[u/mrichter/AliRoot.git] / EVGEN / AliGenParam.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, 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.                  *
 **************************************************************************/

/* $Id$ */

// Class to generate particles from using paramtrized pT and y distributions.
// Distributions are obtained from pointer to object of type AliGenLib.
// (For example AliGenMUONlib)
// Decays are performed using Pythia.
// andreas.morsch@cern.ch

#include "AliGenParam.h"
#include "AliDecayer.h"
#include "AliGenMUONlib.h"
#include "AliRun.h"
#include <TParticle.h>
#include <TParticlePDG.h>
#include <TDatabasePDG.h>
#include <TLorentzVector.h>
#include <TVirtualMC.h>

#include <TF1.h>
#include <TCanvas.h>
#include <TH1.h>
#include "AliMC.h"

ClassImp(AliGenParam)

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

  //Begin_Html
  /*
    <img src="picts/AliGenParam.gif">
  */
  //End_Html

//____________________________________________________________
//____________________________________________________________
AliGenParam::AliGenParam()
{
// Deafault constructor
    fPtPara = 0;
    fYPara  = 0;
    fParam  = 0;
    fAnalog = kAnalog;
    SetDeltaPt();
    fDecayer = 0;


}

AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library,  Int_t param, char* tname):AliGenMC(npart)
{
// Constructor using number of particles parameterisation id and library
    fName = "Param";
    fTitle= "Particle Generator using pT and y parameterisation";
    
    fPtParaFunc = Library->GetPt(param, tname);
    fYParaFunc  = Library->GetY (param, tname);
    fIpParaFunc = Library->GetIp(param, tname);
    
    fPtPara = 0;
    fYPara  = 0;
    fParam  = param;
    fAnalog = kAnalog;
    SetForceDecay();
    SetDeltaPt(); 
}

//____________________________________________________________

AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
{
// Constructor using parameterisation id and number of particles
//
    fName = "Param";
    fTitle= "Particle Generator using pT and y parameterisation";
      
    AliGenLib* pLibrary = new AliGenMUONlib();
 
    fPtParaFunc = pLibrary->GetPt(param, tname);
    fYParaFunc  = pLibrary->GetY (param, tname);
    fIpParaFunc = pLibrary->GetIp(param, tname);
    
    fPtPara = 0;
    fYPara  = 0;
    fParam  = param;
    fAnalog = kAnalog;
    fChildSelect.Set(5);
    for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
    SetForceDecay();
    SetCutOnChild();
    SetChildMomentumRange();
    SetChildPtRange();
    SetChildPhiRange();
    SetChildThetaRange(); 
    SetDeltaPt(); 
}

AliGenParam::AliGenParam(Int_t npart, Int_t param,
                         Double_t (*PtPara) (Double_t*, Double_t*),
                         Double_t (*YPara ) (Double_t* ,Double_t*),
		         Int_t    (*IpPara) (TRandom *))		 
    :AliGenMC(npart)
{
// Constructor
// Gines Martinez 1/10/99 
    fName = "Param";
    fTitle= "Particle Generator using pT and y parameterisation";

    fPtParaFunc = PtPara; 
    fYParaFunc  = YPara;  
    fIpParaFunc = IpPara;
//  
    fPtPara = 0;
    fYPara  = 0;
    fParam  = param;
    fAnalog = kAnalog;
    fChildSelect.Set(5);
    for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
    SetForceDecay();
    SetCutOnChild();
    SetChildMomentumRange();
    SetChildPtRange();
    SetChildPhiRange();
    SetChildThetaRange();  
    SetDeltaPt();
}


AliGenParam::AliGenParam(const AliGenParam & Param)
    :AliGenMC(Param)
{
// Copy constructor
    Param.Copy(*this);
}

//____________________________________________________________
AliGenParam::~AliGenParam()
{
// Destructor
    delete  fPtPara;
    delete  fYPara;
}

//____________________________________________________________
void AliGenParam::Init()
{
// Initialisation

    if (gMC) fDecayer = gMC->GetDecayer();
  //Begin_Html
  /*
    <img src="picts/AliGenParam.gif">
  */
  //End_Html
 
    fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
//  Set representation precision to 10 MeV
    Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
    
    fPtPara->SetNpx(npx);
    
    fYPara  = new TF1("Y-Parametrization",fYParaFunc,fYMin,fYMax,0);
    TF1 ptPara("Pt-Parametrization(0,15)",fPtParaFunc,0,15,0);
    TF1 yPara("Y-Parametrization(-6,6)",fYParaFunc,-6,6,0);

