[u/mrichter/AliRoot.git] / STEER / AliESDcascade.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.                  *
 **************************************************************************/

/* $Id$ */

//-------------------------------------------------------------------------
//               Implementation of the cascade vertex class
//              This is part of the Event Summary Data 
//              which contains the result of the reconstruction
//              and is the main set of classes for analaysis
//    Origin: Christian Kuhn, IReS, Strasbourg, christian.kuhn@ires.in2p3.fr
//     Modified by: Antonin Maire,IPHC, Antonin.Maire@ires.in2p3.fr
//            and  Boris Hippolyte,IPHC, hippolyt@in2p3.fr 
//-------------------------------------------------------------------------

#include <TDatabasePDG.h>
#include <TMath.h>
#include <TVector3.h>

#include "AliLog.h"
#include "AliExternalTrackParam.h"
#include "AliESDv0.h"
#include "AliESDcascade.h"

ClassImp(AliESDcascade)

AliESDcascade::AliESDcascade() : 
  AliESDv0(),
  fEffMassXi(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
  fChi2Xi(1024),
  fDcaXiDaughters(1024),
  fPdgCodeXi(kXiMinus),
  fBachIdx(-1)
{
  //--------------------------------------------------------------------
  // Default constructor  (Xi-)
  //--------------------------------------------------------------------
  for (Int_t j=0; j<3; j++) {
    fPosXi[j]=0.;
    fBachMom[j]=0.;
  }

  fPosCovXi[0]=1024;
  fPosCovXi[1]=fPosCovXi[2]=0.;
  fPosCovXi[3]=1024;
  fPosCovXi[4]=0.;
  fPosCovXi[5]=1024;

  fBachMomCov[0]=1024;
  fBachMomCov[1]=fBachMomCov[2]=0.;
  fBachMomCov[3]=1024;
  fBachMomCov[4]=0.;
  fBachMomCov[5]=1024;
}

AliESDcascade::AliESDcascade(const AliESDcascade& cas) :
  AliESDv0(cas),
  fEffMassXi(cas.fEffMassXi),
  fChi2Xi(cas.fChi2Xi),
  fDcaXiDaughters(cas.fDcaXiDaughters),
  fPdgCodeXi(cas.fPdgCodeXi),
  fBachIdx(cas.fBachIdx)
{
  //--------------------------------------------------------------------
  // The copy constructor
  //--------------------------------------------------------------------
  for (int i=0; i<3; i++) {
    fPosXi[i]     = cas.fPosXi[i];
    fBachMom[i] = cas.fBachMom[i];
  }
  for (int i=0; i<6; i++) {
    fPosCovXi[i]   = cas.fPosCovXi[i];
    fBachMomCov[i] = cas.fBachMomCov[i];
  }
}

AliESDcascade::AliESDcascade(const AliESDv0 &v,
			     const AliExternalTrackParam &t, Int_t i) : 
  AliESDv0(v),
  fEffMassXi(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
  fChi2Xi(1024),
  fDcaXiDaughters(1024),
  fPdgCodeXi(kXiMinus),
  fBachIdx(i)
{
  //--------------------------------------------------------------------
  // Main constructor  (Xi-)
  //--------------------------------------------------------------------

  Double_t r[3]; t.GetXYZ(r);
  Double_t x1=r[0], y1=r[1], z1=r[2]; // position of the bachelor
  Double_t p[3]; t.GetPxPyPz(p);
  Double_t px1=p[0], py1=p[1], pz1=p[2];// momentum of the bachelor track

  Double_t x2,y2,z2;          // position of the V0 
  v.GetXYZ(x2,y2,z2);    
  Double_t px2,py2,pz2;       // momentum of V0
  v.GetPxPyPz(px2,py2,pz2);

  Double_t a2=((x1-x2)*px2+(y1-y2)*py2+(z1-z2)*pz2)/(px2*px2+py2*py2+pz2*pz2);

  Double_t xm=x2+a2*px2;
  Double_t ym=y2+a2*py2;
  Double_t zm=z2+a2*pz2;

  // position of the cascade decay
  
  fPosXi[0]=0.5*(x1+xm); fPosXi[1]=0.5*(y1+ym); fPosXi[2]=0.5*(z1+zm);
    

  // invariant mass of the cascade (default is Ximinus)
  
