[u/mrichter/AliRoot.git] / TPHIC / AliGenTPHIC.cxx

/**************************************************************************
 * Copyright(c) 1998-2003, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 *                                                                        *
 **************************************************************************/

/* $Id$ */

// Event generator of two-photon processes
// in ultra-peripheral ion collisions.
// 5 two-photon process are implemented, see comments to SetProcess().
//%
// The example of the generator initialization for the process
// gamma gamma -> X in CaCa collisions at 7000 TeV/nucleon is the following:
//%
//    AliGenTPHIC *gener = new AliGenTPHIC();
//    gener->SetProcess(1);
//    gener->SetBeamEnergy(3500.);
//    gener->SetBeamZ(20);
//    gener->SetBeamA(40);
//    gener->SetMggRange(70.,200.);
//    gener->SetYggRange(-5.,5.);
//    gener->SetLumFunName("lum_ca_70_200.dat");
//    gener->SetLumFunFlag(-1);
//    gener->Init();
//%
// The two-photon luminosity function needed for the process cross section
// calculation is time-consuming, therefore it can be calculated once for a
// selected two-photon energy and rapidity range and selected ion species,
// saved into a file and then can be reused in further calculation.
//%
// The integral cross section of the process is calculated in each event
// by the Monte Carlo integration procedure, the differential cross section
// of each thrown event is assigned as a weight to each track of the event
// which can be then used during the event analysis by retreiving this weight
// from any of the event tracks.
// 
// The manual of the fortran generator is available in
// $ALICE_ROOT/TPHIC/TPHIC_doc.ps.gz
// For the two-photon physics in heavy ion collisions see
// G.Baur et al, Phys.Rep. 364 (2002), 359.
//%
// Author: Yuri.Kharlov@cern.ch
// 15 April 2003

#include <TParticle.h>
#include <TParticlePDG.h>
#include <TDatabasePDG.h>
#include "AliPythia.h"
#include "AliRun.h"
#include <AliGenTPHIC.h>
#include <TPHICgen.h>
#include <TPHICcommon.h>

ClassImp(AliGenTPHIC)

//------------------------------------------------------------

AliGenTPHIC::AliGenTPHIC()
{
  // Constructor: create generator instance,
  // create particle array
  // Set TPHIC parameters to default values:
  // eta_b production in Ca-Ca collisions at 7 A*TeV

  SetMC(new TPHICgen());
  fPythia = AliPythia::Instance();
  fParticles = new TClonesArray("TParticle",100);

  SetProcess   ();
  SetBeamEnergy();
  SetBeamZ     ();
  SetBeamA     ();
  SetYggRange  ();
  SetMggRange  ();
  SetNgridY    ();
  SetNgridM    ();
  SetLumFunName();
  SetLumFunFlag();
  SetKfOnium   ();
}

//____________________________________________________________
AliGenTPHIC::AliGenTPHIC(const AliGenTPHIC & gen)
{
  // copy constructor
  gen.Copy(*this);
}

//____________________________________________________________
AliGenTPHIC::~AliGenTPHIC()
{
  // Destroys the object, deletes and disposes all TParticles currently on list.
  if (fParticles) {
    fParticles->Delete();
    delete fParticles;
    fParticles = 0;
  }
}

//____________________________________________________________
void AliGenTPHIC::Init()
{
  // Initialize the generator TPHIC

  fTPHICgen->Initialize();
  fEvent = 0;
}

//____________________________________________________________
void AliGenTPHIC::Generate()
{
  // Generate one event of two-photon process.
  // Gaussian smearing on the vertex is done if selected. 
  // All particles from the TPHIC/PYTHIA event listing
  // are stored in TreeK, and only final-state particles are tracked.
  // The event differectial cross section is assigned as a weight
  // to each track of the event.

