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1 | #include "AliGenerator.h" |
2 | #include "AliGenPythia.h" |
3 | #include "TGeant3.h" |
4 | #include "AliRun.h" |
5 | #include "AliPythia.h" |
6 | #include <TDirectory.h> |
7 | #include <TFile.h> |
8 | #include <TTree.h> |
9 | #include <stdlib.h> |
10 | #include <AliPythia.h> |
11 | #include <TMCParticle.h> |
12 | #include <GParticle.h> |
13 | ClassImp(AliGenPythia) |
14 | |
15 | AliGenPythia::AliGenPythia() |
16 | :AliGenerator() |
17 | { |
18 | } |
19 | |
20 | AliGenPythia::AliGenPythia(Int_t npart) |
21 | :AliGenerator(npart) |
22 | { |
23 | // default charm production at 5. 5 TeV |
24 | // semimuonic decay |
25 | // structure function GRVHO |
26 | // |
27 | fXsection = 0.; |
28 | fParentSelect.Set(5); |
29 | fChildSelect.Set(5); |
30 | for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0; |
31 | SetProcess(); |
32 | SetStrucFunc(); |
33 | ForceDecay(); |
34 | SetPtHard(); |
35 | SetEnergyCMS(); |
36 | } |
37 | |
38 | AliGenPythia::~AliGenPythia() |
39 | { |
40 | } |
41 | |
42 | void AliGenPythia::Init() |
43 | { |
44 | SetMC(new AliPythia()); |
45 | fPythia=(AliPythia*) fgMCEvGen; |
46 | // |
47 | fParentWeight=1./Float_t(fNpart); |
48 | // |
49 | // Forward Paramters to the AliPythia object |
50 | fPythia->DefineParticles(); |
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51 | fPythia->SetCKIN(3,fPtHardMin); |
52 | fPythia->SetCKIN(4,fPtHardMax); |
53 | fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc); |
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54 | fPythia->ForceDecay(fForceDecay); |
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55 | fPythia->LuList(0); |
56 | fPythia->PyStat(2); |
57 | // Parent and Children Selection |
58 | switch (fProcess) |
59 | { |
60 | case charm: |
61 | |
62 | fParentSelect[0]=411; |
63 | fParentSelect[1]=421; |
64 | fParentSelect[2]=431; |
65 | fParentSelect[3]=4122; |
66 | break; |
67 | case charm_unforced: |
68 | |
69 | fParentSelect[0]=411; |
70 | fParentSelect[1]=421; |
71 | fParentSelect[2]=431; |
72 | fParentSelect[3]=4122; |
73 | break; |
74 | case beauty: |
75 | fParentSelect[0]=511; |
76 | fParentSelect[1]=521; |
77 | fParentSelect[2]=531; |
78 | fParentSelect[3]=5122; |
79 | break; |
80 | case beauty_unforced: |
81 | fParentSelect[0]=511; |
82 | fParentSelect[1]=521; |
83 | fParentSelect[2]=531; |
84 | fParentSelect[3]=5122; |
85 | break; |
86 | case jpsi_chi: |
87 | case jpsi: |
88 | fParentSelect[0]=443; |
89 | break; |
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90 | case mb: |
91 | break; |
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92 | } |
93 | |
94 | switch (fForceDecay) |
95 | { |
96 | case semielectronic: |
97 | case dielectron: |
98 | case b_jpsi_dielectron: |
99 | case b_psip_dielectron: |
100 | fChildSelect[0]=11; |
101 | break; |
102 | case semimuonic: |
103 | case dimuon: |
104 | case b_jpsi_dimuon: |
105 | case b_psip_dimuon: |
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106 | case pitomu: |
107 | case katomu: |
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108 | fChildSelect[0]=13; |
109 | break; |
110 | } |
111 | } |
112 | |
113 | void AliGenPythia::Generate() |
114 | { |
115 | AliMC* pMC = AliMC::GetMC(); |
116 | |
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117 | Float_t polar[3] = {0,0,0}; |
118 | Float_t origin[3]= {0,0,0}; |
119 | Float_t origin_p[3]= {0,0,0}; |
120 | Float_t origin0[3]= {0,0,0}; |
121 | Float_t p[3], p_p[4], random[6]; |
122 | // converts from mm/c to s |
123 | const Float_t kconv=0.001/2.999792458e8; |
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124 | |
125 | |
126 | // |
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127 | Int_t nt=0; |
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128 | Int_t nt_p=0; |
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129 | Int_t jev=0; |
