Coding Convention Violation correction
[u/mrichter/AliRoot.git] / EVGEN / AliGenParam.cxx
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 /* $Id$ */
17
18 // Class to generate particles from using paramtrized pT and y distributions.
19 // Distributions are obtained from pointer to object of type AliGenLib.
20 // (For example AliGenMUONlib)
21 // Decays are performed using Pythia.
22 // andreas.morsch@cern.ch
23
24 #include <TCanvas.h>
25 #include <TDatabasePDG.h>
26 #include <TF1.h>
27 #include <TH1F.h>
28 #include <TLorentzVector.h>
29 #include <TMath.h>
30 #include <TParticle.h>
31 #include <TParticlePDG.h>
32 #include <TROOT.h>
33 #include <TVirtualMC.h>
34
35 #include "AliDecayer.h"
36 #include "AliGenMUONlib.h"
37 #include "AliGenParam.h"
38 #include "AliMC.h"
39 #include "AliRun.h"
40
41 ClassImp(AliGenParam)
42
43 //------------------------------------------------------------
44
45   //Begin_Html
46   /*
47     <img src="picts/AliGenParam.gif">
48   */
49   //End_Html
50
51 //____________________________________________________________
52 AliGenParam::AliGenParam()
53 {
54 // Deafault constructor
55     fPtPara = 0;
56     fYPara  = 0;
57     fParam  = 0;
58     fAnalog = kAnalog;
59     SetDeltaPt();
60     fDecayer = 0;
61
62
63 }
64 //____________________________________________________________
65 AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library,  Int_t param, char* tname):AliGenMC(npart)
66 {
67 // Constructor using number of particles parameterisation id and library
68     fName = "Param";
69     fTitle= "Particle Generator using pT and y parameterisation";
70     
71     fPtParaFunc = Library->GetPt(param, tname);
72     fYParaFunc  = Library->GetY (param, tname);
73     fIpParaFunc = Library->GetIp(param, tname);
74     
75     fPtPara = 0;
76     fYPara  = 0;
77     fParam  = param;
78     fAnalog = kAnalog;
79     SetForceDecay();
80     SetDeltaPt(); 
81 }
82 //____________________________________________________________
83 AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char* name):AliGenMC(npart)
84 {
85 // Constructor using parameterisation id and number of particles
86 //
87   fName = name;
88   fTitle= "Particle Generator using pT and y parameterisation";
89       
90     AliGenLib* pLibrary = new AliGenMUONlib();
91  
92     fPtParaFunc = pLibrary->GetPt(param, tname);
93     fYParaFunc  = pLibrary->GetY (param, tname);
94     fIpParaFunc = pLibrary->GetIp(param, tname);
95     
96     fPtPara = 0;
97     fYPara  = 0;
98     fParam  = param;
99     fAnalog = kAnalog;
100     fChildSelect.Set(5);
101     for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
102     SetForceDecay();
103     SetCutOnChild();
104     SetChildMomentumRange();
105     SetChildPtRange();
106     SetChildPhiRange();
107     SetChildThetaRange(); 
108     SetDeltaPt(); 
109 }
110 //____________________________________________________________
111
112 AliGenParam::AliGenParam(Int_t npart, Int_t param,
113                          Double_t (*PtPara) (Double_t*, Double_t*),
114                          Double_t (*YPara ) (Double_t* ,Double_t*),
115                          Int_t    (*IpPara) (TRandom *))                 
116     :AliGenMC(npart)
117 {
118 // Constructor
119 // Gines Martinez 1/10/99 
120     fName = "Param";
121     fTitle= "Particle Generator using pT and y parameterisation";
122
123     fPtParaFunc = PtPara; 
124     fYParaFunc  = YPara;  
125     fIpParaFunc = IpPara;
126 //  
127     fPtPara = 0;
128     fYPara  = 0;
129     fParam  = param;
130     fAnalog = kAnalog;
131     fChildSelect.Set(5);
132     for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
133     SetForceDecay();
134     SetCutOnChild();
135     SetChildMomentumRange();
136     SetChildPtRange();
137     SetChildPhiRange();
138     SetChildThetaRange();  
139     SetDeltaPt();
140 }
141
142
143 AliGenParam::AliGenParam(const AliGenParam & Param)
144     :AliGenMC(Param)
145 {
146 // Copy constructor
147     Param.Copy(*this);
148 }
149
150 //____________________________________________________________
151 AliGenParam::~AliGenParam()
152 {
153 // Destructor
154     delete  fPtPara;
155     delete  fYPara;
156 }
157
158 //____________________________________________________________
159 void AliGenParam::Init()
160 {
161 // Initialisation
162
163     if (gMC) fDecayer = gMC->GetDecayer();
164   //Begin_Html