  Double_t e1=TMath::Sqrt(0.13957*0.13957 + px1*px1 + py1*py1 + pz1*pz1);
  Double_t e2=TMath::Sqrt(1.11568*1.11568 + px2*px2 + py2*py2 + pz2*pz2);
  
  fEffMassXi=TMath::Sqrt((e1+e2)*(e1+e2)-
    (px1+px2)*(px1+px2)-(py1+py2)*(py1+py2)-(pz1+pz2)*(pz1+pz2));


  // momenta of the bachelor and the V0
  
  fBachMom[0]=px1; fBachMom[1]=py1; fBachMom[2]=pz1; 

  //PH Covariance matrices: to be calculated correctly in the future
  fPosCovXi[0]=1024;
  fPosCovXi[1]=fPosCovXi[2]=0.;
  fPosCovXi[3]=1024;
  fPosCovXi[4]=0.;
  fPosCovXi[5]=1024;

  fBachMomCov[0]=1024;
  fBachMomCov[1]=fBachMomCov[2]=0.;
  fBachMomCov[3]=1024;
  fBachMomCov[4]=0.;
  fBachMomCov[5]=1024;

  fChi2Xi=1024.;   

}

AliESDcascade& AliESDcascade::operator=(const AliESDcascade& cas)
{
  //--------------------------------------------------------------------
  // The assignment operator
  //--------------------------------------------------------------------

  if(this==&cas) return *this;
  AliESDv0::operator=(cas);

  fEffMassXi = cas.fEffMassXi;
  fChi2Xi    = cas.fChi2Xi;
  fDcaXiDaughters = cas.fDcaXiDaughters;
  fPdgCodeXi      = cas.fPdgCodeXi;
  fBachIdx        = cas.fBachIdx;
  for (int i=0; i<3; i++) {
    fPosXi[i]     = cas.fPosXi[i];
    fBachMom[i]   = cas.fBachMom[i];
  }
  for (int i=0; i<6; i++) {
    fPosCovXi[i]   = cas.fPosCovXi[i];
    fBachMomCov[i] = cas.fBachMomCov[i];
  }
  return *this;
}

void AliESDcascade::Copy(TObject &obj) const {
  
  // this overwrites the virtual TOBject::Copy()
  // to allow run time copying without casting
  // in AliESDEvent

  if(this==&obj)return;
  AliESDcascade *robj = dynamic_cast<AliESDcascade*>(&obj);
  if(!robj)return; // not an AliESDcascade
  *robj = *this;
}

AliESDcascade::~AliESDcascade() {
  //--------------------------------------------------------------------
  // Empty destructor
  //--------------------------------------------------------------------
}

// Start with AliVParticle functions
Double_t AliESDcascade::E() const {
  //--------------------------------------------------------------------
  // This gives the energy assuming the ChangeMassHypothesis was called
  //--------------------------------------------------------------------
  return E(fPdgCodeXi);
}

Double_t AliESDcascade::Y() const {
  //--------------------------------------------------------------------
  // This gives the energy assuming the ChangeMassHypothesis was called
  //--------------------------------------------------------------------
  return Y(fPdgCodeXi);
}

// Then extend AliVParticle functions
Double_t AliESDcascade::E(Int_t pdg) const {
  //--------------------------------------------------------------------
  // This gives the energy with the particle hypothesis as argument 
  //--------------------------------------------------------------------
  Double_t mass = TDatabasePDG::Instance()->GetParticle(pdg)->Mass();
  return TMath::Sqrt(mass*mass+P()*P());
}

Double_t AliESDcascade::Y(Int_t pdg) const {
  //--------------------------------------------------------------------
  // This gives the rapidity with the particle hypothesis as argument 
  //--------------------------------------------------------------------
  return 0.5*TMath::Log((E(pdg)+Pz())/(E(pdg)-Pz()+1.e-13));
}

// Now the functions for analysis consistency
Double_t AliESDcascade::RapXi() const {
  //--------------------------------------------------------------------
  // This gives the pseudorapidity assuming a (Anti) Xi particle
  //--------------------------------------------------------------------
  return Y(kXiMinus);
}

Double_t AliESDcascade::RapOmega() const {
  //--------------------------------------------------------------------
  // This gives the pseudorapidity assuming a (Anti) Omega particle
  //--------------------------------------------------------------------
  return Y(kOmegaMinus);
}

Double_t AliESDcascade::AlphaXi() const {
  //--------------------------------------------------------------------
  // This gives the Armenteros-Podolanski alpha
  //--------------------------------------------------------------------
  TVector3 momBach(fBachMom[0],fBachMom[1],fBachMom[2]);
  TVector3 momV0(fNmom[0]+fPmom[0],fNmom[1]+fPmom[1],fNmom[2]+fPmom[2]);
  TVector3 momTot(Px(),Py(),Pz());