  Float_t polar[3]= {0,0,0};
  Float_t origin0[3],origin[3];
  Float_t p[3], tof;
  Double_t weight;

  Int_t    ks,kf,iparent,nt, trackIt;
  Float_t  random[6];
  const Float_t kconv=0.001/2.999792458e8;

  fTPHICgen->GenerateEvent();
  weight = GetXSectionCurrent();
  if (gAlice->GetEvNumber()>=fDebugEventFirst &&
      gAlice->GetEvNumber()<=fDebugEventLast) fPythia->Pylist(1);
  fPythia->ImportParticles(fParticles,"All");

  if (fDebug == 1)
    Info("Generate()","one event is produced");

  Int_t j;
  for (j=0;j<3;j++) origin[j]=fOrigin[j];
  if(fVertexSmear==kPerEvent) {
    Rndm(random,6);
    for (j=0;j<3;j++) {
      origin0[j]+=fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
	TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
    }
  }

  Int_t ip;
  Int_t np = fParticles->GetEntriesFast();
  TParticle *iparticle;
//   Int_t* pParent   = new Int_t[np];
  for (ip=0; ip<np; ip++) {
    iparticle = (TParticle *) fParticles->At(ip);
    ks = iparticle->GetStatusCode();
//     // No initial state partons
//     if (ks==21) continue;
    p[0] = iparticle->Px();
    p[1] = iparticle->Py();
    p[2] = iparticle->Pz();
    origin[0] = origin0[0]+iparticle->Vx()/10.;
    origin[1] = origin0[1]+iparticle->Vy()/10.;
    origin[2] = origin0[2]+iparticle->Vz()/10.;
    kf = CheckPDGCode(iparticle->GetPdgCode());
    iparent = -1;
    tof     = kconv*iparticle->T();
    if (ks == 1) trackIt = 1;
    else         trackIt = 0;
    PushTrack(fTrackIt*trackIt,iparent,kf,p,origin,polar,tof,kPPrimary,nt,weight,ks);
    KeepTrack(nt); 

    if (fDebug == 2)
      printf("id=%+4d, parent=%3d, ks=%d, p = (%+11.4e,%+11.4e,%+11.4e) GeV\n",
	     kf,iparent,fTrackIt*trackIt,p[0],p[1],p[2]);
  }
  fEvent++;
  fTPHICgen->SetNEVENT(fEvent);
  if (fDebug == 1 && fEvent%100 == 0) {
    Info("Generate","Event %d\n",fEvent);
    fTPHICgen->Finish();
  }
}

//____________________________________________________________
void AliGenTPHIC::SetEventListRange(Int_t eventFirst, Int_t eventLast)
{
  // Set a range of event numbers, for which a table
  // of generated particle will be printed
  fDebugEventFirst = eventFirst;
  fDebugEventLast  = eventLast;
  if (fDebugEventLast==-1) fDebugEventLast=fDebugEventFirst;
}

//____________________________________________________________
void AliGenTPHIC::SetProcess       (Int_t   proc  )
{
  // Set process number:
  // proc=1 - gamma gamma -> X
  // proc=2 - gamma gamma -> quarkonium
  // proc=3 - gamma gamma -> fermion+ fermion-
  // proc=4 - gamma gamma -> W+ W-
  // proc=5 - not implemented
  // proc=6 - gamma gamma -> V1 V2 (vector meson pair)

