1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
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 **************************************************************************/
18 // Generator using AMPT as an external generator
20 #include "AliGenAmpt.h"
22 #include <TClonesArray.h>
25 #include <TLorentzVector.h>
27 #include <TParticle.h>
28 #include <TVirtualMC.h>
29 #include <TParticlePDG.h>
30 #include "AliGenHijingEventHeader.h"
31 #define AliGenAmptEventHeader AliGenHijingEventHeader
32 #include "AliAmptRndm.h"
35 #include "AliDecayer.h"
39 AliGenAmpt::AliGenAmpt()
65 fPhiMaxJet(TMath::TwoPi()),
75 fNoHeavyQuarks(kFALSE),
83 fHeader(new AliGenAmptEventHeader("Ampt")),
88 AliAmptRndm::SetAmptRandom(GetRandom());
91 AliGenAmpt::AliGenAmpt(Int_t npart)
117 fPhiMaxJet(2. * TMath::Pi()),
127 fNoHeavyQuarks(kFALSE),
135 fHeader(new AliGenAmptEventHeader("Ampt")),
138 // Default PbPb collisions at 2.76 TeV
142 fTitle= "Particle Generator using AMPT";
143 AliAmptRndm::SetAmptRandom(GetRandom());
146 AliGenAmpt::~AliGenAmpt()
149 if ( fDsigmaDb) delete fDsigmaDb;
150 if ( fDnDb) delete fDnDb;
151 if ( fHeader) delete fHeader;
154 void AliGenAmpt::Init()
160 fProjectile.Resize(8);
162 fAmpt = new TAmpt(fEnergyCMS, fFrame, fProjectile, fTarget,
163 fAProjectile, fZProjectile, fATarget, fZTarget,
164 fMinImpactParam, fMaxImpactParam);
167 fAmpt->SetIHPR2(2, fRadiation);
168 fAmpt->SetIHPR2(3, fTrigger);
169 fAmpt->SetIHPR2(6, fShadowing);
170 fAmpt->SetIHPR2(12, fDecaysOff);
171 fAmpt->SetIHPR2(21, fKeep);
172 fAmpt->SetHIPR1(8, fPtHardMin);
173 fAmpt->SetHIPR1(9, fPtHardMax);
174 fAmpt->SetHIPR1(10, fPtMinJet);
175 fAmpt->SetHIPR1(50, fSimpleJet);
178 // fQuench = 0: no quenching
179 // fQuench = 1: Hijing default
180 // fQuench = 2: new LHC parameters for HIPR1(11) and HIPR1(14)
181 // fQuench = 3: new RHIC parameters for HIPR1(11) and HIPR1(14)
182 // fQuench = 4: new LHC parameters with log(e) dependence
183 // fQuench = 5: new RHIC parameters with log(e) dependence
184 fAmpt->SetIHPR2(50, 0);
186 fAmpt->SetIHPR2(4, 1);
188 fAmpt->SetIHPR2(4, 0);
191 fAmpt->SetHIPR1(14, 1.1);
192 fAmpt->SetHIPR1(11, 3.7);
193 } else if (fQuench == 3) {
194 fAmpt->SetHIPR1(14, 0.20);
195 fAmpt->SetHIPR1(11, 2.5);
196 } else if (fQuench == 4) {
197 fAmpt->SetIHPR2(50, 1);
198 fAmpt->SetHIPR1(14, 4.*0.34);
