* provided "as is" without express or implied warranty. *
**************************************************************************/
-// $Id: AliCollider.cxx,v 1.6 2003/08/29 09:05:11 nick Exp $
+// $Id: AliCollider.cxx,v 1.12 2004/05/04 15:33:04 nick Exp $
///////////////////////////////////////////////////////////////////////////
// Class AliCollider
//
// gen->Init("fixt",zp,ap,zt,at,158);
//
+// gen->SetTitle("SPS Pb-Pb collision at 158A GeV/c beam energy");
+//
// Int_t nevents=5;
//
// AliRandom rndm;
//
// gen->Init("fixt","nu_mu","p",1e11);
//
+// gen->SetTitle("Atmospheric nu_mu-p interaction at 1e20 eV");
+//
// Int_t nevents=10;
//
// for (Int_t i=0; i<nevents; i++)
//
//
//--- Author: Nick van Eijndhoven 22-nov-2002 Utrecht University
-//- Modified: NvE $Date: 2003/08/29 09:05:11 $ Utrecht University
+//- Modified: NvE $Date: 2004/05/04 15:33:04 $ Utrecht University
///////////////////////////////////////////////////////////////////////////
#include "AliCollider.h"
{
// Default constructor.
// All variables initialised to default values.
+//
+// Some Pythia default MC parameters are automatically modified to provide
+// more suitable running conditions for soft processes in view of
+// nucleus-nucleus interactions and astrophysical processes.
+// The user may initialise the generator with all the default Pythia
+// parameters and obtain full user control to modify the settings by means
+// of the SetUserControl memberfunction.
+//
+// Refer to the SetElastic memberfunction for the inclusion of elastic
+// and diffractive processes.
+// By default these processes are not included.
+
fVertexmode=0; // No vertex structure creation
fResolution=1e-5; // Standard resolution is 0.1 micron
fRunnum=0;
fEventnum=0;
fPrintfreq=1;
+ fUserctrl=0; // Automatic optimisation of some MC parameters
+ fElastic=0; // No elastic and diffractive processes
fEvent=0;
+ fSpecpmin=0;
+
fFrame="none";
fWin=0;
fOutFile=0;
fOutTree=0;
+
+ fSelections=0;
+ fSelect=0;
+
+ TString s=GetName();
+ s+=" (AliCollider)";
+ SetName(s.Data());
}
///////////////////////////////////////////////////////////////////////////
AliCollider::~AliCollider()
delete fOutTree;
fOutTree=0;
}
+ if (fSelections)
+ {
+ delete fSelections;
+ fSelections=0;
+ }
}
///////////////////////////////////////////////////////////////////////////
void AliCollider::SetOutputFile(TString s)
}
}
///////////////////////////////////////////////////////////////////////////
-Int_t AliCollider::GetVertexMode()
+Int_t AliCollider::GetVertexMode() const
{
// Provide the current mode for vertex structure creation.
return fVertexmode;
fResolution=fabs(res);
}
///////////////////////////////////////////////////////////////////////////
-Double_t AliCollider::GetResolution()
+Double_t AliCollider::GetResolution() const
{
// Provide the current resolution (in cm) for resolving (sec.) vertices.
return fResolution;
fRunnum=run;
}
///////////////////////////////////////////////////////////////////////////
-Int_t AliCollider::GetRunNumber()
+Int_t AliCollider::GetRunNumber() const
{
// Provide the user defined run number.
return fRunnum;
fPrintfreq=n;
}
///////////////////////////////////////////////////////////////////////////
-Int_t AliCollider::GetPrintFreq()
+Int_t AliCollider::GetPrintFreq() const
{
// Provide the user selected print frequency.
return fPrintfreq;
}
///////////////////////////////////////////////////////////////////////////
+void AliCollider::SetUserControl(Int_t flag)
+{
+// Set the user control flag w.r.t. disabling automatic optimisation
+// of some Pythia default MC parameters for soft interactions in view of
+// nucleus-nucleus collisions and astrophysical processes.
+// Flag = 0 : Limited user control (automatic optimisation enabled)
+// 1 : Full user control (automatic optimisation disabled)
+// By default the user control is set to 0 (i.e. automatic optimisation).
