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 *
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11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
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14 **************************************************************************/
16 // $Id: AliCollider.cxx,v 1.12 2004/05/04 15:33:04 nick Exp $
18 ///////////////////////////////////////////////////////////////////////////
20 // Pythia based universal physics event generator.
21 // This class is derived from TPythia6 and has some extensions to
22 // support also generation of nucleus-nucleus interactions and to allow
23 // investigation of the effect of detector resolving power.
24 // Furthermore, the produced event information is provided in a format
25 // using the AliEvent structure.
26 // For the produced AliTrack objects, the particle ID code is set to the
27 // Pythia KF value, which is compatible with the PDG identifier.
28 // This will allow a direct analysis of the produced data using the
29 // Ralice physics analysis tools.
31 // For further details concerning the produced output structure,
32 // see the docs of the memberfunctions SetVertexMode and SetResolution.
34 // Example job of minimum biased Pb+Pb interactions :
35 // --------------------------------------------------
37 // gSystem->Load("libEG");
38 // gSystem->Load("libEGPythia6");
39 // gSystem->Load("ralice");
41 // AliCollider* gen=new AliCollider();
43 // gen->SetOutputFile("test.root");
44 // gen->SetVertexMode(3);
45 // gen->SetResolution(1e-6); // 1 micron vertex resolution
47 // gen->SetRunNumber(1);
54 // gen->Init("fixt",zp,ap,zt,at,158);
56 // gen->SetTitle("SPS Pb-Pb collision at 158A GeV/c beam energy");
61 // Float_t* rans=new Float_t[nevents];
62 // rndm.Uniform(rans,nevents,2,ap+at);
64 // for (Int_t i=0; i<nevents; i++)
67 // gen->MakeEvent(npart);
69 // AliEvent* evt=gen->GetEvent();
78 // Example job of a cosmic nu+p atmospheric interaction.
79 // -----------------------------------------------------
81 // gSystem->Load("libEG");
82 // gSystem->Load("libEGPythia6");
83 // gSystem->Load("ralice");
85 // AliCollider* gen=new AliCollider();
87 // gen->SetOutputFile("test.root");
89 // gen->SetRunNumber(1);
91 // gen->Init("fixt","nu_mu","p",1e11);
93 // gen->SetTitle("Atmospheric nu_mu-p interaction at 1e20 eV");
97 // for (Int_t i=0; i<nevents; i++)
99 // gen->MakeEvent(0,1);
101 // AliEvent* evt=gen->GetEvent();
110 //--- Author: Nick van Eijndhoven 22-nov-2002 Utrecht University
111 //- Modified: NvE $Date: 2004/05/04 15:33:04 $ Utrecht University
112 ///////////////////////////////////////////////////////////////////////////
114 #include "AliCollider.h"
115 #include "Riostream.h"
117 ClassImp(AliCollider) // Class implementation to enable ROOT I/O
119 AliCollider::AliCollider() : TPythia6()
121 // Default constructor.
122 // All variables initialised to default values.
124 // Some Pythia default MC parameters are automatically modified to provide
125 // more suitable running conditions for soft processes in view of
126 // nucleus-nucleus interactions and astrophysical processes.
127 // The user may initialise the generator with all the default Pythia
128 // parameters and obtain full user control to modify the settings by means
129 // of the SetUserControl memberfunction.
131 // Refer to the SetElastic memberfunction for the inclusion of elastic
132 // and diffractive processes.
133 // By default these processes are not included.
135 fVertexmode=0; // No vertex structure creation
136 fResolution=1e-7; // Standard resolution is 0.1 micron
140 fUserctrl=0; // Automatic optimisation of some MC parameters
141 fElastic=0; // No elastic and diffractive processes
170 ///////////////////////////////////////////////////////////////////////////
171 AliCollider::~AliCollider()
173 // Default destructor
195 ///////////////////////////////////////////////////////////////////////////
196 void AliCollider::SetOutputFile(TString s)
198 // Create the output file containing all the data in ROOT output format.
