TDPMjet/AliGenDPMjet.cxx

   1 /**************************************************************************
   2  * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
   3  *                                                                        *
   4  * Author: The ALICE Off-line Project.                                    *
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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     SetEnergyCMS();
  62     SetTarget();
  63     SetProjectile();
  64     SetCentral();
  65     SetImpactParameterRange();
  66     SetBoostLHC();
  67
  68     fKeep       =  0;
  69     fDecaysOff  =  1;
  70     fEvaluate   =  0;
  71     fSelectAll  =  0;
  72     fFlavor     =  0;
  73     fSpectators =  1;
  74     fVertex.Set(3);
  75
  76     fParticles = new TClonesArray("TParticle",10000);
  77
  78     // Set random number generator
  79     fDPMjet = 0;
  80     // Instance AliPythia
  81     AliPythia::Instance();
  82     AliDpmJetRndm::SetDpmJetRandom(GetRandom());
  83 }
  84
  85 AliGenDPMjet::AliGenDPMjet(const AliGenDPMjet &/*Dpmjet*/)
  86 :AliGenMC()
  87 {
  88 }
  89
  90 //______________________________________________________________________________
  91 AliGenDPMjet::~AliGenDPMjet()
  92 {
  93 // Destructor
  94     delete fParticles;
  95 }
  96
  97
  98 //______________________________________________________________________________
  99 void AliGenDPMjet::Init()
 100 {
 101 // Initialization
 102
 103     SetMC(new TDPMjet(fProcess, fAProjectile, fZProjectile, fATarget, fZTarget,
 104                       fBeamEn,fEnergyCMS));
 105
 106     fDPMjet=(TDPMjet*) fMCEvGen;
 107     //
 108     // **** Flag to force central production
 109     // fICentr=1. central production forced
 110     // fICentr<0 && fICentr>-100 -> bmin = fMinImpactParam, bmax = fMaxImpactParam
 111     // fICentr<-99 -> fraction of x-sec. = XSFRAC
 112     // fICentr=-1. -> evaporation/fzc suppressed
 113     // fICentr<-1. -> evaporation/fzc suppressed
 114     if (fAProjectile == 1 && fZProjectile == 1) fDPMjet->SetfIdp(1);
 115
 116     fDPMjet->SetfFCentr(fICentr);
 117     fDPMjet->SetbRange(fMinImpactParam, fMaxImpactParam);
 118
 119 //
 120 //  Initialize DPMjet
 121 //
 122     fDPMjet->Initialize();
 123 }
 124
 125
 126 //______________________________________________________________________________
 127 void AliGenDPMjet::Generate()
 128 {
 129 // Generate one event
 130
 131   Float_t polar[3]    =   {0,0,0};
 132   Float_t origin[3]   =   {0,0,0};
 133   Float_t origin0[3]  =   {0,0,0};
 134   Float_t p[3];
 135   Float_t tof;
 136
 137 //  converts from mm/c to s
 138   const Float_t kconv = 0.001/2.999792458e8;
 139   Int_t nt  = 0;
 140   Int_t jev = 0;
 141   Int_t kf, ks, imo;
 142   kf = 0;
 143   fTrials = 0;
 144   //  Set collision vertex position
 145   if (fVertexSmear == kPerEvent) Vertex();
 146
 147   while(1)
 148   {
 149 //    Generate one event
 150 // --------------------------------------------------------------------------
 151       fSpecn = 0;
 152       fSpecp = 0;
 153 // --------------------------------------------------------------------------
 154       fDPMjet->GenerateEvent();
 155       fTrials++;
 156
 157       fDPMjet->ImportParticles(fParticles,"All");
 158       if (fLHC) Boost();
 159
 160       // Temporaneo
 161       fGenImpPar = fDPMjet->GetBImpac();
 162
 163       Int_t np = fParticles->GetEntriesFast();
 164       printf("\n **************************************************%d\n",np);
 165       Int_t nc=0;
 166       if (np==0) continue;
 167       Int_t i;
 168       Int_t* newPos     = new Int_t[np];
 169       Int_t* pSelected  = new Int_t[np];
 170
 171       for (i = 0; i<np; i++) {
 172           newPos[i]    = i;
 173           pSelected[i] = 0;
 174       }
 175
 176 //      Get event vertex
 177
 178       fVertex[0] = origin0[0];
 179       fVertex[1] = origin0[1];
 180       fVertex[2] = origin0[2];
 181
 182 //      First select parent particles
 183
 184       for (i = 0; i<np; i++) {
 185           TParticle *iparticle = (TParticle *) fParticles->At(i);
 186
 187 // Is this a parent particle ?