+// See the Init() memberfunctions for further details w.r.t. the optimisations.
+ fUserctrl=flag;
+}
+///////////////////////////////////////////////////////////////////////////
+Int_t AliCollider::GetUserControl() const
+{
+// Provide the value of the user control flag.
+ return fUserctrl;
+}
+///////////////////////////////////////////////////////////////////////////
+void AliCollider::SetElastic(Int_t flag)
+{
+// Set the flag w.r.t. inclusion of elastic and diffractive processes.
+// By default these processes are not included.
+// Flag = 0 : Do not include elastic and diffractive processes
+// 1 : Elastic and diffractive processes will be included
+ fElastic=flag;
+}
+///////////////////////////////////////////////////////////////////////////
+Int_t AliCollider::GetElastic() const
+{
+// Provide the value of the control flag for elastic and diffractive processes.
+ return fElastic;
+}
+///////////////////////////////////////////////////////////////////////////
void AliCollider::Init(char* frame,char* beam,char* target,Float_t win)
{
// Initialisation of the underlying Pythia generator package.
+// The event number is reset to 0.
// This routine just invokes TPythia6::Initialize(...) and the arguments
// have the corresponding meaning.
-// The event number is reset to 0.
+// Some Pythia default MC parameters are automatically modified to provide
+// more suitable running conditions for soft processes in view of
+// astrophysical processes.
+// The optimisations consist of :
+// * Usage of real photons for photon beams of targets
+// * Minimum CMS energy of 3 GeV for the event
+// * Activation of the default K factor values
+// with separate settings for ordinary and color annihilation graphs.
+// The user may initialise the generator with all the default Pythia
+// parameters and obtain full user control to modify the settings by means
+// of invoking the SetUserControl memberfunction before this initialisation.
+// Note that the inclusion of elastic and diffractive processes is controlled
+// by invokation of the SetElastic memberfunction before this initialisation,
+// irrespective of the UserControl selection.
+
+ if (!fUserctrl) // Optimisation of some MC parameters
+ {
+ SetMSTP(14,10); // Real photons for photon beams or targets
+ SetPARP(2,3.); // Minimum CMS energy for the event
+ SetMSTP(33,2); // Activate K factor. Separate for ordinary and color annih. graphs
+ }
+
+ if (fElastic) SetMSEL(2); // Include low-Pt, elastic and diffractive events
+
fEventnum=0;
fNucl=0;
fFrame=frame;
fWin=win;
Initialize(frame,beam,target,win);
+ cout << endl;
cout << " *AliCollider::Init* Standard Pythia initialisation." << endl;
cout << " Beam particle : " << beam << " Target particle : " << target
<< " Frame = " << frame << " Energy = " << win
{
// Initialisation of the underlying Pythia generator package for the generation
// of nucleus-nucleus interactions.
+// The event number is reset to 0.
// In addition to the Pythia standard arguments 'frame' and 'win', the user
// can specify here (Z,A) values of the projectile and target nuclei.
//
// Note : The 'win' value denotes either the cms energy per nucleon-nucleon collision
// (i.e. frame="cms") or the momentum per nucleon in all other cases.
//
-// The event number is reset to 0.
+// Some Pythia default MC parameters are automatically modified to provide
+// more suitable running conditions for soft processes in view of
+// nucleus-nucleus interactions and astrophysical processes.
+// The optimisations consist of :
+// * Minimum CMS energy of 3 GeV for the event
+// * Activation of the default K factor values
+// with separate settings for ordinary and color annihilation graphs.
+// The user may initialise the generator with all the default Pythia
+// parameters and obtain full user control to modify the settings by means
+// of invoking the SetUserControl memberfunction before this initialisation.
+// Note that the inclusion of elastic and diffractive processes is controlled
+// by invokation of the SetElastic memberfunction before this initialisation,
+// irrespective of the UserControl selection.