204 fOutFile=new TFile(s.Data(),"RECREATE","AliCollider data");
211 fOutTree=new TTree("T","AliCollider event data");
215 fOutTree->Branch("Events","AliEvent",&fEvent,bsize,split);
217 ///////////////////////////////////////////////////////////////////////////
218 void AliCollider::SetVertexMode(Int_t mode)
220 // Set the mode of the vertex structure creation.
222 // By default all generated tracks will only appear in the AliEvent
223 // structure without any primary (and secondary) vertex structure.
224 // The user can build the vertex structure if he/she wants by means
225 // of the beginpoint location of each AliTrack.
227 // However, one can also let AliCollider automatically create
228 // the primary (and secondary) vertex structure(s).
229 // In this case the primary vertex is given Id=1 and all sec. vertices
230 // are given Id's 2,3,4,....
231 // All vertices are created as standalone entities in the AliEvent structure
232 // without any linking between the various vertices.
233 // For this automated process, the user-selected resolution
234 // (see SetResolution) is used to decide whether or not certain vertex
235 // locations can be resolved.
236 // In case no vertex creation is selected (i.e. the default mode=0),
237 // the value of the resolution is totally irrelevant.
239 // The user can also let AliCollider automatically connect the sec. vertices
240 // to the primary vertex (i.e. mode=3). This process will also automatically
241 // generate the tracks connecting the vertices.
242 // Note that the result of the mode=3 operation may be very sensitive to
243 // the resolution parameter. Therefore, no attempt is made to distinguish
244 // between secondary, tertiary etc... vertices. All sec. vertices are
245 // linked to the primary one.
247 // Irrespective of the selected mode, all generated tracks can be obtained
248 // directly from the AliEvent structure.
249 // In case (sec.) vertex creation is selected, all generated vertices can
250 // also be obtained directly from the AliEvent structure.
251 // These (sec.) vertices contain only the corresponding pointers to the various
252 // tracks which are stored in the AliEvent structure.
254 // Overview of vertex creation modes :
255 // -----------------------------------
256 // mode = 0 ==> No vertex structure will be created
257 // 1 ==> Only primary vertex structure will be created
258 // 2 ==> Unconnected primary and secondary vertices will be created
259 // 3 ==> Primary and secondary vertices will be created where all the
260 // sec. vertices will be connected to the primary vertex.
261 // Also the vertex connecting tracks will be automatically
264 if (mode<0 || mode >3)
266 cout << " *AliCollider::SetVertexMode* Invalid argument mode : " << mode << endl;
274 ///////////////////////////////////////////////////////////////////////////
275 Int_t AliCollider::GetVertexMode() const
277 // Provide the current mode for vertex structure creation.
280 ///////////////////////////////////////////////////////////////////////////
281 void AliCollider::SetResolution(Double_t res)
283 // Set the resolution (in meter) for resolving (sec.) vertices.
284 // By default this resolution is set to 0.1 micron.
285 // Note : In case no vertex creation has been selected, the value of
286 // the resolution is totally irrelevant.
287 fResolution=fabs(res);
289 ///////////////////////////////////////////////////////////////////////////
290 Double_t AliCollider::GetResolution() const
292 // Provide the current resolution (in meter) for resolving (sec.) vertices.
295 ///////////////////////////////////////////////////////////////////////////
296 void AliCollider::SetRunNumber(Int_t run)
298 // Set the user defined run number.
299 // By default the run number is set to 0.
302 ///////////////////////////////////////////////////////////////////////////
303 Int_t AliCollider::GetRunNumber() const
305 // Provide the user defined run number.
308 ///////////////////////////////////////////////////////////////////////////
309 void AliCollider::SetPrintFreq(Int_t n)
311 // Set the print frequency for every 'n' events.
312 // By default the printfrequency is set to 1 (i.e. every event).
