;
527 och[1] = origin0[1]+iparticle->Vy()/10;
528 och[2] = origin0[2]+iparticle->Vz()/10;
529 pc[0] = iparticle->Px();
530 pc[1] = iparticle->Py();
531 pc[2] = iparticle->Pz();
532
533 if (ipa > -1) {
534 iparent = pParent[ipa];
535 } else {
536 iparent = -1;
537 }
1242532d 538
a99cf51f 539 SetTrack(fTrackIt*trackIt[i], iparent, kf,
fff02fee 540 pc, och, polar,
541 0, kPDecay, nt, wgtch);
542 pParent[i] = nt;
a99cf51f 543 KeepTrack(nt);
8b31bfac 544 } // Selected
545 } // Particle loop
28337bc1 546 } // Decays by Lujet
8b31bfac 547 particles->Clear();
fff02fee 548 if (pFlag) delete[] pFlag;
549 if (pParent) delete[] pParent;
550 if (pSelected) delete[] pSelected;
8b31bfac 551 if (trackIt) delete[] trackIt;
21aaa175 552 } // kinematic selection
28337bc1 553 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
554 {
555 gAlice->
65fb704d 556 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
28337bc1 557 ipa++;
558 }
fe4da5cc 559 break;
21aaa175 560 } // while
fe4da5cc 561 } // event loop
a99cf51f 562 SetHighWaterMark(nt);
fe4da5cc 563}
564
f87cfe57 565AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
566{
567// Assignment operator
568 return *this;
569}
570
fe4da5cc 571
572