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Correct adding of headers in case object is part of cocktail.
[u/mrichter/AliRoot.git] / EVGEN / AliGenParam.cxx
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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 <TClonesArray.h>
26#include <TDatabasePDG.h>
27#include <TF1.h>
28#include <TH1F.h>
29#include <TLorentzVector.h>
30#include <TMath.h>
31#include <TParticle.h>
32#include <TParticlePDG.h>
33#include <TROOT.h>
34#include <TVirtualMC.h>
35
36#include "AliDecayer.h"
37#include "AliGenMUONlib.h"
38#include "AliGenParam.h"
39#include "AliMC.h"
40#include "AliRun.h"
41#include "AliGenEventHeader.h"
42
43ClassImp(AliGenParam)
44
45//------------------------------------------------------------
46
47 //Begin_Html
48 /*
49 <img src="picts/AliGenParam.gif">
50 */
51 //End_Html
52
53//____________________________________________________________
54 AliGenParam::AliGenParam():
55 fPtParaFunc(0),
56 fYParaFunc(0),
57 fIpParaFunc(0),
58 fPtPara(0),
59 fYPara(0),
60 fParam(0),
61 fdNdy0(0.),
62 fYWgt(0.),
63 fPtWgt(0.),
64 fBias(0.),
65 fTrials(0),
66 fDeltaPt(0.01),
67 fDecayer(0)
68{
69// Default constructor
70}
71//____________________________________________________________
72AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname)
73 :AliGenMC(npart),
74 fPtParaFunc(Library->GetPt(param, tname)),
75 fYParaFunc (Library->GetY (param, tname)),
76 fIpParaFunc(Library->GetIp(param, tname)),
77 fPtPara(0),
78 fYPara(0),
79 fParam(param),
80 fdNdy0(0.),
81 fYWgt(0.),
82 fPtWgt(0.),
83 fBias(0.),
84 fTrials(0),
85 fDeltaPt(0.01),
86 fDecayer(0)
87{
88// Constructor using number of particles parameterisation id and library
89 fName = "Param";
90 fTitle= "Particle Generator using pT and y parameterisation";
91 fAnalog = kAnalog;
92 SetForceDecay();
93}
94//____________________________________________________________
95AliGenParam::AliGenParam(Int_t npart, Int_t param, const char* tname, const char* name):
96 AliGenMC(npart),
97 fPtParaFunc(0),
98 fYParaFunc (0),
99 fIpParaFunc(0),
100 fPtPara(0),
101 fYPara(0),
102 fParam(param),
103 fdNdy0(0.),
104 fYWgt(0.),
105 fPtWgt(0.),
106 fBias(0.),
107 fTrials(0),
108 fDeltaPt(0.01),
109 fDecayer(0)
110{
111// Constructor using parameterisation id and number of particles
112//
113 fName = name;
114 fTitle= "Particle Generator using pT and y parameterisation";
115
116 AliGenLib* pLibrary = new AliGenMUONlib();
117 fPtParaFunc = pLibrary->GetPt(param, tname);
118 fYParaFunc = pLibrary->GetY (param, tname);
119 fIpParaFunc = pLibrary->GetIp(param, tname);
120
121 fAnalog = kAnalog;
122 fChildSelect.Set(5);
123 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
124 SetForceDecay();
125 SetCutOnChild();
126 SetChildMomentumRange();
127 SetChildPtRange();
128 SetChildPhiRange();
129 SetChildThetaRange();
130}
131//____________________________________________________________
132
133AliGenParam::AliGenParam(Int_t npart, Int_t param,
134 Double_t (*PtPara) (Double_t*, Double_t*),
135 Double_t (*YPara ) (Double_t* ,Double_t*),