199 fAmpt->SetHIPR1(11, 3.7);
200 } else if (fQuench == 5) {
201 fAmpt->SetIHPR2(50, 1);
202 fAmpt->SetHIPR1(14, 0.34);
203 fAmpt->SetHIPR1(11, 2.5);
207 if (fNoHeavyQuarks) {
208 fAmpt->SetIHPR2(49, 1);
210 fAmpt->SetIHPR2(49, 0);
214 fAmpt->SetIsoft(fIsoft);
215 fAmpt->SetNtMax(fNtMax);
216 fAmpt->SetIpop(fIpop);
218 fAmpt->SetAlpha(fAlpha);
219 fAmpt->SetStringFrag(fStringA, fStringB);
226 EvaluateCrossSections();
229 void AliGenAmpt::Generate()
231 // Generate one event
233 Float_t polar[3] = {0,0,0};
234 Float_t origin[3] = {0,0,0};
235 Float_t origin0[3] = {0,0,0};
240 // converts from mm/c to s
241 const Float_t kconv = 0.001/2.99792458e8;
245 Int_t j, kf, ks, ksp, imo;
249 for (j = 0;j < 3; j++)
250 origin0[j] = fOrigin[j];
253 if(fVertexSmear == kPerEvent) {
255 for (j=0; j < 3; j++)
256 origin0[j] = fVertex[j];
260 Float_t sign = (fRandomPz && (Rndm() < 0.5))? -1. : 1.;
263 // Generate one event
264 Int_t fpemask = gSystem->GetFPEMask();
265 gSystem->SetFPEMask(0);
266 fAmpt->GenerateEvent();
267 gSystem->SetFPEMask(fpemask);
270 fAmpt->ImportParticles(&fParticles,"All");
271 Int_t np = fParticles.GetEntriesFast();
275 if (fTrigger != kNoTrigger) {
280 AliDecayer *decayer = 0;
282 decayer = gMC->GetDecayer();
284 if (decayer&&fDecay) {
285 TClonesArray arr("TParticle",100);
287 for (Int_t i = 0; i < np; i++) {
288 TParticle *iparticle = (TParticle *)fParticles.At(i);
289 if (!Stable(iparticle))
291 kf = TMath::Abs(iparticle->GetPdgCode());
294 if (0) { // this turned out to be too cumbersome!
295 if (kf!=331&&kf!=3114&&kf!=3114&&kf!=411&&kf!=-4122&&kf!=-3324&&kf!=-3312&&kf!=-3114&&
296 kf!=-311&&kf!=3214&&kf!=-3214&&kf!=-433&&kf!=413&&kf!=3122&&kf!=-3122&&kf!=-413&&
297 kf!=-421&&kf!=-423&&kf!=3324&&kf!=-313&&kf!=213&&kf!=-213&&kf!=3314&&kf!=3222&&
298 kf!=-3222&&kf!=3224&&kf!=-3224&&kf!=-4212&&kf!=4212&&kf!=433&&kf!=423&&kf!=-3322&&
300 continue; //decay eta',Sigma*+,Sigma*-,D+,Lambda_c-,Xi*0_bar,Xi-_bar,Sigma*-,
301 // K0_bar,Sigma*0,Sigma*0_bar,D*_s-,D*+,Lambda0,Lambda0_bar,D*-
302 // D0_bar,D*0_bar,Xi*0,K*0_bar,rho+,rho-,Xi*-,Sigma-,
303 // Sigma+,Sigma*+,Sigma*-,Sigma_c-,Sigma_c+,D*_s+,D*0,Xi0_bar
305 } else { // really only decay particles if there are not known to Geant3
306 if (gMC->IdFromPDG(kf)>0)
309 if (0) { // defining the particle for Geant3 leads to a floating point exception.
