TDPMjet/AliGenDPMjet.cxx

   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   *
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  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 // Generator using DPMJET as an external generator
  18 // The main DPMJET options are accessable for the user through this interface.
  19 // Uses the TDPMjet implementation of TGenerator.
  20
  21 #include <TDPMjet.h>
  22 #include <TRandom.h>
  23 #include <TArrayI.h>
  24 #include <TParticle.h>
  25 #include <TGraph.h>
  26 #include <TDatabasePDG.h>
  27 #include <TParticlePDG.h>
  28 #include <TParticleClassPDG.h>
  29 #include <TPDGCode.h>
  30 #include <TLorentzVector.h>
  31
  32 #include "AliGenDPMjet.h"
  33 #include "AliGenDPMjetEventHeader.h"
  34 #include "AliPythia.h"
  35 #include "AliRun.h"
  36 #include "AliDpmJetRndm.h"
  37
  38  ClassImp(AliGenDPMjet)
  39
  40
  41 //______________________________________________________________________________
  42 AliGenDPMjet::AliGenDPMjet()
  43                  :AliGenMC()
  44 {
  45 // Constructor
  46     fParticles = 0;
  47     fDPMjet = 0;
  48     AliDpmJetRndm::SetDpmJetRandom(GetRandom());
  49 }
  50
  51
  52 //______________________________________________________________________________
  53 AliGenDPMjet::AliGenDPMjet(Int_t npart)
  54     :AliGenMC(npart)
  55 {
  56 // Default PbPb collisions at 5. 5 TeV
  57 //
  58     fName = "DPMJET";
  59     fTitle= "Particle Generator using DPMJET";
  60
  61     SetBeamEnergy();
  62     SetEnergyCMS();
  63     SetTarget();
  64     SetProjectile();
  65     SetCentral();
  66     SetImpactParameterRange();
  67     SetBoostLHC();
  68
  69     fKeep       =  0;
  70     fDecaysOff  =  1;
  71     fEvaluate   =  0;
  72     fSelectAll  =  0;
  73     fFlavor     =  0;
  74     fSpectators =  1;
  75     fVertex.Set(3);
  76
  77     fParticles = new TClonesArray("TParticle",10000);
  78
  79     // Set random number generator
  80     fDPMjet = 0;
  81     // Instance AliPythia
  82     AliPythia::Instance();
  83     AliDpmJetRndm::SetDpmJetRandom(GetRandom());
  84 }
  85
  86
  87 //______________________________________________________________________________
  88 AliGenDPMjet::~AliGenDPMjet()
  89 {
  90 // Destructor
  91     delete fParticles;
  92 }
  93
  94
  95 //______________________________________________________________________________
  96 void AliGenDPMjet::Init()
  97 {
  98 // Initialization
  99
 100     SetMC(new TDPMjet(fAProjectile, fZProjectile, fATarget, fZTarget,
 101                       fBeamEn,fEnergyCMS));
 102
 103     fDPMjet=(TDPMjet*) fgMCEvGen;
 104     //
 105     // **** Flag to force central production
 106     // fICentr=1. central production forced
 107     // fICentr<0 && fICentr>-100 -> bmin = fMinImpactParam, bmax = fMaxImpactParam
 108     // fICentr<-99 -> fraction of x-sec. = XSFRAC
 109     // fICentr=-1. -> evaporation/fzc suppressed
 110     // fICentr<-1. -> evaporation/fzc suppressed
 111     fDPMjet->SetfFCentr(fICentr);
 112     fDPMjet->SetbRange(fMinImpactParam,fMaxImpactParam);
 113
 114 //
 115 //  Initialize DPMjet
 116 //
 117     fDPMjet->Initialize();
 118     //if (fEvaluate) EvaluateCrossSections();
 119
 120     //  Initialize AliIonPDGCodes to define ion PDG codes
 121     /*AliIonPDGCodes *PDGcodes = new AliIonPDGCodes();
 122     PDGcodes->AddParticlesToPdgDataBase();
 123     PDGcodes->MapPDGGEant3Codes();*/
 124 }
 125
 126
 127 //______________________________________________________________________________
 128 void AliGenDPMjet::Generate()
 129 {