+
+ if (!fUserctrl) // Optimisation of some MC parameters
+ {
+ SetPARP(2,3.); // Minimum CMS energy for the event
+ SetMSTP(33,2); // Activate K factor. Separate for ordinary and color annih. graphs
+ }
+
+ if (fElastic) SetMSEL(2); // Include low-Pt, elastic and diffractive events
+
fEventnum=0;
fNucl=1;
fFrame=frame;
if (ap<1 || at<1 || zp>ap || zt>at)
{
+ cout << endl;
cout << " *AliCollider::Init* Invalid input value(s). Zproj = " << zp
<< " Aproj = " << ap << " Ztarg = " << zt << " Atarg = " << at << endl;
return;
fZtarg=zt;
fAtarg=at;
+ cout << endl;
cout << " *AliCollider::Init* Nucleus-Nucleus generator initialisation." << endl;
cout << " Zproj = " << zp << " Aproj = " << ap << " Ztarg = " << zt << " Atarg = " << at
<< " Frame = " << frame << " Energy = " << win
// Generate one event.
// In case of a nucleus-nucleus interaction, the argument 'npt' denotes
// the number of participant nucleons.
+// Normally also the spectator tracks will be stored into the event structure.
+// The spectator tracks have a negative user Id to distinguish them from the
+// ordinary generated tracks.
+// In case the user has selected the creation of vertex structures, the spectator
+// tracks will be linked to the primary vertex.
+// However, specification of npt<0 will suppress the storage of spectator tracks.
+// In the latter case abs(npt) will be taken as the number of participants.
// In case of a standard Pythia run for 'elementary' particle interactions,
// the value of npt is totally irrelevant.
//
// In case of a nucleus-nucleus interaction, the proper A and Z values for
// the projectile and target particles are set in the event structure.
// However, in this case both particle ID's are set to zero.
+//
+// Note : Only in case an event passed the selection criteria as specified
+// via SelectEvent(), the event will appear on the output file.
fEventnum++;
+ Int_t specmode=1;
+ if (npt<0)
+ {
+ specmode=0;
+ npt=abs(npt);
+ }
+
// Counters for the various (proj,targ) combinations : p+p, n+p, p+n and n+n
Int_t ncols[4]={0,0,0,0};
+ Int_t zp=0;
+ Int_t ap=0;
+ Int_t zt=0;
+ Int_t at=0;
+
Int_t ncol=1;
if (fNucl)
{
if (npt%2 && fRan.Uniform()>0.5) ncol+=1;
// Determine the number of the various types of N+N interactions
- Int_t zp=fZproj;
- Int_t ap=fAproj;
- Int_t zt=fZtarg;
- Int_t at=fAtarg;
+ zp=fZproj;
+ ap=fAproj;
+ zt=fZtarg;
+ at=fAtarg;
Int_t maxa=2; // Indicator whether proj (1) or target (2) has maximal A left
if (ap>at) maxa=1;
Float_t* rans=new Float_t[ncol];
{
fEvent=new AliEvent();
fEvent->SetOwner();
+ fEvent->SetName(GetName());
+ fEvent->SetTitle(GetTitle());
}
fEvent->Reset();
AliPosition r,rx;
Float_t v[3];
AliVertex vert;
+ Ali3Vector pproj,ptarg;
if (fVertexmode)
{
Int_t kf=0;
Float_t charge=0,mass=0;
+ TString name;
Int_t ntypes=4;
}
// Generate all the various collisions
- Int_t first=1; // Flag to indicate the first collision process
+ fSelect=0; // Flag to indicate whether the total event is selected or not
+ Int_t select=0; // Flag to indicate whether the sub-event is selected or not
+ Int_t first=1; // Flag to indicate the first collision process
Double_t pnucl;
Int_t npart=0,ntk=0;
Double_t dist=0;
{
GenerateEvent();
+ select=IsSelected();
+ if (select) fSelect=1;
+
if (first) // Store projectile and target information in the event structure