310 TParticlePDG *pdg = iparticle->GetPDG(1);
311 //pdg->Print(); printf("%s\n",pdg->ParticleClass());
312 TString ptype(pdg->ParticleClass());
313 TMCParticleType mctype(kPTUndefined);
314 if (ptype=="Baryon" || ptype=="Meson")
316 gMC->DefineParticle(pdg->PdgCode(), pdg->GetName(), mctype, pdg->Mass(), pdg->Charge(), pdg->Lifetime(),
317 ptype,pdg->Width(), (Int_t)pdg->Spin(), (Int_t)pdg->Parity(), 0,
318 (Int_t)pdg->Isospin(), 0, 0, 0, 0, pdg->Stable());
319 gMC->SetUserDecay(pdg->PdgCode());
323 TLorentzVector pmom(iparticle->Px(),iparticle->Py(),iparticle->Pz(),iparticle->Energy());
324 decayer->Decay(kf,&pmom);
325 decayer->ImportParticles(&arr);
326 Int_t ndecayed = arr.GetEntries();
328 if (np2+ndecayed>fParticles.GetSize())
329 fParticles.Expand(2*fParticles.GetSize());
331 iparticle->SetStatusCode(2);
332 iparticle->SetFirstDaughter(np2);
333 for (Int_t jj = 1; jj < ndecayed; jj++) {
334 TParticle *jp = (TParticle *)arr.At(jj);
335 if (jp->GetFirstMother()!=1)
337 TParticle *newp = new(fParticles[np2]) TParticle(jp->GetPdgCode(),
343 jp->Px(),jp->Py(),jp->Pz(),jp->Energy(),
344 jp->Vx(),jp->Vy(),jp->Vz(),jp->T());
345 newp->SetUniqueID(999);
348 iparticle->SetLastDaughter(np2-1);
351 np = fParticles.GetEntries();
353 AliError(Form("Something is fishy: %d %d\n", np,np2));
357 AliError("No decayer found, but fDecay==kTRUE!");
364 Int_t* newPos = new Int_t[np];
365 Int_t* pSelected = new Int_t[np];
367 for (Int_t i = 0; i < np; i++) {
373 //TParticle * iparticle = (TParticle *) fParticles.At(0);
374 fVertex[0] = origin0[0];
375 fVertex[1] = origin0[1];
376 fVertex[2] = origin0[2];
379 // First select parent particles
380 for (Int_t i = 0; i < np; i++) {
381 TParticle *iparticle = (TParticle *) fParticles.At(i);
383 // Is this a parent particle ?
384 if (Stable(iparticle)) continue;
385 Bool_t selected = kTRUE;
386 Bool_t hasSelectedDaughters = kFALSE;
387 kf = iparticle->GetPdgCode();
388 ks = iparticle->GetStatusCode();
393 selected = KinematicSelection(iparticle, 0) && SelectFlavor(kf);
394 hasSelectedDaughters = DaughtersSelection(iparticle);
396 // Put particle on the stack if it is either selected or
397 // it is the mother of at least one seleted particle
398 if (selected || hasSelectedDaughters) {
402 } // particle loop parents
404 // Now select the final state particles
405 fProjectileSpecn = 0;
406 fProjectileSpecp = 0;
409 for (Int_t i = 0; i<np; i++) {
410 TParticle *iparticle = (TParticle *) fParticles.At(i);
411 // Is this a final state particle ?
412 if (!Stable(iparticle))
414 Bool_t selected = kTRUE;
415 kf = iparticle->GetPdgCode();
418 ks = iparticle->GetStatusCode();
419 ksp = iparticle->GetUniqueID();
421 // --------------------------------------------------------------------------
422 // Count spectator neutrons and protons
423 if(ksp == 0 || ksp == 1) {
424 if(kf == kNeutron) fProjectileSpecn += 1;
425 if(kf == kProton) fProjectileSpecp += 1;
426 } else if(ksp == 10 || ksp == 11) {
427 if(kf == kNeutron) fTargetSpecn += 1;
428 if(kf == kProton) fTargetSpecp += 1;
430 // --------------------------------------------------------------------------
432 selected = KinematicSelection(iparticle,0)&&SelectFlavor(kf);
433 if (!fSpectators && selected)
434 selected = (ksp != 0 && ksp != 1 && ksp != 10 && ksp != 11);
