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 1.18 2000/06/29 21:08:27 morsch
19 All paramatrisation libraries derive from the pure virtual base class AliGenLib.
20 This allows to pass a pointer to a library directly to AliGenParam and avoids the
21 use of function pointers in Config.C.
23 Revision 1.17 2000/06/09 20:33:30 morsch
24 All coding rule violations except RS3 corrected
26 Revision 1.16 2000/05/02 07:51:31 morsch
27 - Control precision of pT sampling TF1::SetNpx(..)
28 - Correct initialisation of child-cuts in all constructors.
29 - Most coding rule violations corrected.
31 Revision 1.15 2000/04/03 15:42:12 morsch
32 Cuts on primary particles are separated from those on the decay products. Methods
33 SetChildMomentumRange, SetChildPtRange, SetChildPhiRange, SetChildThetaRange added.
35 Revision 1.14 1999/11/09 07:38:48 fca
36 Changes for compatibility with version 2.23 of ROOT
38 Revision 1.13 1999/11/04 11:30:31 fca
39 Correct the logics for SetForceDecay
41 Revision 1.12 1999/11/03 17:43:20 fca
42 New version from G.Martinez & A.Morsch
44 Revision 1.11 1999/09/29 09:24:14 fca
45 Introduction of the Copyright and cvs Log
49 #include "AliGenParam.h"
50 #include "AliGenMUONlib.h"
52 #include "AliPythia.h"
53 #include <TParticle.h>
58 //------------------------------------------------------------
62 <img src="picts/AliGenParam.gif">
66 //____________________________________________________________
67 //____________________________________________________________
68 AliGenParam::AliGenParam()
71 // Deafault constructor
77 SetChildMomentumRange();
84 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Param_t param, char* tname):AliGenerator(npart)
86 // Constructor using number of particles parameterisation id and library
88 fPtParaFunc = Library->GetPt(param, tname);
89 fYParaFunc = Library->GetY (param, tname);
90 fIpParaFunc = Library->GetIp(param, tname);
97 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
100 SetChildMomentumRange();
103 SetChildThetaRange();
107 //____________________________________________________________
109 AliGenParam::AliGenParam(Int_t npart, Param_t param, char* tname):AliGenerator(npart)
111 // Constructor using parameterisation id and number of particles
113 AliGenLib* Library = new AliGenMUONlib();
115 fPtParaFunc = Library->GetPt(param, tname);
116 fYParaFunc = Library->GetY (param, tname);
117 fIpParaFunc = Library->GetIp(param, tname);
124 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
127 SetChildMomentumRange();
130 SetChildThetaRange();
134 AliGenParam::AliGenParam(Int_t npart, Param_t param,
135 Double_t (*PtPara) (Double_t*, Double_t*),
136 Double_t (*YPara ) (Double_t* ,Double_t*),
141 // Gines Martinez 1/10/99
142 fPtParaFunc = PtPara;
144 fIpParaFunc = IpPara;
151 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
154 SetChildMomentumRange();
157 SetChildThetaRange();
162 AliGenParam::AliGenParam(const AliGenParam & Paramd)
167 //____________________________________________________________
168 AliGenParam::~AliGenParam()
175 //____________________________________________________________
176 void AliGenParam::Init()
179 SetMC(new AliPythia());
180 fPythia= (AliPythia*) fgMCEvGen;
184 <img src="picts/AliGenParam.gif">
188 fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
189 // Set representation precision to 10 MeV
190 Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
192 fPtPara->SetNpx(npx);
194 fYPara = new TF1("Y -Parametrization",fYParaFunc,fYMin,fYMax,0);
195 TF1* ptPara = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
196 TF1* yPara = new TF1("Y -Parametrization",fYParaFunc,-6,6,0);
203 fdNdy0=fYParaFunc(&y1,&y2);
205 // Integral over generation region
206 Float_t intYS = yPara ->Integral(fYMin, fYMax);
207 Float_t intPt0 = ptPara->Integral(0,15);
208 Float_t intPtS = ptPara->Integral(fPtMin,fPtMax);
209 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
210 if (fAnalog == analog) {
211 fYWgt = intYS/fdNdy0;
212 fPtWgt = intPtS/intPt0;
213 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
215 fYWgt = intYS/fdNdy0;
216 fPtWgt = (fPtMax-fPtMin)/intPt0;
217 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
220 // particle decay related initialization
221 fPythia->DefineParticles();
222 // semimuonic decays of charm and beauty
223 fPythia->ForceDecay(fForceDecay);
229 case b_jpsi_dielectron:
230 case b_psip_dielectron:
252 //____________________________________________________________
253 void AliGenParam::Generate()
256 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
257 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
258 // antineutrons in the the desired theta, phi and momentum windows;
259 // Gaussian smearing on the vertex is done if selected.
