Workaround for an HP compiler problem
[u/mrichter/AliRoot.git] / EVGEN / AliGenPythia.cxx
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4c039060 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/*
17$Log$
084c1b4a 18Revision 1.12 1999/11/03 17:43:20 fca
19New version from G.Martinez & A.Morsch
20
886b6f73 21Revision 1.11 1999/09/29 09:24:14 fca
22Introduction of the Copyright and cvs Log
4c039060 23*/
24
fe4da5cc 25#include "AliGenerator.h"
26#include "AliGenPythia.h"
fe4da5cc 27#include "AliRun.h"
28#include "AliPythia.h"
29#include <TDirectory.h>
30#include <TFile.h>
31#include <TTree.h>
32#include <stdlib.h>
33#include <AliPythia.h>
1578254f 34#include <TParticle.h>
35//#include <GParticle.h>
fe4da5cc 36 ClassImp(AliGenPythia)
37
38AliGenPythia::AliGenPythia()
39 :AliGenerator()
40{
41}
42
43AliGenPythia::AliGenPythia(Int_t npart)
44 :AliGenerator(npart)
45{
46// default charm production at 5. 5 TeV
47// semimuonic decay
48// structure function GRVHO
49//
50 fXsection = 0.;
51 fParentSelect.Set(5);
52 fChildSelect.Set(5);
53 for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0;
54 SetProcess();
55 SetStrucFunc();
886b6f73 56 SetForceDecay();
fe4da5cc 57 SetPtHard();
58 SetEnergyCMS();
59}
60
61AliGenPythia::~AliGenPythia()
62{
63}
64
65void AliGenPythia::Init()
66{
67 SetMC(new AliPythia());
68 fPythia=(AliPythia*) fgMCEvGen;
69//
70 fParentWeight=1./Float_t(fNpart);
71//
72// Forward Paramters to the AliPythia object
73 fPythia->DefineParticles();
fe4da5cc 74 fPythia->SetCKIN(3,fPtHardMin);
75 fPythia->SetCKIN(4,fPtHardMax);
76 fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc);
5be1fe76 77 fPythia->ForceDecay(fForceDecay);
084c1b4a 78 fPythia->Lulist(0);
79 fPythia->Pystat(2);
fe4da5cc 80// Parent and Children Selection
81 switch (fProcess)
82 {
83 case charm:
84
85 fParentSelect[0]=411;
86 fParentSelect[1]=421;
87 fParentSelect[2]=431;
88 fParentSelect[3]=4122;
89 break;
90 case charm_unforced:
91
92 fParentSelect[0]=411;
93 fParentSelect[1]=421;
94 fParentSelect[2]=431;
95 fParentSelect[3]=4122;
96 break;
97 case beauty:
98 fParentSelect[0]=511;
99 fParentSelect[1]=521;
100 fParentSelect[2]=531;
101 fParentSelect[3]=5122;
102 break;
103 case beauty_unforced:
104 fParentSelect[0]=511;
105 fParentSelect[1]=521;
106 fParentSelect[2]=531;
107 fParentSelect[3]=5122;
108 break;
109 case jpsi_chi:
110 case jpsi:
111 fParentSelect[0]=443;
112 break;
5be1fe76 113 case mb:
114 break;
fe4da5cc 115 }
116
117 switch (fForceDecay)
118 {
119 case semielectronic:
120 case dielectron:
121 case b_jpsi_dielectron:
122 case b_psip_dielectron:
123 fChildSelect[0]=11;
124 break;
125 case semimuonic:
126 case dimuon:
127 case b_jpsi_dimuon:
128 case b_psip_dimuon:
5be1fe76 129 case pitomu:
130 case katomu:
fe4da5cc 131 fChildSelect[0]=13;
132 break;
886b6f73 133 case all:
134 case nodecay:
135 break;
fe4da5cc 136 }
137}
138
139void AliGenPythia::Generate()
140{
fe4da5cc 141
5be1fe76 142 Float_t polar[3] = {0,0,0};
143 Float_t origin[3]= {0,0,0};
144 Float_t origin_p[3]= {0,0,0};
145 Float_t origin0[3]= {0,0,0};
146 Float_t p[3], p_p[4], random[6];
09fd3ea2 147 static TClonesArray *particles;
5be1fe76 148// converts from mm/c to s
149 const Float_t kconv=0.001/2.999792458e8;
fe4da5cc 150
151
152//
fe4da5cc 153 Int_t nt=0;
5be1fe76 154 Int_t nt_p=0;
fe4da5cc 155 Int_t jev=0;
7921755b 156 Int_t j, kf;
09fd3ea2 157
158 if(!particles) particles=new TClonesArray("TParticle",1000);
fe4da5cc 159
160 fTrials=0;
161 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
162 if(fVertexSmear==perEvent) {
cfce8870 163 gMC->Rndm(random,6);
fe4da5cc 164 for (j=0;j<3;j++) {
165 origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