 188
 189           if (Stable(iparticle)) continue;
 190
 191           Bool_t  selected             =  kTRUE;
 192           Bool_t  hasSelectedDaughters =  kFALSE;
 193
 194           kf = iparticle->GetPdgCode();
 195           if (kf == 92) continue;
 196           ks = iparticle->GetStatusCode();
 197 // No initial state partons
 198           if (ks==21) continue;
 199
 200           if (!fSelectAll) selected = KinematicSelection(iparticle, 0) &&
 201                                SelectFlavor(kf);
 202           hasSelectedDaughters = DaughtersSelection(iparticle);
 203
 204 // Put particle on the stack if it is either selected or
 205 // it is the mother of at least one seleted particle
 206
 207           if (selected || hasSelectedDaughters) {
 208               nc++;
 209               pSelected[i] = 1;
 210           } // selected
 211       } // particle loop parents
 212
 213 // Now select the final state particles
 214
 215
 216       for (i=0; i<np; i++) {
 217           TParticle *iparticle = (TParticle *) fParticles->At(i);
 218
 219 // Is this a final state particle ?
 220
 221           if (!Stable(iparticle)) continue;
 222
 223           Bool_t  selected =  kTRUE;
 224           kf = iparticle->GetPdgCode();
 225           ks = iparticle->GetStatusCode();
 226
 227 // --------------------------------------------------------------------------
 228 // Count spectator neutrons and protons (ks == 13, 14)
 229           if(ks == 13 || ks == 14){
 230               if(kf == kNeutron) fSpecn += 1;
 231               if(kf == kProton)  fSpecp += 1;
 232           }
 233 // --------------------------------------------------------------------------
 234
 235           if (!fSelectAll) {
 236               selected = KinematicSelection(iparticle,0)&&SelectFlavor(kf);
 237               if (!fSpectators && selected) selected = (ks == 13 || ks == 14);
 238           }
 239
 240 // Put particle on the stack if selected
 241
 242           if (selected) {
 243               nc++;
 244               pSelected[i] = 1;
 245           } // selected
 246       } // particle loop final state
 247
 248 // Write particles to stack
 249
 250       for (i = 0; i<np; i++) {
 251           TParticle *  iparticle = (TParticle *) fParticles->At(i);
 252           Bool_t  hasMother   = (iparticle->GetFirstMother()>=0);
 253           if (pSelected[i]) {
 254
 255               kf   = iparticle->GetPdgCode();
 256               ks   = iparticle->GetStatusCode();
 257
 258               p[0] = iparticle->Px();
 259               p[1] = iparticle->Py();
 260               p[2] = iparticle->Pz();
 261               origin[0] = fVertex[0]+iparticle->Vx()/10; // [cm]
 262               origin[1] = fVertex[1]+iparticle->Vy()/10; // [cm]
 263               origin[2] = fVertex[2]+iparticle->Vz()/10; // [cm]
 264
 265               tof = kconv*iparticle->T();
 266
 267               imo = -1;
 268               TParticle* mother = 0;
 269               if (hasMother) {
 270                   imo = iparticle->GetFirstMother();
 271                   mother = (TParticle *) fParticles->At(imo);
 272                   imo = (mother->GetPdgCode() != 92) ? imo = newPos[imo] : -1;
 273               } // if has mother
 274
 275               Bool_t tFlag = (fTrackIt && (ks == 1));
 276
