[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
//-------------------------------------------------------------------------

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

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

ClassImp(AliESDcascade)

AliESDcascade::AliESDcascade() : 
  AliESDv0(),
  fPdgCode(kXiMinus),
  fEffMass(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
  fChi2Xi(1.e+33),
  fDcaXiDaughters(999),
  fBachIdx(-1)
{
  //--------------------------------------------------------------------
  // Default constructor  (Xi-)
  //--------------------------------------------------------------------
  for (Int_t j=0; j<3; j++) {
    fPosXi[j]=0.;
    fBachMom[j]=0.;
  }

  fPosCovXi[0]=1e10;
  fPosCovXi[1]=fPosCovXi[2]=0.;
  fPosCovXi[3]=1e10;
  fPosCovXi[4]=0.;
  fPosCovXi[5]=1e10;

  fBachMomCov[0]=1e10;
  fBachMomCov[1]=fBachMomCov[2]=0.;
  fBachMomCov[3]=1e10;
  fBachMomCov[4]=0.;
  fBachMomCov[5]=1e10;
}

AliESDcascade::~AliESDcascade() {
}

AliESDcascade::AliESDcascade(const AliESDv0 &v,
			     const AliExternalTrackParam &t, Int_t i) : 
  AliESDv0(v),
  fPdgCode(kXiMinus),
  fChi2Xi(1.e+33),
  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;

  //dca between V0 and bachelor
  
  fDcaXiDaughters = TMath::Sqrt((x1-xm)*(x1-xm) + (y1-ym)*(y1-ym) + (z1-zm)*(z1-zm));

  // 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);
  
  fEffMass=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]=1e10;
  fPosCovXi[1]=fPosCovXi[2]=0.;
  fPosCovXi[3]=1e10;
  fPosCovXi[4]=0.;
  fPosCovXi[5]=1e10;

  fBachMomCov[0]=1e10;
  fBachMomCov[1]=fBachMomCov[2]=0.;
  fBachMomCov[3]=1e10;
  fBachMomCov[4]=0.;
  fBachMomCov[5]=1e10;

  fChi2Xi=7.;   

}

AliESDcascade::AliESDcascade(const AliESDcascade& cas) :
  AliESDv0(cas)
{
  //copy constructor
  fPdgCode = cas.fPdgCode;
  fEffMass = cas.fEffMass;
  fChi2Xi  = cas.fChi2Xi;
  fDcaXiDaughters = cas.fDcaXiDaughters;
  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];
  }
}

AliESDcascade& AliESDcascade::operator=(const AliESDcascade& cas) {
  //assignment operator
  if (this != &cas) {
    AliESDv0::operator=(cas);
    fPdgCode = cas.fPdgCode;
    fEffMass = cas.fEffMass;
    fChi2Xi  = cas.fChi2Xi;
    fDcaXiDaughters = cas.fDcaXiDaughters;
    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;
}

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;

  fPdgCode=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...");
       fPdgCode=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);
  
