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 1.26 2000/12/21 16:24:06 morsch
19 Coding convention clean-up
21 Revision 1.25 2000/11/30 07:12:50 alibrary
22 Introducing new Rndm and QA classes
24 Revision 1.24 2000/10/18 19:11:27 hristov
25 Division by zero fixed
27 Revision 1.23 2000/10/02 21:28:06 fca
28 Removal of useless dependecies via forward declarations
30 Revision 1.22 2000/09/12 14:14:55 morsch
31 Call fDecayer->ForceDecay() at the beginning of Generate().
33 Revision 1.21 2000/09/08 15:39:01 morsch
34 Handle the case fForceDecay=all during the generation, i.e. select all secondaries.
36 Revision 1.20 2000/09/06 14:35:44 morsch
37 Use AliDecayerPythia for particle decays.
39 Revision 1.19 2000/07/11 18:24:56 fca
40 Coding convention corrections + few minor bug fixes
42 Revision 1.18 2000/06/29 21:08:27 morsch
43 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
44 This allows to pass a pointer to a library directly to AliGenParam and avoids the
45 use of function pointers in Config.C.
47 Revision 1.17 2000/06/09 20:33:30 morsch
48 All coding rule violations except RS3 corrected
50 Revision 1.16 2000/05/02 07:51:31 morsch
51 - Control precision of pT sampling TF1::SetNpx(..)
52 - Correct initialisation of child-cuts in all constructors.
53 - Most coding rule violations corrected.
55 Revision 1.15 2000/04/03 15:42:12 morsch
56 Cuts on primary particles are separated from those on the decay products. Methods
57 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
59 Revision 1.14 1999/11/09 07:38:48 fca
60 Changes for compatibility with version 2.23 of ROOT
62 Revision 1.13 1999/11/04 11:30:31 fca
63 Correct the logics for SetForceDecay
65 Revision 1.12 1999/11/03 17:43:20 fca
66 New version from G.Martinez & A.Morsch
68 Revision 1.11 1999/09/29 09:24:14 fca
69 Introduction of the Copyright and cvs Log
73 #include "AliGenParam.h"
74 #include "AliDecayerPythia.h"
75 #include "AliGenMUONlib.h"
77 #include <TParticle.h>
78 #include <TParticlePDG.h>
79 #include <TDatabasePDG.h>
80 #include <TLorentzVector.h>
86 //------------------------------------------------------------
90 <img src="picts/AliGenParam.gif">
94 //____________________________________________________________
95 //____________________________________________________________
96 AliGenParam::AliGenParam()
98 // Deafault constructor
104 SetChildMomentumRange();
107 SetChildThetaRange();
110 // Set random number generator
114 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
116 // Constructor using number of particles parameterisation id and library
118 fPtParaFunc = Library->GetPt(param, tname);
119 fYParaFunc = Library->GetY (param, tname);
120 fIpParaFunc = Library->GetIp(param, tname);
127 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
130 SetChildMomentumRange();
133 SetChildThetaRange();
136 // Set random number generator
140 //____________________________________________________________
142 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
144 // Constructor using parameterisation id and number of particles
146 AliGenLib* pLibrary = new AliGenMUONlib();
148 fPtParaFunc = pLibrary->GetPt(param, tname);
149 fYParaFunc = pLibrary->GetY (param, tname);
150 fIpParaFunc = pLibrary->GetIp(param, tname);
157 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
160 SetChildMomentumRange();
163 SetChildThetaRange();
167 AliGenParam::AliGenParam(Int_t npart, Param_t param,
168 Double_t (*PtPara) (Double_t*, Double_t*),
169 Double_t (*YPara ) (Double_t* ,Double_t*),
170 Int_t (*IpPara) (TRandom *))
174 // Gines Martinez 1/10/99
175 fPtParaFunc = PtPara;
177 fIpParaFunc = IpPara;
184 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
187 SetChildMomentumRange();
190 SetChildThetaRange();
195 AliGenParam::AliGenParam(const AliGenParam & Paramd)
200 //____________________________________________________________
201 AliGenParam::~AliGenParam()
208 //____________________________________________________________
209 void AliGenParam::Init()
213 fDecayer = new AliDecayerPythia();
216 <img src="picts/AliGenParam.gif">
220 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
221 // Set representation precision to 10 MeV
222 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
224 fPtPara->SetNpx(npx);
226 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
227 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
228 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
235 fdNdy0=fYParaFunc(&y1,&y2);
237 // Integral over generation region
238 Float_t intYS = yPara ->Integral(fYMin, fYMax);
239 Float_t intPt0 = ptPara->Integral(0,15);
240 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
241 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
242 if (fAnalog == analog) {
243 fYWgt = intYS/fdNdy0;
244 fPtWgt = intPtS/intPt0;
245 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
247 fYWgt = intYS/fdNdy0;
248 fPtWgt = (fPtMax-fPtMin)/intPt0;
249 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
252 // particle decay related initialization
253 fDecayer->SetForceDecay(fForceDecay);
261 case b_jpsi_dielectron:
262 case b_psip_dielectron:
287 //____________________________________________________________
288 void AliGenParam::Generate()
291 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
292 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
293 // antineutrons in the the desired theta, phi and momentum windows;
294 // Gaussian smearing on the vertex is done if selected.