130 | Int_t j; |
131 | |
132 | fTrials=0; |
133 | for (j=0;j<3;j++) origin0[j]=fOrigin[j]; |
134 | if(fVertexSmear==perEvent) { |
135 | pMC->Rndm(random,6); |
136 | for (j=0;j<3;j++) { |
137 | origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())* |
138 | TMath::Sqrt(-2*TMath::Log(random[2*j+1])); |
139 | fPythia->SetMSTP(151,0); |
140 | } |
141 | } else if (fVertexSmear==perTrack) { |
142 | fPythia->SetMSTP(151,0); |
143 | for (j=0;j<3;j++) { |
144 | fPythia->SetPARP(151+j, fOsigma[j]*10.); |
145 | } |
146 | } |
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147 | while(1) |
148 | { |
149 | fPythia->PyEvnt(); |
150 | fTrials++; |
151 | TObjArray* particles = fPythia->GetPrimaries() ; |
152 | Int_t np = particles->GetEntriesFast(); |
153 | printf("\n **************************************************%d\n",np); |
154 | Int_t nc=0; |
155 | if (np == 0 ) continue; |
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156 | if (fProcess != mb) { |
157 | for (Int_t i = 0; i<np; i++) { |
158 | TMCParticle * iparticle = (TMCParticle *) particles->At(i); |
159 | Int_t kf = iparticle->GetKF(); |
160 | fChildWeight=(fPythia->GetBraPart(kf))*fParentWeight; |
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161 | // |
162 | // Parent |
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163 | if (ParentSelected(TMath::Abs(kf))) { |
164 | if (KinematicSelection(iparticle)) { |
165 | if (nc==0) { |
166 | // |
167 | // Store information concerning the hard scattering process |
168 | // |
169 | Float_t mass_p = fPythia->GetPARI(13); |
170 | Float_t pt_p = fPythia->GetPARI(17); |
171 | Float_t y_p = fPythia->GetPARI(37); |
172 | Float_t xmt_p = sqrt(pt_p*pt_p+mass_p*mass_p); |
173 | Float_t ty = Float_t(TMath::TanH(y_p)); |
174 | p_p[0] = pt_p; |
175 | p_p[1] = 0; |
176 | p_p[2] = xmt_p*ty/sqrt(1.-ty*ty); |
177 | p_p[3] = mass_p; |
178 | gAlice->SetTrack(0,-1,-1, |
179 | p_p,origin_p,polar, |
180 | 0,"Hard Scat.",nt_p,fParentWeight); |
181 | gAlice->KeepTrack(nt_p); |
182 | } |
183 | nc++; |
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184 | // |
185 | // store parent track information |
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186 | p[0]=iparticle->GetPx(); |
187 | p[1]=iparticle->GetPy(); |
188 | p[2]=iparticle->GetPz(); |
189 | origin[0]=origin0[0]+iparticle->GetVx()/10; |
190 | origin[1]=origin0[1]+iparticle->GetVy()/10; |
191 | origin[2]=origin0[2]+iparticle->GetVz()/10; |
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192 | |
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193 | Int_t ifch=iparticle->GetFirstChild(); |
194 | Int_t ilch=iparticle->GetLastChild(); |
195 | if (ifch !=0 && ilch !=0) { |
196 | gAlice->SetTrack(0,nt_p,fPythia->GetGeantCode(kf), |
197 | p,origin,polar, |
198 | 0,"Primary",nt,fParentWeight); |
199 | gAlice->KeepTrack(nt); |
200 | Int_t iparent = nt; |
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201 | // |
202 | // Children |
203 | |
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204 | for (Int_t j=ifch; j<=ilch; j++) |
205 | { |
206 | TMCParticle * ichild = |
207 | (TMCParticle *) particles->At(j-1); |
208 | Int_t kf = ichild->GetKF(); |
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209 | // |
210 | // |
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211 | if (ChildSelected(TMath::Abs(kf))) { |
212 | Int_t kg=fPythia->GetGeantCode(kf); |
213 | origin[0]=ichild->GetVx(); |
214 | origin[1]=ichild->GetVy(); |
215 | origin[2]=ichild->GetVz(); |
216 | p[0]=ichild->GetPx(); |
217 | p[1]=ichild->GetPy(); |
218 | p[2]=ichild->GetPz(); |
219 | Float_t tof=kconv*ichild->GetTime(); |
220 | gAlice->SetTrack(fTrackIt, iparent, kg, |
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 | TMCParticle * iparticle = (TMCParticle *) particles->At(i); |
233 | Int_t kf = iparticle->GetKF(); |
