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