  fTPHICgen->SetIPROC(proc);
}
//____________________________________________________________
  void AliGenTPHIC::SetBeamEnergy  (Float_t energy)
{
  // Set energy of the beam ion per nucleon in GeV
  fTPHICgen->SetEBMN(energy);
}
//____________________________________________________________
  void AliGenTPHIC::SetBeamZ       (Int_t   z     )
{
  // Set beam ion charge
  fTPHICgen->SetIZ(z);
}
//____________________________________________________________
  void AliGenTPHIC::SetBeamA       (Int_t   a     )
{
  // Set beam ion atomic number
  fTPHICgen->SetIA(a);
}
//____________________________________________________________
  void AliGenTPHIC::SetYggRange    (Float_t ymin, Float_t ymax)
{
  // Set rapidity range of 2-photon system for the
  // luminosity function calculation
  fTPHICgen->SetYMIN(ymin);
  fTPHICgen->SetYMAX(ymax);
}
//____________________________________________________________
  void AliGenTPHIC::SetMggRange    (Float_t mmin, Float_t mmax)
{
  // Set invariant mass range of 2-photon system for the
  // luminosity function calculation
  fTPHICgen->SetAMIN(mmin);
  fTPHICgen->SetAMAX(mmax);
}
//____________________________________________________________
  void AliGenTPHIC::SetNgridY      (Int_t   ny    )
{
  // Set number of nodes on the grid along the rapidity axis
  // to calculate the 2-photon luminosity function
  fTPHICgen->SetNY(ny);
}
//____________________________________________________________
  void AliGenTPHIC::SetNgridM      (Int_t   nm    )
{
  // Set number of nodes on the grid along the mass axis
  // to calculate the 2-photon luminosity function
  fTPHICgen->SetNMAS(nm);
}
//____________________________________________________________
  void AliGenTPHIC::SetLumFunName  (TString name  )
{
  // Set filename to store the 2-photon luminosity
  // function calculated on the grid
  fTPHICgen->SetLUMFIL(name);
}
//____________________________________________________________
  void AliGenTPHIC::SetLumFunFlag  (Int_t   flag  )
{
  // Set flag to calculate the 2-photon luminosity function:
  // flag=-1 if a new lumimosity function to be calculated
  //         and stored in a file
  // flag=+1 if a previously calculated function to be read
  //         from a file
  fTPHICgen->SetILUMF(flag);
}
//____________________________________________________________
  void AliGenTPHIC::SetKfFermion   (Int_t   kf    )
{
  // Set a PDG flavour code of a fermion for the process 3,
  // gamma gamma -> fermion+ fermion-
  fTPHICgen->SetKFERM(kf);
}
//____________________________________________________________
  void AliGenTPHIC::SetKfOnium    (Int_t   kf    )
{
  // Set a PDG flavour code of a quarkonium for the process 2,
  // gamma gamma -> quarkonium
  fTPHICgen->SetKFONIUM(kf);
}
//____________________________________________________________
  void AliGenTPHIC::SetMassOnium   (Float_t mass  )
{
  // Set a quarkonium mass [GeV] for the process 2 if it
  // differes from the Pythia's particle table.
  // For the well-known quarkonia no need to set this mass
  // because it will be taken from the Pythia table
  fTPHICgen->SetXMRES(mass);
}
//____________________________________________________________
  void AliGenTPHIC::SetGGwidthOnium(Float_t width )
{
  // Set 2-photon partial width [GeV] of the quarkonium for
  // the process 2 if it differes fromthe Pythia's particle table.
  // For the well-known quarkonia no need to set this width
  // because it will be taken from the Pythia table
  fTPHICgen->SetXGGRES(width);
}
//____________________________________________________________
  void AliGenTPHIC::SetKfVmesons   (Int_t kf1, Int_t kf2)
{
  // Set PDG flavour codes of the two vector vesons
  // for the process 2:  gamma gamma -> V1 V2
  // So far this processes is implemented for the following
  // mesons and their combinations only:
  // pho0 (113), omega (223), phi (333), J/psi (443)
  fTPHICgen->SetKV1(kf1);
  fTPHICgen->SetKV2(kf2);
}
