Introducing hyperons in ESD (Yu.Belikov)

[u/mrichter/AliRoot.git] / ITS / AliV0vertex.cxx

diff --git a/ITS/AliV0vertex.cxx b/ITS/AliV0vertex.cxx
index f663e2f8520df38b6203a62b447a3d41b331848d..9dd719a0872ca550c576822e2f76830a2e872288 100644 (file)
--- a/ITS/AliV0vertex.cxx
+++ b/ITS/AliV0vertex.cxx
@@ -18,32 +18,19 @@
 //
 //     Origin: Iouri Belikov, IReS, Strasbourg, Jouri.Belikov@cern.ch
 //-------------------------------------------------------------------------
-#include <Riostream.h>
 #include <TMath.h>
-#include <TPDGCode.h>
 
 #include "AliV0vertex.h"
 #include "AliITStrackV2.h"
 
 ClassImp(AliV0vertex)
 
-AliV0vertex::AliV0vertex() : TObject() {
-  //--------------------------------------------------------------------
-  // Default constructor  (K0s)
-  //--------------------------------------------------------------------
-  fPdgCode=kK0Short;
-  fEffMass=0.497672;
-  fChi2=1.e+33;
-  fPos[0]=fPos[1]=fPos[2]=0.;
-  fPosCov[0]=fPosCov[1]=fPosCov[2]=fPosCov[3]=fPosCov[4]=fPosCov[5]=0.;
-}
-
 AliV0vertex::AliV0vertex(const AliITStrackV2 &n, const AliITStrackV2 &p) {
   //--------------------------------------------------------------------
   // Main constructor
   //--------------------------------------------------------------------
   fPdgCode=kK0Short;
-  fNlab=n.GetLabel(); fPlab=p.GetLabel();
+  fNidx=n.GetLabel(); fPidx=p.GetLabel(); //indices in the array of ESD tracks
 
   //Trivial estimation of the vertex parameters
   Double_t pt, phi, x, par[5];
@@ -86,128 +73,4 @@ AliV0vertex::AliV0vertex(const AliITStrackV2 &n, const AliITStrackV2 &p) {
 
   fChi2=7.;   
 }
-/*
-Double_t AliV0vertex::ChangeMassHypothesis(Int_t code) {
-  //--------------------------------------------------------------------
-  // This function changes the mass hypothesis for this V0
-  // and returns the "kinematical quality" of this hypothesis 
-  //--------------------------------------------------------------------
-  Double_t nmass=0.13957, pmass=0.13957, mass=0.49767, des=0;
-
-  fPdgCode=code;
-
-  switch (code) {
-  case kLambda0:
-    nmass=0.13957; pmass=0.93827; mass=1.1157; des=0.9437-0.1723; break;
-  case kLambda0Bar:
-    pmass=0.13957; nmass=0.93827; mass=1.1157; des=0.1723-0.9437; break;
-  case kK0Short: 
-    break;
-  default:
-    cerr<<"AliV0vertex::ChangeMassHypothesis: ";
-    cerr<<"invalide PDG code ! Assuming K0s...\n";
-    fPdgCode=kK0Short;
-    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 en=TMath::Sqrt(nmass*nmass + pxn*pxn + pyn*pyn + pzn*pzn);
-  Double_t ep=TMath::Sqrt(pmass*pmass + pxp*pxp + pyp*pyp + pzp*pzp);
-  Double_t pxl=pxn+pxp, pyl=pyn+pyp, pzl=pzn+pzp;
-  Double_t pl=TMath::Sqrt(pxl*pxl + pyl*pyl + pzl*pzl);
-
-  fEffMass=TMath::Sqrt((en+ep)*(en+ep)-pl*pl);
-
-  Double_t gamma=(en+ep)/mass, betagamma=pl/mass;
-  Double_t pln=(pxn*pxl + pyn*pyl + pzn*pzl)/pl;
-  Double_t plp=(pxp*pxl + pyp*pyl + pzp*pzl)/pl;
-  Double_t plps=gamma*plp - betagamma*ep;
-
-  Double_t diff=2*gamma*plps + betagamma*des;
-
-  return (plp-pln-diff);
-  
-}
-*/
-Double_t AliV0vertex::ChangeMassHypothesis(Int_t code) {
-  //--------------------------------------------------------------------
-  // This function changes the mass hypothesis for this V0
-  // and returns the "kinematical quality" of this hypothesis 
-  //--------------------------------------------------------------------
-  Double_t nmass=0.13957, pmass=0.13957, mass=0.49767, ps=0.206;
-
-  fPdgCode=code;
-
-  switch (code) {
-  case kLambda0:
-    nmass=0.13957; pmass=0.93827; mass=1.1157; ps=0.101; break;
-  case kLambda0Bar:
-    pmass=0.13957; nmass=0.93827; mass=1.1157; ps=0.101; break;
-  case kK0Short: 
-    break;
-  default:
-    cerr<<"AliV0vertex::ChangeMassHypothesis: ";
-    cerr<<"invalide PDG code ! Assuming K0s...\n";
-    fPdgCode=kK0Short;
-    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 en=TMath::Sqrt(nmass*nmass + pxn*pxn + pyn*pyn + pzn*pzn);
-  Double_t ep=TMath::Sqrt(pmass*pmass + pxp*pxp + pyp*pyp + pzp*pzp);
-  Double_t pxl=pxn+pxp, pyl=pyn+pyp, pzl=pzn+pzp;
-  Double_t pl=TMath::Sqrt(pxl*pxl + pyl*pyl + pzl*pzl);
-
-  fEffMass=TMath::Sqrt((en+ep)*(en+ep)-pl*pl);
-
-  Double_t beta=pl/(en+ep);
-  Double_t pln=(pxn*pxl + pyn*pyl + pzn*pzl)/pl;
-  Double_t plp=(pxp*pxl + pyp*pyl + pzp*pzl)/pl;
-
-  Double_t pt2=pxp*pxp + pyp*pyp + pzp*pzp - plp*plp;
-
-  Double_t a=(plp-pln)/(plp+pln);
-  a -= (pmass*pmass-nmass*nmass)/(mass*mass);
-  a = 0.25*beta*beta*mass*mass*a*a + pt2;
-
-  return (a - ps*ps);
-  
-}
-
-void AliV0vertex::GetPxPyPz(Double_t &px, Double_t &py, Double_t &pz) const {
-  //--------------------------------------------------------------------
-  // This function returns V0's momentum (global)
-  //--------------------------------------------------------------------
-  px=fNmom[0]+fPmom[0]; 
-  py=fNmom[1]+fPmom[1]; 
-  pz=fNmom[2]+fPmom[2]; 
-}
-
-void AliV0vertex::GetXYZ(Double_t &x, Double_t &y, Double_t &z) const {
-  //--------------------------------------------------------------------
-  // This function returns V0's position (global)
-  //--------------------------------------------------------------------
-  x=fPos[0]; 
-  y=fPos[1]; 
-  z=fPos[2]; 
-}
 
-Double_t AliV0vertex::GetD(Double_t x0, Double_t y0, Double_t z0) const {
-  //--------------------------------------------------------------------
-  // This function returns V0's impact parameter
-  //--------------------------------------------------------------------
-  Double_t x=fPos[0],y=fPos[1],z=fPos[2];
-  Double_t px=fNmom[0]+fPmom[0];
-  Double_t py=fNmom[1]+fPmom[1];
-  Double_t pz=fNmom[2]+fPmom[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;
-}