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

/* $Id$ */

// Base class for generators using external MC generators.
// For example AliGenPythia using Pythia.
// Provides basic functionality: setting of kinematic cuts on 
// decay products and particle selection.
// andreas.morsch@cern.ch

#include <TClonesArray.h>
#include <TMath.h>
#include <TPDGCode.h>
#include <TParticle.h>

#include "AliGenMC.h"
#include "AliGeometry.h"

ClassImp(AliGenMC)

AliGenMC::AliGenMC()
    :AliGenerator(),
     fParticles(0),
     fParentSelect(8),
     fChildSelect(8),
     fCutOnChild(0),
     fChildPtMin(0.),
     fChildPtMax(1.e10),
     fChildPMin(0.),
     fChildPMax(1.e10),
     fChildPhiMin(0.),
     fChildPhiMax(2. * TMath::Pi()),
     fChildThetaMin(0.),
     fChildThetaMax(TMath::Pi()),
     fChildYMin(-12.),
     fChildYMax(12.),
     fXingAngleX(0.),
     fXingAngleY(0.),
     fForceDecay(kAll),
     fMaxLifeTime(1.e-15),
     fAProjectile(1),
     fZProjectile(1),
     fATarget(1),
     fZTarget(1),
     fProjectile("P"),
     fTarget("P"),    
     fDyBoost(0.),
     fGeometryAcceptance(0),
     fPdgCodeParticleforAcceptanceCut(0),
     fNumberOfAcceptedParticles(2)
{
// Default Constructor
}

AliGenMC::AliGenMC(Int_t npart)
    :AliGenerator(npart),
     fParticles(0),
     fParentSelect(8),
     fChildSelect(8),
     fCutOnChild(0),
     fChildPtMin(0.),
     fChildPtMax(1.e10),
     fChildPMin(0.),
     fChildPMax(1.e10),
     fChildPhiMin(0.),
     fChildPhiMax(2. * TMath::Pi()),
     fChildThetaMin(0.),
     fChildThetaMax(TMath::Pi()),
     fChildYMin(-12.),
     fChildYMax(12.),
     fXingAngleX(0.),
     fXingAngleY(0.),
     fForceDecay(kAll),
     fMaxLifeTime(1.e-15),
     fAProjectile(1),
     fZProjectile(1),
     fATarget(1),
     fZTarget(1),
     fProjectile("P"),
     fTarget("P"),    
     fDyBoost(0.),
     fGeometryAcceptance(0),
     fPdgCodeParticleforAcceptanceCut(0),
     fNumberOfAcceptedParticles(2)
{
//  Constructor
// 
    for (Int_t i=0; i<8; i++) fParentSelect[i]=fChildSelect[i]=0;
}

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

void AliGenMC::Init()
{
//
//  Initialization
    switch (fForceDecay) {
    case kBSemiElectronic:
    case kSemiElectronic:
    case kDiElectron:
    case kBJpsiDiElectron:
    case kBPsiPrimeDiElectron:
	fChildSelect[0] = kElectron;	
	break;
    case kHardMuons:	
    case kBSemiMuonic:
    case kSemiMuonic:
    case kDiMuon:
    case kBJpsiDiMuon:
    case kBPsiPrimeDiMuon:
    case kPiToMu:
    case kKaToMu:
    case kWToMuon:
    case kWToCharmToMuon:
    case kZDiMuon:
	fChildSelect[0]=kMuonMinus;
	break;
    case kWToCharm:
	break;
    case kHadronicD:
    case kHadronicDWithout4Bodies:
	fChildSelect[0]=kPiPlus;
	fChildSelect[1]=kKPlus;
	break;
    case kPhiKK:
	fChildSelect[0]=kKPlus;
	break;
    case kBJpsi:
	fChildSelect[0]=443;
	break;
    case kOmega:	
    case kAll:
    case kAllMuonic:
    case kNoDecay:
    case kNoDecayHeavy:
    case kNeutralPion:
	break;
    }

    if (fZTarget != 0 && fAProjectile != 0) 
    {
	fDyBoost    = - 0.5 * TMath::Log(Double_t(fZProjectile) * Double_t(fATarget) / 
					 (Double_t(fZTarget)    * Double_t(fAProjectile)));
    }
}