166 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
167 fPythia->SetMSTP(151,0);
168 }
169 } else if (fVertexSmear==perTrack) {
170 fPythia->SetMSTP(151,0);
171 for (j=0;j<3;j++) {
172 fPythia->SetPARP(151+j, fOsigma[j]*10.);
173 }
174 }
fe4da5cc 175 while(1)
176 {
084c1b4a 177 fPythia->Pyevnt();
fe4da5cc 178 fTrials++;
f1092809 179 fPythia->ImportParticles(particles,"All");
fe4da5cc 180 Int_t np = particles->GetEntriesFast();
181 printf("\n **************************************************%d\n",np);
182 Int_t nc=0;
183 if (np == 0 ) continue;
5be1fe76 184 if (fProcess != mb) {
185 for (Int_t i = 0; i<np; i++) {
1578254f 186 TParticle * iparticle = (TParticle *) particles->At(i);
a8228d85 187 kf = CheckPDGCode(iparticle->GetPdgCode());
5be1fe76 188 fChildWeight=(fPythia->GetBraPart(kf))*fParentWeight;
fe4da5cc 189//
190// Parent
5be1fe76 191 if (ParentSelected(TMath::Abs(kf))) {
192 if (KinematicSelection(iparticle)) {
193 if (nc==0) {
194//
195// Store information concerning the hard scattering process
196//
197 Float_t mass_p = fPythia->GetPARI(13);
198 Float_t pt_p = fPythia->GetPARI(17);
199 Float_t y_p = fPythia->GetPARI(37);
200 Float_t xmt_p = sqrt(pt_p*pt_p+mass_p*mass_p);
201 Float_t ty = Float_t(TMath::TanH(y_p));
202 p_p[0] = pt_p;
203 p_p[1] = 0;
204 p_p[2] = xmt_p*ty/sqrt(1.-ty*ty);
205 p_p[3] = mass_p;
206 gAlice->SetTrack(0,-1,-1,
207 p_p,origin_p,polar,
208 0,"Hard Scat.",nt_p,fParentWeight);
209 gAlice->KeepTrack(nt_p);
210 }
211 nc++;
fe4da5cc 212//
213// store parent track information
1578254f 214 p[0]=iparticle->Px();
215 p[1]=iparticle->Py();
216 p[2]=iparticle->Pz();
217 origin[0]=origin0[0]+iparticle->Vx()/10;
218 origin[1]=origin0[1]+iparticle->Vy()/10;
219 origin[2]=origin0[2]+iparticle->Vz()/10;
fe4da5cc 220
1578254f 221 Int_t ifch=iparticle->GetFirstDaughter();
222 Int_t ilch=iparticle->GetLastDaughter();
5be1fe76 223 if (ifch !=0 && ilch !=0) {
1578254f 224 gAlice->SetTrack(0,nt_p,kf,
5be1fe76 225 p,origin,polar,
226 0,"Primary",nt,fParentWeight);
227 gAlice->KeepTrack(nt);
228 Int_t iparent = nt;
fe4da5cc 229//
230// Children
231
7921755b 232 for (j=ifch; j<=ilch; j++)
5be1fe76 233 {
1578254f 234 TParticle * ichild =
235 (TParticle *) particles->At(j-1);
a8228d85 236 kf = CheckPDGCode(ichild->GetPdgCode());
fe4da5cc 237//
238//
5be1fe76 239 if (ChildSelected(TMath::Abs(kf))) {
1578254f 240 origin[0]=ichild->Vx();
241 origin[1]=ichild->Vy();
242 origin[2]=ichild->Vz();
243 p[0]=ichild->Px();
244 p[1]=ichild->Py();
245 p[2]=ichild->Pz();
246 Float_t tof=kconv*ichild->T();
247 gAlice->SetTrack(fTrackIt, iparent, kf,
5be1fe76 248 p,origin,polar,
249 tof,"Decay",nt,fChildWeight);
250 gAlice->KeepTrack(nt);
251 } // select child
252 } // child loop
253 }
254 } // kinematic selection
255 } // select particle
256 } // particle loop
257 } else {
258 for (Int_t i = 0; i<np; i++) {
1578254f 259 TParticle * iparticle = (TParticle *) particles->At(i);
a8228d85 260 kf = CheckPDGCode(iparticle->GetPdgCode());
1578254f 261 Int_t ks = iparticle->GetStatusCode();
262 if (ks==1 && kf!=0 && KinematicSelection(iparticle)) {
5be1fe76 263 nc++;
264//
265// store track information
1578254f 266 p[0]=iparticle->Px();
267 p[1]=iparticle->Py();
268 p[2]=iparticle->Pz();
269 origin[0]=origin0[0]+iparticle->Vx()/10;
270 origin[1]=origin0[1]+iparticle->Vy()/10;
271 origin[2]=origin0[2]+iparticle->Vz()/10;
272 Float_t tof=kconv*iparticle->T();
273 gAlice->SetTrack(fTrackIt,-1,kf,p,origin,polar,
5be1fe76 274 tof,"Primary",nt);
275 gAlice->KeepTrack(nt);
276 } // select particle
277 } // particle loop
278 printf("\n I've put %i particles on the stack \n",nc);
279 } // mb ?