 277               PushTrack(tFlag,imo,kf,p,origin,polar,tof,kPNoProcess,nt, 1., ks);
 278               KeepTrack(nt);
 279               newPos[i] = nt;
 280           } // if selected
 281       } // particle loop
 282       delete[] newPos;
 283       delete[] pSelected;
 284       if (nc>0) {
 285           jev += nc;
 286           if (jev >= fNpart || fNpart == -1) {
 287               break;
 288           }
 289       }
 290   } // event loop
 291   MakeHeader();
 292   SetHighWaterMark(nt);
 293 }
 294
 295
 296 //______________________________________________________________________________
 297 void AliGenDPMjet::KeepFullEvent()
 298 {
 299     fKeep=1;
 300 }
 301
 302
 303 //______________________________________________________________________________
 304 /*void AliGenDPMjet::EvaluateCrossSections()
 305 {
 306 //     Glauber Calculation of geometrical x-section
 307 //
 308     Float_t xTot       = 0.;          // barn
 309     Float_t xTotHard   = 0.;          // barn
 310     Float_t xPart      = 0.;          // barn
 311     Float_t xPartHard  = 0.;          // barn
 312     Float_t sigmaHard  = 0.1;         // mbarn
 313     Float_t bMin       = 0.;
 314     Float_t bMax       = fDPMjet->GetProjRadius()+fDPMjet->GetTargRadius();
 315     const Float_t kdib = 0.2;
 316     Int_t   kMax       = Int_t((bMax-bMin)/kdib)+1;
 317
 318
 319     printf("\n Projectile Radius (fm): %f \n",fDPMjet->GetProjRadius());
 320     printf("\n Target     Radius (fm): %f \n",fDPMjet->GetTargRadius());
 321     Int_t i;
 322     Float_t oldvalue= 0.;
 323
 324     Float_t* b   = new Float_t[kMax];
 325     Float_t* si1 = new Float_t[kMax];
 326     Float_t* si2 = new Float_t[kMax];
 327
 328     for (i = 0; i < kMax; i++)
 329     {
 330         Float_t xb  = bMin+i*kdib;
 331         Float_t ov;
 332         ov=fDPMjet->Profile(xb);
 333         // ATT!->Manca la x-sec anel. nucleone-nucleone
 334         Float_t gb  =  2.*0.01*fDPMjet->TMath::Pi()*kdib*xb*(1.-TMath::Exp(-fDPMjet->GetXSFrac()*ov));
 335         Float_t gbh =  2.*0.01*fDPMjet->TMath::Pi()*kdib*xb*sigmaHard*ov;
 336         xTot+=gb;
 337         xTotHard += gbh;
 338         if (xb > fMinImpactParam && xb < fMaxImpactParam)
 339         {
 340             xPart += gb;
 341             xPartHard += gbh;
 342         }
 343
 344         if(oldvalue) if ((xTot-oldvalue)/oldvalue<0.0001) break;
 345         oldvalue = xTot;
 346         printf("\n Total cross section (barn): %d %f %f \n",i, xb, xTot);
 347         printf("\n Hard  cross section (barn): %d %f %f \n\n",i, xb, xTotHard);
 348         if (i>0) {
 349             si1[i] = gb/kdib;
 350             si2[i] = gbh/gb;
 351             b[i]  = xb;
 352         }
 353     }
 354
 355     printf("\n Total cross section (barn): %f \n",xTot);
 356     printf("\n Hard  cross section (barn): %f \n \n",xTotHard);
 357     printf("\n Partial       cross section (barn): %f %f \n",xPart, xPart/xTot*100.);
 358     printf("\n Partial  hard cross section (barn): %f %f \n",xPartHard, xPartHard/xTotHard*100.);
 359
 360 //  Store result as a graph
 361     b[0] = 0;
 362     si1[0] = 0;
 363     si2[0]=si2[1];
 364
 365     fDsigmaDb  = new TGraph(i, b, si1);
 366     fDnDb      = new TGraph(i, b, si2);
 367 }*/
 368
 369
 370 //______________________________________________________________________________
