1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 Revision 1.31 2001/07/13 10:58:54 morsch
19 - Some coded moved to AliGenMC
20 - Improved handling of secondary vertices.
22 Revision 1.30 2001/06/15 07:55:04 morsch
23 Put only first generation decay products on the stack.
25 Revision 1.29 2001/03/27 10:58:41 morsch
26 Initialize decayer before generation. Important if run inside cocktail.
28 Revision 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
32 Revision 1.27 2001/02/02 15:21:10 morsch
33 Set high water mark after last particle.
34 Use Vertex() method for Vertex.
36 Revision 1.26 2000/12/21 16:24:06 morsch
37 Coding convention clean-up
39 Revision 1.25 2000/11/30 07:12:50 alibrary
40 Introducing new Rndm and QA classes
42 Revision 1.24 2000/10/18 19:11:27 hristov
43 Division by zero fixed
45 Revision 1.23 2000/10/02 21:28:06 fca
46 Removal of useless dependecies via forward declarations
48 Revision 1.22 2000/09/12 14:14:55 morsch
49 Call fDecayer->ForceDecay() at the beginning of Generate().
51 Revision 1.21 2000/09/08 15:39:01 morsch
52 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
54 Revision 1.20 2000/09/06 14:35:44 morsch
55 Use AliDecayerPythia for particle decays.
57 Revision 1.19 2000/07/11 18:24:56 fca
58 Coding convention corrections + few minor bug fixes
60 Revision 1.18 2000/06/29 21:08:27 morsch
61 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
62 This allows to pass a pointer to a library directly to AliGenParam and avoids the
63 use of function pointers in Config.C.
65 Revision 1.17 2000/06/09 20:33:30 morsch
66 All coding rule violations except RS3 corrected
68 Revision 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.
73 Revision 1.15 2000/04/03 15:42:12 morsch
74 Cuts on primary particles are separated from those on the decay products. Methods
75 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
77 Revision 1.14 1999/11/09 07:38:48 fca
78 Changes for compatibility with version 2.23 of ROOT
80 Revision 1.13 1999/11/04 11:30:31 fca
81 Correct the logics for SetForceDecay
83 Revision 1.12 1999/11/03 17:43:20 fca
84 New version from G.Martinez & A.Morsch
86 Revision 1.11 1999/09/29 09:24:14 fca
87 Introduction of the Copyright and cvs Log
91 #include "AliGenParam.h"
92 #include "AliDecayerPythia.h"
93 #include "AliGenMUONlib.h"
95 #include <TParticle.h>
96 #include <TParticlePDG.h>
97 #include <TDatabasePDG.h>
98 #include <TLorentzVector.h>
102 ClassImp(AliGenParam)
104 //------------------------------------------------------------
108 <img src="picts/AliGenParam.gif">
112 //____________________________________________________________
113 //____________________________________________________________
114 AliGenParam::AliGenParam()
116 // Deafault constructor
123 // Set random number generator
127 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
129 // Constructor using number of particles parameterisation id and library
131 fPtParaFunc = Library->GetPt(param, tname);
132 fYParaFunc = Library->GetY (param, tname);
133 fIpParaFunc = Library->GetIp(param, tname);
142 // Set random number generator
146 //____________________________________________________________
148 AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
150 // Constructor using parameterisation id and number of particles
152 AliGenLib* pLibrary = new AliGenMUONlib();
154 fPtParaFunc = pLibrary->GetPt(param, tname);
155 fYParaFunc = pLibrary->GetY (param, tname);
156 fIpParaFunc = pLibrary->GetIp(param, tname);
163 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
166 SetChildMomentumRange();
169 SetChildThetaRange();
173 AliGenParam::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 *))
180 // Gines Martinez 1/10/99
181 fPtParaFunc = PtPara;
183 fIpParaFunc = IpPara;
190 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
193 SetChildMomentumRange();
196 SetChildThetaRange();
201 AliGenParam::AliGenParam(const AliGenParam & Paramd)
206 //____________________________________________________________
207 AliGenParam::~AliGenParam()
214 //____________________________________________________________
215 void AliGenParam::Init()
219 fDecayer = new AliDecayerPythia();
222 <img src="picts/AliGenParam.gif">
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);
230 fPtPara->SetNpx(npx);
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);
241 fdNdy0=fYParaFunc(&y1,&y2);
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;
253 fYWgt = intYS/fdNdy0;
254 fPtWgt = (fPtMax-fPtMin)/intPt0;
255 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
258 // particle decay related initialization
259 fDecayer->SetForceDecay(fForceDecay);
266 //____________________________________________________________
267 void AliGenParam::Generate()
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))
280 // Reinitialize decayer
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
288 och[3]; // Momentum, polarisation and origin of the children particles from lujet
293 static TClonesArray *particles;
295 if(!particles) particles = new TClonesArray("TParticle",1000);
297 static TDatabasePDG *pDataBase = new TDatabasePDG();
298 if(!pDataBase) pDataBase = new TDatabasePDG();
302 // Calculating vertex position per event
303 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
304 if(fVertexSmear==kPerEvent) {
306 for (j=0;j<3;j++) origin0[j]=fVertex[j];
311 // Generating fNpart particles
316 Int_t iPart = fIpParaFunc(fRandom);
317 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
318 TParticlePDG *particle = pDataBase->GetParticle(iPart);
319 Float_t am = particle->Mass();
324 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
327 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
330 if (fAnalog == kAnalog) {
331 pt=fPtPara->GetRandom();
335 pt=fPtMin+random[1]*(fPtMax-fPtMin);
337 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
338 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
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);
345 if(theta<fThetaMin || theta>fThetaMax) continue;
346 ptot=TMath::Sqrt(pt*pt+pl*pl);
348 if(ptot<fPMin || ptot>fPMax) continue;
350 p[0]=pt*TMath::Cos(phi);
351 p[1]=pt*TMath::Sin(phi);
353 if(fVertexSmear==kPerTrack) {
357 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
358 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
362 // Looking at fForceDecay :
363 // if fForceDecay != none Primary particle decays using
364 // AliPythia and children are tracked by GEANT
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)
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);
376 // select decay particles
377 Int_t np=fDecayer->ImportParticles(particles);
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];
384 for (i=0; i<np; i++) {
391 TParticle* iparticle = (TParticle *) particles->At(0);
393 for (i = 1; i<np ; i++) {
395 iparticle = (TParticle *) particles->At(i);
396 Int_t kf = iparticle->GetPdgCode();
397 Int_t ks = iparticle->GetStatusCode();
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;
408 // flag decay products of particles with long life-time (c tau > .3 mum)
411 TParticlePDG *particle = pDataBase->GetParticle(kf);
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;
428 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
431 pc[0]=iparticle->Px();
432 pc[1]=iparticle->Py();
433 pc[2]=iparticle->Pz();
434 Bool_t childok = KinematicSelection(iparticle, 1);
445 } // if child selection
447 } // decay particle loop
448 } // if decay products
451 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
455 SetTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
461 for (i = 1; i < np; i++) {
463 TParticle* iparticle = (TParticle *) particles->At(i);
464 Int_t kf = iparticle->GetPdgCode();
465 Int_t ipa = iparticle->GetFirstMother()-1;
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();
475 iparent = pParent[ipa];
479 printf("\n SetTrack %d %d %d %d", i, kf, iparent, trackIt[i]);
480 SetTrack(fTrackIt*trackIt[i], iparent, kf,
482 0, kPDecay, nt, wgtch);
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)
497 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
503 SetHighWaterMark(nt);
506 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
508 // Assignment operator