  fEffMass=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;
}
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
e23730c7	24	//-------------------------------------------------------------------------
4f679a16	25
90e48c0c	26	#include <TDatabasePDG.h>
e23730c7	27	#include <TMath.h>
e23730c7	28
5f7789fc	29	#include "AliLog.h"
c7bafca9	30	#include "AliExternalTrackParam.h"
c7bafca9	31	#include "AliESDv0.h"
e23730c7	32	#include "AliESDcascade.h"
e23730c7	33
	34	ClassImp(AliESDcascade)
	35
90e48c0c	36	AliESDcascade::AliESDcascade() :
c028b974	37	AliESDv0(),
90e48c0c	38	fPdgCode(kXiMinus),
90e48c0c	39	fEffMass(TDatabasePDG::Instance()->GetParticle(kXiMinus)->Mass()),
c028b974	40	fChi2Xi(1.e+33),
c028b974	41	fDcaXiDaughters(999),
bfb36bff	42	fBachIdx(-1)
90e48c0c	43	{
e23730c7	44	//--------------------------------------------------------------------
	45	// Default constructor (Xi-)
	46	//--------------------------------------------------------------------
bfb36bff	47	for (Int_t j=0; j<3; j++) {
c028b974	48	fPosXi[j]=0.;
bfb36bff	49	fBachMom[j]=0.;
	50	}
	51
c028b974	52	fPosCovXi[0]=1e10;
	53	fPosCovXi[1]=fPosCovXi[2]=0.;
	54	fPosCovXi[3]=1e10;
	55	fPosCovXi[4]=0.;
	56	fPosCovXi[5]=1e10;
bfb36bff	57
	58	fBachMomCov[0]=1e10;
	59	fBachMomCov[1]=fBachMomCov[2]=0.;
	60	fBachMomCov[3]=1e10;
	61	fBachMomCov[4]=0.;
	62	fBachMomCov[5]=1e10;
e23730c7	63	}
e23730c7	64
c028b974	65	AliESDcascade::~AliESDcascade() {
	66	}
	67
c7bafca9	68	AliESDcascade::AliESDcascade(const AliESDv0 &v,
c7bafca9	69	const AliExternalTrackParam &t, Int_t i) :
c028b974	70	AliESDv0(v),
c7bafca9	71	fPdgCode(kXiMinus),
c028b974	72	fChi2Xi(1.e+33),
c7bafca9	73	fBachIdx(i)
c7bafca9	74	{
c028b974	75	//---------------------------------------------------------------------------------------------
c7bafca9	76	// Main constructor (Xi-)
c028b974	77	//---------------------------------------------------------------------------------------------
c7bafca9	78
	79	Double_t r[3]; t.GetXYZ(r);
	80	Double_t x1=r[0], y1=r[1], z1=r[2]; // position of the bachelor
	81	Double_t p[3]; t.GetPxPyPz(p);
	82	Double_t px1=p[0], py1=p[1], pz1=p[2];// momentum of the bachelor track
	83
	84	Double_t x2,y2,z2; // position of the V0
	85	v.GetXYZ(x2,y2,z2);
	86	Double_t px2,py2,pz2; // momentum of V0
	87	v.GetPxPyPz(px2,py2,pz2);
	88
	89	Double_t a2=((x1-x2)px2+(y1-y2)py2+(z1-z2)pz2)/(px2px2+py2py2+pz2pz2);
	90
	91	Double_t xm=x2+a2*px2;
	92	Double_t ym=y2+a2*py2;
	93	Double_t zm=z2+a2*pz2;
	94
c028b974	95	//dca between V0 and bachelor
	96
	97	fDcaXiDaughters = TMath::Sqrt((x1-xm)(x1-xm) + (y1-ym)(y1-ym) + (z1-zm)*(z1-zm));
	98
c7bafca9	99	// position of the cascade decay
c7bafca9	100
c028b974	101	fPosXi[0]=0.5(x1+xm); fPosXi[1]=0.5(y1+ym); fPosXi[2]=0.5*(z1+zm);
c7bafca9	102
	103
	104	// invariant mass of the cascade (default is Ximinus)
	105
	106	Double_t e1=TMath::Sqrt(0.139570.13957 + px1px1 + py1py1 + pz1pz1);
	107	Double_t e2=TMath::Sqrt(1.115681.11568 + px2px2 + py2py2 + pz2pz2);
	108
	109	fEffMass=TMath::Sqrt((e1+e2)*(e1+e2)-
	110	(px1+px2)(px1+px2)-(py1+py2)(py1+py2)-(pz1+pz2)*(pz1+pz2));
	111
	112
	113	// momenta of the bachelor and the V0
	114
	115	fBachMom[0]=px1; fBachMom[1]=py1; fBachMom[2]=pz1;
c7bafca9	116