260 // The decay of heavy mesons is done using lujet,
261 // and the childern particle are tracked by GEANT
262 // However, light mesons are directly tracked by GEANT
263 // setting fForceDecay = nodecay (SetForceDecay(nodecay))
267 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
268 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
269 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
270 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
272 och[3], pch[10][3]; // Momentum, polarisation and origin of the children particles from lujet
274 Int_t nt, i, j, kfch[10];
277 static TClonesArray *particles;
279 if(!particles) particles=new TClonesArray("TParticle",1000);
283 // Calculating vertex position per event
284 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
285 if(fVertexSmear==kPerEvent) {
288 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
289 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
293 // Generating fNpart particles
298 Int_t iPart = fIpParaFunc();
299 fChildWeight=(fPythia->GetBraPart(iPart))*fParentWeight;
300 Float_t am=fPythia->GetPMAS(fPythia->Lucomp(iPart),1);
304 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
307 ty=Float_t(TMath::TanH(fYPara->GetRandom()));
310 if (fAnalog == analog) {
311 pt=fPtPara->GetRandom();
315 pt=fPtMin+random[1]*(fPtMax-fPtMin);
317 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
318 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
320 xmt=sqrt(pt*pt+am*am);
321 pl=xmt*ty/sqrt(1.-ty*ty);
322 theta=TMath::ATan2(pt,pl);
324 if(theta<fThetaMin || theta>fThetaMax) continue;
325 ptot=TMath::Sqrt(pt*pt+pl*pl);
327 if(ptot<fPMin || ptot>fPMax) continue;
328 p[0]=pt*TMath::Cos(phi);
329 p[1]=pt*TMath::Sin(phi);
331 if(fVertexSmear==kPerTrack) {
335 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
336 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
340 // Looking at fForceDecay :
341 // if fForceDecay != none Primary particle decays using
342 // AliPythia and children are tracked by GEANT
344 // if fForceDecay == none Primary particle is tracked by GEANT
345 // (In the latest, make sure that GEANT actually does all the decays you want)
347 if (fForceDecay != nodecay) {
348 // Using lujet to decay particle
349 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
350 fPythia->DecayParticle(iPart,energy,theta,phi);
352 // select decay particles
353 Int_t np=fPythia->ImportParticles(particles,"All");
355 for (i = 1; i<np; i++) {
356 TParticle * iparticle = (TParticle *) particles->At(i);
357 Int_t kf = iparticle->GetPdgCode();
360 if (ChildSelected(TMath::Abs(kf)))
362 pc[0]=iparticle->Px();
363 pc[1]=iparticle->Py();
364 pc[2]=iparticle->Pz();
365 och[0]=origin0[0]+iparticle->Vx()/10;
366 och[1]=origin0[1]+iparticle->Vy()/10;
367 och[2]=origin0[2]+iparticle->Vz()/10;
369 Float_t ptChild=TMath::Sqrt(pc[0]*pc[0]+pc[1]*pc[1]);
370 Float_t pChild=TMath::Sqrt(ptChild*ptChild+pc[2]*pc[2]);
371 Float_t thetaChild=TMath::ATan2(ptChild,pc[2]);
372 Float_t phiChild=TMath::ATan2(pc[1],pc[0]);
374 ((ptChild > fChildPtMin && ptChild <fChildPtMax) &&
375 (pChild > fChildPMin && pChild <fChildPMax) &&
376 (thetaChild > fChildThetaMin && thetaChild <fChildThetaMax) &&
377 (phiChild > fChildPhiMin && phiChild <fChildPhiMax));
395 } // if child selection
397 } // decay particle loop
399 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
404 SetTrack(0,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
406 gAlice->KeepTrack(nt);
407 for (i=0; i< ncsel; i++) {
408 gAlice->SetTrack(fTrackIt,iparent,kfch[i],
409 &pch[i][0],och,polar,
411 gAlice->KeepTrack(nt);
414 } // kinematic selection
415 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
418 SetTrack(fTrackIt,-1,iPart,p,origin0,polar,0,"Primary",nt,wgtp);
426 Bool_t AliGenParam::ChildSelected(Int_t ip)
428 // True if particle is in list of selected children
429 for (Int_t i=0; i<5; i++)
431 if (fChildSelect[i]==ip) return kTRUE;
436 Bool_t AliGenParam::KinematicSelection(TParticle *particle)
438 // Perform kinematic cuts
439 Float_t px=particle->Px();
440 Float_t py=particle->Py();
441 Float_t pz=particle->Pz();
444 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
445 if (p > fPMax || p < fPMin)
447 // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
450 Float_t pt=TMath::Sqrt(px*px+py*py);
454 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(p)));
455 if (theta > fThetaMax || theta < fThetaMin)
457 // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
465 AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
467 // Assignment operator