[u/mrichter/AliRoot.git] / EVGEN / AliGenPythia.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.                  *
 **************************************************************************/

/*
$Log$
Revision 1.16  2000/05/15 15:04:20  morsch
The full event is written for fNtrack = -1
Coding rule violations corrected.

Revision 1.15  2000/04/26 10:14:24  morsch
Particles array has one entry more than pythia particle list. Upper bound of
particle loop changed to np-1 (R. Guernane, AM)

Revision 1.14  2000/04/05 08:36:13  morsch
Check status code of particles in Pythia event
to avoid double counting as partonic state and final state particle.

Revision 1.13  1999/11/09 07:38:48  fca
Changes for compatibility with version 2.23 of ROOT

Revision 1.12  1999/11/03 17:43:20  fca
New version from G.Martinez & A.Morsch

Revision 1.11  1999/09/29 09:24:14  fca
Introduction of the Copyright and cvs Log
*/

#include "AliGenPythia.h"
#include "AliRun.h"
#include "AliPythia.h"
#include <TParticle.h>

 ClassImp(AliGenPythia)

AliGenPythia::AliGenPythia()
                 :AliGenerator()
{
// Constructor
}

AliGenPythia::AliGenPythia(Int_t npart)
                 :AliGenerator(npart)
{
// default charm production at 5. 5 TeV
// semimuonic decay
// structure function GRVHO
//
    fXsection  = 0.;
    fParentSelect.Set(5);
    fChildSelect.Set(5);
    for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0;
    SetProcess();
    SetStrucFunc();
    SetForceDecay();
    SetPtHard();
    SetEnergyCMS();
}

AliGenPythia::AliGenPythia(const AliGenPythia & Pythia)
{
// copy constructor
}

AliGenPythia::~AliGenPythia()
{
// Destructor
}

void AliGenPythia::Init()
{
// Initialisation
    SetMC(new AliPythia());
    fPythia=(AliPythia*) fgMCEvGen;
//
    fParentWeight=1./Float_t(fNpart);
//
//  Forward Paramters to the AliPythia object
    fPythia->DefineParticles();
    fPythia->SetCKIN(3,fPtHardMin);
    fPythia->SetCKIN(4,fPtHardMax);    
    fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc);
    fPythia->ForceDecay(fForceDecay);
    fPythia->Lulist(0);
    fPythia->Pystat(2);
//  Parent and Children Selection
    switch (fProcess) 
    {
    case charm:

	fParentSelect[0]=411;
	fParentSelect[1]=421;
	fParentSelect[2]=431;
	fParentSelect[3]=4122;	
	break;
    case charm_unforced:

	fParentSelect[0]=411;
	fParentSelect[1]=421;
	fParentSelect[2]=431;
	fParentSelect[3]=4122;	
	break;
    case beauty:
	fParentSelect[0]=511;
	fParentSelect[1]=521;
	fParentSelect[2]=531;
	fParentSelect[3]=5122;	
	break;
    case beauty_unforced:
	fParentSelect[0]=511;
	fParentSelect[1]=521;
	fParentSelect[2]=531;
	fParentSelect[3]=5122;	
	break;
    case jpsi_chi:
    case jpsi:
	fParentSelect[0]=443;
	break;
    case mb:
	break;
    }

    switch (fForceDecay) 
    {
    case semielectronic:
    case dielectron:
    case b_jpsi_dielectron:
    case b_psip_dielectron:
	fChildSelect[0]=11;	
	break;
    case semimuonic:
    case dimuon:
    case b_jpsi_dimuon:
    case b_psip_dimuon:
    case pitomu:
    case katomu:
	fChildSelect[0]=13;
	break;
    case all:
    case nodecay:
	break;
    }
}

void AliGenPythia::Generate()
{
// Generate one event

    Float_t polar[3] =   {0,0,0};
    Float_t origin[3]=   {0,0,0};
    Float_t originP[3]= {0,0,0};
    Float_t origin0[3]=  {0,0,0};
    Float_t p[3], pP[4], random[6];
    static TClonesArray *particles;
//  converts from mm/c to s
    const Float_t kconv=0.001/2.999792458e8;
    