//
// dN/dy| y=0
    Double_t y1=0;
    Double_t y2=0;
    
    fdNdy0=fYParaFunc(&y1,&y2);
//
// Integral over generation region
    Float_t intYS  = yPara.Integral(fYMin, fYMax);
    Float_t intPt0 = ptPara.Integral(0,15);
    Float_t intPtS = ptPara.Integral(fPtMin,fPtMax);
    Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
    if (fAnalog == kAnalog) {
	fYWgt  = intYS/fdNdy0;
	fPtWgt = intPtS/intPt0;
	fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
    } else {
	fYWgt = intYS/fdNdy0;
	fPtWgt = (fPtMax-fPtMin)/intPt0;
	fParentWeight = fYWgt*fPtWgt*phiWgt/fNpart;
    }
//
// particle decay related initialization
    fDecayer->SetForceDecay(fForceDecay);
    fDecayer->Init();

//
    AliGenMC::Init();
}

//____________________________________________________________
void AliGenParam::Generate()
{
//
// Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
// Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and 
// antineutrons in the the desired theta, phi and momentum windows; 
// Gaussian smearing on the vertex is done if selected. 
// The decay of heavy mesons is done using lujet, 
//    and the childern particle are tracked by GEANT
// However, light mesons are directly tracked by GEANT 
// setting fForceDecay = nodecay (SetForceDecay(nodecay)) 
//
//
//  Reinitialize decayer
    fDecayer->Init();
//
  Float_t polar[3]= {0,0,0};  // Polarisation of the parent particle (for GEANT tracking)
  Float_t origin0[3];         // Origin of the generated parent particle (for GEANT tracking)
  Float_t pt, pl, ptot;       // Transverse, logitudinal and total momenta of the parent particle
  Float_t phi, theta;         // Phi and theta spherical angles of the parent particle momentum
  Float_t p[3], pc[3], 
          och[3];             // Momentum, polarisation and origin of the children particles from lujet
  Double_t ty, xmt;
  Int_t nt, i, j;
  Float_t  wgtp, wgtch;
  Double_t dummy;
  static TClonesArray *particles;
  //
  if(!particles) particles = new TClonesArray("TParticle",1000);
  
  TDatabasePDG *pDataBase = TDatabasePDG::Instance();
  //
  Float_t random[6];
 
// Calculating vertex position per event
  for (j=0;j<3;j++) origin0[j]=fOrigin[j];
  if(fVertexSmear==kPerEvent) {
      Vertex();
      for (j=0;j<3;j++) origin0[j]=fVertex[j];
  }
  
  Int_t ipa=0;
  
// Generating fNpart particles
  while (ipa<fNpart) {
      while(1) {
//
// particle type
	  Int_t iPart = fIpParaFunc(fRandom);
	  fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;	   
	  TParticlePDG *particle = pDataBase->GetParticle(iPart);
	  Float_t am = particle->Mass();
	  
	  Rndm(random,2);
//
// phi
	  phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
//
// y
	  ty = TMath::TanH(fYPara->GetRandom());
//
// pT
	  if (fAnalog == kAnalog) {
	      pt=fPtPara->GetRandom();
	      wgtp=fParentWeight;
	      wgtch=fChildWeight;
	  } else {
	      pt=fPtMin+random[1]*(fPtMax-fPtMin);
	      Double_t ptd=pt;
	      wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
	      wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
	  }
	  xmt=sqrt(pt*pt+am*am);
	  if (TMath::Abs(ty)==1.) {
	      ty=0.;
	      Fatal("AliGenParam", 
		    "Division by 0: Please check you rapidity range !");
	  }
	  
	  pl=xmt*ty/sqrt(1.-ty*ty);
	  theta=TMath::ATan2(pt,pl);
// Cut on theta
	  if(theta<fThetaMin || theta>fThetaMax) continue;
	  ptot=TMath::Sqrt(pt*pt+pl*pl);
// Cut on momentum
	  if(ptot<fPMin || ptot>fPMax) continue;
//
	  p[0]=pt*TMath::Cos(phi);
	  p[1]=pt*TMath::Sin(phi);
	  p[2]=pl;
	  if(fVertexSmear==kPerTrack) {
	      Rndm(random,6);
	      for (j=0;j<3;j++) {
		  origin0[j]=
		      fOrigin[j]+fOsigma[j]*TMath::Cos(2*random[2*j]*TMath::Pi())*
		      TMath::Sqrt(-2*TMath::Log(random[2*j+1]));
	      }
	  }
	  