234 | Int_t ks = iparticle->GetKS(); |
235 | Int_t gc = fPythia->GetGeantCode(kf); |
236 | if (ks==1 && gc!=0 && KinematicSelection(iparticle)) { |
237 | nc++; |
238 | // |
239 | // store track information |
240 | p[0]=iparticle->GetPx(); |
241 | p[1]=iparticle->GetPy(); |
242 | p[2]=iparticle->GetPz(); |
243 | origin[0]=origin0[0]+iparticle->GetVx()/10; |
244 | origin[1]=origin0[1]+iparticle->GetVy()/10; |
245 | origin[2]=origin0[2]+iparticle->GetVz()/10; |
246 | Float_t tof=kconv*iparticle->GetTime(); |
247 | gAlice->SetTrack(fTrackIt,-1,gc,p,origin,polar, |
248 | tof,"Primary",nt); |
249 | gAlice->KeepTrack(nt); |
250 | } // select particle |
251 | } // particle loop |
252 | printf("\n I've put %i particles on the stack \n",nc); |
253 | } // mb ? |
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254 | if (nc > 0) { |
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255 | jev+=nc; |
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256 | if (jev >= fNpart) { |
257 | fKineBias=Float_t(fNpart)/Float_t(fTrials); |
258 | printf("\n Trials: %i\n",fTrials); |
259 | break; |
260 | } |
261 | } |
262 | } // event loop |
263 | // adjust weight due to kinematic selection |
264 | AdjustWeights(); |
265 | // get cross-section |
266 | fXsection=fPythia->GetPARI(1); |
267 | } |
268 | |
269 | Bool_t AliGenPythia::ParentSelected(Int_t ip) |
270 | { |
271 | for (Int_t i=0; i<5; i++) |
272 | { |
273 | if (fParentSelect[i]==ip) return kTRUE; |
274 | } |
275 | return kFALSE; |
276 | } |
277 | |
278 | Bool_t AliGenPythia::ChildSelected(Int_t ip) |
279 | { |
280 | for (Int_t i=0; i<5; i++) |
281 | { |
282 | if (fChildSelect[i]==ip) return kTRUE; |
283 | } |
284 | return kFALSE; |
285 | } |
286 | |
287 | Bool_t AliGenPythia::KinematicSelection(TMCParticle *particle) |
288 | { |
289 | Float_t px=particle->GetPx(); |
290 | Float_t py=particle->GetPy(); |
291 | Float_t pz=particle->GetPz(); |
292 | Float_t e=particle->GetEnergy(); |
293 | |
294 | // |
295 | // transverse momentum cut |
296 | Float_t pt=TMath::Sqrt(px*px+py*py); |
297 | if (pt > fPtMax || pt < fPtMin) |
298 | { |
299 | // printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax); |
300 | return kFALSE; |
301 | } |
302 | // |
303 | // momentum cut |
304 | Float_t p=TMath::Sqrt(px*px+py*py+pz*pz); |
305 | if (p > fPMax || p < fPMin) |
306 | { |
307 | // printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax); |
308 | return kFALSE; |
309 | } |
310 | |
311 | // |
312 | // theta cut |
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313 | Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz))); |
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314 | if (theta > fThetaMax || theta < fThetaMin) |
315 | { |
316 | // printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax); |
317 | return kFALSE; |
318 | } |
319 | |
320 | // |
321 | // rapidity cut |
322 | Float_t y = 0.5*TMath::Log((e+pz)/(e-pz)); |
323 | if (y > fYMax || y < fYMin) |
324 | { |
325 | // printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax); |
326 | return kFALSE; |
327 | } |
328 | |
329 | // |
330 | // phi cut |
331 | Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)))+TMath::Pi(); |
332 | if (phi > fPhiMax || phi < fPhiMin) |
333 | { |
334 | // printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax); |
335 | return kFALSE; |
336 | } |
337 | |
338 | return kTRUE; |
339 | } |
340 | void AliGenPythia::AdjustWeights() |
341 | { |
342 | TClonesArray *PartArray = gAlice->Particles(); |
343 | GParticle *Part; |
344 | Int_t ntrack=gAlice->GetNtrack(); |
345 | for (Int_t i=0; i<ntrack; i++) { |
346 | Part= (GParticle*) PartArray->UncheckedAt(i); |
347 | Part->SetWgt(Part->GetWgt()*fKineBias); |
348 | } |
349 | } |
350 | |
351 | |
352 | |
353 | |
354 | |
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355 | |
356 | |
357 | |
358 | |