136 Int_t (*IpPara) (TRandom *))
137 :AliGenMC(npart),
138
139 fPtParaFunc(PtPara),
140 fYParaFunc(YPara),
141 fIpParaFunc(IpPara),
142 fPtPara(0),
143 fYPara(0),
144 fParam(param),
145 fdNdy0(0.),
146 fYWgt(0.),
147 fPtWgt(0.),
148 fBias(0.),
149 fTrials(0),
150 fDeltaPt(0.01),
151 fDecayer(0)
152{
153// Constructor
154// Gines Martinez 1/10/99
155 fName = "Param";
156 fTitle= "Particle Generator using pT and y parameterisation";
157
158 fAnalog = kAnalog;
159 fChildSelect.Set(5);
160 for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
161 SetForceDecay();
162 SetCutOnChild();
163 SetChildMomentumRange();
164 SetChildPtRange();
165 SetChildPhiRange();
166 SetChildThetaRange();
167}
168
169//____________________________________________________________
170AliGenParam::~AliGenParam()
171{
172// Destructor
173 delete fPtPara;
174 delete fYPara;
175}
176
177//____________________________________________________________
178void AliGenParam::Init()
179{
180// Initialisation
181
182 if (gMC) fDecayer = gMC->GetDecayer();
183 //Begin_Html
184 /*
185 <img src="picts/AliGenParam.gif">
186 */
187 //End_Html
188 char name[256];
189 sprintf(name, "pt-parameterisation for %s", GetName());
190
191 if (fPtPara) fPtPara->Delete();
192 fPtPara = new TF1(name, fPtParaFunc, fPtMin, fPtMax,0);
193 gROOT->GetListOfFunctions()->Remove(fPtPara);
194// Set representation precision to 10 MeV
195 Int_t npx= Int_t((fPtMax - fPtMin) / fDeltaPt);
196
197 fPtPara->SetNpx(npx);
198
199 sprintf(name, "y-parameterisation for %s", GetName());
200 if (fYPara) fYPara->Delete();
201 fYPara = new TF1(name, fYParaFunc, fYMin, fYMax, 0);
202 gROOT->GetListOfFunctions()->Remove(fYPara);
203
204
205 sprintf(name, "pt-for-%s", GetName());
206 TF1 ptPara(name ,fPtParaFunc, 0, 15, 0);
207 sprintf(name, "y-for-%s", GetName());
208 TF1 yPara(name, fYParaFunc, -6, 6, 0);
209
210//
211// dN/dy| y=0
212 Double_t y1=0;
213 Double_t y2=0;
214
215 fdNdy0=fYParaFunc(&y1,&y2);
216//
217// Integral over generation region
218 Float_t intYS = yPara.Integral(fYMin, fYMax,(Double_t*) 0x0,1.e-6);
219 Float_t intPt0 = ptPara.Integral(0,15,(Double_t *) 0x0,1.e-6);
220 Float_t intPtS = ptPara.Integral(fPtMin,fPtMax,(Double_t*) 0x0,1.e-6);
221 Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
222 if (fAnalog == kAnalog) {
223 fYWgt = intYS/fdNdy0;
224 fPtWgt = intPtS/intPt0;
225 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
226 } else {
227 fYWgt = intYS/fdNdy0;
228 fPtWgt = (fPtMax-fPtMin)/intPt0;
229 fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
230 }
231//
232// particle decay related initialization
233 fDecayer->SetForceDecay(fForceDecay);
234 fDecayer->Init();
235
236//
237 AliGenMC::Init();
238}
239
240//____________________________________________________________
241void AliGenParam::Generate()
242{
243//
244// Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
245// Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
246// antineutrons in the the desired theta, phi and momentum windows;
247// Gaussian smearing on the vertex is done if selected.