 130 // Generate one event
 131
 132   Float_t polar[3]    =   {0,0,0};
 133   Float_t origin[3]   =   {0,0,0};
 134   Float_t origin0[3]  =   {0,0,0};
 135   Float_t p[3], random[6];
 136   Float_t tof;
 137
 138 //  converts from mm/c to s
 139   const Float_t kconv = 0.001/2.999792458e8;
 140   Int_t nt  = 0;
 141   Int_t jev = 0;
 142   Int_t j, kf, ks, imo;
 143   kf = 0;
 144
 145   fTrials = 0;
 146   for (j = 0;j < 3; j++) origin0[j] = fOrigin[j];
 147   if(fVertexSmear == kPerEvent) {
 148       Float_t dv[3];
 149       dv[2] = 1.e10;
 150       while(TMath::Abs(dv[2])>fCutVertexZ*fOsigma[2]) {
 151           Rndm(random,6);
 152           for (j=0; j < 3; j++) {
 153               dv[j] = fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
 154                   TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
 155           }
 156       }
 157       for (j=0; j < 3; j++) origin0[j] += dv[j];
 158   }
 159
 160   while(1)
 161   {
 162 //    Generate one event
 163 // --------------------------------------------------------------------------
 164       fSpecn = 0;
 165       fSpecp = 0;
 166 // --------------------------------------------------------------------------
 167       fDPMjet->GenerateEvent();
 168       fTrials++;
 169
 170       fDPMjet->ImportParticles(fParticles,"All");
 171       if (fLHC) Boost();
 172
 173       // Temporaneo
 174       fGenImpPar = fDPMjet->GetBImpac();
 175
 176       Int_t np = fParticles->GetEntriesFast();
 177       printf("\n **************************************************%d\n",np);
 178       Int_t nc=0;
 179       if (np==0) continue;
 180       Int_t i;
 181       Int_t* newPos     = new Int_t[np];
 182       Int_t* pSelected  = new Int_t[np];
 183
 184       for (i = 0; i<np; i++) {
 185           newPos[i]    = i;
 186           pSelected[i] = 0;
 187       }
 188
 189 //      Get event vertex
 190
 191       //TParticle *iparticle = (TParticle*) fParticles->At(0);
 192       fVertex[0] = origin0[0];
 193       fVertex[1] = origin0[1];
 194       fVertex[2] = origin0[2];
 195       //for(int jj=0; jj<3; jj++) printf("      fEventVertex[%d] = %f\n",jj,fEventVertex[jj]);
 196
 197 //      First select parent particles
 198
 199       for (i = 0; i<np; i++) {
 200           TParticle *iparticle = (TParticle *) fParticles->At(i);
 201           //if(!iparticle) iparticle->Print("");
 202
 203 // Is this a parent particle ?
 204
 205           if (Stable(iparticle)) continue;
 206
 207           Bool_t  selected             =  kTRUE;
 208           Bool_t  hasSelectedDaughters =  kFALSE;
 209
 210           kf = iparticle->GetPdgCode();
 211           if (kf == 92) continue;
 212           ks = iparticle->GetStatusCode();
 213 // No initial state partons
 214           if (ks==21) continue;
 215
 216           if (!fSelectAll) selected = KinematicSelection(iparticle, 0) &&
 217                                SelectFlavor(kf);
 218           hasSelectedDaughters = DaughtersSelection(iparticle);
 219
 220 // Put particle on the stack if it is either selected or
 221 // it is the mother of at least one seleted particle
 222
 223           if (selected || hasSelectedDaughters) {
 224               nc++;
 225               pSelected[i] = 1;
 226           } // selected
 227       } // particle loop parents
 228
 229 // Now select the final state particles
 230
 231
 232       for (i=0; i<np; i++) {
 233           TParticle *iparticle = (TParticle *) fParticles->At(i);
 234           //if(!iparticle) printf("     i = %d -> iparticle==0\n",i);
 235
 236 // Is this a final state particle ?
