From aad8d4351811da9476e0d6d477ab0a76baa9b255 Mon Sep 17 00:00:00 2001
From: hristov <hristov@f7af4fe6-9843-0410-8265-dc069ae4e863>
Date: Tue, 7 Aug 2007 20:58:00 +0000
Subject: [PATCH] Add required AliVParticle functionality (Markus)

---
 STEER/AliESDtrack.cxx | 26 ++++++++++++++++++++++++++
 STEER/AliESDtrack.h   |  3 +++
 2 files changed, 29 insertions(+)

diff --git a/STEER/AliESDtrack.cxx b/STEER/AliESDtrack.cxx
index 2b40838cb84..b2eb9dbc68d 100644
--- a/STEER/AliESDtrack.cxx
+++ b/STEER/AliESDtrack.cxx
@@ -549,6 +549,32 @@ Double_t AliESDtrack::GetMass() const {
   return AliPID::ParticleMass(AliPID::kPion);
 }
 
+//______________________________________________________________________________
+Double_t AliESDtrack::E() const
+{
+  // Returns the energy of the particle given its assumed mass.
+  // Assumes the pion mass if the particle can't be identified properly.
+  
+  Double_t m = M();
+  Double_t p = P();
+  return TMath::Sqrt(p*p + m*m);
+}
+
+//______________________________________________________________________________
+Double_t AliESDtrack::Y() const
+{
+  // Returns the rapidity of a particle given its assumed mass.
+  // Assumes the pion mass if the particle can't be identified properly.
+  
+  Double_t e = E();
+  Double_t pz = Pz();
+  if (e!=pz) { // energy was not equal to pz
+    return 0.5*TMath::Log((e+pz)/(e-pz));
+  } else { // energy was equal to pz
+    return -999.;
+  }
+}
+
 //_______________________________________________________________________
 Bool_t AliESDtrack::UpdateTrackParams(const AliKalmanTrack *t, ULong_t flags){
   //
diff --git a/STEER/AliESDtrack.h b/STEER/AliESDtrack.h
index 5b5fe49c421..56d668fda4f 100644
--- a/STEER/AliESDtrack.h
+++ b/STEER/AliESDtrack.h
@@ -68,6 +68,9 @@ public:
   Double_t GetIntegratedLength() const {return fTrackLength;}
   void GetIntegratedTimes(Double_t *times) const;
   Double_t GetMass() const;
+  Double_t M() const { return GetMass(); }
+  Double_t E() const;
+  Double_t Y() const;
 
   Bool_t GetConstrainedPxPyPz(Double_t *p) const {
     if (!fCp) return kFALSE;
-- 
2.39.3