315 ///////////////////////////////////////////////////////////////////////////
316 Int_t AliCollider::GetPrintFreq() const
318 // Provide the user selected print frequency.
321 ///////////////////////////////////////////////////////////////////////////
322 void AliCollider::SetUserControl(Int_t flag)
324 // Set the user control flag w.r.t. disabling automatic optimisation
325 // of some Pythia default MC parameters for soft interactions in view of
326 // nucleus-nucleus collisions and astrophysical processes.
327 // Flag = 0 : Limited user control (automatic optimisation enabled)
328 // 1 : Full user control (automatic optimisation disabled)
329 // By default the user control is set to 0 (i.e. automatic optimisation).
330 // See the Init() memberfunctions for further details w.r.t. the optimisations.
333 ///////////////////////////////////////////////////////////////////////////
334 Int_t AliCollider::GetUserControl() const
336 // Provide the value of the user control flag.
339 ///////////////////////////////////////////////////////////////////////////
340 void AliCollider::SetElastic(Int_t flag)
342 // Set the flag w.r.t. inclusion of elastic and diffractive processes.
343 // By default these processes are not included.
344 // Flag = 0 : Do not include elastic and diffractive processes
345 // 1 : Elastic and diffractive processes will be included
348 ///////////////////////////////////////////////////////////////////////////
349 Int_t AliCollider::GetElastic() const
351 // Provide the value of the control flag for elastic and diffractive processes.
354 ///////////////////////////////////////////////////////////////////////////
355 void AliCollider::Init(char* frame,char* beam,char* target,Float_t win)
357 // Initialisation of the underlying Pythia generator package.
358 // The event number is reset to 0.
359 // This routine just invokes TPythia6::Initialize(...) and the arguments
360 // have the corresponding meaning.
361 // Some Pythia default MC parameters are automatically modified to provide
362 // more suitable running conditions for soft processes in view of
363 // astrophysical processes.
364 // The optimisations consist of :
365 // * Usage of real photons for photon beams or targets
366 // * Minimum CMS energy of 3 GeV for the event
367 // * Activation of the default K factor values
368 // with separate settings for ordinary and color annihilation graphs.
369 // The user may initialise the generator with all the default Pythia
370 // parameters and obtain full user control to modify the settings by means
371 // of invoking the SetUserControl memberfunction before this initialisation.
372 // Note that the inclusion of elastic and diffractive processes is controlled
373 // by invokation of the SetElastic memberfunction before this initialisation,
374 // irrespective of the UserControl selection.
376 if (!fUserctrl) // Optimisation of some MC parameters
378 SetMSTP(14,10); // Real photons for photon beams or targets
379 SetPARP(2,3.); // Minimum CMS energy for the event
380 SetMSTP(33,2); // Activate K factor. Separate for ordinary and color annih. graphs
383 if (fElastic) SetMSEL(2); // Include low-Pt, elastic and diffractive events
389 Initialize(frame,beam,target,win);
392 cout << " *AliCollider::Init* Standard Pythia initialisation." << endl;
393 cout << " Beam particle : " << beam << " Target particle : " << target
394 << " Frame = " << frame << " Energy = " << win
397 ///////////////////////////////////////////////////////////////////////////
398 void AliCollider::Init(char* frame,Int_t zp,Int_t ap,Int_t zt,Int_t at,Float_t win)
400 // Initialisation of the underlying Pythia generator package for the generation
401 // of nucleus-nucleus interactions.
402 // The event number is reset to 0.
403 // In addition to the Pythia standard arguments 'frame' and 'win', the user
404 // can specify here (Z,A) values of the projectile and target nuclei.
406 // Note : The 'win' value denotes either the cms energy per nucleon-nucleon collision
407 // (i.e. frame="cms") or the momentum per nucleon in all other cases.
409 // Some Pythia default MC parameters are automatically modified to provide
410 // more suitable running conditions for soft processes in view of
411 // nucleus-nucleus interactions and astrophysical processes.