// Looking at fForceDecay : 
// if fForceDecay != none Primary particle decays using 
// AliPythia and children are tracked by GEANT
//
// if fForceDecay == none Primary particle is tracked by GEANT 
// (In the latest, make sure that GEANT actually does all the decays you want)	  
//

	  if (fForceDecay != kNoDecay) {
// Using lujet to decay particle
	      Float_t energy=TMath::Sqrt(ptot*ptot+am*am);
	      TLorentzVector pmom(p[0], p[1], p[2], energy);
	      fDecayer->Decay(iPart,&pmom);
//
// select decay particles
	      Int_t np=fDecayer->ImportParticles(particles);

	      //  Selecting  GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
	      if (fGeometryAcceptance) 
		if (!CheckAcceptanceGeometry(np,particles)) continue;
	      Int_t ncsel=0;
	      Int_t* pFlag      = new Int_t[np];
	      Int_t* pParent    = new Int_t[np];
	      Int_t* pSelected  = new Int_t[np];
	      Int_t* trackIt    = new Int_t[np];

	      for (i=0; i<np; i++) {
		  pFlag[i]     =  0;
		  pSelected[i] =  0;
		  pParent[i]   = -1;
	      }
	      
	      if (np >1) {
		  TParticle* iparticle =  (TParticle *) particles->At(0);
		  Int_t ipF, ipL;
		  for (i = 1; i<np ; i++) {
		      trackIt[i] = 1;
		      iparticle = (TParticle *) particles->At(i);
		      Int_t kf = iparticle->GetPdgCode();
		      Int_t ks = iparticle->GetStatusCode();
// flagged particle

		      if (pFlag[i] == 1) {
			  ipF = iparticle->GetFirstDaughter();
			  ipL = iparticle->GetLastDaughter();	
			  if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
			  continue;
		      }

// flag decay products of particles with long life-time (c tau > .3 mum)		      
		      
		      if (ks != 1) { 
//			  TParticlePDG *particle = pDataBase->GetParticle(kf);
			  
			  Double_t lifeTime = fDecayer->GetLifetime(kf);
//			  Double_t mass     = particle->Mass();
//			  Double_t width    = particle->Width();
			  if (lifeTime > (Double_t) fMaxLifeTime) {
			      ipF = iparticle->GetFirstDaughter();
			      ipL = iparticle->GetLastDaughter();	
			      if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
			  } else{
			      trackIt[i]     = 0;
			      pSelected[i]   = 1;
			  }
		      } // ks==1 ?
//
// children
		      
		      if (ChildSelected(TMath::Abs(kf)) || fForceDecay == kAll && trackIt[i])
		      {
			  if (fCutOnChild) {
			      pc[0]=iparticle->Px();
			      pc[1]=iparticle->Py();
			      pc[2]=iparticle->Pz();
			      Bool_t  childok = KinematicSelection(iparticle, 1);
			      if(childok) {
				  pSelected[i]  = 1;
				  ncsel++;
			      } else {
				  ncsel=-1;
				  break;
			      } // child kine cuts
			  } else {
			      pSelected[i]  = 1;
			      ncsel++;
			  } // if child selection
		      } // select muon
		  } // decay particle loop
	      } // if decay products
	      
	      Int_t iparent;
	      if ((fCutOnChild && ncsel >0) || !fCutOnChild){
		  ipa++;
//
// Parent
		  PushTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
		  pParent[0] = nt;
		  KeepTrack(nt); 
//
// Decay Products
//		  
		  for (i = 1; i < np; i++) {
		      if (pSelected[i]) {
			  TParticle* iparticle = (TParticle *) particles->At(i);
			  Int_t kf  = iparticle->GetPdgCode();
			  Int_t ipa = iparticle->GetFirstMother()-1;
			  
			  och[0] = origin0[0]+iparticle->Vx()/10;
			  och[1] = origin0[1]+iparticle->Vy()/10;
			  och[2] = origin0[2]+iparticle->Vz()/10;
			  pc[0]  = iparticle->Px();
			  pc[1]  = iparticle->Py();
			  pc[2]  = iparticle->Pz();
			  
			  if (ipa > -1) {
			      iparent = pParent[ipa];
			  } else {
			      iparent = -1;
			  }
			 