  Double_t QlBach = momBach.Dot(momTot)/momTot.Mag();
  Double_t QlV0 = momV0.Dot(momTot)/momTot.Mag();

  return 1.-2./(1.+QlBach/QlV0);
}

Double_t AliESDcascade::PtArmXi() const {
  //--------------------------------------------------------------------
  // This gives the Armenteros-Podolanski ptarm
  //--------------------------------------------------------------------
  TVector3 momBach(fBachMom[0],fBachMom[1],fBachMom[2]);
  TVector3 momTot(Px(),Py(),Pz());

  return momBach.Perp(momTot);
}

// Then the older functions
Double_t AliESDcascade::ChangeMassHypothesis(Double_t &v0q, Int_t code) {
  //--------------------------------------------------------------------
  // This function changes the mass hypothesis for this cascade
  // and returns the "kinematical quality" of this hypothesis
  // together with the "quality" of associated V0 (argument v0q) 
  //--------------------------------------------------------------------
  Double_t nmass=0.13957, pmass=0.93827, ps0=0.101; 
  Double_t bmass=0.13957, mass =1.3213,  ps =0.139;

  fPdgCodeXi=code;

  switch (code) {
  case 213: 
       bmass=0.93827; 
       break;
  case kXiMinus:
       break;
  case kXiPlusBar:
       nmass=0.93827; pmass=0.13957; 
       break;
  case kOmegaMinus: 
       bmass=0.49368; mass=1.67245; ps=0.211;
       break;
  case kOmegaPlusBar: 
       nmass=0.93827; pmass=0.13957; 
       bmass=0.49368; mass=1.67245; ps=0.211;
       break;
  default:
       AliError("Invalide PDG code !  Assuming XiMinus's...");
       fPdgCodeXi=kXiMinus;
    break;
  }

  Double_t pxn=fNmom[0], pyn=fNmom[1], pzn=fNmom[2];
  Double_t pxp=fPmom[0], pyp=fPmom[1], pzp=fPmom[2];

  Double_t px0=pxn+pxp, py0=pyn+pyp, pz0=pzn+pzp;
  Double_t p0=TMath::Sqrt(px0*px0 + py0*py0 + pz0*pz0);

  Double_t e0=TMath::Sqrt(1.11568*1.11568 + p0*p0);
  Double_t beta0=p0/e0;
  Double_t pln=(pxn*px0 + pyn*py0 + pzn*pz0)/p0;
  Double_t plp=(pxp*px0 + pyp*py0 + pzp*pz0)/p0;
  Double_t pt2=pxp*pxp + pyp*pyp + pzp*pzp - plp*plp;

  Double_t a=(plp-pln)/(plp+pln);
  a -= (pmass*pmass-nmass*nmass)/(1.11568*1.11568);
  a = 0.25*beta0*beta0*1.11568*1.11568*a*a + pt2;


  v0q=a - ps0*ps0;


  Double_t pxb=fBachMom[0], pyb=fBachMom[1], pzb=fBachMom[2]; 

  Double_t eb=TMath::Sqrt(bmass*bmass + pxb*pxb + pyb*pyb + pzb*pzb);
  Double_t pxl=px0+pxb, pyl=py0+pyb, pzl=pz0+pzb;
  Double_t pl=TMath::Sqrt(pxl*pxl + pyl*pyl + pzl*pzl);
  
  fEffMassXi=TMath::Sqrt((e0+eb)*(e0+eb) - pl*pl);

  Double_t beta=pl/(e0+eb);
  Double_t pl0=(px0*pxl + py0*pyl + pz0*pzl)/pl;
  Double_t plb=(pxb*pxl + pyb*pyl + pzb*pzl)/pl;
  pt2=p0*p0 - pl0*pl0;

  a=(pl0-plb)/(pl0+plb);
  a -= (1.11568*1.11568-bmass*bmass)/(mass*mass);
  a = 0.25*beta*beta*mass*mass*a*a + pt2;

  return (a - ps*ps);
}

void 
AliESDcascade::GetPxPyPz(Double_t &px, Double_t &py, Double_t &pz) const {
  //--------------------------------------------------------------------
  // This function returns the cascade momentum (global)
  //--------------------------------------------------------------------
  px=fNmom[0]+fPmom[0]+fBachMom[0];
  py=fNmom[1]+fPmom[1]+fBachMom[1]; 
  pz=fNmom[2]+fPmom[2]+fBachMom[2]; 
}

void AliESDcascade::GetXYZcascade(Double_t &x, Double_t &y, Double_t &z) const {
  //--------------------------------------------------------------------
  // This function returns cascade position (global)
  //--------------------------------------------------------------------
  x=fPosXi[0];
  y=fPosXi[1];
  z=fPosXi[2];
}