{
if (fNucl)
v[0]=GetP(1,1);
v[1]=GetP(1,2);
v[2]=GetP(1,3);
- pnucl=sqrt(v[0]*v[0]+v[1]*v[1]+v[2]*v[2]);
+ pproj.SetVector(v,"car");
+ pnucl=pproj.GetNorm();
fEvent->SetProjectile(fAproj,fZproj,pnucl);
v[0]=GetP(2,1);
v[1]=GetP(2,2);
v[2]=GetP(2,3);
- pnucl=sqrt(v[0]*v[0]+v[1]*v[1]+v[2]*v[2]);
+ ptarg.SetVector(v,"car");
+ pnucl=ptarg.GetNorm();
fEvent->SetTarget(fAtarg,fZtarg,pnucl);
}
else
if (medit >= 0) Pyedit(medit); // Define which particles are to be kept
- if (mlist >= 0) Pylist(mlist);
+ if (mlist>=0 && select)
+ {
+ Pylist(mlist);
+ cout << endl;
+ }
npart=GetN();
for (Int_t jpart=1; jpart<=npart; jpart++)
kf=GetK(jpart,2);
charge=Pychge(kf)/3.;
mass=GetP(jpart,5);
+ name=GetPyname(kf);
// 3-momentum in GeV/c
v[0]=GetP(jpart,1);
t.Reset();
t.SetId(ntk);
t.SetParticleCode(kf);
+ t.SetName(name.Data());
t.SetCharge(charge);
t.SetMass(mass);
t.Set3Momentum(p);
}
}
- if (mlist && !(fEventnum%fPrintfreq)) cout << endl; // Create empty output line after the event
- if (fOutTree) fOutTree->Fill();
+ // Include the spectator tracks in the event structure.
+ if (fNucl && specmode)
+ {
+ v[0]=0;
+ v[1]=0;
+ v[2]=0;
+ r.SetPosition(v,"car");
+
+ zp=fZproj-(ncols[0]+ncols[2]);
+ if (zp<0) zp=0;
+ ap=fAproj-(ncols[0]+ncols[1]+ncols[2]+ncols[3]);
+ if (ap<0) ap=0;
+ zt=fZtarg-(ncols[0]+ncols[1]);
+ if (zt<0) zt=0;
+ at=fAtarg-(ncols[0]+ncols[1]+ncols[2]+ncols[3]);
+ if (at<0) at=0;
+
+ Int_t nspec=0;
+
+ if (pproj.GetNorm() > fSpecpmin)
+ {
+ kf=2212; // Projectile spectator protons
+ charge=Pychge(kf)/3.;
+ mass=GetPMAS(Pycomp(kf),1);
+ name=GetPyname(kf);
+ for (Int_t iprojp=1; iprojp<=zp; iprojp++)
+ {
+ nspec++;
+ t.Reset();
+ t.SetId(-nspec);
+ t.SetParticleCode(kf);
+ t.SetName(name.Data());
+ t.SetTitle("Projectile spectator proton");
+ t.SetCharge(charge);
+ t.SetMass(mass);
+ t.Set3Momentum(pproj);
+ t.SetBeginPoint(r);
+
+ fEvent->AddTrack(t);
+ }
+
+ kf=2112; // Projectile spectator neutrons
+ charge=Pychge(kf)/3.;
+ mass=GetPMAS(Pycomp(kf),1);
+ name=GetPyname(kf);
+ for (Int_t iprojn=1; iprojn<=(ap-zp); iprojn++)
+ {
+ nspec++;
+ t.Reset();
+ t.SetId(-nspec);
+ t.SetParticleCode(kf);
+ t.SetName(name.Data());
+ t.SetTitle("Projectile spectator neutron");
+ t.SetCharge(charge);
+ t.SetMass(mass);
+ t.Set3Momentum(pproj);
+ t.SetBeginPoint(r);
+
+ fEvent->AddTrack(t);
+ }
+ }
+
+ if (ptarg.GetNorm() > fSpecpmin)
+ {
+ kf=2212; // Target spectator protons
+ charge=Pychge(kf)/3.;
+ mass=GetPMAS(Pycomp(kf),1);
+ name=GetPyname(kf);
+ for (Int_t itargp=1; itargp<=zt; itargp++)
+ {
+ nspec++;
+ t.Reset();
+ t.SetId(-nspec);
+ t.SetParticleCode(kf);
+ t.SetName(name.Data());
+ t.SetTitle("Target spectator proton");
+ t.SetCharge(charge);
+ t.SetMass(mass);
+ t.Set3Momentum(ptarg);
+ t.SetBeginPoint(r);
+
+ fEvent->AddTrack(t);
+ }
+
+ kf=2112; // Target spectator neutrons
+ charge=Pychge(kf)/3.;
+ mass=GetPMAS(Pycomp(kf),1);
+ name=GetPyname(kf);
+ for (Int_t itargn=1; itargn<=(at-zt); itargn++)
+ {
+ nspec++;
+ t.Reset();
+ t.SetId(-nspec);
+ t.SetParticleCode(kf);
+ t.SetName(name.Data());
+ t.SetTitle("Target spectator neutron");
+ t.SetCharge(charge);
+ t.SetMass(mass);
+ t.Set3Momentum(ptarg);
+ t.SetBeginPoint(r);
+
+ fEvent->AddTrack(t);
+ }
+ }
+
+ // Link the spectator tracks to the primary vertex.