			  PushTrack(fTrackIt*trackIt[i], iparent, kf,
					   pc, och, polar,
					   0, kPDecay, nt, wgtch);
			  pParent[i] = nt;
			  KeepTrack(nt); 
		      } // Selected
		  } // Particle loop 
	      }  // Decays by Lujet
	      particles->Clear();
	      if (pFlag)      delete[] pFlag;
	      if (pParent)    delete[] pParent;
	      if (pSelected)  delete[] pSelected;	   
	      if (trackIt)    delete[] trackIt;
	  } // kinematic selection
	  else  // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
	  {
	    gAlice->GetMCApp()->
		PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
            ipa++; 
	  }
	  break;
    } // while
  } // event loop
  SetHighWaterMark(nt);
}

void AliGenParam::Draw( const char * /*opt*/)
{
    //
    // Draw the pT and y Distributions
    //
     TCanvas *c0 = new TCanvas("c0","Canvas 0",400,10,600,700);
     c0->Divide(2,1);
     c0->cd(1);
     fPtPara->Draw();
     fPtPara->GetHistogram()->SetXTitle("p_{T} (GeV)");     
     c0->cd(2);
     fYPara->Draw();
     fYPara->GetHistogram()->SetXTitle("y");     
}

AliGenParam& AliGenParam::operator=(const  AliGenParam& rhs)
{
// Assignment operator
    rhs.Copy(*this);
    return *this;
}
Commit	Line	Data
4c039060	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	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
88cb7938	16	/* $Id$ */
6d4dd317	17
	18	// Class to generate particles from using paramtrized pT and y distributions.
	19	// Distributions are obtained from pointer to object of type AliGenLib.
	20	// (For example AliGenMUONlib)
	21	// Decays are performed using Pythia.
	22	// andreas.morsch@cern.ch
	23
fe4da5cc	24	#include "AliGenParam.h"
2904363f	25	#include "AliDecayer.h"
fe4da5cc	26	#include "AliGenMUONlib.h"
fe4da5cc	27	#include "AliRun.h"
1578254f	28	#include <TParticle.h>
fa480368	29	#include <TParticlePDG.h>
	30	#include <TDatabasePDG.h>
	31	#include <TLorentzVector.h>
5d12ce38	32	#include <TVirtualMC.h>
fa480368	33
f87cfe57	34	#include <TF1.h>
5bd39445	35	#include <TCanvas.h>
5bd39445	36	#include <TH1.h>
5d12ce38	37	#include "AliMC.h"
fe4da5cc	38
	39	ClassImp(AliGenParam)
	40
	41	//------------------------------------------------------------
	42
	43	//Begin_Html
	44	/*
1439f98e	45	<img src="picts/AliGenParam.gif">
fe4da5cc	46	*/
	47	//End_Html
	48
	49	//____________________________________________________________
	50	//____________________________________________________________
	51	AliGenParam::AliGenParam()
fe4da5cc	52	{
b22ee262	53	// Deafault constructor
	54	fPtPara = 0;
	55	fYPara = 0;
34f60c01	56	fParam = 0;
34f60c01	57	fAnalog = kAnalog;
b22ee262	58	SetDeltaPt();
2685bf00	59	fDecayer = 0;
8b31bfac	60
8b31bfac	61
b22ee262	62	}
b22ee262	63
fff02fee	64	AliGenParam::AliGenParam(Int_t npart, AliGenLib * Library, Int_t param, char* tname):AliGenMC(npart)
b22ee262	65	{
b22ee262	66	// Constructor using number of particles parameterisation id and library
8b31bfac	67	fName = "Param";
8b31bfac	68	fTitle= "Particle Generator using pT and y parameterisation";
b22ee262	69
	70	fPtParaFunc = Library->GetPt(param, tname);
	71	fYParaFunc = Library->GetY (param, tname);
	72	fIpParaFunc = Library->GetIp(param, tname);
	73
	74	fPtPara = 0;
	75	fYPara = 0;
	76	fParam = param;
34f60c01	77	fAnalog = kAnalog;
b22ee262	78	SetForceDecay();