    
//
    Int_t nt=0;
    Int_t ntP=0;
    Int_t jev=0;
    Int_t j, kf;

    if(!particles) particles=new TClonesArray("TParticle",1000);
    
    fTrials=0;
    for (j=0;j<3;j++) origin0[j]=fOrigin[j];
    if(fVertexSmear==perEvent) {
	gMC->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]));
	    fPythia->SetMSTP(151,0);
	}
    } else if (fVertexSmear==perTrack) {
	fPythia->SetMSTP(151,0);
	for (j=0;j<3;j++) {
	    fPythia->SetPARP(151+j, fOsigma[j]*10.);
	}
    }
    while(1)
    {
	fPythia->Pyevnt();
//	fPythia->Lulist(1);
	fTrials++;
	fPythia->ImportParticles(particles,"All");
	Int_t np = particles->GetEntriesFast();
	printf("\n **************************************************%d\n",np);
	Int_t nc=0;
	if (np == 0 ) continue;
	if (fProcess != mb) {
	    for (Int_t i = 0; i<np-1; i++) {
		TParticle *  iparticle = (TParticle *) particles->At(i);
		Int_t ks = iparticle->GetStatusCode();
		kf = CheckPDGCode(iparticle->GetPdgCode());
		if (ks==21) continue;

		fChildWeight=(fPythia->GetBraPart(kf))*fParentWeight;	  
//
// Parent
		if (ParentSelected(TMath::Abs(kf))) {
		    if (KinematicSelection(iparticle)) {
			if (nc==0) {
//
// Store information concerning the hard scattering process
//
			    Float_t massP  = fPythia->GetPARI(13);
			    Float_t   ptP  = fPythia->GetPARI(17);
			    Float_t    yP  = fPythia->GetPARI(37);
			    Float_t  xmtP  = sqrt(ptP*ptP+massP*massP);
			    Float_t    ty  = Float_t(TMath::TanH(yP));
			    pP[0] = ptP;
			    pP[1] = 0;
			    pP[2] = xmtP*ty/sqrt(1.-ty*ty);
			    pP[3] = massP;
			    gAlice->SetTrack(0,-1,-1,
					     pP,originP,polar,
					     0,"Hard Scat.",ntP,fParentWeight);
			    gAlice->KeepTrack(ntP);
			}
			nc++;
//
// store parent track information
			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;

			Int_t ifch=iparticle->GetFirstDaughter();
			Int_t ilch=iparticle->GetLastDaughter();	
			if (ifch !=0 && ilch !=0) {
			    gAlice->SetTrack(0,ntP,kf,
					     p,origin,polar,
					     0,"Primary",nt,fParentWeight);
			    gAlice->KeepTrack(nt);
			    Int_t iparent = nt;
//
// Children	    

			    for (j=ifch; j<=ilch; j++)
			    {
				TParticle *  ichild = 
				    (TParticle *) particles->At(j-1);
				kf = CheckPDGCode(ichild->GetPdgCode());
//
// 
				if (ChildSelected(TMath::Abs(kf))) {
				    origin[0]=ichild->Vx();
				    origin[1]=ichild->Vy();
				    origin[2]=ichild->Vz();		
				    p[0]=ichild->Px();
				    p[1]=ichild->Py();
				    p[2]=ichild->Pz();
				    Float_t tof=kconv*ichild->T();
				    gAlice->SetTrack(fTrackIt, iparent, kf,
						     p,origin,polar,
						     tof,"Decay",nt,fChildWeight);
				    gAlice->KeepTrack(nt);
				} // select child
			    } // child loop
			}
		    } // kinematic selection
		} // select particle
	    } // particle loop
	} else {
	    for (Int_t i = 0; i<np-1; i++) {
		TParticle *  iparticle = (TParticle *) particles->At(i);
		kf = CheckPDGCode(iparticle->GetPdgCode());
		Int_t ks = iparticle->GetStatusCode();

		if (ks==1 && kf!=0 && KinematicSelection(iparticle)) {
			nc++;
//
// store track information
			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;
			Float_t tof=kconv*iparticle->T();
			gAlice->SetTrack(fTrackIt,-1,kf,p,origin,polar,
					 tof,"Primary",nt);
			gAlice->KeepTrack(nt);
		} // select particle
	    } // particle loop 
	    printf("\n I've put %i particles on the stack \n",nc);
	} // mb ?
	if (nc > 0) {
	    jev+=nc;
	    if (jev >= fNpart || fNpart == -1) {
		fKineBias=Float_t(fNpart)/Float_t(fTrials);
		printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
		break;
	    }
	}
    } // event loop
//  adjust weight due to kinematic selection
    AdjustWeights();
//  get cross-section
    fXsection=fPythia->GetPARI(1);
}

