Avoid warnings on SunOS
[u/mrichter/AliRoot.git] / EVGEN / AliGenPythia.cxx
1 #include "AliGenerator.h"
2 #include "AliGenPythia.h"
3 #include "AliRun.h"
4 #include "AliPythia.h"
5 #include <TDirectory.h>
6 #include <TFile.h>
7 #include <TTree.h>
8 #include <stdlib.h>
9 #include <AliPythia.h>
10 #include <TParticle.h>
11 //#include <GParticle.h>
12  ClassImp(AliGenPythia)
13
14 AliGenPythia::AliGenPythia()
15                  :AliGenerator()
16 {
17 }
18
19 AliGenPythia::AliGenPythia(Int_t npart)
20                  :AliGenerator(npart)
21 {
22 // default charm production at 5. 5 TeV
23 // semimuonic decay
24 // structure function GRVHO
25 //
26     fXsection  = 0.;
27     fParentSelect.Set(5);
28     fChildSelect.Set(5);
29     for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0;
30     SetProcess();
31     SetStrucFunc();
32     ForceDecay();
33     SetPtHard();
34     SetEnergyCMS();
35 }
36
37 AliGenPythia::~AliGenPythia()
38 {
39 }
40
41 void AliGenPythia::Init()
42 {
43     SetMC(new AliPythia());
44     fPythia=(AliPythia*) fgMCEvGen;
45 //
46     fParentWeight=1./Float_t(fNpart);
47 //
48 //  Forward Paramters to the AliPythia object
49     fPythia->DefineParticles();
50     fPythia->SetCKIN(3,fPtHardMin);
51     fPythia->SetCKIN(4,fPtHardMax);    
52     fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc);
53     fPythia->ForceDecay(fForceDecay);
54     fPythia->LuList(0);
55     fPythia->PyStat(2);
56 //  Parent and Children Selection
57     switch (fProcess) 
58     {
59     case charm:
60
61         fParentSelect[0]=411;
62         fParentSelect[1]=421;
63         fParentSelect[2]=431;
64         fParentSelect[3]=4122;  
65         break;
66     case charm_unforced:
67
68         fParentSelect[0]=411;
69         fParentSelect[1]=421;
70         fParentSelect[2]=431;
71         fParentSelect[3]=4122;  
72         break;
73     case beauty:
74         fParentSelect[0]=511;
75         fParentSelect[1]=521;
76         fParentSelect[2]=531;
77         fParentSelect[3]=5122;  
78         break;
79     case beauty_unforced:
80         fParentSelect[0]=511;
81         fParentSelect[1]=521;
82         fParentSelect[2]=531;
83         fParentSelect[3]=5122;  
84         break;
85     case jpsi_chi:
86     case jpsi:
87         fParentSelect[0]=443;
88         break;
89     case mb:
90         break;
91     }
92
93     switch (fForceDecay) 
94     {
95     case semielectronic:
96     case dielectron:
97     case b_jpsi_dielectron:
98     case b_psip_dielectron:
99         fChildSelect[0]=11;     
100         break;
101     case semimuonic:
102     case dimuon:
103     case b_jpsi_dimuon:
104     case b_psip_dimuon:
105     case pitomu:
106     case katomu:
107         fChildSelect[0]=13;
108         break;
109     }
110 }
111
112 void AliGenPythia::Generate()
113 {
114
115     Float_t polar[3] =   {0,0,0};
116     Float_t origin[3]=   {0,0,0};
117     Float_t origin_p[3]= {0,0,0};
118     Float_t origin0[3]=  {0,0,0};
119     Float_t p[3], p_p[4], random[6];
120     static TClonesArray *particles;
121 //  converts from mm/c to s
122     const Float_t kconv=0.001/2.999792458e8;
123     
124     
125 //
126     Int_t nt=0;
127     Int_t nt_p=0;
128     Int_t jev=0;
129     Int_t j, kf;
130
131     if(!particles) particles=new TClonesArray("TParticle",1000);
132     
133     fTrials=0;
134     for (j=0;j<3;j++) origin0[j]=fOrigin[j];
135     if(fVertexSmear==perEvent) {
136         gMC->Rndm(random,6);
137         for (j=0;j<3;j++) {
138             origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
139                 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
140             fPythia->SetMSTP(151,0);
141         }
142     } else if (fVertexSmear==perTrack) {
143         fPythia->SetMSTP(151,0);
144         for (j=0;j<3;j++) {
145             fPythia->SetPARP(151+j, fOsigma[j]*10.);
146         }
147     }
148     while(1)
149     {
150         fPythia->PyEvnt();
151         fTrials++;