fe4da5cc 280 if (nc > 0) {
5be1fe76 281 jev+=nc;
fe4da5cc 282 if (jev >= fNpart) {
283 fKineBias=Float_t(fNpart)/Float_t(fTrials);
284 printf("\n Trials: %i\n",fTrials);
285 break;
286 }
287 }
288 } // event loop
289// adjust weight due to kinematic selection
290 AdjustWeights();
291// get cross-section
292 fXsection=fPythia->GetPARI(1);
293}
294
295Bool_t AliGenPythia::ParentSelected(Int_t ip)
296{
297 for (Int_t i=0; i<5; i++)
298 {
299 if (fParentSelect[i]==ip) return kTRUE;
300 }
301 return kFALSE;
302}
303
304Bool_t AliGenPythia::ChildSelected(Int_t ip)
305{
306 for (Int_t i=0; i<5; i++)
307 {
308 if (fChildSelect[i]==ip) return kTRUE;
309 }
310 return kFALSE;
311}
312
1578254f 313Bool_t AliGenPythia::KinematicSelection(TParticle *particle)
fe4da5cc 314{
1578254f 315 Float_t px=particle->Px();
316 Float_t py=particle->Py();
317 Float_t pz=particle->Pz();
318 Float_t e=particle->Energy();
fe4da5cc 319
320//
321// transverse momentum cut
322 Float_t pt=TMath::Sqrt(px*px+py*py);
323 if (pt > fPtMax || pt < fPtMin)
324 {
325// printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
326 return kFALSE;
327 }
328//
329// momentum cut
330 Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
331 if (p > fPMax || p < fPMin)
332 {
333// printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
334 return kFALSE;
335 }
336
337//
338// theta cut
5be1fe76 339 Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz)));
fe4da5cc 340 if (theta > fThetaMax || theta < fThetaMin)
341 {
342// printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
343 return kFALSE;
344 }
345
346//
347// rapidity cut
348 Float_t y = 0.5*TMath::Log((e+pz)/(e-pz));
349 if (y > fYMax || y < fYMin)
350 {
351// printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
352 return kFALSE;
353 }
354
355//
356// phi cut
357 Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)))+TMath::Pi();
358 if (phi > fPhiMax || phi < fPhiMin)
359 {
360// printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
361 return kFALSE;
362 }
363
364 return kTRUE;
365}
366void AliGenPythia::AdjustWeights()
367{
368 TClonesArray *PartArray = gAlice->Particles();
1578254f 369 TParticle *Part;
fe4da5cc 370 Int_t ntrack=gAlice->GetNtrack();
371 for (Int_t i=0; i<ntrack; i++) {
1578254f 372 Part= (TParticle*) PartArray->UncheckedAt(i);
373 Part->SetWeight(Part->GetWeight()*fKineBias);
fe4da5cc 374 }
375}
376
a8228d85 377Int_t AliGenPythia::CheckPDGCode(Int_t pdgcode)
378{
379//
380// If the particle is in a diffractive state, then take action accordigly
381 switch (pdgcode) {
382 case 110:
383 //rho_diff0 -- difficult to translate, return rho0
384 return 113;
385 case 210:
386 //pi_diffr+ -- change to pi+
387 return 211;
388 case 220:
389 //omega_di0 -- change to omega0
390 return 223;
391 case 330:
392 //phi_diff0 -- return phi0
393 return 333;
394 case 440:
395 //J/psi_di0 -- return J/psi
396 return 443;
397 case 2110:
398 //n_diffr -- return neutron
399 return 2112;
400 case 2210:
401 //p_diffr+ -- return proton
402 return 2212;
403 }
404 //non diffractive state -- return code unchanged
405 return pdgcode;
406}
407
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