437 // Put particle on the stack if selected
441 if (0) printf("---> %d %d %d %s\n",i,nc,kf,iparticle->GetName());
443 } // particle loop final state
445 // Write particles to stack
446 for (Int_t i = 0; i<np; i++) {
447 TParticle *iparticle = (TParticle *) fParticles.At(i);
448 Bool_t hasMother = (iparticle->GetFirstMother() >=0);
449 Bool_t hasDaughter = (iparticle->GetFirstDaughter() >=0);
451 kf = iparticle->GetPdgCode();
452 ks = iparticle->GetStatusCode();
453 p[0] = iparticle->Px();
454 p[1] = iparticle->Py();
455 p[2] = iparticle->Pz() * sign;
456 origin[0] = origin0[0]+iparticle->Vx()/10;
457 origin[1] = origin0[1]+iparticle->Vy()/10;
458 origin[2] = origin0[2]+iparticle->Vz()/10;
459 tof = time0+kconv * iparticle->T();
462 TParticle* mother = 0;
464 imo = iparticle->GetFirstMother();
465 mother = (TParticle *) fParticles.At(imo);
466 imo = (mother->GetPdgCode() != 92) ? newPos[imo] : -1;
468 Bool_t tFlag = (fTrackIt && !hasDaughter);
469 PushTrack(tFlag,imo,kf,p,origin,polar,tof,kPNoProcess,nt, 1., ks);
478 AliInfo(Form("\n I've put %i particles on the stack \n",nc));
481 if (jev >= fNpart || fNpart == -1) {
482 fKineBias = Float_t(fNpart)/Float_t(fTrials);
483 AliInfo(Form("\n Trials: %i %i %i\n",fTrials, fNpart, jev));
489 SetHighWaterMark(nt);
492 void AliGenAmpt::EvaluateCrossSections()
494 // Glauber Calculation of geometrical x-section
496 Float_t xTot = 0.; // barn
497 Float_t xTotHard = 0.; // barn
498 Float_t xPart = 0.; // barn
499 Float_t xPartHard = 0.; // barn
500 Float_t sigmaHard = 0.1; // mbarn
502 Float_t bMax = fAmpt->GetHIPR1(34)+fAmpt->GetHIPR1(35);
503 const Float_t kdib = 0.2;
504 Int_t kMax = Int_t((bMax-bMin)/kdib)+1;
506 printf("\n Projectile Radius (fm): %f \n",fAmpt->GetHIPR1(34));
507 printf("\n Target Radius (fm): %f \n",fAmpt->GetHIPR1(35));
510 Float_t oldvalue= 0.;
511 Float_t* b = new Float_t[kMax]; memset(b,0,kMax*sizeof(Float_t));
512 Float_t* si1 = new Float_t[kMax]; memset(si1,0,kMax*sizeof(Float_t));
513 Float_t* si2 = new Float_t[kMax]; memset(si2,0,kMax*sizeof(Float_t));
514 for (i = 0; i < kMax; i++) {
515 Float_t xb = bMin+i*kdib;
516 Float_t ov=fAmpt->Profile(xb);
517 Float_t gb = 2.*0.01*fAmpt->GetHIPR1(40)*kdib*xb*(1.-TMath::Exp(-fAmpt->GetHINT1(12)*ov));
518 Float_t gbh = 2.*0.01*fAmpt->GetHIPR1(40)*kdib*xb*sigmaHard*ov;
521 printf("profile %f %f %f\n", xb, ov, fAmpt->GetHINT1(12));
523 if (xb > fMinImpactParam && xb < fMaxImpactParam) {
528 if ((oldvalue) && ((xTot-oldvalue)/oldvalue<0.0001))
531 printf("\n Total cross section (barn): %d %f %f \n",i, xb, xTot);
532 printf("\n Hard cross section (barn): %d %f %f \n\n",i, xb, xTotHard);
540 printf("\n Total cross section (barn): %f \n",xTot);
541 printf("\n Hard cross section (barn): %f \n \n",xTotHard);
542 printf("\n Partial cross section (barn): %f %f \n",xPart, xPart/xTot*100.);
543 printf("\n Partial hard cross section (barn): %f %f \n",xPartHard, xPartHard/xTotHard*100.);
545 // Store result as a graph
550 fDsigmaDb = new TGraph(i, b, si1);
552 fDnDb = new TGraph(i, b, si2);
555 Bool_t AliGenAmpt::DaughtersSelection(TParticle* iparticle)
557 // Looks recursively if one of the daughters has been selected
558 //printf("\n Consider daughters %d:",iparticle->GetPdgCode());
561 Bool_t hasDaughters = (iparticle->GetFirstDaughter() >=0);