Bool_t AliGenPythia::ParentSelected(Int_t ip)
{
// True if particle is in list of parent particles to be selected
    for (Int_t i=0; i<5; i++)
    {
	if (fParentSelect[i]==ip) return kTRUE;
    }
    return kFALSE;
}

Bool_t AliGenPythia::ChildSelected(Int_t ip)
{
// True if particle is in list of decay products to be selected
    for (Int_t i=0; i<5; i++)
    {
	if (fChildSelect[i]==ip) return kTRUE;
    }
    return kFALSE;
}

Bool_t AliGenPythia::KinematicSelection(TParticle *particle)
{
// Perform kinematic selection
    Float_t px=particle->Px();
    Float_t py=particle->Py();
    Float_t pz=particle->Pz();
    Float_t  e=particle->Energy();

//
//  transverse momentum cut    
    Float_t pt=TMath::Sqrt(px*px+py*py);
    if (pt > fPtMax || pt < fPtMin) 
    {
//	printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
	return kFALSE;
    }
//
// momentum cut
    Float_t p=TMath::Sqrt(px*px+py*py+pz*pz);
    if (p > fPMax || p < fPMin) 
    {
//	printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
	return kFALSE;
    }
    
//
// theta cut
    Float_t  theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz)));
    if (theta > fThetaMax || theta < fThetaMin) 
    {
//	printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
	return kFALSE;
    }

//
// rapidity cut
    Float_t y = 0.5*TMath::Log((e+pz)/(e-pz));
    if (y > fYMax || y < fYMin)
    {
//	printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
	return kFALSE;
    }

//
// phi cut
    Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)));
    if (phi > fPhiMax || phi < fPhiMin)
    {
//	printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
	return kFALSE;
    }

    return kTRUE;
}
void AliGenPythia::AdjustWeights()
{
// Adjust the weights after generation of all events
//
    TClonesArray *partArray = gAlice->Particles();
    TParticle *part;
    Int_t ntrack=gAlice->GetNtrack();
    for (Int_t i=0; i<ntrack; i++) {
	part= (TParticle*) partArray->UncheckedAt(i);
	part->SetWeight(part->GetWeight()*fKineBias);
    }
}

Int_t AliGenPythia::CheckPDGCode(Int_t pdgcode)
{
//
//  If the particle is in a diffractive state, then take action accordingly
  switch (pdgcode) {
  case 110:
    //rho_diff0 -- difficult to translate, return rho0
    return 113;
  case 210:
    //pi_diffr+ -- change to pi+
    return 211;
  case 220:
    //omega_di0 -- change to omega0
    return 223;
  case 330:
    //phi_diff0 -- return phi0
    return 333;
  case 440:
    //J/psi_di0 -- return J/psi
    return 443;
  case 2110:
    //n_diffr -- return neutron
    return 2112;
  case 2210:
    //p_diffr+ -- return proton
    return 2212;
  }
  //non diffractive state -- return code unchanged
  return pdgcode;
}
		  