Double_t AliESDcascade::GetDcascade(Double_t x0, Double_t y0, Double_t z0) const {
  //--------------------------------------------------------------------
  // This function returns the cascade impact parameter
  //--------------------------------------------------------------------

  Double_t x=fPosXi[0],y=fPosXi[1],z=fPosXi[2];
  Double_t px=fNmom[0]+fPmom[0]+fBachMom[0];
  Double_t py=fNmom[1]+fPmom[1]+fBachMom[1];
  Double_t pz=fNmom[2]+fPmom[2]+fBachMom[2];

  Double_t dx=(y0-y)*pz - (z0-z)*py; 
  Double_t dy=(x0-x)*pz - (z0-z)*px;
  Double_t dz=(x0-x)*py - (y0-y)*px;
  Double_t d=TMath::Sqrt((dx*dx+dy*dy+dz*dz)/(px*px+py*py+pz*pz));

  return d;
}

Double_t AliESDcascade::GetCascadeCosineOfPointingAngle(Double_t& refPointX, Double_t& refPointY, Double_t& refPointZ) const {
  // calculates the pointing angle of the cascade wrt a reference point

  Double_t momCas[3]; //momentum of the cascade
  GetPxPyPz(momCas[0],momCas[1],momCas[2]);

  Double_t deltaPos[3]; //vector between the reference point and the cascade vertex
  deltaPos[0] = fPosXi[0] - refPointX;
  deltaPos[1] = fPosXi[1] - refPointY;
  deltaPos[2] = fPosXi[2] - refPointZ;

  Double_t momCas2    = momCas[0]*momCas[0] + momCas[1]*momCas[1] + momCas[2]*momCas[2];
  Double_t deltaPos2 = deltaPos[0]*deltaPos[0] + deltaPos[1]*deltaPos[1] + deltaPos[2]*deltaPos[2];

  Double_t cosinePointingAngle = (deltaPos[0]*momCas[0] +
				  deltaPos[1]*momCas[1] +
				  deltaPos[2]*momCas[2] ) /
    TMath::Sqrt(momCas2 * deltaPos2);
  
