[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 <TF1.h>
#include <TCanvas.h>
#include <TH1.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 = new TF1("Pt-Parametrization",fPtParaFunc,0,15,0);
    TF1* yPara  = new TF1("Y -Parametrization",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->
		PushTrack(fTrackIt,-1,iPart,p,origin0,polar,0,kPPrimary,nt,wgtp);
            ipa++; 
	  }
	  break;
    } // while
  } // event loop
  SetHighWaterMark(nt);
}

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