412 // The optimisations consist of :
413 // * Minimum CMS energy of 3 GeV for the event
414 // * Activation of the default K factor values
415 // with separate settings for ordinary and color annihilation graphs.
416 // The user may initialise the generator with all the default Pythia
417 // parameters and obtain full user control to modify the settings by means
418 // of invoking the SetUserControl memberfunction before this initialisation.
419 // Note that the inclusion of elastic and diffractive processes is controlled
420 // by invokation of the SetElastic memberfunction before this initialisation,
421 // irrespective of the UserControl selection.
423 if (!fUserctrl) // Optimisation of some MC parameters
425 SetPARP(2,3.); // Minimum CMS energy for the event
426 SetMSTP(33,2); // Activate K factor. Separate for ordinary and color annih. graphs
429 if (fElastic) SetMSEL(2); // Include low-Pt, elastic and diffractive events
444 if (ap<1 || at<1 || zp>ap || zt>at)
447 cout << " *AliCollider::Init* Invalid input value(s). Zproj = " << zp
448 << " Aproj = " << ap << " Ztarg = " << zt << " Atarg = " << at << endl;
458 cout << " *AliCollider::Init* Nucleus-Nucleus generator initialisation." << endl;
459 cout << " Zproj = " << zp << " Aproj = " << ap << " Ztarg = " << zt << " Atarg = " << at
460 << " Frame = " << frame << " Energy = " << win
463 ///////////////////////////////////////////////////////////////////////////
464 void AliCollider::GetFractions(Float_t zp,Float_t ap,Float_t zt,Float_t at)
466 // Determine the fractions for the various N-N collision processes.
467 // The various processes are : p+p, n+p, p+n and n+n.
478 fFracpp=(zp/ap)*(zt/at);
479 fFracnp=(1.-zp/ap)*(zt/at);
480 fFracpn=(zp/ap)*(1.-zt/at);
481 fFracnn=(1.-zp/ap)*(1.-zt/at);
484 ///////////////////////////////////////////////////////////////////////////
485 void AliCollider::MakeEvent(Int_t npt,Int_t mlist,Int_t medit)
487 // Generate one event.
488 // In case of a nucleus-nucleus interaction, the argument 'npt' denotes
489 // the number of participant nucleons.
490 // Normally also the spectator tracks will be stored into the event structure.
491 // The spectator tracks have a negative user Id to distinguish them from the
492 // ordinary generated tracks.
493 // In case the user has selected the creation of vertex structures, the spectator
494 // tracks will be linked to the primary vertex.
495 // However, specification of npt<0 will suppress the storage of spectator tracks.
496 // In the latter case abs(npt) will be taken as the number of participants.
497 // In case of a standard Pythia run for 'elementary' particle interactions,
498 // the value of npt is totally irrelevant.
500 // The argument 'mlist' denotes the list mode used for Pylist().
501 // Note : mlist<0 suppresses the invokation of Pylist().
502 // By default, no listing is produced (i.e. mlist=-1).
504 // The argument 'medit' denotes the edit mode used for Pyedit().
505 // Note : medit<0 suppresses the invokation of Pyedit().
506 // By default, only 'stable' final particles are kept (i.e. medit=1).
508 // In the case of a standard Pythia run concerning 'elementary' particle
509 // interactions, the projectile and target particle ID's for the created
510 // event structure are set to the corresponding Pythia KF codes.
511 // All the A and Z values are in that case set to zero.
512 // In case of a nucleus-nucleus interaction, the proper A and Z values for
513 // the projectile and target particles are set in the event structure.
514 // However, in this case both particle ID's are set to zero.
516 // Note : Only in case an event passed the selection criteria as specified
517 // via SelectEvent(), the event will appear on the output file.