+ if (fVertexmode)
+ {
+ AliVertex* vp=fEvent->GetIdVertex(1);
+ if (vp)
+ {
+ for (Int_t ispec=1; ispec<=nspec; ispec++)
+ {
+ AliTrack* tx=fEvent->GetIdTrack(-ispec);
+ if (tx) vp->AddTrack(tx);
+ }
+ }
+ }
+}
+
+ if (!(fEventnum%fPrintfreq) && (mlist || fEvent))
+ {
+ if (fEvent)
+ {
+ cout << " Number of tracks in the event structure : "
+ << fEvent->GetNtracks() << endl;
+ }
+ cout << endl; // Create empty output line after the event
+ }
+
+ if (fOutTree && fSelect) fOutTree->Fill();
}
///////////////////////////////////////////////////////////////////////////
-AliEvent* AliCollider::GetEvent()
+AliEvent* AliCollider::GetEvent(Int_t select) const
{
// Provide pointer to the generated event structure.
- return fEvent;
+//
+// select = 0 : Always return the pointer to the generated event.
+// 1 : Only return the pointer to the generated event in case
+// the event passed the selection criteria as specified via
+// SelectEvent(). Otherwise the value 0 will be returned.
+//
+// By invoking GetEvent() the default of select=0 will be used.
+
+ if (!select || fSelect)
+ {
+ return fEvent;
+ }
+ else
+ {
+ return 0;
+ }
}
///////////////////////////////////////////////////////////////////////////
void AliCollider::EndRun()
}
}
///////////////////////////////////////////////////////////////////////////
+void AliCollider::SetStable(Int_t id,Int_t mode)
+{
+// Declare whether a particle must be regarded as stable or not.
+// The parameter "id" indicates the Pythia KF particle code, which
+// basically is the PDG particle identifier code.
+// The parameter "mode" indicates the action to be taken.
+//
+// mode = 0 : Particle will be able to decay
+// 1 : Particle will be regarded as stable.
+//
+// In case the user does NOT explicitly invoke this function, the standard
+// Pythia settings for the decay tables are used.
+//
+// When this function is invoked without the "mode" argument, then the
+// default of mode=1 will be used for the specified particle.
+//
+// Notes :
+// -------
+// 1) This function should be invoked after the initialisation call
+// to AliCollider::Init.
+// 2) Due to the internals of Pythia, there is no need to specify particles
+// and their corresponding anti-particles separately as (un)stable.
+// Once a particle has been declared (un)stable, the corresponding
+// anti-particle will be treated in the same way.
+
+ if (mode==0 || mode==1)
+ {
+ Int_t kc=Pycomp(id);
+ Int_t decay=1-mode;
+ if (kc>0)
+ {
+ SetMDCY(kc,1,decay);
+ }
+ else
+ {
+ cout << " *AliCollider::SetStable* Unknown particle code. id = " << id << endl;
+ }
+ }
+ else
+ {
+ cout << " *AliCollider::SetStable* Invalid parameter. mode = " << mode << endl;
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+void AliCollider::SelectEvent(Int_t id)
+{
+// Add a particle to the event selection list.
+// The parameter "id" indicates the Pythia KF particle code, which
+// basically is the PDG particle identifier code.
+// In case the user has built a selection list via this procedure, only the
+// events in which one of the particles specified in the list was generated
+// will be kept.