//____________________________________________________________
  Float_t AliGenTPHIC::GetGGmass    ()
{
  // Get invariant mass of generated 2-photon system
  return fTPHICgen->GetWSQ();
}
//____________________________________________________________
  Float_t AliGenTPHIC::GetGGrapidity()
{
  // Get rapidity of generated 2-photon system
  return fTPHICgen->GetYGG();
}
//____________________________________________________________
  Float_t AliGenTPHIC::GetG1mass    ()
{
  // Get a mass of the first virtual photon of
  // the 2-photon process (-sqrt(q1^2)).
  return fTPHICgen->GetXMG1();
}
//____________________________________________________________
  Float_t AliGenTPHIC::GetG2mass    ()
{
  // Get a mass of the second virtual photon of
  // the 2-photon process (-sqrt(q2^2)).
  return fTPHICgen->GetXMG2();
}
//____________________________________________________________
  TClonesArray*  AliGenTPHIC::GetParticleList ()
{
  // Get array of particles of the event listing
  return fParticles;
}
//____________________________________________________________
  TLorentzVector AliGenTPHIC::MomentumRecNucl1()
{
  // Get 4-momentum of the first recoil nucleus after
  // the 2-photon process.
  return TLorentzVector(fTPHICgen->GetPTAG1(1),
			fTPHICgen->GetPTAG1(2),
			fTPHICgen->GetPTAG1(3),
			fTPHICgen->GetPTAG1(4));
}
//____________________________________________________________
  TLorentzVector AliGenTPHIC::MomentumRecNucl2()
{
  // Get 4-momentum of the first recoil nucleus after
  // the 2-photon process.
  return TLorentzVector(fTPHICgen->GetPTAG2(1),
			fTPHICgen->GetPTAG2(2),
			fTPHICgen->GetPTAG2(3),
			fTPHICgen->GetPTAG2(4));
}
//____________________________________________________________
  Float_t AliGenTPHIC::GetXSectionCurrent()
{
  // Get the cross section of the produced event for the
  // Monte Carlo integral cross section calculation
  return fTPHICgen->GetXSCUR();
}
//____________________________________________________________
  Float_t AliGenTPHIC::GetXSection       ()
{
  // Get the integral cross section of the process
  // calculated so far
  return fTPHICgen->GetXSTOT();
}
//____________________________________________________________
  Float_t AliGenTPHIC::GetXSectionError  ()
{
  // Get the error of the integral cross section of the process
  // calculated so far
  return fTPHICgen->GetXSTOTE();
}
Commit	Line	Data
0b5dd071	1	/**************************************************************************
	2	* Copyright(c) 1998-2003, 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 *
	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	* *
	15	**************************************************************************/
	16
	17	/* $Id$ */
	18
0b5dd071	19	// Event generator of two-photon processes
	20	// in ultra-peripheral ion collisions.
	21	// 5 two-photon process are implemented, see comments to SetProcess().
	22	//%
	23	// The example of the generator initialization for the process
	24	// gamma gamma -> X in CaCa collisions at 7000 TeV/nucleon is the following:
	25	//%
	26	// AliGenTPHIC *gener = new AliGenTPHIC();
	27	// gener->SetProcess(1);
	28	// gener->SetBeamEnergy(3500.);
	29	// gener->SetBeamZ(20);
	30	// gener->SetBeamA(40);
	31	// gener->SetMggRange(70.,200.);
	32	// gener->SetYggRange(-5.,5.);
	33	// gener->SetLumFunName("lum_ca_70_200.dat");
	34	// gener->SetLumFunFlag(-1);
	35	// gener->Init();
	36	//%
	37	// The two-photon luminosity function needed for the process cross section
	38	// calculation is time-consuming, therefore it can be calculated once for a
	39	// selected two-photon energy and rapidity range and selected ion species,
	40	// saved into a file and then can be reused in further calculation.
	41	//%
	42	// The integral cross section of the process is calculated in each event
	43	// by the Monte Carlo integration procedure, the differential cross section
	44	// of each thrown event is assigned as a weight to each track of the event