 237
 238           if (!Stable(iparticle)) continue;
 239
 240           Bool_t  selected =  kTRUE;
 241           kf = iparticle->GetPdgCode();
 242           ks = iparticle->GetStatusCode();
 243
 244 // --------------------------------------------------------------------------
 245 // Count spectator neutrons and protons (ks == 13, 14)
 246           if(ks == 13 || ks == 14){
 247               if(kf == kNeutron) fSpecn += 1;
 248               if(kf == kProton)  fSpecp += 1;
 249           }
 250 // --------------------------------------------------------------------------
 251
 252           if (!fSelectAll) {
 253               selected = KinematicSelection(iparticle,0)&&SelectFlavor(kf);
 254               if (!fSpectators && selected) selected = (ks == 13 || ks == 14);
 255           }
 256
 257 // Put particle on the stack if selected
 258
 259           if (selected) {
 260               nc++;
 261               pSelected[i] = 1;
 262           } // selected
 263       } // particle loop final state
 264
 265 // Write particles to stack
 266
 267       for (i = 0; i<np; i++) {
 268           TParticle *  iparticle = (TParticle *) fParticles->At(i);
 269           Bool_t  hasMother   = (iparticle->GetFirstMother()>=0);
 270           Bool_t  hasDaughter = (iparticle->GetFirstDaughter()>=0);
 271
 272           if (pSelected[i]) {
 273
 274               kf   = iparticle->GetPdgCode();
 275               if(kf==99999) continue;
 276               ks   = iparticle->GetStatusCode();
 277
 278               p[0] = iparticle->Px();
 279               p[1] = iparticle->Py();
 280               p[2] = iparticle->Pz();
 281               origin[0] = origin0[0]+iparticle->Vx()/10;
 282               origin[1] = origin0[1]+iparticle->Vy()/10;
 283               origin[2] = origin0[2]+iparticle->Vz()/10;
 284               tof = kconv*iparticle->T();
 285
 286               imo = -1;
 287               TParticle* mother = 0;
 288               if (hasMother) {
 289                   imo = iparticle->GetFirstMother();
 290                   mother = (TParticle *) fParticles->At(imo);
 291                   imo = (mother->GetPdgCode() != 92) ? imo = newPos[imo] : -1;
 292               } // if has mother
 293
 294               // --- Nucleons and photons from nucleus evaporation
 295               //if(ks==-1 && (kf==2212 || kf==2112 || kf==22)) imo=-1;
 296
 297               // --- Offset added to nuclei, alpha particles, deuteron
 298               // --- and triton PDG codes (according to TGeant3 PDG codes)
 299               //if(ks==1000 || ks==1001) kf += 10000000;
 300               if(kf>10000) kf += 10000000;
 301
 302               if(kf>10000 || ks==1000 || ks==1001) printf(" kf = %d, ks = %d imo = %d \n", kf,ks,imo);
 303
 304
 305               Bool_t tFlag = (fTrackIt && (ks == 1));
 306
 307 /*            // --- Particle NOT to be tracked:
 308               // --- (1) chains from valence quark system (idhkk=99999)
 309               // --- (2) quark, diquarks and gluons (idhkk=1->8,...,idhkk=21)
 310               if(kf==99999 || kf==1 || kf==2 || kf==3 || kf==4 || kf==5 ||
 311                  kf==6 || kf==7 || kf==8 || kf==21 ||
 312                  kf==1103 || kf==2101 || kf==2103 || kf==2203 || kf==3101 ||
 313                  kf==3103 || kf==3201 || kf==3203 || kf==3303 || kf==4101 ||
 314                  kf==4103 || kf==4201 || kf==4203 || kf==4301 || kf==4303 ||
 315                  kf==4403 || kf==5101 || kf==5103 || kf==5201 || kf==5203 ||
 316                  kf==5301 || kf==5303 || kf==5401 || kf==5403 || kf==5503)
 317                  tFlag=kFALSE;
 318 */
 319               SetTrack(tFlag,imo,kf,p,origin,polar,tof,kPNoProcess,nt, 1., ks);
 320               KeepTrack(nt);
 321               newPos[i] = nt;
 322           } // if selected
 323       } // particle loop
 324       delete[] newPos;
 325       delete[] pSelected;
 326
 327       printf("\n I've put %i particles on the stack \n",nc);
 328       if (nc>0) {
 329           jev += nc;
 330           if (jev >= fNpart || fNpart == -1) {