295 // The decay of heavy mesons is done using lujet,
296 // and the childern particle are tracked by GEANT
297 // However, light mesons are directly tracked by GEANT
298 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
301 fDecayer->ForceDecay();
302 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
303 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
304 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
305 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
307 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
309 Int_t nt, i, j, kfch[10];
312 static TClonesArray *particles;
314 if(!particles) particles=new TClonesArray("TParticle",1000);
316 static TDatabasePDG *pDataBase = new TDatabasePDG();
317 if(!pDataBase) pDataBase = new TDatabasePDG();
321 // Calculating vertex position per event
322 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
323 if(fVertexSmear==kPerEvent) {
325 // for (j=0;j<3;j++) {
326 // origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
327 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
328 // TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
332 for (j=0;j<3;j++) origin0[j]=fVertex[j];
336 // Generating fNpart particles
341 Int_t iPart = fIpParaFunc(fRandom);
342 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
343 TParticlePDG *particle = pDataBase->GetParticle(iPart);
344 Float_t am = particle->Mass();
349 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
352 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
355 if (fAnalog == analog) {
356 pt=fPtPara->GetRandom();
360 pt=fPtMin+random[1]*(fPtMax-fPtMin);
362 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
363 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
365 xmt=sqrt(pt*pt+am*am);
366 if (TMath::Abs(ty)==1) ty=0;
367 pl=xmt*ty/sqrt(1.-ty*ty);
368 theta=TMath::ATan2(pt,pl);
370 if(theta<fThetaMin || theta>fThetaMax) continue;
371 ptot=TMath::Sqrt(pt*pt+pl*pl);
373 if(ptot<fPMin || ptot>fPMax) continue;
374 p[0]=pt*TMath::Cos(phi);
375 p[1]=pt*TMath::Sin(phi);
377 if(fVertexSmear==kPerTrack) {
381 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
382 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
386 // Looking at fForceDecay :
387 // if fForceDecay != none Primary particle decays using
388 // AliPythia and children are tracked by GEANT
390 // if fForceDecay == none Primary particle is tracked by GEANT
391 // (In the latest, make sure that GEANT actually does all the decays you want)
393 if (fForceDecay != nodecay) {
394 // Using lujet to decay particle
395 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
396 TLorentzVector pmom(p[0], p[1], p[2], energy);
397 fDecayer->Decay(iPart,&pmom);
399 // select decay particles
400 Int_t np=fDecayer->ImportParticles(particles);
402 for (i = 1; i<np; i++) {
403 TParticle * iparticle = (TParticle *) particles->At(i);
404 Int_t kf = iparticle->GetPdgCode();
407 if (ChildSelected(TMath::Abs(kf)) || fForceDecay==all)
409 pc[0]=iparticle->Px();
410 pc[1]=iparticle->Py();
411 pc[2]=iparticle->Pz();
412 och[0]=origin0[0]+iparticle->Vx()/10;
413 och[1]=origin0[1]+iparticle->Vy()/10;
414 och[2]=origin0[2]+iparticle->Vz()/10;
416 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
417 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
418 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
419 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
421 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
422 (pChild > fChildPMin && pChild <fChildPMax) &&
423 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
424 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
442 } // if child selection
444 } // decay particle loop
446 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
451 SetTrack(0,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
453 gAlice->KeepTrack(nt);
454 for (i=0; i< ncsel; i++) {
455 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
456 &pch[i][0],och,polar,
458 gAlice->KeepTrack(nt);
461 } // kinematic selection
462 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
465 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
471 gAlice->SetHighWaterMark(nt);
475 Bool_t AliGenParam::ChildSelected(Int_t ip)
477 // True if particle is in list of selected children
478 for (Int_t i=0; i<5; i++)
480 if (fChildSelect[i]==ip) return kTRUE;
485 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
487 // Perform kinematic cuts
488 Float_t px=particle->Px();
489 Float_t py=particle->Py();
490 Float_t pz=particle->Pz();
493 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
494 if (p > fPMax || p < fPMin)
496 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
499 Float_t pt=TMath::Sqrt(px*px+py*py);
503 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
504 if (theta > fThetaMax || theta < fThetaMin)
506 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
514 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
516 // Assignment operator