	45	// which can be then used during the event analysis by retreiving this weight
	46	// from any of the event tracks.
	47	//
	48	// The manual of the fortran generator is available in
	49	// $ALICE_ROOT/TPHIC/TPHIC_doc.ps.gz
	50	// For the two-photon physics in heavy ion collisions see
	51	// G.Baur et al, Phys.Rep. 364 (2002), 359.
	52	//%
	53	// Author: Yuri.Kharlov@cern.ch
	54	// 15 April 2003
	55
	56	#include <TParticle.h>
	57	#include <TParticlePDG.h>
	58	#include <TDatabasePDG.h>
	59	#include "AliPythia.h"
	60	#include "AliRun.h"
	61	#include <AliGenTPHIC.h>
	62	#include <TPHICgen.h>
	63	#include <TPHICcommon.h>
	64
	65	ClassImp(AliGenTPHIC)
	66
	67	//------------------------------------------------------------
	68
	69	AliGenTPHIC::AliGenTPHIC()
	70	{
	71	// Constructor: create generator instance,
	72	// create particle array
	73	// Set TPHIC parameters to default values:
	74	// eta_b production in Ca-Ca collisions at 7 A*TeV
	75
	76	SetMC(new TPHICgen());
	77	fPythia = AliPythia::Instance();
	78	fParticles = new TClonesArray("TParticle",100);
	79
	80	SetProcess ();
	81	SetBeamEnergy();
	82	SetBeamZ ();
83	SetBeamA ();
84	SetYggRange ();
85	SetMggRange ();
86	SetNgridY ();
87	SetNgridM ();
88	SetLumFunName();
89	SetLumFunFlag();
90	SetKfOnium ();
91	}
92
93	//____________________________________________________________
94	AliGenTPHIC::AliGenTPHIC(const AliGenTPHIC & gen)
95	{
96	// copy constructor
97	gen.Copy(*this);
98	}
99
100	//____________________________________________________________
101	AliGenTPHIC::~AliGenTPHIC()
102	{
103	// Destroys the object, deletes and disposes all TParticles currently on list.
104	if (fParticles) {
105	fParticles->Delete();
106	delete fParticles;
107	fParticles = 0;
108	}
109	}
110
111	//____________________________________________________________
112	void AliGenTPHIC::Init()
113	{
114	// Initialize the generator TPHIC
115
116	fTPHICgen->Initialize();
117	fEvent = 0;
118	}
119
120	//____________________________________________________________
121	void AliGenTPHIC::Generate()
122	{
123	// Generate one event of two-photon process.
124	// Gaussian smearing on the vertex is done if selected.
125	// All particles from the TPHIC/PYTHIA event listing
126	// are stored in TreeK, and only final-state particles are tracked.
127	// The event differectial cross section is assigned as a weight
128	// to each track of the event.
129
130	Float_t polar[3]= {0,0,0};
131	Float_t origin0[3],origin[3];
132	Float_t p[3], tof;
133	Double_t weight;
134
135	Int_t ks,kf,iparent,nt, trackIt;
136	Float_t random[6];
137	const Float_t kconv=0.001/2.999792458e8;
138
139	fTPHICgen->GenerateEvent();
140	weight = GetXSectionCurrent();
141	if (gAlice->GetEvNumber()>=fDebugEventFirst &&
142	gAlice->GetEvNumber()<=fDebugEventLast) fPythia->Pylist(1);
143	fPythia->ImportParticles(fParticles,"All");
144
145	if (fDebug == 1)
146	Info("Generate()","one event is produced");
147
148	Int_t j;
149	for (j=0;j<3;j++) origin[j]=fOrigin[j];
150	if(fVertexSmear==kPerEvent) {
151	Rndm(random,6);
152	for (j=0;j<3;j++) {
153	origin0[j]+=fOsigma[j]TMath::Cos(2random[2j]TMath::Pi())*
154	TMath::Sqrt(-2TMath::Log(random[2j+1]));
155	}
156	}
157
158	Int_t ip;
159	Int_t np = fParticles->GetEntriesFast();
160	TParticle *iparticle;
161	// Int_t* pParent = new Int_t[np];
162	for (ip=0; ip<np; ip++) {
163	iparticle = (TParticle *) fParticles->At(ip);
164	ks = iparticle->GetStatusCode();
165	// // No initial state partons
166	// if (ks==21) continue;
167	p[0] = iparticle->Px();
168	p[1] = iparticle->Py();
169	p[2] = iparticle->Pz();
170	origin[0] = origin0[0]+iparticle->Vx()/10.;
171	origin[1] = origin0[1]+iparticle->Vy()/10.;
172	origin[2] = origin0[2]+iparticle->Vz()/10.;
173	kf = CheckPDGCode(iparticle->GetPdgCode());
174	iparent = -1;
175	tof = kconv*iparticle->T();
176	if (ks == 1) trackIt = 1;
177	else trackIt = 0;
642f15cf	178	PushTrack(fTrackIt*trackIt,iparent,kf,p,origin,polar,tof,kPPrimary,nt,weight,ks);