b22ee262	79	SetDeltaPt();
fe4da5cc	80	}
	81
	82	//____________________________________________________________
886b6f73	83
fff02fee	84	AliGenParam::AliGenParam(Int_t npart, Int_t param, char* tname):AliGenMC(npart)
fe4da5cc	85	{
b22ee262	86	// Constructor using parameterisation id and number of particles
8b31bfac	87	//
	88	fName = "Param";
	89	fTitle= "Particle Generator using pT and y parameterisation";
	90
675e9664	91	AliGenLib* pLibrary = new AliGenMUONlib();
b22ee262	92
675e9664	93	fPtParaFunc = pLibrary->GetPt(param, tname);
	94	fYParaFunc = pLibrary->GetY (param, tname);
	95	fIpParaFunc = pLibrary->GetIp(param, tname);
b22ee262	96
	97	fPtPara = 0;
	98	fYPara = 0;
	99	fParam = param;
34f60c01	100	fAnalog = kAnalog;
b22ee262	101	fChildSelect.Set(5);
	102	for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
	103	SetForceDecay();
	104	SetCutOnChild();
	105	SetChildMomentumRange();
	106	SetChildPtRange();
	107	SetChildPhiRange();
	108	SetChildThetaRange();
	109	SetDeltaPt();
fe4da5cc	110	}
fe4da5cc	111
34f60c01	112	AliGenParam::AliGenParam(Int_t npart, Int_t param,
886b6f73	113	Double_t (PtPara) (Double_t, Double_t*),
886b6f73	114	Double_t (YPara ) (Double_t ,Double_t*),
65fb704d	115	Int_t (IpPara) (TRandom ))
fff02fee	116	:AliGenMC(npart)
886b6f73	117	{
749070b6	118	// Constructor
28337bc1	119	// Gines Martinez 1/10/99
8b31bfac	120	fName = "Param";
	121	fTitle= "Particle Generator using pT and y parameterisation";
	122
886b6f73	123	fPtParaFunc = PtPara;
	124	fYParaFunc = YPara;
	125	fIpParaFunc = IpPara;
28337bc1	126	//
886b6f73	127	fPtPara = 0;
	128	fYPara = 0;
	129	fParam = param;
34f60c01	130	fAnalog = kAnalog;
886b6f73	131	fChildSelect.Set(5);
	132	for (Int_t i=0; i<5; i++) fChildSelect[i]=0;
	133	SetForceDecay();
	134	SetCutOnChild();
749070b6	135	SetChildMomentumRange();
	136	SetChildPtRange();
	137	SetChildPhiRange();
	138	SetChildThetaRange();
	139	SetDeltaPt();
886b6f73	140	}
886b6f73	141
f87cfe57	142
6d4dd317	143	AliGenParam::AliGenParam(const AliGenParam & Param)
198bb1c7	144	:AliGenMC(Param)
f87cfe57	145	{
198bb1c7	146	// Copy constructor
6d4dd317	147	Param.Copy(*this);
f87cfe57	148	}
f87cfe57	149
fe4da5cc	150	//____________________________________________________________
	151	AliGenParam::~AliGenParam()
	152	{
749070b6	153	// Destructor
fe4da5cc	154	delete fPtPara;
	155	delete fYPara;
	156	}
	157
	158	//____________________________________________________________
	159	void AliGenParam::Init()
	160	{
749070b6	161	// Initialisation
fa480368	162
2904363f	163	if (gMC) fDecayer = gMC->GetDecayer();
fe4da5cc	164	//Begin_Html
fe4da5cc	165	/*
1439f98e	166	<img src="picts/AliGenParam.gif">
fe4da5cc	167	*/
	168	//End_Html
	169
749070b6	170	fPtPara = new TF1("Pt-Parametrization",fPtParaFunc,fPtMin,fPtMax,0);
	171	// Set representation precision to 10 MeV
	172	Int_t npx= Int_t((fPtMax-fPtMin)/fDeltaPt);
	173
	174	fPtPara->SetNpx(npx);
	175
2a336e15	176	fYPara = new TF1("Y-Parametrization",fYParaFunc,fYMin,fYMax,0);
	177	TF1 ptPara("Pt-Parametrization(0,15)",fPtParaFunc,0,15,0);
	178	TF1 yPara("Y-Parametrization(-6,6)",fYParaFunc,-6,6,0);
b7601ac4	179
fe4da5cc	180	//
fe4da5cc	181	// dN/dy\| y=0
749070b6	182	Double_t y1=0;
	183	Double_t y2=0;
	184
	185	fdNdy0=fYParaFunc(&y1,&y2);
fe4da5cc	186	//
fe4da5cc	187	// Integral over generation region