Bool_t AliGenMC::ParentSelected(Int_t ip) const
{
// True if particle is in list of parent particles to be selected
    for (Int_t i=0; i<8; i++)
    {
	if (fParentSelect.At(i) == ip) return kTRUE;
    }
    return kFALSE;
}

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

Bool_t AliGenMC::KinematicSelection(TParticle *particle, Int_t flag) const
{
// Perform kinematic selection
    Float_t pz    = particle->Pz();
    Float_t  e    = particle->Energy();
    Float_t pt    = particle->Pt();
    Float_t p     = particle->P();
    Float_t theta = particle->Theta();
    Float_t mass  = particle->GetCalcMass();
    Float_t mt2   = pt * pt + mass * mass;
    Float_t phi   = particle->Phi();
    
    Double_t y, y0;

    if (TMath::Abs(pz) <  e) {
	y = 0.5*TMath::Log((e+pz)/(e-pz));
    } else {
	y = 1.e10;
    }
    
    if (mt2) {
	y0 = 0.5*TMath::Log((e+TMath::Abs(pz))*(e+TMath::Abs(pz))/mt2);
    } else {
	if (TMath::Abs(y) < 1.e10) {
	    y0 = y;
	} else {
	    y0 = 1.e10;
	}
    }
      
    y = (pz < 0) ? -y0 : y0;
    
    if (flag == 0) {
//
// Primary particle cuts
//
//  transverse momentum cut    
	if (pt > fPtMax || pt < fPtMin) {
//	    printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
	    return kFALSE;
	}
//
// momentum cut
	if (p > fPMax || p < fPMin) {
//	    printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
	    return kFALSE;
	}
//
// theta cut
	if (theta > fThetaMax || theta < fThetaMin) {
//	    printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
	    return kFALSE;
	}
//
// rapidity cut
	if (y > fYMax || y < fYMin) {
//	    printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
	    return kFALSE;
	}
//
// phi cut
	if (phi > fPhiMax || phi < fPhiMin) {
//	    printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
	    return kFALSE;
	}
    } else {
//
// Decay product cuts
//
//  transverse momentum cut    
	if (pt > fChildPtMax || pt < fChildPtMin) {
//	    printf("\n failed pt cut %f %f %f \n",pt,fChildPtMin,fChildPtMax);
	    return kFALSE;
	}
//
// momentum cut
	if (p > fChildPMax || p < fChildPMin) {
//	    printf("\n failed p cut %f %f %f \n",p,fChildPMin,fChildPMax);
	    return kFALSE;
	}
//
// theta cut
	if (theta > fChildThetaMax || theta < fChildThetaMin) {
//	    printf("\n failed theta cut %f %f %f \n",theta,fChildThetaMin,fChildThetaMax);
	    return kFALSE;
	}
//
// rapidity cut
	if (y > fChildYMax || y < fChildYMin) {
//	    printf("\n failed y cut %f %f %f \n",y,fChildYMin,fChildYMax);
	    return kFALSE;
	}
//
// phi cut
	if (phi > fChildPhiMax || phi < fChildPhiMin) {
//	    printf("\n failed phi cut %f %f %f \n",phi,fChildPhiMin,fChildPhiMax);
	    return kFALSE;
	}
    }
    
    return kTRUE;
}

Bool_t AliGenMC::CheckAcceptanceGeometry(Int_t np, TClonesArray* particles)
{
// Check the geometrical acceptance for particle.