248// The decay of heavy mesons is done using lujet,
249// and the childern particle are tracked by GEANT
250// However, light mesons are directly tracked by GEANT
251// setting fForceDecay = nodecay (SetForceDecay(nodecay))
252//
253//
254// Reinitialize decayer
255 fDecayer->SetForceDecay(fForceDecay);
256 fDecayer->Init();
257
258//
259 Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
260 Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
261 Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
262 Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
263 Float_t p[3], pc[3],
264 och[3]; // Momentum, polarisation and origin of the children particles from lujet
265 Double_t ty, xmt;
266 Int_t nt, i, j;
267 Float_t wgtp, wgtch;
268 Double_t dummy;
269 static TClonesArray *particles;
270 //
271 if(!particles) particles = new TClonesArray("TParticle",1000);
272
273 TDatabasePDG *pDataBase = TDatabasePDG::Instance();
274 //
275 Float_t random[6];
276
277// Calculating vertex position per event
278 for (j=0;j<3;j++) origin0[j]=fOrigin[j];
279 if(fVertexSmear==kPerEvent) {
280 Vertex();
281 for (j=0;j<3;j++) origin0[j]=fVertex[j];
282 }
283
284 Int_t ipa=0;
285
286// Generating fNpart particles
287 fNprimaries = 0;
288
289 while (ipa<fNpart) {
290 while(1) {
291//
292// particle type
293 Int_t iPart = fIpParaFunc(fRandom);
294 fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
295 TParticlePDG *particle = pDataBase->GetParticle(iPart);
296 Float_t am = particle->Mass();
297
298 Rndm(random,2);
299//
300// phi
301 phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
302//
303// y
304 ty = TMath::TanH(fYPara->GetRandom());
305//
306// pT
307 if (fAnalog == kAnalog) {
308 pt=fPtPara->GetRandom();
309 wgtp=fParentWeight;
310 wgtch=fChildWeight;
311 } else {
312 pt=fPtMin+random[1]*(fPtMax-fPtMin);
313 Double_t ptd=pt;
314 wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
315 wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
316 }
317 xmt=sqrt(pt*pt+am*am);
318 if (TMath::Abs(ty)==1.) {
319 ty=0.;
320 Fatal("AliGenParam",
321 "Division by 0: Please check you rapidity range !");
322 }
323
324 pl=xmt*ty/sqrt(1.-ty*ty);
325 theta=TMath::ATan2(pt,pl);
326// Cut on theta
327 if(theta<fThetaMin || theta>fThetaMax) continue;
328 ptot=TMath::Sqrt(pt*pt+pl*pl);
329// Cut on momentum
330 if(ptot<fPMin || ptot>fPMax) continue;
331//
332 p[0]=pt*TMath::Cos(phi);
333 p[1]=pt*TMath::Sin(phi);
334 p[2]=pl;
335 if(fVertexSmear==kPerTrack) {
336 Rndm(random,6);
337 for (j=0;j<3;j++) {
338 origin0[j]=
339 fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
340 TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
341 }
342 }
343
344// Looking at fForceDecay :
345// if fForceDecay != none Primary particle decays using
346// AliPythia and children are tracked by GEANT
347//
348// if fForceDecay == none Primary particle is tracked by GEANT
349// (In the latest, make sure that GEANT actually does all the decays you want)
350//
351
352 if (fForceDecay != kNoDecay) {
353// Using lujet to decay particle
354 Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
355 TLorentzVector pmom(p[0], p[1], p[2], energy);
356 fDecayer->Decay(iPart,&pmom);
357//
358// select decay particles
359 Int_t np=fDecayer->ImportParticles(particles);
360
361 // Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
362 if (fGeometryAcceptance)
363 if (!CheckAcceptanceGeometry(np,particles)) continue;
364 Int_t ncsel=0;
365 Int_t* pFlag = new Int_t[np];
366 Int_t* pParent = new Int_t[np];
367 Int_t* pSelected = new Int_t[np];
368 Int_t* trackIt = new Int_t[np];
369
370 for (i=0; i<np; i++) {
371 pFlag[i] = 0;
372 pSelected[i] = 0;
373 pParent[i] = -1;
374 }
375
376 if (np >1) {
377 TParticle* iparticle = (TParticle *) particles->At(0);
378 Int_t ipF, ipL;
379 for (i = 1; i<np ; i++) {
380 trackIt[i] = 1;
381 iparticle = (TParticle *) particles->At(i);
382 Int_t kf = iparticle->GetPdgCode();
383 Int_t ks = iparticle->GetStatusCode();
384// flagged particle
385
386 if (pFlag[i] == 1) {
387 ipF = iparticle->GetFirstDaughter();
388 ipL = iparticle->GetLastDaughter();
389 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
390 continue;
391 }
392
393// flag decay products of particles with long life-time (c tau > .3 mum)
394
395 if (ks != 1) {
396// TParticlePDG *particle = pDataBase->GetParticle(kf);
397
398 Double_t lifeTime = fDecayer->GetLifetime(kf);
399// Double_t mass = particle->Mass();
400// Double_t width = particle->Width();
401 if (lifeTime > (Double_t) fMaxLifeTime) {
402 ipF = iparticle->GetFirstDaughter();
403 ipL = iparticle->GetLastDaughter();
404 if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
405 } else{
406 trackIt[i] = 0;
407 pSelected[i] = 1;
408 }
409 } // ks==1 ?