2a336e15	188	Float_t intYS = yPara.Integral(fYMin, fYMax);
	189	Float_t intPt0 = ptPara.Integral(0,15);
	190	Float_t intPtS = ptPara.Integral(fPtMin,fPtMax);
749070b6	191	Float_t phiWgt=(fPhiMax-fPhiMin)/2./TMath::Pi();
34f60c01	192	if (fAnalog == kAnalog) {
749070b6	193	fYWgt = intYS/fdNdy0;
	194	fPtWgt = intPtS/intPt0;
	195	fParentWeight = fYWgtfPtWgtphiWgt/fNpart;
	196	} else {
	197	fYWgt = intYS/fdNdy0;
	198	fPtWgt = (fPtMax-fPtMin)/intPt0;
	199	fParentWeight = fYWgtfPtWgtphiWgt/fNpart;
	200	}
fe4da5cc	201	//
fe4da5cc	202	// particle decay related initialization
00d6ce7d	203	fDecayer->SetForceDecay(fForceDecay);
fa480368	204	fDecayer->Init();
00d6ce7d	205
fe4da5cc	206	//
fff02fee	207	AliGenMC::Init();
fe4da5cc	208	}
	209
	210	//____________________________________________________________
	211	void AliGenParam::Generate()
	212	{
28337bc1	213	//
	214	// Generate 'npart' of light and heavy mesons (J/Psi, upsilon or phi, Pion,
	215	// Kaons, Etas, Omegas) and Baryons (proton, antiprotons, neutrons and
	216	// antineutrons in the the desired theta, phi and momentum windows;
	217	// Gaussian smearing on the vertex is done if selected.
cc5d764c	218	// The decay of heavy mesons is done using lujet,
	219	// and the childern particle are tracked by GEANT
	220	// However, light mesons are directly tracked by GEANT
	221	// setting fForceDecay = nodecay (SetForceDecay(nodecay))
28337bc1	222	//
771bbe45	223	//
	224	// Reinitialize decayer
	225	fDecayer->Init();
	226	//
28337bc1	227	Float_t polar[3]= {0,0,0}; // Polarisation of the parent particle (for GEANT tracking)
	228	Float_t origin0[3]; // Origin of the generated parent particle (for GEANT tracking)
	229	Float_t pt, pl, ptot; // Transverse, logitudinal and total momenta of the parent particle
	230	Float_t phi, theta; // Phi and theta spherical angles of the parent particle momentum
	231	Float_t p[3], pc[3],
fff02fee	232	och[3]; // Momentum, polarisation and origin of the children particles from lujet
2d7a47be	233	Double_t ty, xmt;
fff02fee	234	Int_t nt, i, j;
fe4da5cc	235	Float_t wgtp, wgtch;
fe4da5cc	236	Double_t dummy;
09fd3ea2	237	static TClonesArray *particles;
fe4da5cc	238	//
fff02fee	239	if(!particles) particles = new TClonesArray("TParticle",1000);
8b31bfac	240
349be858	241	TDatabasePDG *pDataBase = TDatabasePDG::Instance();
fe4da5cc	242	//
fe4da5cc	243	Float_t random[6];
28337bc1	244
28337bc1	245	// Calculating vertex position per event
fe4da5cc	246	for (j=0;j<3;j++) origin0[j]=fOrigin[j];
aee8290b	247	if(fVertexSmear==kPerEvent) {
d9ea0e3b	248	Vertex();
d9ea0e3b	249	for (j=0;j<3;j++) origin0[j]=fVertex[j];
fe4da5cc	250	}
d9ea0e3b	251
21aaa175	252	Int_t ipa=0;
fff02fee	253
28337bc1	254	// Generating fNpart particles
21aaa175	255	while (ipa<fNpart) {
cc5d764c	256	while(1) {
fe4da5cc	257	//
fe4da5cc	258	// particle type
65fb704d	259	Int_t iPart = fIpParaFunc(fRandom);
fa480368	260	fChildWeight=(fDecayer->GetPartialBranchingRatio(iPart))*fParentWeight;
675e9664	261	TParticlePDG *particle = pDataBase->GetParticle(iPart);
fa480368	262	Float_t am = particle->Mass();
8b31bfac	263
65fb704d	264	Rndm(random,2);
fe4da5cc	265	//
	266	// phi
	267	phi=fPhiMin+random[0]*(fPhiMax-fPhiMin);
	268	//
	269	// y
2d7a47be	270	ty = TMath::TanH(fYPara->GetRandom());
fe4da5cc	271	//