bfb36bff	117	//PH Covariance matrices: to be calculated correctly in the future
c028b974	118	fPosCovXi[0]=1e10;
	119	fPosCovXi[1]=fPosCovXi[2]=0.;
	120	fPosCovXi[3]=1e10;
	121	fPosCovXi[4]=0.;
	122	fPosCovXi[5]=1e10;
bfb36bff	123
	124	fBachMomCov[0]=1e10;
	125	fBachMomCov[1]=fBachMomCov[2]=0.;
	126	fBachMomCov[3]=1e10;
	127	fBachMomCov[4]=0.;
	128	fBachMomCov[5]=1e10;
c7bafca9	129
c028b974	130	fChi2Xi=7.;
c7bafca9	131
	132	}
	133
c028b974	134	AliESDcascade::AliESDcascade(const AliESDcascade& cas) :
	135	AliESDv0(cas)
	136	{
	137	//copy constructor
	138	fPdgCode = cas.fPdgCode;
	139	fEffMass = cas.fEffMass;
	140	fChi2Xi = cas.fChi2Xi;
	141	fDcaXiDaughters = cas.fDcaXiDaughters;
	142	fBachIdx = cas.fBachIdx;
	143	for (int i=0; i<3; i++) {
	144	fPosXi[i] = cas.fPosXi[i];
	145	fBachMom[i] = cas.fBachMom[i];
	146	}
	147	for (int i=0; i<6; i++) {
	148	fPosCovXi[i] = cas.fPosCovXi[i];
	149	fBachMomCov[i] = cas.fBachMomCov[i];
	150	}
	151	}
	152
	153	AliESDcascade& AliESDcascade::operator=(const AliESDcascade& cas) {
	154	//assignment operator
	155	if (this != &cas) {
	156	AliESDv0::operator=(cas);
	157	fPdgCode = cas.fPdgCode;
	158	fEffMass = cas.fEffMass;
	159	fChi2Xi = cas.fChi2Xi;
	160	fDcaXiDaughters = cas.fDcaXiDaughters;
	161	fBachIdx = cas.fBachIdx;
	162	for (int i=0; i<3; i++) {
	163	fPosXi[i] = cas.fPosXi[i];
	164	fBachMom[i] = cas.fBachMom[i];
	165	}
	166	for (int i=0; i<6; i++) {
	167	fPosCovXi[i] = cas.fPosCovXi[i];
	168	fBachMomCov[i] = cas.fBachMomCov[i];
	169	}
	170	}
	171	return *this;
	172	}
	173
e23730c7	174	Double_t AliESDcascade::ChangeMassHypothesis(Double_t &v0q, Int_t code) {
	175	//--------------------------------------------------------------------
	176	// This function changes the mass hypothesis for this cascade
	177	// and returns the "kinematical quality" of this hypothesis
	178	// together with the "quality" of associated V0 (argument v0q)
	179	//--------------------------------------------------------------------
	180	Double_t nmass=0.13957, pmass=0.93827, ps0=0.101;
	181	Double_t bmass=0.13957, mass =1.3213, ps =0.139;
	182
	183	fPdgCode=code;
	184
	185	switch (code) {
	186	case 213:
	187	bmass=0.93827;
	188	break;
	189	case kXiMinus:
	190	break;
	191	case kXiPlusBar:
	192	nmass=0.93827; pmass=0.13957;
	193	break;
	194	case kOmegaMinus:
	195	bmass=0.49368; mass=1.67245; ps=0.211;
	196	break;
	197	case kOmegaPlusBar:
	198	nmass=0.93827; pmass=0.13957;
	199	bmass=0.49368; mass=1.67245; ps=0.211;
	200	break;
	201	default:
5f7789fc	202	AliError("Invalide PDG code ! Assuming XiMinus's...");
e23730c7	203	fPdgCode=kXiMinus;
	204	break;
	205	}
	206
c028b974	207	Double_t pxn=fNmom[0], pyn=fNmom[1], pzn=fNmom[2];
c028b974	208	Double_t pxp=fPmom[0], pyp=fPmom[1], pzp=fPmom[2];
e23730c7	209	Double_t px0=pxn+pxp, py0=pyn+pyp, pz0=pzn+pzp;
	210	Double_t p0=TMath::Sqrt(px0px0 + py0py0 + pz0*pz0);
	211
	212	Double_t e0=TMath::Sqrt(1.115681.11568 + p0p0);
	213	Double_t beta0=p0/e0;
	214	Double_t pln=(pxnpx0 + pynpy0 + pzn*pz0)/p0;
	215	Double_t plp=(pxppx0 + pyppy0 + pzp*pz0)/p0;
	216	Double_t pt2=pxppxp + pyppyp + pzppzp - plpplp;
	217
	218	Double_t a=(plp-pln)/(plp+pln);
	219	a -= (pmasspmass-nmassnmass)/(1.11568*1.11568);
	220	a = 0.25beta0beta01.115681.11568aa + pt2;