  Bool_t check ;  
  Int_t numberOfPdgCodeParticleforAcceptanceCut = 0;
  Int_t numberOfAcceptedPdgCodeParticleforAcceptanceCut = 0;
  TParticle * particle;
  Int_t i;
  for (i = 0; i < np; i++) {
    particle =  (TParticle *) particles->At(i);
    if( TMath::Abs( particle->GetPdgCode() ) == TMath::Abs( fPdgCodeParticleforAcceptanceCut ) ) {
      numberOfPdgCodeParticleforAcceptanceCut++;
      if (fGeometryAcceptance->Impact(particle)) numberOfAcceptedPdgCodeParticleforAcceptanceCut++;
    }   
  }
  if ( numberOfAcceptedPdgCodeParticleforAcceptanceCut > (fNumberOfAcceptedParticles-1) )
    check = kTRUE;
  else
    check = kFALSE;

  return check;
}

Int_t AliGenMC::CheckPDGCode(Int_t pdgcode) const
{
//
//  If the particle is in a diffractive state, then take action accordingly
  switch (pdgcode) {
  case 91:
    return 92;
  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;
}

void AliGenMC::Boost()
{
//
// Boost cms into LHC lab frame
//

    Double_t beta  = TMath::TanH(fDyBoost);
    Double_t gamma = 1./TMath::Sqrt(1.-beta*beta);
    Double_t gb    = gamma * beta;

    //    printf("\n Boosting particles to lab frame %f %f %f", fDyBoost, beta, gamma);
    
    Int_t i;
    Int_t np = fParticles->GetEntriesFast();
    for (i = 0; i < np; i++) 
    {
	TParticle* iparticle = (TParticle*) fParticles->At(i);

	Double_t e   = iparticle->Energy();
	Double_t px  = iparticle->Px();
	Double_t py  = iparticle->Py();
	Double_t pz  = iparticle->Pz();

	Double_t eb  = gamma * e -      gb * pz;
	Double_t pzb =   -gb * e +   gamma * pz;