  return cosinePointingAngle;
}

void AliESDcascade::GetPosCovXi(Double_t cov[6]) const {

  for (Int_t i=0; i<6; ++i) cov[i] = fPosCovXi[i];
}
Commit	Line	Data
e23730c7	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
4f679a16	16	/* $Id$ */
4f679a16	17
e23730c7	18	//-------------------------------------------------------------------------
e23730c7	19	// Implementation of the cascade vertex class
4f679a16	20	// This is part of the Event Summary Data
	21	// which contains the result of the reconstruction
	22	// and is the main set of classes for analaysis
e23730c7	23	// Origin: Christian Kuhn, IReS, Strasbourg, christian.kuhn@ires.in2p3.fr
3e27a419	24	// Modified by: Antonin Maire,IPHC, Antonin.Maire@ires.in2p3.fr
3e27a419	25	// and Boris Hippolyte,IPHC, hippolyt@in2p3.fr
e23730c7	26	//-------------------------------------------------------------------------
4f679a16	27
90e48c0c	28	#include <TDatabasePDG.h>
e23730c7	29	#include <TMath.h>
3e27a419	30	#include <TVector3.h>
e23730c7	31
5f7789fc	32	#include "AliLog.h"
c7bafca9	33	#include "AliExternalTrackParam.h"
c7bafca9	34	#include "AliESDv0.h"
e23730c7	35	#include "AliESDcascade.h"
e23730c7	36
	37	ClassImp(AliESDcascade)
	38
90e48c0c	39	AliESDcascade::AliESDcascade() :
c028b974	40	AliESDv0(),
8668c148	41	fEffMassXi(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
562dd0b4	42	fChi2Xi(1024),
	43	fDcaXiDaughters(1024),
	44	fPdgCodeXi(kXiMinus),
bfb36bff	45	fBachIdx(-1)
90e48c0c	46	{
e23730c7	47	//--------------------------------------------------------------------
	48	// Default constructor (Xi-)
	49	//--------------------------------------------------------------------
bfb36bff	50	for (Int_t j=0; j<3; j++) {
c028b974	51	fPosXi[j]=0.;
bfb36bff	52	fBachMom[j]=0.;
	53	}
	54
562dd0b4	55	fPosCovXi[0]=1024;
c028b974	56	fPosCovXi[1]=fPosCovXi[2]=0.;
562dd0b4	57	fPosCovXi[3]=1024;
c028b974	58	fPosCovXi[4]=0.;
562dd0b4	59	fPosCovXi[5]=1024;
bfb36bff	60
562dd0b4	61	fBachMomCov[0]=1024;
bfb36bff	62	fBachMomCov[1]=fBachMomCov[2]=0.;
562dd0b4	63	fBachMomCov[3]=1024;
bfb36bff	64	fBachMomCov[4]=0.;
562dd0b4	65	fBachMomCov[5]=1024;
e23730c7	66	}
e23730c7	67
3e27a419	68	AliESDcascade::AliESDcascade(const AliESDcascade& cas) :
	69	AliESDv0(cas),
	70	fEffMassXi(cas.fEffMassXi),
	71	fChi2Xi(cas.fChi2Xi),
	72	fDcaXiDaughters(cas.fDcaXiDaughters),
	73	fPdgCodeXi(cas.fPdgCodeXi),
	74	fBachIdx(cas.fBachIdx)
	75	{
	76	//--------------------------------------------------------------------
	77	// The copy constructor
	78	//--------------------------------------------------------------------
	79	for (int i=0; i<3; i++) {
	80	fPosXi[i] = cas.fPosXi[i];
	81	fBachMom[i] = cas.fBachMom[i];
	82	}
	83	for (int i=0; i<6; i++) {
	84	fPosCovXi[i] = cas.fPosCovXi[i];
	85	fBachMomCov[i] = cas.fBachMomCov[i];
	86	}
c028b974	87	}
c028b974	88
c7bafca9	89	AliESDcascade::AliESDcascade(const AliESDv0 &v,
c7bafca9	90	const AliExternalTrackParam &t, Int_t i) :
c028b974	91	AliESDv0(v),
562dd0b4	92	fEffMassXi(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
	93	fChi2Xi(1024),
	94	fDcaXiDaughters(1024),
8668c148	95	fPdgCodeXi(kXiMinus),
c7bafca9	96	fBachIdx(i)
c7bafca9	97	{
3e27a419	98	//--------------------------------------------------------------------
c7bafca9	99	// Main constructor (Xi-)
3e27a419	100	//--------------------------------------------------------------------
c7bafca9	101
	102	Double_t r[3]; t.GetXYZ(r);
	103	Double_t x1=r[0], y1=r[1], z1=r[2]; // position of the bachelor
	104	Double_t p[3]; t.GetPxPyPz(p);
	105	Double_t px1=p[0], py1=p[1], pz1=p[2];// momentum of the bachelor track
	106
	107	Double_t x2,y2,z2; // position of the V0
	108	v.GetXYZ(x2,y2,z2);
	109	Double_t px2,py2,pz2; // momentum of V0