528 // Counters for the various (proj,targ) combinations : p+p, n+p, p+n and n+n
529 Int_t ncols[4]={0,0,0,0};
539 if (npt<1 || npt>(fAproj+fAtarg))
541 cout << " *AliCollider::MakeEvent* Invalid input value. npt = " << npt
542 << " Aproj = " << fAproj << " Atarg = " << fAtarg << endl;
546 // Determine the number of nucleon-nucleon collisions
548 if (npt%2 && fRan.Uniform()>0.5) ncol+=1;
550 // Determine the number of the various types of N+N interactions
555 Int_t maxa=2; // Indicator whether proj (1) or target (2) has maximal A left
557 Float_t* rans=new Float_t[ncol];
558 fRan.Uniform(rans,ncol);
560 for (Int_t i=0; i<ncol; i++)
562 GetFractions(zp,ap,zt,at);
564 if (rndm<=fFracpp) // p+p interaction
578 if (rndm>fFracpp && rndm<=(fFracpp+fFracnp)) // n+p interaction
591 if (rndm>(fFracpp+fFracnp) && rndm<=(fFracpp+fFracnp+fFracpn)) // p+n interaction
604 if (rndm>(fFracpp+fFracnp+fFracpn)) // n+n interaction
620 if (!(fEventnum%fPrintfreq))
622 cout << " *AliCollider::MakeEvent* Run : " << fRunnum << " Event : " << fEventnum
626 cout << " npart = " << npt << " ncol = " << ncol
627 << " ncolpp = " << ncols[0] << " ncolnp = " << ncols[1]
628 << " ncolpn = " << ncols[2] << " ncolnn = " << ncols[3] << endl;
634 fEvent=new AliEvent();
636 fEvent->SetName(GetName());
637 fEvent->SetTitle(GetTitle());
641 fEvent->SetRunNumber(fRunnum);
642 fEvent->SetEventNumber(fEventnum);
649 Ali3Vector pproj,ptarg;
653 // Make sure the primary vertex gets correct location and Id=1
657 r.SetPosition(v,"car");
661 r.SetPositionErrors(v,"car");
664 vert.SetTrackCopy(0);
665 vert.SetVertexCopy(0);
667 fEvent->AddVertex(vert,0);
671 Float_t charge=0,mass=0;
676 // Singular settings for a normal Pythia elementary particle interation
683 // Generate all the various collisions
684 fSelect=0; // Flag to indicate whether the total event is selected or not
685 Int_t select=0; // Flag to indicate whether the sub-event is selected or not
686 Int_t first=1; // Flag to indicate the first collision process
690 for (Int_t itype=0; itype<ntypes; itype++)
694 if (itype==0 && ncols[itype]) Initialize(fFrame,"p","p",fWin);
695 if (itype==1 && ncols[itype]) Initialize(fFrame,"n","p",fWin);
696 if (itype==2 && ncols[itype]) Initialize(fFrame,"p","n",fWin);
697 if (itype==3 && ncols[itype]) Initialize(fFrame,"n","n",fWin);
699 for (Int_t jcol=0; jcol<ncols[itype]; jcol++)
704 if (select) fSelect=1;
706 if (first) // Store generator parameter information in the event structure
708 // Enter generator parameters as a device in the event
710 params.SetNameTitle("AliCollider","AliCollider generator parameters");
711 params.SetSlotName("Medit",1);
712 params.SetSlotName("Vertexmode",2);
713 params.SetSlotName("Resolution",3);
714 params.SetSlotName("Userctrl",4);
715 params.SetSlotName("Elastic",5);
717 params.SetSignal(medit,1);
718 params.SetSignal(fVertexmode,2);