152         fPythia->ImportParticles(particles,"All");
153         Int_t np = particles->GetEntriesFast();
154         printf("\n **************************************************%d\n",np);
155         Int_t nc=0;
156         if (np == 0 ) continue;
157         if (fProcess != mb) {
158             for (Int_t i = 0; i<np; i++) {
159                 TParticle *  iparticle = (TParticle *) particles->At(i);
160                 kf = iparticle->GetPdgCode();
161                 fChildWeight=(fPythia->GetBraPart(kf))*fParentWeight;     
162 //
163 // Parent
164                 if (ParentSelected(TMath::Abs(kf))) {
165                     if (KinematicSelection(iparticle)) {
166                         if (nc==0) {
167 //
168 // Store information concerning the hard scattering process
169 //
170                             Float_t mass_p = fPythia->GetPARI(13);
171                             Float_t   pt_p = fPythia->GetPARI(17);
172                             Float_t    y_p = fPythia->GetPARI(37);
173                             Float_t  xmt_p = sqrt(pt_p*pt_p+mass_p*mass_p);
174                             Float_t     ty = Float_t(TMath::TanH(y_p));
175                             p_p[0] = pt_p;
176                             p_p[1] = 0;
177                             p_p[2] = xmt_p*ty/sqrt(1.-ty*ty);
178                             p_p[3] = mass_p;
179                             gAlice->SetTrack(0,-1,-1,
180                                              p_p,origin_p,polar,
181                                              0,"Hard Scat.",nt_p,fParentWeight);
182                             gAlice->KeepTrack(nt_p);
183                         }
184                         nc++;
185 //
186 // store parent track information
187                         p[0]=iparticle->Px();
188                         p[1]=iparticle->Py();
189                         p[2]=iparticle->Pz();
190                         origin[0]=origin0[0]+iparticle->Vx()/10;
191                         origin[1]=origin0[1]+iparticle->Vy()/10;
192                         origin[2]=origin0[2]+iparticle->Vz()/10;
193
194                         Int_t ifch=iparticle->GetFirstDaughter();
195                         Int_t ilch=iparticle->GetLastDaughter();        
196                         if (ifch !=0 && ilch !=0) {
197                             gAlice->SetTrack(0,nt_p,kf,
198                                              p,origin,polar,
199                                              0,"Primary",nt,fParentWeight);
200                             gAlice->KeepTrack(nt);
201                             Int_t iparent = nt;
202 //
203 // Children         
204
205                             for (j=ifch; j<=ilch; j++)
206                             {
207                                 TParticle *  ichild = 
208                                     (TParticle *) particles->At(j-1);
209                                 Int_t kf = ichild->GetPdgCode();
210 //
211 // 
212                                 if (ChildSelected(TMath::Abs(kf))) {
213                                     origin[0]=ichild->Vx();
214                                     origin[1]=ichild->Vy();
215                                     origin[2]=ichild->Vz();             
216                                     p[0]=ichild->Px();
217                                     p[1]=ichild->Py();
218                                     p[2]=ichild->Pz();
219                                     Float_t tof=kconv*ichild->T();
220                                     gAlice->SetTrack(fTrackIt, iparent, kf,
221                                                      p,origin,polar,
222                                                      tof,"Decay",nt,fChildWeight);
223                                     gAlice->KeepTrack(nt);
224                                 } // select child
225                             } // child loop
226                         }
227                     } // kinematic selection