	110	v.GetPxPyPz(px2,py2,pz2);
	111
	112	Double_t a2=((x1-x2)px2+(y1-y2)py2+(z1-z2)pz2)/(px2px2+py2py2+pz2pz2);
	113
	114	Double_t xm=x2+a2*px2;
	115	Double_t ym=y2+a2*py2;
	116	Double_t zm=z2+a2*pz2;
	117
	118	// position of the cascade decay
	119
c028b974	120	fPosXi[0]=0.5(x1+xm); fPosXi[1]=0.5(y1+ym); fPosXi[2]=0.5*(z1+zm);
c7bafca9	121
	122
	123	// invariant mass of the cascade (default is Ximinus)
	124
	125	Double_t e1=TMath::Sqrt(0.139570.13957 + px1px1 + py1py1 + pz1pz1);
	126	Double_t e2=TMath::Sqrt(1.115681.11568 + px2px2 + py2py2 + pz2pz2);
	127
8668c148	128	fEffMassXi=TMath::Sqrt((e1+e2)*(e1+e2)-
c7bafca9	129	(px1+px2)(px1+px2)-(py1+py2)(py1+py2)-(pz1+pz2)*(pz1+pz2));
	130
	131
	132	// momenta of the bachelor and the V0
	133
	134	fBachMom[0]=px1; fBachMom[1]=py1; fBachMom[2]=pz1;
c7bafca9	135
bfb36bff	136	//PH Covariance matrices: to be calculated correctly in the future
562dd0b4	137	fPosCovXi[0]=1024;
c028b974	138	fPosCovXi[1]=fPosCovXi[2]=0.;
562dd0b4	139	fPosCovXi[3]=1024;
c028b974	140	fPosCovXi[4]=0.;
562dd0b4	141	fPosCovXi[5]=1024;
bfb36bff	142
562dd0b4	143	fBachMomCov[0]=1024;
bfb36bff	144	fBachMomCov[1]=fBachMomCov[2]=0.;
562dd0b4	145	fBachMomCov[3]=1024;
bfb36bff	146	fBachMomCov[4]=0.;
562dd0b4	147	fBachMomCov[5]=1024;
c7bafca9	148
562dd0b4	149	fChi2Xi=1024.;
c7bafca9	150
	151	}
	152
3e27a419	153	AliESDcascade& AliESDcascade::operator=(const AliESDcascade& cas)
c028b974	154	{
3e27a419	155	//--------------------------------------------------------------------
	156	// The assignment operator
	157	//--------------------------------------------------------------------
732a24fe	158
	159	if(this==&cas) return *this;
	160	AliESDv0::operator=(cas);
	161
	162	fEffMassXi = cas.fEffMassXi;
	163	fChi2Xi = cas.fChi2Xi;
	164	fDcaXiDaughters = cas.fDcaXiDaughters;
	165	fPdgCodeXi = cas.fPdgCodeXi;
	166	fBachIdx = cas.fBachIdx;
	167	for (int i=0; i<3; i++) {
	168	fPosXi[i] = cas.fPosXi[i];
	169	fBachMom[i] = cas.fBachMom[i];
	170	}
	171	for (int i=0; i<6; i++) {
	172	fPosCovXi[i] = cas.fPosCovXi[i];
	173	fBachMomCov[i] = cas.fBachMomCov[i];
	174	}
	175	return *this;
	176	}
	177
	178	void AliESDcascade::Copy(TObject &obj) const {
	179
	180	// this overwrites the virtual TOBject::Copy()
	181	// to allow run time copying without casting
	182	// in AliESDEvent
	183
	184	if(this==&obj)return;
	185	AliESDcascade robj = dynamic_cast<AliESDcascade>(&obj);
	186	if(!robj)return; // not an AliESDcascade
	187	robj = this;
3e27a419	188	}
732a24fe	189
3e27a419	190	AliESDcascade::~AliESDcascade() {
	191	//--------------------------------------------------------------------
	192	// Empty destructor
	193	//--------------------------------------------------------------------
732a24fe	194	}
732a24fe	195
646c9704	196	// Start with AliVParticle functions
	197	Double_t AliESDcascade::E() const {
	198	//--------------------------------------------------------------------
	199	// This gives the energy assuming the ChangeMassHypothesis was called
	200	//--------------------------------------------------------------------
3e27a419	201	return E(fPdgCodeXi);
	202	}
	203
	204	Double_t AliESDcascade::Y() const {
	205	//--------------------------------------------------------------------
	206	// This gives the energy assuming the ChangeMassHypothesis was called
	207	//--------------------------------------------------------------------
	208	return Y(fPdgCodeXi);
	209	}
	210
	211	// Then extend AliVParticle functions
	212	Double_t AliESDcascade::E(Int_t pdg) const {
	213	//--------------------------------------------------------------------
	214	// This gives the energy with the particle hypothesis as argument