165   /*
166     <img src="picts/AliGenParam.gif">
167   */
168   //End_Html
169     char name[256];
170     sprintf(name, "pt-parameterisation for %s", GetName());
171     
172     if (fPtPara) fPtPara->Delete();
173     fPtPara = new TF1(name, fPtParaFunc, fPtMin, fPtMax,0);
174     gROOT->GetListOfFunctions()->Remove(fPtPara);
175 //  Set representation precision to 10 MeV
176     Int_t npx= Int_t((fPtMax - fPtMin) / fDeltaPt);
177     
178     fPtPara->SetNpx(npx);
179
180     sprintf(name, "y-parameterisation  for %s", GetName());
181     if (fYPara) fYPara->Delete();
182     fYPara  = new TF1(name, fYParaFunc, fYMin, fYMax, 0);
183     gROOT->GetListOfFunctions()->Remove(fYPara);
184
185     
186     sprintf(name, "pt-for-%s", GetName());
187     TF1 ptPara(name ,fPtParaFunc, 0, 15, 0);
188     sprintf(name, "y-for-%s", GetName());
189     TF1 yPara(name, fYParaFunc, -6, 6, 0);
190
191 //
192 // dN/dy| y=0
193     Double_t y1=0;
194     Double_t y2=0;
195     
196     fdNdy0=fYParaFunc(&y1,&y2);
197 //
198 // Integral over generation region
199     Float_t intYS  = yPara.Integral(fYMin, fYMax);
200     Float_t intPt0 = ptPara.Integral(0,15);
201     Float_t intPtS = ptPara.Integral(fPtMin,fPtMax);
202     Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
203     if (fAnalog == kAnalog) {
204         fYWgt  = intYS/fdNdy0;
205         fPtWgt = intPtS/intPt0;
206         fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
207     } else {
208         fYWgt = intYS/fdNdy0;
209         fPtWgt = (fPtMax-fPtMin)/intPt0;
210         fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
211     }
212 //
213 // particle decay related initialization
214     fDecayer->SetForceDecay(fForceDecay);
215     fDecayer->Init();
216
217 //
218     AliGenMC::Init();
219 }
220
221 //____________________________________________________________
222 void AliGenParam::Generate()
223 {
224 //
225 // Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
226 // Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and 
227 // antineutrons in the the desired theta, phi and momentum windows; 
228 // Gaussian smearing on the vertex is done if selected. 
229 // The decay of heavy mesons is done using lujet, 
230 //    and the childern particle are tracked by GEANT
231 // However, light mesons are directly tracked by GEANT 
232 // setting fForceDecay = nodecay (SetForceDecay(nodecay)) 
233 //
234 //
235 //  Reinitialize decayer
236   fDecayer->SetForceDecay(fForceDecay);
237   fDecayer->Init();
238
239 //
240   Float_t polar[3]= {0,0,0};  // Polarisation of the parent particle (for GEANT tracking)
241   Float_t origin0[3];         // Origin of the generated parent particle (for GEANT tracking)
242   Float_t pt, pl, ptot;       // Transverse, logitudinal and total momenta of the parent particle
243   Float_t phi, theta;         // Phi and theta spherical angles of the parent particle momentum
244   Float_t p[3], pc[3], 
245           och[3];             // Momentum, polarisation and origin of the children particles from lujet
246   Double_t ty, xmt;
247   Int_t nt, i, j;
248   Float_t  wgtp, wgtch;
249   Double_t dummy;
250   static TClonesArray *particles;
251   //
252   if(!particles) particles = new TClonesArray("TParticle",1000);
253   
254   TDatabasePDG *pDataBase = TDatabasePDG::Instance();
255   //
256   Float_t random[6];
257  
258 // Calculating vertex position per event
259   for (j=0;j<3;j++) origin0[j]=fOrigin[j];
260   if(fVertexSmear==kPerEvent) {
261       Vertex();
262       for (j=0;j<3;j++) origin0[j]=fVertex[j];
263   }
264   
265   Int_t ipa=0;
266   
267 // Generating fNpart particles
268   while (ipa<fNpart) {
269       while(1) {
270 //
271 // particle type 
272           Int_t iPart = fIpParaFunc(fRandom);
273           fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;          
274           TParticlePDG *particle = pDataBase->GetParticle(iPart);
275           Float_t am = particle->Mass();
276           
277           Rndm(random,2);
278 //
279 // phi
280           phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
281 //
282 // y
283           ty = TMath::TanH(fYPara->GetRandom());
284 //
285 // pT
286           if (fAnalog == kAnalog) {
287               pt=fPtPara->GetRandom();
288               wgtp=fParentWeight;
289               wgtch=fChildWeight;
290           } else {
291               pt=fPtMin+random[1]*(fPtMax-fPtMin);