0b5dd071	179	KeepTrack(nt);
	180
	181	if (fDebug == 2)
	182	printf("id=%+4d, parent=%3d, ks=%d, p = (%+11.4e,%+11.4e,%+11.4e) GeV\n",
	183	kf,iparent,fTrackIt*trackIt,p[0],p[1],p[2]);
	184	}
	185	fEvent++;
	186	fTPHICgen->SetNEVENT(fEvent);
	187	if (fDebug == 1 && fEvent%100 == 0) {
	188	Info("Generate","Event %d\n",fEvent);
	189	fTPHICgen->Finish();
	190	}
	191	}
	192
	193	//____________________________________________________________
	194	void AliGenTPHIC::SetEventListRange(Int_t eventFirst, Int_t eventLast)
	195	{
	196	// Set a range of event numbers, for which a table
	197	// of generated particle will be printed
	198	fDebugEventFirst = eventFirst;
	199	fDebugEventLast = eventLast;
	200	if (fDebugEventLast==-1) fDebugEventLast=fDebugEventFirst;
	201	}
	202
	203	//____________________________________________________________
	204	void AliGenTPHIC::SetProcess (Int_t proc )
	205	{
	206	// Set process number:
	207	// proc=1 - gamma gamma -> X
	208	// proc=2 - gamma gamma -> quarkonium
	209	// proc=3 - gamma gamma -> fermion+ fermion-
	210	// proc=4 - gamma gamma -> W+ W-
	211	// proc=5 - not implemented
	212	// proc=6 - gamma gamma -> V1 V2 (vector meson pair)
	213
	214	fTPHICgen->SetIPROC(proc);
	215	}
	216	//____________________________________________________________
	217	void AliGenTPHIC::SetBeamEnergy (Float_t energy)
	218	{
	219	// Set energy of the beam ion per nucleon in GeV
	220	fTPHICgen->SetEBMN(energy);
	221	}
	222	//____________________________________________________________
	223	void AliGenTPHIC::SetBeamZ (Int_t z )
	224	{
	225	// Set beam ion charge
	226	fTPHICgen->SetIZ(z);
	227	}
	228	//____________________________________________________________
	229	void AliGenTPHIC::SetBeamA (Int_t a )
	230	{
	231	// Set beam ion atomic number
	232	fTPHICgen->SetIA(a);
	233	}
	234	//____________________________________________________________
	235	void AliGenTPHIC::SetYggRange (Float_t ymin, Float_t ymax)
	236	{
	237	// Set rapidity range of 2-photon system for the
	238	// luminosity function calculation
	239	fTPHICgen->SetYMIN(ymin);
	240	fTPHICgen->SetYMAX(ymax);
	241	}
	242	//____________________________________________________________
243	void AliGenTPHIC::SetMggRange (Float_t mmin, Float_t mmax)
244	{
245	// Set invariant mass range of 2-photon system for the
246	// luminosity function calculation
247	fTPHICgen->SetAMIN(mmin);
248	fTPHICgen->SetAMAX(mmax);
249	}
250	//____________________________________________________________
251	void AliGenTPHIC::SetNgridY (Int_t ny )
252	{
253	// Set number of nodes on the grid along the rapidity axis
254	// to calculate the 2-photon luminosity function
255	fTPHICgen->SetNY(ny);
256	}
257	//____________________________________________________________
258	void AliGenTPHIC::SetNgridM (Int_t nm )
259	{
260	// Set number of nodes on the grid along the mass axis
261	// to calculate the 2-photon luminosity function
262	fTPHICgen->SetNMAS(nm);
263	}
264	//____________________________________________________________
265	void AliGenTPHIC::SetLumFunName (TString name )
266	{
267	// Set filename to store the 2-photon luminosity
268	// function calculated on the grid
269	fTPHICgen->SetLUMFIL(name);
270	}
271	//____________________________________________________________
272	void AliGenTPHIC::SetLumFunFlag (Int_t flag )
273	{
274	// Set flag to calculate the 2-photon luminosity function:
275	// flag=-1 if a new lumimosity function to be calculated
276	// and stored in a file
277	// flag=+1 if a previously calculated function to be read
278	// from a file
279	fTPHICgen->SetILUMF(flag);
280	}
281	//____________________________________________________________
282	void AliGenTPHIC::SetKfFermion (Int_t kf )
283	{
284	// Set a PDG flavour code of a fermion for the process 3,
285	// gamma gamma -> fermion+ fermion-
286	fTPHICgen->SetKFERM(kf);
287	}
288	//____________________________________________________________
289	void AliGenTPHIC::SetKfOnium (Int_t kf )