	215	//--------------------------------------------------------------------
	216	Double_t mass = TDatabasePDG::Instance()->GetParticle(pdg)->Mass();
646c9704	217	return TMath::Sqrt(massmass+P()P());
	218	}
	219
3e27a419	220	Double_t AliESDcascade::Y(Int_t pdg) const {
	221	//--------------------------------------------------------------------
	222	// This gives the rapidity with the particle hypothesis as argument
	223	//--------------------------------------------------------------------
	224	return 0.5*TMath::Log((E(pdg)+Pz())/(E(pdg)-Pz()+1.e-13));
	225	}
	226
	227	// Now the functions for analysis consistency
	228	Double_t AliESDcascade::RapXi() const {
	229	//--------------------------------------------------------------------
	230	// This gives the pseudorapidity assuming a (Anti) Xi particle
	231	//--------------------------------------------------------------------
	232	return Y(kXiMinus);
	233	}
	234
	235	Double_t AliESDcascade::RapOmega() const {
	236	//--------------------------------------------------------------------
	237	// This gives the pseudorapidity assuming a (Anti) Omega particle
	238	//--------------------------------------------------------------------
	239	return Y(kOmegaMinus);
	240	}
	241
	242	Double_t AliESDcascade::AlphaXi() const {
	243	//--------------------------------------------------------------------
	244	// This gives the Armenteros-Podolanski alpha
	245	//--------------------------------------------------------------------
	246	TVector3 momBach(fBachMom[0],fBachMom[1],fBachMom[2]);
	247	TVector3 momV0(fNmom[0]+fPmom[0],fNmom[1]+fPmom[1],fNmom[2]+fPmom[2]);
	248	TVector3 momTot(Px(),Py(),Pz());
	249
	250	Double_t QlBach = momBach.Dot(momTot)/momTot.Mag();
	251	Double_t QlV0 = momV0.Dot(momTot)/momTot.Mag();
	252
	253	return 1.-2./(1.+QlBach/QlV0);
	254	}
	255
	256	Double_t AliESDcascade::PtArmXi() const {
	257	//--------------------------------------------------------------------
	258	// This gives the Armenteros-Podolanski ptarm
	259	//--------------------------------------------------------------------
	260	TVector3 momBach(fBachMom[0],fBachMom[1],fBachMom[2]);
	261	TVector3 momTot(Px(),Py(),Pz());
	262
	263	return momBach.Perp(momTot);
	264	}
	265
646c9704	266	// Then the older functions
e23730c7	267	Double_t AliESDcascade::ChangeMassHypothesis(Double_t &v0q, Int_t code) {
	268	//--------------------------------------------------------------------
	269	// This function changes the mass hypothesis for this cascade
	270	// and returns the "kinematical quality" of this hypothesis
	271	// together with the "quality" of associated V0 (argument v0q)
	272	//--------------------------------------------------------------------
	273	Double_t nmass=0.13957, pmass=0.93827, ps0=0.101;
	274	Double_t bmass=0.13957, mass =1.3213, ps =0.139;
	275
8668c148	276	fPdgCodeXi=code;
e23730c7	277
	278	switch (code) {
	279	case 213:
	280	bmass=0.93827;
	281	break;
	282	case kXiMinus:
	283	break;
	284	case kXiPlusBar:
	285	nmass=0.93827; pmass=0.13957;
	286	break;
	287	case kOmegaMinus:
	288	bmass=0.49368; mass=1.67245; ps=0.211;
	289	break;
	290	case kOmegaPlusBar:
	291	nmass=0.93827; pmass=0.13957;
	292	bmass=0.49368; mass=1.67245; ps=0.211;
	293	break;
	294	default:
5f7789fc	295	AliError("Invalide PDG code ! Assuming XiMinus's...");
8668c148	296	fPdgCodeXi=kXiMinus;
e23730c7	297	break;
	298	}
	299
c028b974	300	Double_t pxn=fNmom[0], pyn=fNmom[1], pzn=fNmom[2];
c028b974	301	Double_t pxp=fPmom[0], pyp=fPmom[1], pzp=fPmom[2];
8668c148	302
e23730c7	303	Double_t px0=pxn+pxp, py0=pyn+pyp, pz0=pzn+pzp;
	304	Double_t p0=TMath::Sqrt(px0px0 + py0py0 + pz0*pz0);
	305
	306	Double_t e0=TMath::Sqrt(1.115681.11568 + p0p0);
	307	Double_t beta0=p0/e0;