410//
411// children
412
413 if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
414 {
415 if (fCutOnChild) {
416 pc[0]=iparticle->Px();
417 pc[1]=iparticle->Py();
418 pc[2]=iparticle->Pz();
419 Bool_t childok = KinematicSelection(iparticle, 1);
420 if(childok) {
421 pSelected[i] = 1;
422 ncsel++;
423 } else {
424 ncsel=-1;
425 break;
426 } // child kine cuts
427 } else {
428 pSelected[i] = 1;
429 ncsel++;
430 } // if child selection
431 } // select muon
432 } // decay particle loop
433 } // if decay products
434
435 Int_t iparent;
436 if ((fCutOnChild && ncsel >0) || !fCutOnChild){
437 ipa++;
438//
439// Parent
440 PushTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
441 pParent[0] = nt;
442 KeepTrack(nt);
443 fNprimaries++;
444
445//
446// Decay Products
447//
448 for (i = 1; i < np; i++) {
449 if (pSelected[i]) {
450 TParticle* iparticle = (TParticle *) particles->At(i);
451 Int_t kf = iparticle->GetPdgCode();
452 Int_t ipa = iparticle->GetFirstMother()-1;
453
454 och[0] = origin0[0]+iparticle->Vx()/10;
455 och[1] = origin0[1]+iparticle->Vy()/10;
456 och[2] = origin0[2]+iparticle->Vz()/10;
457 pc[0] = iparticle->Px();
458 pc[1] = iparticle->Py();
459 pc[2] = iparticle->Pz();
460
461 if (ipa > -1) {
462 iparent = pParent[ipa];
463 } else {
464 iparent = -1;
465 }
466
467 PushTrack(fTrackIt*trackIt[i], iparent, kf,
468 pc, och, polar,
469 0, kPDecay, nt, wgtch);
470 pParent[i] = nt;
471 KeepTrack(nt);
472 fNprimaries++;
473 } // Selected
474 } // Particle loop
475 } // Decays by Lujet
476 particles->Clear();
477 if (pFlag) delete[] pFlag;
478 if (pParent) delete[] pParent;
479 if (pSelected) delete[] pSelected;
480 if (trackIt) delete[] trackIt;
481 } // kinematic selection
482 else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
483 {
484 gAlice->GetMCApp()->
485 PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
486 ipa++;
487 fNprimaries++;
488 }
489 break;
490 } // while
491 } // event loop
492
493 SetHighWaterMark(nt);
494
495 AliGenEventHeader* header = new AliGenEventHeader("PARAM");
496 header->SetPrimaryVertex(fVertex);
497 header->SetNProduced(fNprimaries);
498 AddHeader(header);
499}
500//____________________________________________________________________________________
501Float_t AliGenParam::GetRelativeArea(Float_t ptMin, Float_t ptMax, Float_t yMin, Float_t yMax, Float_t phiMin, Float_t phiMax)
502{
503//
504// Normalisation for selected kinematic region
505//
506 Float_t ratio =
507 fPtPara->Integral(ptMin,ptMax,(Double_t *)0,1.e-6) / fPtPara->Integral( fPtPara->GetXmin(), fPtPara->GetXmax(),(Double_t *)0,1.e-6) *
508 fYPara->Integral(yMin,yMax,(Double_t *)0,1.e-6)/fYPara->Integral(fYPara->GetXmin(),fYPara->GetXmax(),(Double_t *)0,1.e-6) *
509 (phiMax-phiMin)/360.;
510 return TMath::Abs(ratio);
511}
512
513//____________________________________________________________________________________
514
515void AliGenParam::Draw( const char * /*opt*/)
516{
517 //
518 // Draw the pT and y Distributions
519 //
520 TCanvas *c0 = new TCanvas("c0","Canvas 0",400,10,600,700);
521 c0->Divide(2,1);
522 c0->cd(1);
523 fPtPara->Draw();
524 fPtPara->GetHistogram()->SetXTitle("p_{T} (GeV)");
525 c0->cd(2);
526 fYPara->Draw();
527 fYPara->GetHistogram()->SetXTitle("y");
528}
529
530
531
532