290	{
291	// Set a PDG flavour code of a quarkonium for the process 2,
292	// gamma gamma -> quarkonium
293	fTPHICgen->SetKFONIUM(kf);
294	}
295	//____________________________________________________________
296	void AliGenTPHIC::SetMassOnium (Float_t mass )
297	{
298	// Set a quarkonium mass [GeV] for the process 2 if it
299	// differes from the Pythia's particle table.
300	// For the well-known quarkonia no need to set this mass
301	// because it will be taken from the Pythia table
302	fTPHICgen->SetXMRES(mass);
303	}
304	//____________________________________________________________
305	void AliGenTPHIC::SetGGwidthOnium(Float_t width )
306	{
307	// Set 2-photon partial width [GeV] of the quarkonium for
308	// the process 2 if it differes fromthe Pythia's particle table.
309	// For the well-known quarkonia no need to set this width
310	// because it will be taken from the Pythia table
311	fTPHICgen->SetXGGRES(width);
312	}
313	//____________________________________________________________
314	void AliGenTPHIC::SetKfVmesons (Int_t kf1, Int_t kf2)
315	{
316	// Set PDG flavour codes of the two vector vesons
317	// for the process 2: gamma gamma -> V1 V2
318	// So far this processes is implemented for the following
319	// mesons and their combinations only:
320	// pho0 (113), omega (223), phi (333), J/psi (443)
321	fTPHICgen->SetKV1(kf1);
322	fTPHICgen->SetKV2(kf2);
323	}
324	//____________________________________________________________
325	Float_t AliGenTPHIC::GetGGmass ()
326	{
327	// Get invariant mass of generated 2-photon system
328	return fTPHICgen->GetWSQ();
329	}
330	//____________________________________________________________
331	Float_t AliGenTPHIC::GetGGrapidity()
332	{
333	// Get rapidity of generated 2-photon system
334	return fTPHICgen->GetYGG();
335	}
336	//____________________________________________________________
337	Float_t AliGenTPHIC::GetG1mass ()
338	{
339	// Get a mass of the first virtual photon of
340	// the 2-photon process (-sqrt(q1^2)).
341	return fTPHICgen->GetXMG1();
342	}
343	//____________________________________________________________
344	Float_t AliGenTPHIC::GetG2mass ()
345	{
346	// Get a mass of the second virtual photon of
347	// the 2-photon process (-sqrt(q2^2)).
348	return fTPHICgen->GetXMG2();
349	}
350	//____________________________________________________________
351	TClonesArray* AliGenTPHIC::GetParticleList ()
352	{
353	// Get array of particles of the event listing
354	return fParticles;
355	}
356	//____________________________________________________________
357	TLorentzVector AliGenTPHIC::MomentumRecNucl1()
358	{
359	// Get 4-momentum of the first recoil nucleus after
360	// the 2-photon process.
361	return TLorentzVector(fTPHICgen->GetPTAG1(1),
362	fTPHICgen->GetPTAG1(2),
363	fTPHICgen->GetPTAG1(3),
364	fTPHICgen->GetPTAG1(4));
365	}
366	//____________________________________________________________
367	TLorentzVector AliGenTPHIC::MomentumRecNucl2()
368	{
369	// Get 4-momentum of the first recoil nucleus after
370	// the 2-photon process.
371	return TLorentzVector(fTPHICgen->GetPTAG2(1),
372	fTPHICgen->GetPTAG2(2),
373	fTPHICgen->GetPTAG2(3),
374	fTPHICgen->GetPTAG2(4));
375	}
376	//____________________________________________________________
377	Float_t AliGenTPHIC::GetXSectionCurrent()
378	{
379	// Get the cross section of the produced event for the
380	// Monte Carlo integral cross section calculation
381	return fTPHICgen->GetXSCUR();
382	}
383	//____________________________________________________________
384	Float_t AliGenTPHIC::GetXSection ()
385	{
386	// Get the integral cross section of the process
387	// calculated so far
388	return fTPHICgen->GetXSTOT();
389	}
390	//____________________________________________________________
391	Float_t AliGenTPHIC::GetXSectionError ()
392	{
393	// Get the error of the integral cross section of the process
394	// calculated so far
395	return fTPHICgen->GetXSTOTE();
396	}