719 params.SetSignal(fResolution,3);
720 params.SetSignal(fUserctrl,4);
721 params.SetSignal(fElastic,5);
723 // Store projectile and target information in the event structure
729 pproj.SetVector(v,"car");
730 pnucl=pproj.GetNorm();
731 fEvent->SetProjectile(fAproj,fZproj,pnucl);
735 ptarg.SetVector(v,"car");
736 pnucl=ptarg.GetNorm();
737 fEvent->SetTarget(fAtarg,fZtarg,pnucl);
739 params.AddNamedSlot("specmode");
740 params.AddNamedSlot("Specpmin");
741 params.AddNamedSlot("npart");
742 params.AddNamedSlot("ncolpp");
743 params.AddNamedSlot("ncolnp");
744 params.AddNamedSlot("ncolpn");
745 params.AddNamedSlot("ncolnn");
747 params.SetSignal(specmode,"specmode");
748 params.SetSignal(fSpecpmin,"Specpmin");
749 params.SetSignal(npt,"npart");
750 params.SetSignal(ncols[0],"ncolpp");
751 params.SetSignal(ncols[1],"ncolnp");
752 params.SetSignal(ncols[2],"ncolpn");
753 params.SetSignal(ncols[3],"ncolnn");
760 pnucl=sqrt(v[0]*v[0]+v[1]*v[1]+v[2]*v[2]);
762 fEvent->SetProjectile(0,0,pnucl,kf);
766 pnucl=sqrt(v[0]*v[0]+v[1]*v[1]+v[2]*v[2]);
768 fEvent->SetTarget(0,0,pnucl,kf);
771 fEvent->AddDevice(params);
776 if (medit >= 0) Pyedit(medit); // Define which particles are to be kept
778 if (mlist>=0 && select)
785 for (Int_t jpart=1; jpart<=npart; jpart++)
788 charge=Pychge(kf)/3.;
792 // 3-momentum in GeV/c
796 p.SetVector(v,"car");
798 // Production location in meter.
799 v[0]=GetV(jpart,1)/1000.;
800 v[1]=GetV(jpart,2)/1000.;
801 v[2]=GetV(jpart,3)/1000.;
802 r.SetPosition(v,"car");
808 t.SetParticleCode(kf);
809 t.SetName(name.Data());
817 // Build the vertex structures if requested
820 // Check if track belongs within the resolution to an existing vertex
822 for (Int_t jv=1; jv<=fEvent->GetNvertices(); jv++)
824 AliVertex* vx=fEvent->GetVertex(jv);
827 rx=vx->GetPosition();
828 dist=rx.GetDistance(r);
829 if (dist < fResolution)
831 AliTrack* tx=fEvent->GetIdTrack(ntk);
839 if (add) break; // No need to look further for vertex candidates
842 // If track was not close enough to an existing vertex
843 // a new secondary vertex is created
844 if (!add && fVertexmode>1)
846 AliTrack* tx=fEvent->GetIdTrack(ntk);
852 r.SetPositionErrors(v,"car");
854 vert.SetTrackCopy(0);
855 vert.SetVertexCopy(0);
856 vert.SetId((fEvent->GetNvertices())+1);
859 fEvent->AddVertex(vert,0);
863 } // End of loop over the produced particles for each collision
864 } // End of loop over number of collisions for each type
865 } // End of loop over collision types
867 // Link sec. vertices to primary if requested
868 // Note that also the connecting tracks are automatically created
871 AliVertex* vp=fEvent->GetIdVertex(1); // Primary vertex
874 for (Int_t i=2; i<=fEvent->GetNvertices(); i++)
876 AliVertex* vx=fEvent->GetVertex(i);
879 if (vx->GetId() != 1) vp->AddVertex(vx);
885 // Include the spectator tracks in the event structure.