+// The investigation of the generated particles takes place when the complete
+// event is in memory, including all (shortlived) mother particles and resonances.
+// So, the settings of the various particle decay modes have no influence on
+// the event selection described here.
+//
+// If no list has been specified, all events will be accepted.
+//
+// Note : id=0 will delete the selection list.
+//
+// Be aware of the fact that severe selection criteria (i.e. selecting only
+// rare events) may result in long runtimes before an event sample has been
+// obtained.
+//
+ if (!id)
+ {
+ if (fSelections)
+ {
+ delete fSelections;
+ fSelections=0;
+ }
+ }
+ else
+ {
+ Int_t kc=Pycomp(id);
+ if (!fSelections)
+ {
+ fSelections=new TArrayI(1);
+ fSelections->AddAt(kc,0);
+ }
+ else
+ {
+ Int_t exist=0;
+ Int_t size=fSelections->GetSize();
+ for (Int_t i=0; i<size; i++)
+ {
+ if (kc==fSelections->At(i))
+ {
+ exist=1;
+ break;
+ }
+ }
+
+ if (!exist)
+ {
+ fSelections->Set(size+1);
+ fSelections->AddAt(kc,size);
+ }
+ }
+ }
+}
+///////////////////////////////////////////////////////////////////////////
+Int_t AliCollider::GetSelectionFlag() const
+{
+// Return the value of the selection flag for the total event.
+// When the event passed the selection criteria as specified via
+// SelectEvent() the value 1 is returned, otherwise the value 0 is returned.
+ return fSelect;
+}
+///////////////////////////////////////////////////////////////////////////
+Int_t AliCollider::IsSelected()
+{
+// Check whether the generated (sub)event contains one of the particles
+// specified in the selection list via SelectEvent().
+// If this is the case or when no selection list is present, the value 1
+// will be returned, indicating the event is selected to be kept.
+// Otherwise the value 0 will be returned.
+
+ if (!fSelections) return 1;
+
+ Int_t nsel=fSelections->GetSize();
+ Int_t npart=GetN();
+ Int_t kf,kc;
+
+ Int_t select=0;
+ for (Int_t jpart=1; jpart<=npart; jpart++)
+ {
+ kf=GetK(jpart,2);
+ kc=Pycomp(kf);
+ for (Int_t i=0; i<nsel; i++)
+ {
+ if (kc==fSelections->At(i))
+ {
+ select=1;
+ break;
+ }
+ }
+ if (select) break;
+ }
+ return select;
+}
+///////////////////////////////////////////////////////////////////////////
+void AliCollider::SetSpectatorPmin(Float_t pmin)
+{
+// Set minimal momentum in GeV/c for spectator tracks to be stored.
+// Spectator tracks with a momentum below this threshold will not be stored
+// in the (output) event structure.
+// This facility allows to minimise the output file size.
+// Note that when the user wants to boost the event into another reference
+// frame these spectator tracks might have got momenta above the threshold.
+// However, when the spectator tracks were not stored in the event structure
+// in the original frame, there is no way to retreive them anymore.
+ fSpecpmin=pmin;
+}
+///////////////////////////////////////////////////////////////////////////
+Float_t AliCollider::GetSpectatorPmin() const
+{
+// Provide the minimal spectator momentum in GeV/c.
+ return fSpecpmin;
+}
+///////////////////////////////////////////////////////////////////////////
+TString AliCollider::GetPyname(Int_t kf)
+{
+// Provide the correctly truncated Pythia particle name for PGD code kf
+//
+// The TPythia6::Pyname returned name is copied into a TString and truncated
+// at the first blank to prevent funny trailing characters due to incorrect
+// stripping of empty characters in TPythia6::Pyname.
+// The truncation at the first blank is allowed due to the Pythia convention
+// that particle names never contain blanks.
+ char name[16];
+ TString sname;
+ Pyname(kf,name);
+ sname=name[0];
+ for (Int_t i=1; i<16; i++)
+ {
+ if (name[i]==' ') break;
+ sname=sname+name[i];
+ }
+ return sname;
+}
+///////////////////////////////////////////////////////////////////////////