	221
	222
	223	v0q=a - ps0*ps0;
	224
	225
	226	Double_t pxb=fBachMom[0], pyb=fBachMom[1], pzb=fBachMom[2];
	227
	228	Double_t eb=TMath::Sqrt(bmassbmass + pxbpxb + pybpyb + pzbpzb);
	229	Double_t pxl=px0+pxb, pyl=py0+pyb, pzl=pz0+pzb;
	230	Double_t pl=TMath::Sqrt(pxlpxl + pylpyl + pzl*pzl);
	231
	232	fEffMass=TMath::Sqrt((e0+eb)(e0+eb) - plpl);
	233
	234	Double_t beta=pl/(e0+eb);
	235	Double_t pl0=(px0pxl + py0pyl + pz0*pzl)/pl;
	236	Double_t plb=(pxbpxl + pybpyl + pzb*pzl)/pl;
	237	pt2=p0p0 - pl0pl0;
	238
	239	a=(pl0-plb)/(pl0+plb);
	240	a -= (1.115681.11568-bmassbmass)/(mass*mass);
	241	a = 0.25betabetamassmassaa + pt2;
	242
	243	return (a - ps*ps);
	244	}
	245
	246	void
	247	AliESDcascade::GetPxPyPz(Double_t &px, Double_t &py, Double_t &pz) const {
	248	//--------------------------------------------------------------------
	249	// This function returns the cascade momentum (global)
	250	//--------------------------------------------------------------------
c028b974	251	px=fNmom[0]+fPmom[0]+fBachMom[0];
	252	py=fNmom[1]+fPmom[1]+fBachMom[1];
	253	pz=fNmom[2]+fPmom[2]+fBachMom[2];
e23730c7	254	}
e23730c7	255
c028b974	256	void AliESDcascade::GetXYZcascade(Double_t &x, Double_t &y, Double_t &z) const {
e23730c7	257	//--------------------------------------------------------------------
	258	// This function returns cascade position (global)
	259	//--------------------------------------------------------------------
c028b974	260	x=fPosXi[0];
	261	y=fPosXi[1];
	262	z=fPosXi[2];
e23730c7	263	}
e23730c7	264
c028b974	265	Double_t AliESDcascade::GetDcascade(Double_t x0, Double_t y0, Double_t z0) const {
e23730c7	266	//--------------------------------------------------------------------
	267	// This function returns the cascade impact parameter
	268	//--------------------------------------------------------------------
	269
c028b974	270	Double_t x=fPosXi[0],y=fPosXi[1],z=fPosXi[2];
	271	Double_t px=fNmom[0]+fPmom[0]+fBachMom[0];
	272	Double_t py=fNmom[1]+fPmom[1]+fBachMom[1];
	273	Double_t pz=fNmom[2]+fPmom[2]+fBachMom[2];
e23730c7	274
	275	Double_t dx=(y0-y)pz - (z0-z)py;
	276	Double_t dy=(x0-x)pz - (z0-z)px;
	277	Double_t dz=(x0-x)py - (y0-y)px;
	278	Double_t d=TMath::Sqrt((dxdx+dydy+dzdz)/(pxpx+pypy+pzpz));
	279
	280	return d;
	281	}
	282
c028b974	283	Double_t AliESDcascade::GetCascadeCosineOfPointingAngle(Double_t& refPointX, Double_t& refPointY, Double_t& refPointZ) const {
	284	// calculates the pointing angle of the cascade wrt a reference point
	285
	286	Double_t momCas[3]; //momentum of the cascade
	287	GetPxPyPz(momCas[0],momCas[1],momCas[2]);
	288
	289	Double_t deltaPos[3]; //vector between the reference point and the cascade vertex
	290	deltaPos[0] = fPosXi[0] - refPointX;
	291	deltaPos[1] = fPosXi[1] - refPointY;
	292	deltaPos[2] = fPosXi[2] - refPointZ;
	293
	294	Double_t momCas2 = momCas[0]momCas[0] + momCas[1]momCas[1] + momCas[2]*momCas[2];
	295	Double_t deltaPos2 = deltaPos[0]deltaPos[0] + deltaPos[1]deltaPos[1] + deltaPos[2]*deltaPos[2];
	296
	297	Double_t cosinePointingAngle = (deltaPos[0]*momCas[0] +
	298	deltaPos[1]*momCas[1] +
	299	deltaPos[2]*momCas[2] ) /
	300	TMath::Sqrt(momCas2 * deltaPos2);
	301
	302	return cosinePointingAngle;
	303	}