	iparticle->SetMomentum(px, py, pzb, eb);
    }
}
Commit	Line	Data
e36044d6	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	/* $Id$ */
e36044d6	17
62d0ae06	18	// Base class for generators using external MC generators.
	19	// For example AliGenPythia using Pythia.
	20	// Provides basic functionality: setting of kinematic cuts on
	21	// decay products and particle selection.
	22	// andreas.morsch@cern.ch
	23
ac3faee4	24	#include <TClonesArray.h>
65de9f86	25	#include <TMath.h>
116cbefd	26	#include <TPDGCode.h>
e36044d6	27	#include <TParticle.h>
e36044d6	28
116cbefd	29	#include "AliGenMC.h"
ac3faee4	30	#include "AliGeometry.h"
116cbefd	31
198bb1c7	32	ClassImp(AliGenMC)
e36044d6	33
e36044d6	34	AliGenMC::AliGenMC()
1c56e311	35	:AliGenerator(),
	36	fParticles(0),
	37	fParentSelect(8),
	38	fChildSelect(8),
	39	fCutOnChild(0),
	40	fChildPtMin(0.),
	41	fChildPtMax(1.e10),
	42	fChildPMin(0.),
	43	fChildPMax(1.e10),
	44	fChildPhiMin(0.),
	45	fChildPhiMax(2. * TMath::Pi()),
	46	fChildThetaMin(0.),
	47	fChildThetaMax(TMath::Pi()),
	48	fChildYMin(-12.),
	49	fChildYMax(12.),
	50	fXingAngleX(0.),
	51	fXingAngleY(0.),
	52	fForceDecay(kAll),
	53	fMaxLifeTime(1.e-15),
	54	fAProjectile(1),
	55	fZProjectile(1),
	56	fATarget(1),
	57	fZTarget(1),
	58	fProjectile("P"),
	59	fTarget("P"),
	60	fDyBoost(0.),
	61	fGeometryAcceptance(0),
	62	fPdgCodeParticleforAcceptanceCut(0),
	63	fNumberOfAcceptedParticles(2)
e36044d6	64	{
e36044d6	65	// Default Constructor
e36044d6	66	}
	67
	68	AliGenMC::AliGenMC(Int_t npart)
1c56e311	69	:AliGenerator(npart),
	70	fParticles(0),
	71	fParentSelect(8),
	72	fChildSelect(8),
	73	fCutOnChild(0),
	74	fChildPtMin(0.),
	75	fChildPtMax(1.e10),
	76	fChildPMin(0.),
	77	fChildPMax(1.e10),
	78	fChildPhiMin(0.),
	79	fChildPhiMax(2. * TMath::Pi()),
	80	fChildThetaMin(0.),
	81	fChildThetaMax(TMath::Pi()),
	82	fChildYMin(-12.),
	83	fChildYMax(12.),
	84	fXingAngleX(0.),
	85	fXingAngleY(0.),
	86	fForceDecay(kAll),
	87	fMaxLifeTime(1.e-15),
	88	fAProjectile(1),
	89	fZProjectile(1),
	90	fATarget(1),
	91	fZTarget(1),
	92	fProjectile("P"),
	93	fTarget("P"),
	94	fDyBoost(0.),
	95	fGeometryAcceptance(0),
	96	fPdgCodeParticleforAcceptanceCut(0),
	97	fNumberOfAcceptedParticles(2)
e36044d6	98	{
e36044d6	99	// Constructor
e36044d6	100	//
e36044d6	101	for (Int_t i=0; i<8; i++) fParentSelect[i]=fChildSelect[i]=0;
	102	}
	103
e36044d6	104	AliGenMC::~AliGenMC()
	105	{
	106	// Destructor
	107	}
	108
	109	void AliGenMC::Init()
	110	{
	111	//
	112	// Initialization
	113	switch (fForceDecay) {
e345c619	114	case kBSemiElectronic:
e36044d6	115	case kSemiElectronic:
	116	case kDiElectron:
	117	case kBJpsiDiElectron:
	118	case kBPsiPrimeDiElectron:
47fc6bd5	119	fChildSelect[0] = kElectron;
e36044d6	120	break;
2dcb5874	121	case kHardMuons:
e345c619	122	case kBSemiMuonic:
e36044d6	123	case kSemiMuonic:
	124	case kDiMuon:
	125	case kBJpsiDiMuon:
	126	case kBPsiPrimeDiMuon:
	127	case kPiToMu:
	128	case kKaToMu:
cd159249	129	case kWToMuon:
cd159249	130	case kWToCharmToMuon:
2f299526	131	case kZDiMuon:
e36044d6	132	fChildSelect[0]=kMuonMinus;
e36044d6	133	break;
cd159249	134	case kWToCharm:
cd159249	135	break;
e36044d6	136	case kHadronicD:
af33df34	137	case kHadronicDWithout4Bodies:
e36044d6	138	fChildSelect[0]=kPiPlus;
	139	fChildSelect[1]=kKPlus;
	140	break;
00cb2f27	141	case kPhiKK:
027677ae	142	fChildSelect[0]=kKPlus;
56d47239	143	break;
	144	case kBJpsi:
	145	fChildSelect[0]=443;
	146	break;
62d0ae06	147	case kOmega:
e36044d6	148	case kAll:
2b1f8257	149	case kAllMuonic:
e36044d6	150	case kNoDecay:
d5f86442	151	case kNoDecayHeavy:
847af604	152	case kNeutralPion:
e36044d6	153	break;
e36044d6	154	}
36d770d9	155
	156	if (fZTarget != 0 && fAProjectile != 0)
	157	{
	158	fDyBoost = - 0.5 * TMath::Log(Double_t(fZProjectile) * Double_t(fATarget) /
	159	(Double_t(fZTarget) * Double_t(fAProjectile)));
	160	}
e36044d6	161	}
	162
	163
62d0ae06	164	Bool_t AliGenMC::ParentSelected(Int_t ip) const
e36044d6	165	{
	166	// True if particle is in list of parent particles to be selected
	167	for (Int_t i=0; i<8; i++)
	168	{
62d0ae06	169	if (fParentSelect.At(i) == ip) return kTRUE;
e36044d6	170	}
	171	return kFALSE;
	172	}
	173
62d0ae06	174	Bool_t AliGenMC::ChildSelected(Int_t ip) const
e36044d6	175	{
	176	// True if particle is in list of decay products to be selected
	177	for (Int_t i=0; i<5; i++)
	178	{
62d0ae06	179	if (fChildSelect.At(i) == ip) return kTRUE;
e36044d6	180	}
	181	return kFALSE;
	182	}
	183
62d0ae06	184	Bool_t AliGenMC::KinematicSelection(TParticle *particle, Int_t flag) const
e36044d6	185	{
e36044d6	186	// Perform kinematic selection
e36044d6	187	Float_t pz = particle->Pz();
	188	Float_t e = particle->Energy();
	189	Float_t pt = particle->Pt();
	190	Float_t p = particle->P();
	191	Float_t theta = particle->Theta();
cf01ee36	192	Float_t mass = particle->GetCalcMass();
95450c6d	193	Float_t mt2 = pt * pt + mass * mass;
0b6d2cb3	194	Float_t phi = particle->Phi();
95450c6d	195
95450c6d	196	Double_t y, y0;
95450c6d	197
fef61e14	198	if (TMath::Abs(pz) < e) {
95450c6d	199	y = 0.5*TMath::Log((e+pz)/(e-pz));
	200	} else {
	201	y = 1.e10;
	202	}
e36044d6	203
95450c6d	204	if (mt2) {
95450c6d	205	y0 = 0.5TMath::Log((e+TMath::Abs(pz))(e+TMath::Abs(pz))/mt2);
e36044d6	206	} else {
95450c6d	207	if (TMath::Abs(y) < 1.e10) {
	208	y0 = y;
	209	} else {
	210	y0 = 1.e10;
	211	}
e36044d6	212	}
95450c6d	213
95450c6d	214	y = (pz < 0) ? -y0 : y0;
e36044d6	215
	216	if (flag == 0) {
	217	//
	218	// Primary particle cuts
	219	//
	220	// transverse momentum cut
	221	if (pt > fPtMax \|\| pt < fPtMin) {
	222	// printf("\n failed pt cut %f %f %f \n",pt,fPtMin,fPtMax);
	223	return kFALSE;
	224	}
	225	//
	226	// momentum cut
	227	if (p > fPMax \|\| p < fPMin) {
	228	// printf("\n failed p cut %f %f %f \n",p,fPMin,fPMax);
	229	return kFALSE;
	230	}
	231	//
	232	// theta cut
	233	if (theta > fThetaMax \|\| theta < fThetaMin) {
	234	// printf("\n failed theta cut %f %f %f \n",theta,fThetaMin,fThetaMax);
	235	return kFALSE;
	236	}
	237	//
	238	// rapidity cut
	239	if (y > fYMax \|\| y < fYMin) {
	240	// printf("\n failed y cut %f %f %f \n",y,fYMin,fYMax);
	241	return kFALSE;
	242	}
	243	//
	244	// phi cut
	245	if (phi > fPhiMax \|\| phi < fPhiMin) {
	246	// printf("\n failed phi cut %f %f %f \n",phi,fPhiMin,fPhiMax);
	247	return kFALSE;
	248	}
	249	} else {
	250	//
	251	// Decay product cuts
	252	//
	253	// transverse momentum cut
	254	if (pt > fChildPtMax \|\| pt < fChildPtMin) {
	255	// printf("\n failed pt cut %f %f %f \n",pt,fChildPtMin,fChildPtMax);
	256	return kFALSE;
	257	}
	258	//
	259	// momentum cut
	260	if (p > fChildPMax \|\| p < fChildPMin) {