228                 } // select particle
229             } // particle loop
230         } else {
231             for (Int_t i = 0; i<np; i++) {
232                 TParticle *  iparticle = (TParticle *) particles->At(i);
233                 Int_t kf = iparticle->GetPdgCode();
234                 Int_t ks = iparticle->GetStatusCode();
235                 if (ks==1 && kf!=0 && KinematicSelection(iparticle)) {
236                         nc++;
237 //
238 // store track information
239                         p[0]=iparticle->Px();
240                         p[1]=iparticle->Py();
241                         p[2]=iparticle->Pz();
242                         origin[0]=origin0[0]+iparticle->Vx()/10;
243                         origin[1]=origin0[1]+iparticle->Vy()/10;
244                         origin[2]=origin0[2]+iparticle->Vz()/10;
245                         Float_t tof=kconv*iparticle->T();
246                         gAlice->SetTrack(fTrackIt,-1,kf,p,origin,polar,
247                                          tof,"Primary",nt);
248                         gAlice->KeepTrack(nt);
249                 } // select particle
250             } // particle loop 
251             printf("\n I've put %i particles on the stack \n",nc);
252         } // mb ?
253         if (nc > 0) {
254             jev+=nc;
255             if (jev >= fNpart) {
256                 fKineBias=Float_t(fNpart)/Float_t(fTrials);
257                 printf("\n Trials: %i\n",fTrials);
258                 break;
259             }
260         }
261     } // event loop
262 //  adjust weight due to kinematic selection
263     AdjustWeights();
264 //  get cross-section
265     fXsection=fPythia->GetPARI(1);
266 }
267
268 Bool_t AliGenPythia::ParentSelected(Int_t ip)
269 {
270     for (Int_t i=0; i<5; i++)
271     {
272         if (fParentSelect[i]==ip) return kTRUE;
273     }
274     return kFALSE;
275 }
276
277 Bool_t AliGenPythia::ChildSelected(Int_t ip)
278 {
279     for (Int_t i=0; i<5; i++)
280     {
281         if (fChildSelect[i]==ip) return kTRUE;
282     }
283     return kFALSE;
284 }
285
286 Bool_t AliGenPythia::KinematicSelection(TParticle *particle)
287 {
288     Float_t px=particle->Px();
289     Float_t py=particle->Py();
290     Float_t pz=particle->Pz();
291     Float_t  e=particle->Energy();
292
293 //
294 //  transverse momentum cut    
295     Float_t pt=TMath::Sqrt(px*px+py*py);
296     if (pt > fPtMax || pt < fPtMin) 
297     {
298 //      printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
299         return kFALSE;
300     }
301 //
302 // momentum cut
303     Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
304     if (p > fPMax || p < fPMin) 
305     {
306 //      printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
307         return kFALSE;
308     }
309     
310 //
311 // theta cut
312     Float_t  theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz)));
313     if (theta > fThetaMax || theta < fThetaMin) 
314     {
315 //      printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
316         return kFALSE;
317     }
318
319 //
320 // rapidity cut
321     Float_t y = 0.5*TMath::Log((e+pz)/(e-pz));
322     if (y > fYMax || y < fYMin)
323     {
324 //      printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
325         return kFALSE;
326     }
327
328 //
329 // phi cut
330     Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)))+TMath::Pi();
331     if (phi > fPhiMax || phi < fPhiMin)
332     {
333 //      printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
334         return kFALSE;
335     }
336
337     return kTRUE;
338 }
339 void AliGenPythia::AdjustWeights()
340 {
341     TClonesArray *PartArray = gAlice->Particles();
342     TParticle *Part;
343     Int_t ntrack=gAlice->GetNtrack();
344     for (Int_t i=0; i<ntrack; i++) {
345         Part= (TParticle*) PartArray->UncheckedAt(i);
346         Part->SetWeight(Part->GetWeight()*fKineBias);
347     }
348 }
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