	308	Double_t pln=(pxnpx0 + pynpy0 + pzn*pz0)/p0;
	309	Double_t plp=(pxppx0 + pyppy0 + pzp*pz0)/p0;
	310	Double_t pt2=pxppxp + pyppyp + pzppzp - plpplp;
	311
	312	Double_t a=(plp-pln)/(plp+pln);
	313	a -= (pmasspmass-nmassnmass)/(1.11568*1.11568);
	314	a = 0.25beta0beta01.115681.11568aa + pt2;
	315
	316
	317	v0q=a - ps0*ps0;
	318
	319
	320	Double_t pxb=fBachMom[0], pyb=fBachMom[1], pzb=fBachMom[2];
	321
	322	Double_t eb=TMath::Sqrt(bmassbmass + pxbpxb + pybpyb + pzbpzb);
	323	Double_t pxl=px0+pxb, pyl=py0+pyb, pzl=pz0+pzb;
	324	Double_t pl=TMath::Sqrt(pxlpxl + pylpyl + pzl*pzl);
	325
8668c148	326	fEffMassXi=TMath::Sqrt((e0+eb)(e0+eb) - plpl);
e23730c7	327
	328	Double_t beta=pl/(e0+eb);
	329	Double_t pl0=(px0pxl + py0pyl + pz0*pzl)/pl;
	330	Double_t plb=(pxbpxl + pybpyl + pzb*pzl)/pl;
	331	pt2=p0p0 - pl0pl0;
	332
	333	a=(pl0-plb)/(pl0+plb);
	334	a -= (1.115681.11568-bmassbmass)/(mass*mass);
	335	a = 0.25betabetamassmassaa + pt2;
	336
	337	return (a - ps*ps);
	338	}
	339
	340	void
	341	AliESDcascade::GetPxPyPz(Double_t &px, Double_t &py, Double_t &pz) const {
	342	//--------------------------------------------------------------------
	343	// This function returns the cascade momentum (global)
	344	//--------------------------------------------------------------------
8668c148	345	px=fNmom[0]+fPmom[0]+fBachMom[0];
c028b974	346	py=fNmom[1]+fPmom[1]+fBachMom[1];
c028b974	347	pz=fNmom[2]+fPmom[2]+fBachMom[2];
e23730c7	348	}
e23730c7	349
c028b974	350	void AliESDcascade::GetXYZcascade(Double_t &x, Double_t &y, Double_t &z) const {
e23730c7	351	//--------------------------------------------------------------------
	352	// This function returns cascade position (global)
	353	//--------------------------------------------------------------------
c028b974	354	x=fPosXi[0];
	355	y=fPosXi[1];
	356	z=fPosXi[2];
e23730c7	357	}
e23730c7	358
c028b974	359	Double_t AliESDcascade::GetDcascade(Double_t x0, Double_t y0, Double_t z0) const {
e23730c7	360	//--------------------------------------------------------------------
	361	// This function returns the cascade impact parameter
	362	//--------------------------------------------------------------------
	363
c028b974	364	Double_t x=fPosXi[0],y=fPosXi[1],z=fPosXi[2];
	365	Double_t px=fNmom[0]+fPmom[0]+fBachMom[0];
	366	Double_t py=fNmom[1]+fPmom[1]+fBachMom[1];
	367	Double_t pz=fNmom[2]+fPmom[2]+fBachMom[2];
e23730c7	368
	369	Double_t dx=(y0-y)pz - (z0-z)py;
	370	Double_t dy=(x0-x)pz - (z0-z)px;
	371	Double_t dz=(x0-x)py - (y0-y)px;
	372	Double_t d=TMath::Sqrt((dxdx+dydy+dzdz)/(pxpx+pypy+pzpz));
	373
	374	return d;
	375	}
	376
c028b974	377	Double_t AliESDcascade::GetCascadeCosineOfPointingAngle(Double_t& refPointX, Double_t& refPointY, Double_t& refPointZ) const {
	378	// calculates the pointing angle of the cascade wrt a reference point
	379
	380	Double_t momCas[3]; //momentum of the cascade
	381	GetPxPyPz(momCas[0],momCas[1],momCas[2]);
	382
	383	Double_t deltaPos[3]; //vector between the reference point and the cascade vertex
	384	deltaPos[0] = fPosXi[0] - refPointX;
	385	deltaPos[1] = fPosXi[1] - refPointY;
	386	deltaPos[2] = fPosXi[2] - refPointZ;
	387
	388	Double_t momCas2 = momCas[0]momCas[0] + momCas[1]momCas[1] + momCas[2]*momCas[2];
	389	Double_t deltaPos2 = deltaPos[0]deltaPos[0] + deltaPos[1]deltaPos[1] + deltaPos[2]*deltaPos[2];
	390
	391	Double_t cosinePointingAngle = (deltaPos[0]*momCas[0] +
	392	deltaPos[1]*momCas[1] +
	393	deltaPos[2]*momCas[2] ) /
	394	TMath::Sqrt(momCas2 * deltaPos2);
	395
	396	return cosinePointingAngle;
	397	}
074f017b	398
	399	void AliESDcascade::GetPosCovXi(Double_t cov[6]) const {
	400
	401	for (Int_t i=0; i<6; ++i) cov[i] = fPosCovXi[i];
	402	}