fe4da5cc	272	// pT
34f60c01	273	if (fAnalog == kAnalog) {
fe4da5cc	274	pt=fPtPara->GetRandom();
	275	wgtp=fParentWeight;
	276	wgtch=fChildWeight;
	277	} else {
	278	pt=fPtMin+random[1]*(fPtMax-fPtMin);
	279	Double_t ptd=pt;
	280	wgtp=fParentWeight*fPtParaFunc(& ptd, &dummy);
	281	wgtch=fChildWeight*fPtParaFunc(& ptd, &dummy);
	282	}
	283	xmt=sqrt(ptpt+amam);
2d7a47be	284	if (TMath::Abs(ty)==1.) {
	285	ty=0.;
	286	Fatal("AliGenParam",
	287	"Division by 0: Please check you rapidity range !");
	288	}
	289
fe4da5cc	290	pl=xmtty/sqrt(1.-tyty);
fe4da5cc	291	theta=TMath::ATan2(pt,pl);
cc5d764c	292	// Cut on theta
fe4da5cc	293	if(theta<fThetaMin \|\| theta>fThetaMax) continue;
fe4da5cc	294	ptot=TMath::Sqrt(ptpt+plpl);
cc5d764c	295	// Cut on momentum
fe4da5cc	296	if(ptot<fPMin \|\| ptot>fPMax) continue;
fff02fee	297	//
fe4da5cc	298	p[0]=pt*TMath::Cos(phi);
	299	p[1]=pt*TMath::Sin(phi);
	300	p[2]=pl;
aee8290b	301	if(fVertexSmear==kPerTrack) {
65fb704d	302	Rndm(random,6);
fe4da5cc	303	for (j=0;j<3;j++) {
	304	origin0[j]=
	305	fOrigin[j]+fOsigma[j]TMath::Cos(2random[2j]TMath::Pi())*
	306	TMath::Sqrt(-2TMath::Log(random[2j+1]));
	307	}
	308	}
28337bc1	309
28337bc1	310	// Looking at fForceDecay :
cc5d764c	311	// if fForceDecay != none Primary particle decays using
cc5d764c	312	// AliPythia and children are tracked by GEANT
28337bc1	313	//
cc5d764c	314	// if fForceDecay == none Primary particle is tracked by GEANT
cc5d764c	315	// (In the latest, make sure that GEANT actually does all the decays you want)
fe4da5cc	316	//
fff02fee	317
34f60c01	318	if (fForceDecay != kNoDecay) {
28337bc1	319	// Using lujet to decay particle
886b6f73	320	Float_t energy=TMath::Sqrt(ptotptot+amam);
fa480368	321	TLorentzVector pmom(p[0], p[1], p[2], energy);
fa480368	322	fDecayer->Decay(iPart,&pmom);
fe4da5cc	323	//
cc5d764c	324	// select decay particles
fa480368	325	Int_t np=fDecayer->ImportParticles(particles);
1242532d	326
	327	// Selecting GeometryAcceptance for particles fPdgCodeParticleforAcceptanceCut;
	328	if (fGeometryAcceptance)
	329	if (!CheckAcceptanceGeometry(np,particles)) continue;
886b6f73	330	Int_t ncsel=0;
fff02fee	331	Int_t* pFlag = new Int_t[np];
	332	Int_t* pParent = new Int_t[np];
	333	Int_t* pSelected = new Int_t[np];
	334	Int_t* trackIt = new Int_t[np];
	335
	336	for (i=0; i<np; i++) {
	337	pFlag[i] = 0;
	338	pSelected[i] = 0;
	339	pParent[i] = -1;
	340	}
	341
6ba00c52	342	if (np >1) {
6ba00c52	343	TParticle* iparticle = (TParticle *) particles->At(0);
fff02fee	344	Int_t ipF, ipL;
	345	for (i = 1; i<np ; i++) {
	346	trackIt[i] = 1;
6ba00c52	347	iparticle = (TParticle *) particles->At(i);
6ba00c52	348	Int_t kf = iparticle->GetPdgCode();
fff02fee	349	Int_t ks = iparticle->GetStatusCode();
	350	// flagged particle
	351
	352	if (pFlag[i] == 1) {
fff02fee	353	ipF = iparticle->GetFirstDaughter();
	354	ipL = iparticle->GetLastDaughter();
	355	if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
	356	continue;
	357	}
	358
	359	// flag decay products of particles with long life-time (c tau > .3 mum)
	360
	361	if (ks != 1) {
2d7a47be	362	// TParticlePDG *particle = pDataBase->GetParticle(kf);
fff02fee	363
fff02fee	364	Double_t lifeTime = fDecayer->GetLifetime(kf);
2d7a47be	365	// Double_t mass = particle->Mass();
2d7a47be	366	// Double_t width = particle->Width();