	261	// printf("\n failed p cut %f %f %f \n",p,fChildPMin,fChildPMax);
	262	return kFALSE;
	263	}
	264	//
	265	// theta cut
	266	if (theta > fChildThetaMax \|\| theta < fChildThetaMin) {
	267	// printf("\n failed theta cut %f %f %f \n",theta,fChildThetaMin,fChildThetaMax);
	268	return kFALSE;
	269	}
	270	//
	271	// rapidity cut
	272	if (y > fChildYMax \|\| y < fChildYMin) {
	273	// printf("\n failed y cut %f %f %f \n",y,fChildYMin,fChildYMax);
	274	return kFALSE;
	275	}
	276	//
	277	// phi cut
	278	if (phi > fChildPhiMax \|\| phi < fChildPhiMin) {
279	// printf("\n failed phi cut %f %f %f \n",phi,fChildPhiMin,fChildPhiMax);
280	return kFALSE;
281	}
282	}
283
e36044d6	284	return kTRUE;
	285	}
	286
65de9f86	287	Bool_t AliGenMC::CheckAcceptanceGeometry(Int_t np, TClonesArray* particles)
65de9f86	288	{
e033748b	289	// Check the geometrical acceptance for particle.
	290
	291	Bool_t check ;
	292	Int_t numberOfPdgCodeParticleforAcceptanceCut = 0;
	293	Int_t numberOfAcceptedPdgCodeParticleforAcceptanceCut = 0;
65de9f86	294	TParticle * particle;
65de9f86	295	Int_t i;
e033748b	296	for (i = 0; i < np; i++) {
65de9f86	297	particle = (TParticle *) particles->At(i);
65de9f86	298	if( TMath::Abs( particle->GetPdgCode() ) == TMath::Abs( fPdgCodeParticleforAcceptanceCut ) ) {
e033748b	299	numberOfPdgCodeParticleforAcceptanceCut++;
e033748b	300	if (fGeometryAcceptance->Impact(particle)) numberOfAcceptedPdgCodeParticleforAcceptanceCut++;
65de9f86	301	}
65de9f86	302	}
e033748b	303	if ( numberOfAcceptedPdgCodeParticleforAcceptanceCut > (fNumberOfAcceptedParticles-1) )
e033748b	304	check = kTRUE;
65de9f86	305	else
e033748b	306	check = kFALSE;
65de9f86	307
e033748b	308	return check;
65de9f86	309	}
65de9f86	310
62d0ae06	311	Int_t AliGenMC::CheckPDGCode(Int_t pdgcode) const
e36044d6	312	{
	313	//
	314	// If the particle is in a diffractive state, then take action accordingly
	315	switch (pdgcode) {
	316	case 91:
	317	return 92;
	318	case 110:
	319	//rho_diff0 -- difficult to translate, return rho0
	320	return 113;
	321	case 210:
	322	//pi_diffr+ -- change to pi+
	323	return 211;
	324	case 220:
	325	//omega_di0 -- change to omega0
	326	return 223;
	327	case 330:
	328	//phi_diff0 -- return phi0
	329	return 333;
	330	case 440:
	331	//J/psi_di0 -- return J/psi
	332	return 443;
	333	case 2110:
	334	//n_diffr -- return neutron
	335	return 2112;
	336	case 2210:
	337	//p_diffr+ -- return proton
	338	return 2212;
	339	}
	340	//non diffractive state -- return code unchanged
	341	return pdgcode;
	342	}
3b945a60	343
36d770d9	344	void AliGenMC::Boost()
3b945a60	345	{
	346	//
	347	// Boost cms into LHC lab frame
	348	//
	349
36d770d9	350	Double_t beta = TMath::TanH(fDyBoost);
3b945a60	351	Double_t gamma = 1./TMath::Sqrt(1.-beta*beta);
	352	Double_t gb = gamma * beta;
	353
7cdba479	354	// printf("\n Boosting particles to lab frame %f %f %f", fDyBoost, beta, gamma);
3b945a60	355
	356	Int_t i;
	357	Int_t np = fParticles->GetEntriesFast();
	358	for (i = 0; i < np; i++)
	359	{
	360	TParticle* iparticle = (TParticle*) fParticles->At(i);
	361
	362	Double_t e = iparticle->Energy();
	363	Double_t px = iparticle->Px();
	364	Double_t py = iparticle->Py();
	365	Double_t pz = iparticle->Pz();
	366
	367	Double_t eb = gamma * e - gb * pz;
	368	Double_t pzb = -gb * e + gamma * pz;
	369
	370	iparticle->SetMomentum(px, py, pzb, eb);
	371	}
	372	}