292               Double_t ptd=pt;
293               wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
294               wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
295           }
296           xmt=sqrt(pt*pt+am*am);
297           if (TMath::Abs(ty)==1.) {
298               ty=0.;
299               Fatal("AliGenParam", 
300                     "Division by 0: Please check you rapidity range !");
301           }
302           
303           pl=xmt*ty/sqrt(1.-ty*ty);
304           theta=TMath::ATan2(pt,pl);
305 // Cut on theta
306           if(theta<fThetaMin || theta>fThetaMax) continue;
307           ptot=TMath::Sqrt(pt*pt+pl*pl);
308 // Cut on momentum
309           if(ptot<fPMin || ptot>fPMax) continue;
310 //
311           p[0]=pt*TMath::Cos(phi);
312           p[1]=pt*TMath::Sin(phi);
313           p[2]=pl;
314           if(fVertexSmear==kPerTrack) {
315               Rndm(random,6);
316               for (j=0;j<3;j++) {
317                   origin0[j]=
318                       fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
319                       TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
320               }
321           }
322           
323 // Looking at fForceDecay : 
324 // if fForceDecay != none Primary particle decays using 
325 // AliPythia and children are tracked by GEANT
326 //
327 // if fForceDecay == none Primary particle is tracked by GEANT 
328 // (In the latest, make sure that GEANT actually does all the decays you want)    
329 //
330
331           if (fForceDecay != kNoDecay) {
332 // Using lujet to decay particle
333               Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
334               TLorentzVector pmom(p[0], p[1], p[2], energy);
335               fDecayer->Decay(iPart,&pmom);
336 //
337 // select decay particles
338               Int_t np=fDecayer->ImportParticles(particles);
339
340               //  Selecting  GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
341               if (fGeometryAcceptance) 
342                 if (!CheckAcceptanceGeometry(np,particles)) continue;
343               Int_t ncsel=0;
344               Int_t* pFlag      = new Int_t[np];
345               Int_t* pParent    = new Int_t[np];
346               Int_t* pSelected  = new Int_t[np];
347               Int_t* trackIt    = new Int_t[np];
348
349               for (i=0; i<np; i++) {
350                   pFlag[i]     =  0;
351                   pSelected[i] =  0;
352                   pParent[i]   = -1;
353               }
354               
355               if (np >1) {
356                   TParticle* iparticle =  (TParticle *) particles->At(0);
357                   Int_t ipF, ipL;
358                   for (i = 1; i<np ; i++) {
359                       trackIt[i] = 1;
360                       iparticle = (TParticle *) particles->At(i);
361                       Int_t kf = iparticle->GetPdgCode();
362                       Int_t ks = iparticle->GetStatusCode();
363 // flagged particle
364
365                       if (pFlag[i] == 1) {
366                           ipF = iparticle->GetFirstDaughter();
367                           ipL = iparticle->GetLastDaughter();   
368                           if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
369                           continue;
370                       }
371
372 // flag decay products of particles with long life-time (c tau > .3 mum)                      
373                       
374                       if (ks != 1) { 
375 //                        TParticlePDG *particle = pDataBase->GetParticle(kf);
376                           
377                           Double_t lifeTime = fDecayer->GetLifetime(kf);
378 //                        Double_t mass     = particle->Mass();
379 //                        Double_t width    = particle->Width();
380                           if (lifeTime > (Double_t) fMaxLifeTime) {
381                               ipF = iparticle->GetFirstDaughter();
382                               ipL = iparticle->GetLastDaughter();       
383                               if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
384                           } else{
385                               trackIt[i]     = 0;
386                               pSelected[i]   = 1;
387                           }
388                       } // ks==1 ?