47fc6bd5	367	if (lifeTime > (Double_t) fMaxLifeTime) {
fff02fee	368	ipF = iparticle->GetFirstDaughter();
	369	ipL = iparticle->GetLastDaughter();
	370	if (ipF > 0) for (j=ipF-1; j<ipL; j++) pFlag[j]=1;
	371	} else{
	372	trackIt[i] = 0;
	373	pSelected[i] = 1;
	374	}
	375	} // ks==1 ?
fe4da5cc	376	//
fe4da5cc	377	// children
47fc6bd5	378
fff02fee	379	if (ChildSelected(TMath::Abs(kf)) \|\| fForceDecay == kAll && trackIt[i])
6ba00c52	380	{
6ba00c52	381	if (fCutOnChild) {
fff02fee	382	pc[0]=iparticle->Px();
	383	pc[1]=iparticle->Py();
	384	pc[2]=iparticle->Pz();
	385	Bool_t childok = KinematicSelection(iparticle, 1);
	386	if(childok) {
	387	pSelected[i] = 1;
6ba00c52	388	ncsel++;
	389	} else {
	390	ncsel=-1;
	391	break;
	392	} // child kine cuts
	393	} else {
fff02fee	394	pSelected[i] = 1;
886b6f73	395	ncsel++;
6ba00c52	396	} // if child selection
	397	} // select muon
	398	} // decay particle loop
	399	} // if decay products
	400
886b6f73	401	Int_t iparent;
	402	if ((fCutOnChild && ncsel >0) \|\| !fCutOnChild){
	403	ipa++;
21aaa175	404	//
fff02fee	405	// Parent
642f15cf	406	PushTrack(0, -1, iPart, p, origin0, polar, 0, kPPrimary, nt, wgtp);
fff02fee	407	pParent[0] = nt;
a99cf51f	408	KeepTrack(nt);
fff02fee	409	//
	410	// Decay Products
	411	//
	412	for (i = 1; i < np; i++) {
	413	if (pSelected[i]) {
	414	TParticle* iparticle = (TParticle *) particles->At(i);
	415	Int_t kf = iparticle->GetPdgCode();
	416	Int_t ipa = iparticle->GetFirstMother()-1;
	417
	418	och[0] = origin0[0]+iparticle->Vx()/10;
	419	och[1] = origin0[1]+iparticle->Vy()/10;
	420	och[2] = origin0[2]+iparticle->Vz()/10;
	421	pc[0] = iparticle->Px();
	422	pc[1] = iparticle->Py();
	423	pc[2] = iparticle->Pz();
	424
	425	if (ipa > -1) {
	426	iparent = pParent[ipa];
	427	} else {
	428	iparent = -1;
	429	}
1242532d	430
642f15cf	431	PushTrack(fTrackIt*trackIt[i], iparent, kf,
fff02fee	432	pc, och, polar,
	433	0, kPDecay, nt, wgtch);
	434	pParent[i] = nt;
a99cf51f	435	KeepTrack(nt);
8b31bfac	436	} // Selected
8b31bfac	437	} // Particle loop
28337bc1	438	} // Decays by Lujet
8b31bfac	439	particles->Clear();
fff02fee	440	if (pFlag) delete[] pFlag;
	441	if (pParent) delete[] pParent;
	442	if (pSelected) delete[] pSelected;
8b31bfac	443	if (trackIt) delete[] trackIt;
21aaa175	444	} // kinematic selection
28337bc1	445	else // nodecay option, so parent will be tracked by GEANT (pions, kaons, eta, omegas, baryons)
28337bc1	446	{
5d12ce38	447	gAlice->GetMCApp()->
642f15cf	448	PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
28337bc1	449	ipa++;
28337bc1	450	}
fe4da5cc	451	break;
21aaa175	452	} // while
fe4da5cc	453	} // event loop
a99cf51f	454	SetHighWaterMark(nt);
fe4da5cc	455	}
fe4da5cc	456
dc1d768c	457	void AliGenParam::Draw( const char * /opt/)
5bd39445	458	{
	459	//
	460	// Draw the pT and y Distributions
	461	//
	462	TCanvas *c0 = new TCanvas("c0","Canvas 0",400,10,600,700);
	463	c0->Divide(2,1);
	464	c0->cd(1);
	465	fPtPara->Draw();
	466	fPtPara->GetHistogram()->SetXTitle("p_{T} (GeV)");
	467	c0->cd(2);
	468	fYPara->Draw();
	469	fYPara->GetHistogram()->SetXTitle("y");
	470	}
	471
f87cfe57	472	AliGenParam& AliGenParam::operator=(const AliGenParam& rhs)
	473	{
	474	// Assignment operator
198bb1c7	475	rhs.Copy(*this);
f87cfe57	476	return *this;
	477	}
	478
fe4da5cc	479
fe4da5cc	480