 371 Bool_t AliGenDPMjet::DaughtersSelection(TParticle* iparticle)
 372 {
 373 //
 374 // Looks recursively if one of the daughters has been selected
 375 //
 376 //    printf("\n Consider daughters %d:",iparticle->GetPdgCode());
 377     Int_t imin = -1;
 378     Int_t imax = -1;
 379     Int_t i;
 380     Bool_t hasDaughters = (iparticle->GetFirstDaughter() >=0);
 381     Bool_t selected = kFALSE;
 382     if (hasDaughters) {
 383         imin = iparticle->GetFirstDaughter();
 384         imax = iparticle->GetLastDaughter();
 385         for (i = imin; i <= imax; i++){
 386             TParticle *  jparticle = (TParticle *) fParticles->At(i);
 387             Int_t ip = jparticle->GetPdgCode();
 388             if (KinematicSelection(jparticle,0)&&SelectFlavor(ip)) {
 389                 selected=kTRUE; break;
 390             }
 391             if (DaughtersSelection(jparticle)) {selected=kTRUE; break; }
 392         }
 393     } else {
 394         return kFALSE;
 395     }
 396     return selected;
 397 }
 398
 399
 400
 401 //______________________________________________________________________________
 402 Bool_t AliGenDPMjet::SelectFlavor(Int_t pid)
 403 {
 404 // Select flavor of particle
 405 // 0: all
 406 // 4: charm and beauty
 407 // 5: beauty
 408     Bool_t res = 0;
 409
 410     if (fFlavor == 0) {
 411         res = kTRUE;
 412     } else {
 413         Int_t ifl = TMath::Abs(pid/100);
 414         if (ifl > 10) ifl/=10;
 415         res = (fFlavor == ifl);
 416     }
 417 //
 418 //  This part if gamma writing is inhibited
 419     if (fNoGammas)
 420         res = res && (pid != kGamma && pid != kPi0);
 421 //
 422     return res;
 423 }
 424
 425 //______________________________________________________________________________
 426 Bool_t AliGenDPMjet::Stable(TParticle*  particle)
 427 {
 428 // Return true for a stable particle
 429 //
 430
 431 //    if (particle->GetFirstDaughter() < 0 ) return kTRUE;
 432     if (particle->GetStatusCode() == 1) return kTRUE;
 433     else return kFALSE;
 434
 435 }
 436
 437 //______________________________________________________________________________
 438 void AliGenDPMjet::MakeHeader()
 439 {
 440 // Builds the event header, to be called after each event
 441     AliGenEventHeader* header = new AliGenDPMjetEventHeader("DPMJET");
 442     ((AliGenDPMjetEventHeader*) header)->SetNProduced(fDPMjet->GetNumStablePc());
 443     ((AliGenDPMjetEventHeader*) header)->SetImpactParameter(fDPMjet->GetBImpac());
 444     ((AliGenDPMjetEventHeader*) header)->SetTotalEnergy(fDPMjet->GetTotEnergy());
 445     ((AliGenDPMjetEventHeader*) header)->SetParticipants(fDPMjet->GetfIp(),
 446                                                          fDPMjet->GetfIt());
 447
 448 // Bookkeeping for kinematic bias
 449     ((AliGenDPMjetEventHeader*) header)->SetTrials(fTrials);
 450 // Event Vertex
 451     header->SetPrimaryVertex(fVertex);
 452     gAlice->SetGenEventHeader(header);
 453 }
 454
 455
 456
 457 //______________________________________________________________________________
 458 AliGenDPMjet& AliGenDPMjet::operator=(const  AliGenDPMjet& /*rhs*/)
 459 {
 460 // Assignment operator
 461     return *this;
 462 }
 463
 464
 465
 466 //______________________________________________________________________________