AliGenPythia& AliGenPythia::operator=(const  AliGenPythia& rhs)
{
// Assignment operator
    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
	16	/*
	17	$Log$
f87cfe57	18	Revision 1.16 2000/05/15 15:04:20 morsch
	19	The full event is written for fNtrack = -1
	20	Coding rule violations corrected.
	21
5ddeb374	22	Revision 1.15 2000/04/26 10:14:24 morsch
	23	Particles array has one entry more than pythia particle list. Upper bound of
	24	particle loop changed to np-1 (R. Guernane, AM)
	25
2a0e6f5b	26	Revision 1.14 2000/04/05 08:36:13 morsch
	27	Check status code of particles in Pythia event
	28	to avoid double counting as partonic state and final state particle.
	29
23211d3e	30	Revision 1.13 1999/11/09 07:38:48 fca
	31	Changes for compatibility with version 2.23 of ROOT
	32
084c1b4a	33	Revision 1.12 1999/11/03 17:43:20 fca
	34	New version from G.Martinez & A.Morsch
	35
886b6f73	36	Revision 1.11 1999/09/29 09:24:14 fca
886b6f73	37	Introduction of the Copyright and cvs Log
4c039060	38	*/
4c039060	39
fe4da5cc	40	#include "AliGenPythia.h"
fe4da5cc	41	#include "AliRun.h"
fe4da5cc	42	#include "AliPythia.h"
1578254f	43	#include <TParticle.h>
f87cfe57	44
fe4da5cc	45	ClassImp(AliGenPythia)
	46
	47	AliGenPythia::AliGenPythia()
	48	:AliGenerator()
	49	{
5ddeb374	50	// Constructor
fe4da5cc	51	}
	52
	53	AliGenPythia::AliGenPythia(Int_t npart)
	54	:AliGenerator(npart)
	55	{
	56	// default charm production at 5. 5 TeV
	57	// semimuonic decay
	58	// structure function GRVHO
	59	//
	60	fXsection = 0.;
	61	fParentSelect.Set(5);
	62	fChildSelect.Set(5);
	63	for (Int_t i=0; i<5; i++) fParentSelect[i]=fChildSelect[i]=0;
	64	SetProcess();
	65	SetStrucFunc();
886b6f73	66	SetForceDecay();
fe4da5cc	67	SetPtHard();
	68	SetEnergyCMS();
	69	}
	70
f87cfe57	71	AliGenPythia::AliGenPythia(const AliGenPythia & Pythia)
	72	{
	73	// copy constructor
	74	}
	75
fe4da5cc	76	AliGenPythia::~AliGenPythia()
fe4da5cc	77	{
5ddeb374	78	// Destructor
fe4da5cc	79	}
	80
	81	void AliGenPythia::Init()
	82	{
5ddeb374	83	// Initialisation
fe4da5cc	84	SetMC(new AliPythia());
	85	fPythia=(AliPythia*) fgMCEvGen;
	86	//
	87	fParentWeight=1./Float_t(fNpart);
	88	//
	89	// Forward Paramters to the AliPythia object
	90	fPythia->DefineParticles();
fe4da5cc	91	fPythia->SetCKIN(3,fPtHardMin);
	92	fPythia->SetCKIN(4,fPtHardMax);
	93	fPythia->ProcInit(fProcess,fEnergyCMS,fStrucFunc);
5be1fe76	94	fPythia->ForceDecay(fForceDecay);
084c1b4a	95	fPythia->Lulist(0);
084c1b4a	96	fPythia->Pystat(2);
fe4da5cc	97	// Parent and Children Selection
	98	switch (fProcess)
	99	{
	100	case charm:
	101
	102	fParentSelect[0]=411;
	103	fParentSelect[1]=421;
	104	fParentSelect[2]=431;
	105	fParentSelect[3]=4122;
	106	break;
	107	case charm_unforced:
	108
	109	fParentSelect[0]=411;
	110	fParentSelect[1]=421;
	111	fParentSelect[2]=431;
	112	fParentSelect[3]=4122;
	113	break;
	114	case beauty:
	115	fParentSelect[0]=511;
	116	fParentSelect[1]=521;
	117	fParentSelect[2]=531;
	118	fParentSelect[3]=5122;
	119	break;
	120	case beauty_unforced:
	121	fParentSelect[0]=511;
	122	fParentSelect[1]=521;
	123	fParentSelect[2]=531;
	124	fParentSelect[3]=5122;