 331               printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
 332               break;
 333           }
 334           printf("\n Not breaking ### Trials: %i %i %i\n",fTrials, fNpart, jev);
 335       }
 336   } // event loop
 337   MakeHeader();
 338   SetHighWaterMark(nt);
 339 }
 340
 341
 342 //______________________________________________________________________________
 343 void AliGenDPMjet::KeepFullEvent()
 344 {
 345     fKeep=1;
 346 }
 347
 348
 349 //______________________________________________________________________________
 350 /*void AliGenDPMjet::EvaluateCrossSections()
 351 {
 352 //     Glauber Calculation of geometrical x-section
 353 //
 354     Float_t xTot       = 0.;          // barn
 355     Float_t xTotHard   = 0.;          // barn
 356     Float_t xPart      = 0.;          // barn
 357     Float_t xPartHard  = 0.;          // barn
 358     Float_t sigmaHard  = 0.1;         // mbarn
 359     Float_t bMin       = 0.;
 360     Float_t bMax       = fDPMjet->GetProjRadius()+fDPMjet->GetTargRadius();
 361     const Float_t kdib = 0.2;
 362     Int_t   kMax       = Int_t((bMax-bMin)/kdib)+1;
 363
 364
 365     printf("\n Projectile Radius (fm): %f \n",fDPMjet->GetProjRadius());
 366     printf("\n Target     Radius (fm): %f \n",fDPMjet->GetTargRadius());
 367     Int_t i;
 368     Float_t oldvalue= 0.;
 369
 370     Float_t* b   = new Float_t[kMax];
 371     Float_t* si1 = new Float_t[kMax];
 372     Float_t* si2 = new Float_t[kMax];
 373
 374     for (i = 0; i < kMax; i++)
 375     {
 376         Float_t xb  = bMin+i*kdib;
 377         Float_t ov;
 378         ov=fDPMjet->Profile(xb);
 379         // ATT!->Manca la x-sec anel. nucleone-nucleone
 380         Float_t gb  =  2.*0.01*fDPMjet->TMath::Pi()*kdib*xb*(1.-TMath::Exp(-fDPMjet->GetXSFrac()*ov));
 381         Float_t gbh =  2.*0.01*fDPMjet->TMath::Pi()*kdib*xb*sigmaHard*ov;
 382         xTot+=gb;
 383         xTotHard += gbh;
 384         if (xb > fMinImpactParam && xb < fMaxImpactParam)
 385         {
 386             xPart += gb;
 387             xPartHard += gbh;
 388         }
 389
 390         if(oldvalue) if ((xTot-oldvalue)/oldvalue<0.0001) break;
 391         oldvalue = xTot;
 392         printf("\n Total cross section (barn): %d %f %f \n",i, xb, xTot);
 393         printf("\n Hard  cross section (barn): %d %f %f \n\n",i, xb, xTotHard);
 394         if (i>0) {
 395             si1[i] = gb/kdib;
 396             si2[i] = gbh/gb;
 397             b[i]  = xb;
 398         }
 399     }
 400
 401     printf("\n Total cross section (barn): %f \n",xTot);
 402     printf("\n Hard  cross section (barn): %f \n \n",xTotHard);
 403     printf("\n Partial       cross section (barn): %f %f \n",xPart, xPart/xTot*100.);
 404     printf("\n Partial  hard cross section (barn): %f %f \n",xPartHard, xPartHard/xTotHard*100.);
 405
 406 //  Store result as a graph
 407     b[0] = 0;
 408     si1[0] = 0;
 409     si2[0]=si2[1];
 410
 411     fDsigmaDb  = new TGraph(i, b, si1);
 412     fDnDb      = new TGraph(i, b, si2);
 413 }*/
 414
 415
 416 //______________________________________________________________________________
 417 Bool_t AliGenDPMjet::DaughtersSelection(TParticle* iparticle)
 418 {
 419 //
 420 // Looks recursively if one of the daughters has been selected
 421 //
 422 //    printf("\n Consider daughters %d:",iparticle->GetPdgCode());
 423     Int_t imin = -1;
 424     Int_t imax = -1;
 425     Int_t i;
 426     Bool_t hasDaughters = (iparticle->GetFirstDaughter() >=0);
 427     Bool_t selected = kFALSE;
 428     if (hasDaughters) {
 429         imin = iparticle->GetFirstDaughter();
 430         imax = iparticle->GetLastDaughter();
 431         for (i = imin; i <= imax; i++){
 432             TParticle *  jparticle = (TParticle *) fParticles->At(i);
 433             Int_t ip = jparticle->GetPdgCode();
 434             if (KinematicSelection(jparticle,0)&&SelectFlavor(ip)) {
 435                 selected=kTRUE; break;
 436             }
 437             if (DaughtersSelection(jparticle)) {selected=kTRUE; break; }
 438         }
 439     } else {
 440         return kFALSE;