562 Bool_t selected = kFALSE;
564 imin = iparticle->GetFirstDaughter();
565 imax = iparticle->GetLastDaughter();
566 for (Int_t i = imin; i <= imax; i++){
567 TParticle * jparticle = (TParticle *) fParticles.At(i);
568 Int_t ip = jparticle->GetPdgCode();
569 if (KinematicSelection(jparticle,0)&&SelectFlavor(ip)) {
570 selected=kTRUE; break;
572 if (DaughtersSelection(jparticle)) {selected=kTRUE; break; }
580 Bool_t AliGenAmpt::SelectFlavor(Int_t pid)
582 // Select flavor of particle
584 // 4: charm and beauty
591 Int_t ifl = TMath::Abs(pid/100);
592 if (ifl > 10) ifl/=10;
593 res = (fFlavor == ifl);
596 // This part if gamma writing is inhibited
598 res = res && (pid != kGamma && pid != kPi0);
603 Bool_t AliGenAmpt::Stable(TParticle* particle) const
605 // Return true for a stable particle
609 if (particle->GetFirstDaughter() < 0 )
614 void AliGenAmpt::MakeHeader()
616 // Fills the event header, to be called after each event
618 fHeader->SetNProduced(fNprimaries);
619 fHeader->SetImpactParameter(fAmpt->GetHINT1(19));
620 fHeader->SetTotalEnergy(fAmpt->GetEATT());
621 fHeader->SetHardScatters(fAmpt->GetJATT());
622 fHeader->SetParticipants(fAmpt->GetNP(), fAmpt->GetNT());
623 fHeader->SetCollisions(fAmpt->GetN0(),
627 fHeader->SetSpectators(fProjectileSpecn, fProjectileSpecp,
628 fTargetSpecn,fTargetSpecp);
629 fHeader->SetReactionPlaneAngle(fAmpt->GetHINT1(20));
630 //printf("Impact Parameter %13.3f \n", fAmpt->GetHINT1(19));
632 // 4-momentum vectors of the triggered jets.
633 // Before final state gluon radiation.
634 TLorentzVector* jet1 = new TLorentzVector(fAmpt->GetHINT1(21),
637 fAmpt->GetHINT1(24));
639 TLorentzVector* jet2 = new TLorentzVector(fAmpt->GetHINT1(31),
642 fAmpt->GetHINT1(34));
643 // After final state gluon radiation.
644 TLorentzVector* jet3 = new TLorentzVector(fAmpt->GetHINT1(26),
647 fAmpt->GetHINT1(29));
649 TLorentzVector* jet4 = new TLorentzVector(fAmpt->GetHINT1(36),
652 fAmpt->GetHINT1(39));
653 fHeader->SetJets(jet1, jet2, jet3, jet4);
654 // Bookkeeping for kinematic bias
655 fHeader->SetTrials(fTrials);
657 fHeader->SetPrimaryVertex(fVertex);
658 fHeader->SetInteractionTime(fTime);
660 fCollisionGeometry = fHeader;
665 Bool_t AliGenAmpt::CheckTrigger()
667 // Check the kinematic trigger condition
669 Bool_t triggered = kFALSE;
673 TLorentzVector* jet1 = new TLorentzVector(fAmpt->GetHINT1(26),
676 fAmpt->GetHINT1(29));
678 TLorentzVector* jet2 = new TLorentzVector(fAmpt->GetHINT1(36),
681 fAmpt->GetHINT1(39));
682 Double_t eta1 = jet1->Eta();
683 Double_t eta2 = jet2->Eta();
684 Double_t phi1 = jet1->Phi();
685 Double_t phi2 = jet2->Phi();
686 //printf("\n Trigger: %f %f %f %f", fEtaMinJet, fEtaMaxJet, fPhiMinJet, fPhiMaxJet);
687 if ( (eta1 < fEtaMaxJet && eta1 > fEtaMinJet &&
688 phi1 < fPhiMaxJet && phi1 > fPhiMinJet)
690 (eta2 < fEtaMaxJet && eta2 > fEtaMinJet &&
691 phi2 < fPhiMaxJet && phi2 > fPhiMinJet)
694 } else if (fTrigger == 2) {
696 Int_t np = fParticles.GetEntriesFast();
697 for (Int_t i = 0; i < np; i++) {
698 TParticle* part = (TParticle*) fParticles.At(i);
699 Int_t kf = part->GetPdgCode();
700 Int_t ksp = part->GetUniqueID();
701 if (kf == 22 && ksp == 40) {
702 Float_t phi = part->Phi();
703 Float_t eta = part->Eta();
704 if (eta < fEtaMaxJet &&
710 } // check phi,eta within limits