	125	break;
	126	case jpsi_chi:
	127	case jpsi:
	128	fParentSelect[0]=443;
	129	break;
5be1fe76	130	case mb:
5be1fe76	131	break;
fe4da5cc	132	}
	133
	134	switch (fForceDecay)
	135	{
	136	case semielectronic:
	137	case dielectron:
	138	case b_jpsi_dielectron:
	139	case b_psip_dielectron:
	140	fChildSelect[0]=11;
	141	break;
	142	case semimuonic:
	143	case dimuon:
	144	case b_jpsi_dimuon:
	145	case b_psip_dimuon:
5be1fe76	146	case pitomu:
5be1fe76	147	case katomu:
fe4da5cc	148	fChildSelect[0]=13;
fe4da5cc	149	break;
886b6f73	150	case all:
	151	case nodecay:
	152	break;
fe4da5cc	153	}
	154	}
	155
	156	void AliGenPythia::Generate()
	157	{
5ddeb374	158	// Generate one event
fe4da5cc	159
5be1fe76	160	Float_t polar[3] = {0,0,0};
5be1fe76	161	Float_t origin[3]= {0,0,0};
5ddeb374	162	Float_t originP[3]= {0,0,0};
5be1fe76	163	Float_t origin0[3]= {0,0,0};
5ddeb374	164	Float_t p[3], pP[4], random[6];
09fd3ea2	165	static TClonesArray *particles;
5be1fe76	166	// converts from mm/c to s
5be1fe76	167	const Float_t kconv=0.001/2.999792458e8;
fe4da5cc	168
	169
	170	//
fe4da5cc	171	Int_t nt=0;
5ddeb374	172	Int_t ntP=0;
fe4da5cc	173	Int_t jev=0;
7921755b	174	Int_t j, kf;
09fd3ea2	175
09fd3ea2	176	if(!particles) particles=new TClonesArray("TParticle",1000);
fe4da5cc	177
	178	fTrials=0;
	179	for (j=0;j<3;j++) origin0[j]=fOrigin[j];
	180	if(fVertexSmear==perEvent) {
cfce8870	181	gMC->Rndm(random,6);
fe4da5cc	182	for (j=0;j<3;j++) {
	183	origin0[j]+=fOsigma[j]TMath::Cos(2random[2j]TMath::Pi())*
	184	TMath::Sqrt(-2TMath::Log(random[2j+1]));
	185	fPythia->SetMSTP(151,0);
	186	}
	187	} else if (fVertexSmear==perTrack) {
	188	fPythia->SetMSTP(151,0);
	189	for (j=0;j<3;j++) {
	190	fPythia->SetPARP(151+j, fOsigma[j]*10.);
	191	}
	192	}
fe4da5cc	193	while(1)
fe4da5cc	194	{
084c1b4a	195	fPythia->Pyevnt();
f87cfe57	196	// fPythia->Lulist(1);
fe4da5cc	197	fTrials++;
f1092809	198	fPythia->ImportParticles(particles,"All");
fe4da5cc	199	Int_t np = particles->GetEntriesFast();
	200	printf("\n **************************************************%d\n",np);
	201	Int_t nc=0;
	202	if (np == 0 ) continue;
5be1fe76	203	if (fProcess != mb) {
2a0e6f5b	204	for (Int_t i = 0; i<np-1; i++) {
1578254f	205	TParticle * iparticle = (TParticle *) particles->At(i);
23211d3e	206	Int_t ks = iparticle->GetStatusCode();
a8228d85	207	kf = CheckPDGCode(iparticle->GetPdgCode());
2a0e6f5b	208	if (ks==21) continue;
2a0e6f5b	209
5be1fe76	210	fChildWeight=(fPythia->GetBraPart(kf))*fParentWeight;
fe4da5cc	211	//
fe4da5cc	212	// Parent
5be1fe76	213	if (ParentSelected(TMath::Abs(kf))) {
	214	if (KinematicSelection(iparticle)) {
	215	if (nc==0) {
	216	//
	217	// Store information concerning the hard scattering process
	218	//
5ddeb374	219	Float_t massP = fPythia->GetPARI(13);
	220	Float_t ptP = fPythia->GetPARI(17);
	221	Float_t yP = fPythia->GetPARI(37);
	222	Float_t xmtP = sqrt(ptPptP+massPmassP);
	223	Float_t ty = Float_t(TMath::TanH(yP));
	224	pP[0] = ptP;
	225	pP[1] = 0;
	226	pP[2] = xmtPty/sqrt(1.-tyty);
	227	pP[3] = massP;
5be1fe76	228	gAlice->SetTrack(0,-1,-1,
5ddeb374	229	pP,originP,polar,