 441     }
 442     return selected;
 443 }
 444
 445
 446
 447 //______________________________________________________________________________
 448 Bool_t AliGenDPMjet::SelectFlavor(Int_t pid)
 449 {
 450 // Select flavor of particle
 451 // 0: all
 452 // 4: charm and beauty
 453 // 5: beauty
 454     Bool_t res = 0;
 455
 456     if (fFlavor == 0) {
 457         res = kTRUE;
 458     } else {
 459         Int_t ifl = TMath::Abs(pid/100);
 460         if (ifl > 10) ifl/=10;
 461         res = (fFlavor == ifl);
 462     }
 463 //
 464 //  This part if gamma writing is inhibited
 465     if (fNoGammas)
 466         res = res && (pid != kGamma && pid != kPi0);
 467 //
 468     return res;
 469 }
 470
 471 //______________________________________________________________________________
 472 Bool_t AliGenDPMjet::Stable(TParticle*  particle)
 473 {
 474 // Return true for a stable particle
 475 //
 476
 477 //    if (particle->GetFirstDaughter() < 0 ) return kTRUE;
 478     if (particle->GetStatusCode() == 1) return kTRUE;
 479     else return kFALSE;
 480
 481 }
 482
 483
 484
 485 //______________________________________________________________________________
 486 /*void AliGenDPMjet::Boost(TClonesArray* particles)
 487 {
 488 //
 489 // Boost cms into LHC lab frame
 490 //
 491     Double_t dy    = - 0.5 * TMath::Log(Double_t(fZProjectile) * Double_t(fATarget) /
 492                                       (Double_t(fZTarget)    * Double_t(fAProjectile)));
 493     Double_t beta  = TMath::TanH(dy);
 494     Double_t gamma = 1./TMath::Sqrt(1.-beta*beta);
 495     Double_t gb    = gamma * beta;
 496
 497     printf("\n Boosting particles to lab frame %f %f %f", dy, beta, gamma);
 498
 499     Int_t i;
 500     Int_t np = particles->GetEntriesFast();
 501     for (i = 0; i < np; i++)
 502     {
 503         TParticle* iparticle = (TParticle*) fParticles->At(i);
 504
 505         Double_t e   = iparticle->Energy();
 506         Double_t px  = iparticle->Px();
 507         Double_t py  = iparticle->Py();
 508         Double_t pz  = iparticle->Pz();
 509
 510         Double_t eb  = gamma * e -      gb * pz;
 511         Double_t pzb =   -gb * e +   gamma * pz;
 512
 513         iparticle->SetMomentum(px, py, pzb, eb);
 514     }
 515 }*/
 516
 517
 518
 519 //______________________________________________________________________________
 520 void AliGenDPMjet::MakeHeader()
 521 {
 522 // Builds the event header, to be called after each event
 523     AliGenEventHeader* header = new AliGenDPMjetEventHeader("DPMJET");
 524     ((AliGenDPMjetEventHeader*) header)->SetNProduced(fDPMjet->GetNumStablePc());
 525     ((AliGenDPMjetEventHeader*) header)->SetImpactParameter(fDPMjet->GetBImpac());
 526     ((AliGenDPMjetEventHeader*) header)->SetTotalEnergy(fDPMjet->GetTotEnergy());
 527 //    ((AliGenDPMjetEventHeader*) header)->SetWounded(fDPMjet->GetProjWounded(),
 528 //                                                  fDPMjet->GetTargWounded());
 529     ((AliGenDPMjetEventHeader*) header)->SetParticipants(fDPMjet->GetfIp(),
 530                                                          fDPMjet->GetfIt());
 531     /*((AliGenDPMjetEventHeader*) header)->SetCollisions(fDPMjet->GetN0(),
 532                                                        fDPMjet->GetN01(),
 533                                                        fDPMjet->GetN10(),
 534                                                        fDPMjet->GetN11());*/
 535     ((AliGenDPMjetEventHeader*) header)->SetSpectators(fSpecn, fSpecp);
 536
 537 // Bookkeeping for kinematic bias
 538     ((AliGenDPMjetEventHeader*) header)->SetTrials(fTrials);
 539 // Event Vertex
 540     header->SetPrimaryVertex(fVertex);
 541     gAlice->SetGenEventHeader(header);
 542 }
 543
 544
 545
 546 //______________________________________________________________________________
 547 AliGenDPMjet& AliGenDPMjet::operator=(const  AliGenDPMjet& rhs)
 548 {
 549 // Assignment operator
 550     return *this;
 551 }
 552
 553
 554
 555 //______________________________________________________________________________