389 //
390 // children
391                       
392                       if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
393                       {
394                           if (fCutOnChild) {
395                               pc[0]=iparticle->Px();
396                               pc[1]=iparticle->Py();
397                               pc[2]=iparticle->Pz();
398                               Bool_t  childok = KinematicSelection(iparticle, 1);
399                               if(childok) {
400                                   pSelected[i]  = 1;
401                                   ncsel++;
402                               } else {
403                                   ncsel=-1;
404                                   break;
405                               } // child kine cuts
406                           } else {
407                               pSelected[i]  = 1;
408                               ncsel++;
409                           } // if child selection
410                       } // select muon
411                   } // decay particle loop
412               } // if decay products
413               
414               Int_t iparent;
415               if ((fCutOnChild && ncsel >0) || !fCutOnChild){
416                   ipa++;
417 //
418 // Parent
419                   PushTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
420                   pParent[0] = nt;
421                   KeepTrack(nt); 
422 //
423 // Decay Products
424 //                
425                   for (i = 1; i < np; i++) {
426                       if (pSelected[i]) {
427                           TParticle* iparticle = (TParticle *) particles->At(i);
428                           Int_t kf  = iparticle->GetPdgCode();
429                           Int_t ipa = iparticle->GetFirstMother()-1;
430                           
431                           och[0] = origin0[0]+iparticle->Vx()/10;
432                           och[1] = origin0[1]+iparticle->Vy()/10;
433                           och[2] = origin0[2]+iparticle->Vz()/10;
434                           pc[0]  = iparticle->Px();
435                           pc[1]  = iparticle->Py();
436                           pc[2]  = iparticle->Pz();
437                           
438                           if (ipa > -1) {
439                               iparent = pParent[ipa];
440                           } else {
441                               iparent = -1;
442                           }
443                          
444                           PushTrack(fTrackIt*trackIt[i], iparent, kf,
445                                            pc, och, polar,
446                                            0, kPDecay, nt, wgtch);
447                           pParent[i] = nt;
448                           KeepTrack(nt); 
449                       } // Selected
450                   } // Particle loop 
451               }  // Decays by Lujet
452               particles->Clear();
453               if (pFlag)      delete[] pFlag;
454               if (pParent)    delete[] pParent;
455               if (pSelected)  delete[] pSelected;          
456               if (trackIt)    delete[] trackIt;
457           } // kinematic selection
458           else  // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
459           {
460             gAlice->GetMCApp()->
461                 PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
462             ipa++; 
463           }
464           break;
465     } // while
466   } // event loop
467   SetHighWaterMark(nt);
468 }
469 //____________________________________________________________________________________
470 Float_t AliGenParam::GetRelativeArea(Float_t ptMin, Float_t ptMax, Float_t yMin, Float_t yMax, Float_t phiMin, Float_t phiMax)
471 {
472 //
473 // Normalisation for selected kinematic region
474 //
475   Float_t ratio =  
476     fPtPara->Integral(ptMin,ptMax) / fPtPara->Integral( fPtPara->GetXmin(), fPtPara->GetXmax()) *
477     fYPara->Integral(yMin,yMax)/fYPara->Integral(fYPara->GetXmin(),fYPara->GetXmax())   *
478     (phiMax-phiMin)/360.;
479   return TMath::Abs(ratio);
480 }
481
482 //____________________________________________________________________________________
483
484 void AliGenParam::Draw( const char * /*opt*/)
485 {
486     //
487     // Draw the pT and y Distributions
488     //
489      TCanvas *c0 = new TCanvas("c0","Canvas 0",400,10,600,700);
490      c0->Divide(2,1);
491      c0->cd(1);
492      fPtPara->Draw();
493      fPtPara->GetHistogram()->SetXTitle("p_{T} (GeV)");     
494      c0->cd(2);
495      fYPara->Draw();
496      fYPara->GetHistogram()->SetXTitle("y");     
497 }
498
499 AliGenParam& AliGenParam::operator=(const  AliGenParam& rhs)
500 {
501 // Assignment operator
502     rhs.Copy(*this);
503     return *this;
504 }
505
506
507