	230	0,"Hard Scat.",ntP,fParentWeight);
	231	gAlice->KeepTrack(ntP);
5be1fe76	232	}
5be1fe76	233	nc++;
fe4da5cc	234	//
fe4da5cc	235	// store parent track information
1578254f	236	p[0]=iparticle->Px();
	237	p[1]=iparticle->Py();
	238	p[2]=iparticle->Pz();
	239	origin[0]=origin0[0]+iparticle->Vx()/10;
	240	origin[1]=origin0[1]+iparticle->Vy()/10;
	241	origin[2]=origin0[2]+iparticle->Vz()/10;
fe4da5cc	242
1578254f	243	Int_t ifch=iparticle->GetFirstDaughter();
1578254f	244	Int_t ilch=iparticle->GetLastDaughter();
5be1fe76	245	if (ifch !=0 && ilch !=0) {
5ddeb374	246	gAlice->SetTrack(0,ntP,kf,
5be1fe76	247	p,origin,polar,
	248	0,"Primary",nt,fParentWeight);
	249	gAlice->KeepTrack(nt);
	250	Int_t iparent = nt;
fe4da5cc	251	//
	252	// Children
	253
7921755b	254	for (j=ifch; j<=ilch; j++)
5be1fe76	255	{
1578254f	256	TParticle * ichild =
1578254f	257	(TParticle *) particles->At(j-1);
a8228d85	258	kf = CheckPDGCode(ichild->GetPdgCode());
fe4da5cc	259	//
fe4da5cc	260	//
5be1fe76	261	if (ChildSelected(TMath::Abs(kf))) {
1578254f	262	origin[0]=ichild->Vx();
	263	origin[1]=ichild->Vy();
	264	origin[2]=ichild->Vz();
	265	p[0]=ichild->Px();
	266	p[1]=ichild->Py();
	267	p[2]=ichild->Pz();
	268	Float_t tof=kconv*ichild->T();
	269	gAlice->SetTrack(fTrackIt, iparent, kf,
5be1fe76	270	p,origin,polar,
	271	tof,"Decay",nt,fChildWeight);
	272	gAlice->KeepTrack(nt);
	273	} // select child
	274	} // child loop
	275	}
	276	} // kinematic selection
	277	} // select particle
	278	} // particle loop
	279	} else {
2a0e6f5b	280	for (Int_t i = 0; i<np-1; i++) {
1578254f	281	TParticle * iparticle = (TParticle *) particles->At(i);
a8228d85	282	kf = CheckPDGCode(iparticle->GetPdgCode());
1578254f	283	Int_t ks = iparticle->GetStatusCode();
2a0e6f5b	284
1578254f	285	if (ks==1 && kf!=0 && KinematicSelection(iparticle)) {
5be1fe76	286	nc++;
	287	//
	288	// store track information
1578254f	289	p[0]=iparticle->Px();
	290	p[1]=iparticle->Py();
	291	p[2]=iparticle->Pz();
	292	origin[0]=origin0[0]+iparticle->Vx()/10;
	293	origin[1]=origin0[1]+iparticle->Vy()/10;
	294	origin[2]=origin0[2]+iparticle->Vz()/10;
	295	Float_t tof=kconv*iparticle->T();
	296	gAlice->SetTrack(fTrackIt,-1,kf,p,origin,polar,
5be1fe76	297	tof,"Primary",nt);
	298	gAlice->KeepTrack(nt);
	299	} // select particle
	300	} // particle loop
	301	printf("\n I've put %i particles on the stack \n",nc);
	302	} // mb ?
fe4da5cc	303	if (nc > 0) {
5be1fe76	304	jev+=nc;
5ddeb374	305	if (jev >= fNpart \|\| fNpart == -1) {
fe4da5cc	306	fKineBias=Float_t(fNpart)/Float_t(fTrials);
23211d3e	307	printf("\n Trials: %i %i %i\n",fTrials, fNpart, jev);
fe4da5cc	308	break;
	309	}
	310	}
	311	} // event loop
	312	// adjust weight due to kinematic selection
	313	AdjustWeights();
	314	// get cross-section
	315	fXsection=fPythia->GetPARI(1);
	316	}
	317
	318	Bool_t AliGenPythia::ParentSelected(Int_t ip)
	319	{
5ddeb374	320	// True if particle is in list of parent particles to be selected
fe4da5cc	321	for (Int_t i=0; i<5; i++)
	322	{
	323	if (fParentSelect[i]==ip) return kTRUE;
	324	}
	325	return kFALSE;
	326	}
	327
	328	Bool_t AliGenPythia::ChildSelected(Int_t ip)