886 if (fNucl && specmode)
891 r.SetPosition(v,"car");
893 zp=fZproj-(ncols[0]+ncols[2]);
895 ap=fAproj-(ncols[0]+ncols[1]+ncols[2]+ncols[3]);
897 zt=fZtarg-(ncols[0]+ncols[1]);
899 at=fAtarg-(ncols[0]+ncols[1]+ncols[2]+ncols[3]);
904 if (pproj.GetNorm() > fSpecpmin)
906 kf=2212; // Projectile spectator protons
907 charge=Pychge(kf)/3.;
908 mass=GetPMAS(Pycomp(kf),1);
910 for (Int_t iprojp=1; iprojp<=zp; iprojp++)
915 t.SetParticleCode(kf);
916 t.SetName(name.Data());
917 t.SetTitle("Projectile spectator proton");
920 t.Set3Momentum(pproj);
926 kf=2112; // Projectile spectator neutrons
927 charge=Pychge(kf)/3.;
928 mass=GetPMAS(Pycomp(kf),1);
930 for (Int_t iprojn=1; iprojn<=(ap-zp); iprojn++)
935 t.SetParticleCode(kf);
936 t.SetName(name.Data());
937 t.SetTitle("Projectile spectator neutron");
940 t.Set3Momentum(pproj);
947 if (ptarg.GetNorm() > fSpecpmin)
949 kf=2212; // Target spectator protons
950 charge=Pychge(kf)/3.;
951 mass=GetPMAS(Pycomp(kf),1);
953 for (Int_t itargp=1; itargp<=zt; itargp++)
958 t.SetParticleCode(kf);
959 t.SetName(name.Data());
960 t.SetTitle("Target spectator proton");
963 t.Set3Momentum(ptarg);
969 kf=2112; // Target spectator neutrons
970 charge=Pychge(kf)/3.;
971 mass=GetPMAS(Pycomp(kf),1);
973 for (Int_t itargn=1; itargn<=(at-zt); itargn++)
978 t.SetParticleCode(kf);
979 t.SetName(name.Data());
980 t.SetTitle("Target spectator neutron");
983 t.Set3Momentum(ptarg);
990 // Link the spectator tracks to the primary vertex.
993 AliVertex* vp=fEvent->GetIdVertex(1);
996 for (Int_t ispec=1; ispec<=nspec; ispec++)
998 AliTrack* tx=fEvent->GetIdTrack(-ispec);
999 if (tx) vp->AddTrack(tx);
1005 if (!(fEventnum%fPrintfreq) && (mlist || fEvent))
1009 cout << " Number of tracks in the event structure : "
1010 << fEvent->GetNtracks() << endl;
1012 cout << endl; // Create empty output line after the event
1015 if (fOutTree && fSelect) fOutTree->Fill();
1017 ///////////////////////////////////////////////////////////////////////////
1018 AliEvent* AliCollider::GetEvent(Int_t select) const
1020 // Provide pointer to the generated event structure.
1022 // select = 0 : Always return the pointer to the generated event.
1023 // 1 : Only return the pointer to the generated event in case
1024 // the event passed the selection criteria as specified via
1025 // SelectEvent(). Otherwise the value 0 will be returned.
1027 // By invoking GetEvent() the default of select=0 will be used.
1029 if (!select || fSelect)
1038 ///////////////////////////////////////////////////////////////////////////
1039 void AliCollider::EndRun()
1041 // Properly close the output file (if needed).
1046 cout << " *AliCollider::EndRun* Output file correctly closed." << endl;
1049 ///////////////////////////////////////////////////////////////////////////
1050 void AliCollider::SetStable(Int_t id,Int_t mode)
1052 // Declare whether a particle must be regarded as stable or not.
1053 // The parameter "id" indicates the Pythia KF particle code, which
1054 // basically is the PDG particle identifier code.
1055 // The parameter "mode" indicates the action to be taken.
1057 // mode = 0 : Particle will be able to decay
1058 // 1 : Particle will be regarded as stable.
1060 // In case the user does NOT explicitly invoke this function, the standard
1061 // Pythia settings for the decay tables are used.
1063 // When this function is invoked without the "mode" argument, then the
1064 // default of mode=1 will be used for the specified particle.
1068 // 1) This function should be invoked after the initialisation call
1069 // to AliCollider::Init.
1070 // 2) Due to the internals of Pythia, there is no need to specify particles
1071 // and their corresponding anti-particles separately as (un)stable.
1072 // Once a particle has been declared (un)stable, the corresponding
1073 // anti-particle will be treated in the same way.
