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