	329	{
5ddeb374	330	// True if particle is in list of decay products to be selected
fe4da5cc	331	for (Int_t i=0; i<5; i++)
	332	{
	333	if (fChildSelect[i]==ip) return kTRUE;
	334	}
	335	return kFALSE;
	336	}
	337
1578254f	338	Bool_t AliGenPythia::KinematicSelection(TParticle *particle)
fe4da5cc	339	{
5ddeb374	340	// Perform kinematic selection
1578254f	341	Float_t px=particle->Px();
	342	Float_t py=particle->Py();
	343	Float_t pz=particle->Pz();
	344	Float_t e=particle->Energy();
fe4da5cc	345
	346	//
	347	// transverse momentum cut
	348	Float_t pt=TMath::Sqrt(pxpx+pypy);
	349	if (pt > fPtMax \|\| pt < fPtMin)
	350	{
	351	// printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
	352	return kFALSE;
	353	}
	354	//
	355	// momentum cut
	356	Float_t p=TMath::Sqrt(pxpx+pypy+pz*pz);
	357	if (p > fPMax \|\| p < fPMin)
	358	{
	359	// printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
	360	return kFALSE;
	361	}
	362
	363	//
	364	// theta cut
5be1fe76	365	Float_t theta = Float_t(TMath::ATan2(Double_t(pt),Double_t(pz)));
fe4da5cc	366	if (theta > fThetaMax \|\| theta < fThetaMin)
	367	{
	368	// printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
	369	return kFALSE;
	370	}
	371
	372	//
	373	// rapidity cut
	374	Float_t y = 0.5*TMath::Log((e+pz)/(e-pz));
	375	if (y > fYMax \|\| y < fYMin)
	376	{
	377	// printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
	378	return kFALSE;
	379	}
	380
	381	//
	382	// phi cut
f87cfe57	383	Float_t phi=Float_t(TMath::ATan2(Double_t(py),Double_t(px)));
fe4da5cc	384	if (phi > fPhiMax \|\| phi < fPhiMin)
	385	{
	386	// printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
	387	return kFALSE;
	388	}
	389
	390	return kTRUE;
	391	}
	392	void AliGenPythia::AdjustWeights()
	393	{
5ddeb374	394	// Adjust the weights after generation of all events
	395	//
	396	TClonesArray *partArray = gAlice->Particles();
	397	TParticle *part;
fe4da5cc	398	Int_t ntrack=gAlice->GetNtrack();
fe4da5cc	399	for (Int_t i=0; i<ntrack; i++) {
5ddeb374	400	part= (TParticle*) partArray->UncheckedAt(i);
5ddeb374	401	part->SetWeight(part->GetWeight()*fKineBias);
fe4da5cc	402	}
	403	}
	404
a8228d85	405	Int_t AliGenPythia::CheckPDGCode(Int_t pdgcode)
	406	{
	407	//
23211d3e	408	// If the particle is in a diffractive state, then take action accordingly
a8228d85	409	switch (pdgcode) {
	410	case 110:
	411	//rho_diff0 -- difficult to translate, return rho0
	412	return 113;
	413	case 210:
	414	//pi_diffr+ -- change to pi+
	415	return 211;
	416	case 220:
	417	//omega_di0 -- change to omega0
	418	return 223;
	419	case 330:
	420	//phi_diff0 -- return phi0
	421	return 333;
	422	case 440:
	423	//J/psi_di0 -- return J/psi
	424	return 443;
	425	case 2110:
	426	//n_diffr -- return neutron
	427	return 2112;
	428	case 2210:
	429	//p_diffr+ -- return proton
	430	return 2212;
	431	}
	432	//non diffractive state -- return code unchanged
	433	return pdgcode;
	434	}
	435
f87cfe57	436	AliGenPythia& AliGenPythia::operator=(const AliGenPythia& rhs)
	437	{
	438	// Assignment operator
	439	return *this;
	440	}
fe4da5cc	441
	442
	443
5be1fe76	444
	445
	446
	447