1075 if (mode==0 || mode==1)
1077 Int_t kc=Pycomp(id);
1081 SetMDCY(kc,1,decay);
1085 cout << " *AliCollider::SetStable* Unknown particle code. id = " << id << endl;
1090 cout << " *AliCollider::SetStable* Invalid parameter. mode = " << mode << endl;
1093 ///////////////////////////////////////////////////////////////////////////
1094 void AliCollider::SelectEvent(Int_t id)
1096 // Add a particle to the event selection list.
1097 // The parameter "id" indicates the Pythia KF particle code, which
1098 // basically is the PDG particle identifier code.
1099 // In case the user has built a selection list via this procedure, only the
1100 // events in which one of the particles specified in the list was generated
1102 // The investigation of the generated particles takes place when the complete
1103 // event is in memory, including all (shortlived) mother particles and resonances.
1104 // So, the settings of the various particle decay modes have no influence on
1105 // the event selection described here.
1107 // If no list has been specified, all events will be accepted.
1109 // Note : id=0 will delete the selection list.
1111 // Be aware of the fact that severe selection criteria (i.e. selecting only
1112 // rare events) may result in long runtimes before an event sample has been
1125 Int_t kc=Pycomp(id);
1128 fSelections=new TArrayI(1);
1129 fSelections->AddAt(kc,0);
1134 Int_t size=fSelections->GetSize();
1135 for (Int_t i=0; i<size; i++)
1137 if (kc==fSelections->At(i))
1146 fSelections->Set(size+1);
1147 fSelections->AddAt(kc,size);
1152 ///////////////////////////////////////////////////////////////////////////
1153 Int_t AliCollider::GetSelectionFlag() const
1155 // Return the value of the selection flag for the total event.
1156 // When the event passed the selection criteria as specified via
1157 // SelectEvent() the value 1 is returned, otherwise the value 0 is returned.
1160 ///////////////////////////////////////////////////////////////////////////
1161 Int_t AliCollider::IsSelected()
1163 // Check whether the generated (sub)event contains one of the particles
1164 // specified in the selection list via SelectEvent().
1165 // If this is the case or when no selection list is present, the value 1
1166 // will be returned, indicating the event is selected to be kept.
1167 // Otherwise the value 0 will be returned.
1169 if (!fSelections) return 1;
1171 Int_t nsel=fSelections->GetSize();
1176 for (Int_t jpart=1; jpart<=npart; jpart++)
1180 for (Int_t i=0; i<nsel; i++)
1182 if (kc==fSelections->At(i))
1192 ///////////////////////////////////////////////////////////////////////////
1193 void AliCollider::SetSpectatorPmin(Float_t pmin)
1195 // Set minimal momentum in GeV/c for spectator tracks to be stored.
1196 // Spectator tracks with a momentum below this threshold will not be stored
1197 // in the (output) event structure.
1198 // This facility allows to minimise the output file size.
1199 // Note that when the user wants to boost the event into another reference
1200 // frame these spectator tracks might have got momenta above the threshold.
1201 // However, when the spectator tracks were not stored in the event structure
1202 // in the original frame, there is no way to retreive them anymore.
1205 ///////////////////////////////////////////////////////////////////////////
1206 Float_t AliCollider::GetSpectatorPmin() const
1208 // Provide the minimal spectator momentum in GeV/c.
1211 ///////////////////////////////////////////////////////////////////////////
1212 TString AliCollider::GetPyname(Int_t kf)
1214 // Provide the correctly truncated Pythia particle name for PGD code kf
1216 // The TPythia6::Pyname returned name is copied into a TString and truncated
1217 // at the first blank to prevent funny trailing characters due to incorrect
1218 // stripping of empty characters in TPythia6::Pyname.
1219 // The truncation at the first blank is allowed due to the Pythia convention
1220 // that particle names never contain blanks.
1225 for (Int_t i=1; i<16; i++)
1227 if (name[i]==' ') break;
1228 sname=sname+name[i];
1232 ///////////////////////////////////////////////////////////////////////////