New class AliHMPIDPid added. Now HMPID could run PID even on ESD within the same...

[u/mrichter/AliRoot.git] / HMPID / AliHMPIDPid.cxx

diff --git a/HMPID/AliHMPIDPid.cxx b/HMPID/AliHMPIDPid.cxx
new file mode 100644 (file)
index 0000000..0715c35
--- /dev/null
+++ b/HMPID/AliHMPIDPid.cxx
@@ -0,0 +1,74 @@
+/**************************************************************************
+ * 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.                  *
+ **************************************************************************/
+
+//////////////////////////////////////////////////////////////////////////
+//                                                                      //
+// AliHMPIDPid                                                          //
+//                                                                      //
+// HMPID class to perfom particle identification                        //
+//                                                                      //
+//////////////////////////////////////////////////////////////////////////
+
+#include "AliHMPIDPid.h"       //class header
+#include "AliHMPIDParam.h"     //class header
+#include <AliESDEvent.h>       //FindPid()
+
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+AliHMPIDPid::AliHMPIDPid():TTask("HMPIDrec","HMPIDPid")
+{
+//..
+//init of data members
+//..
+}
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+void AliHMPIDPid::FindPid(AliESDEvent *pESD)
+{
+// Calculates probability to be a electron-muon-pion-kaon-proton
+// from the given Cerenkov angle and momentum assuming no initial particle composition
+// (i.e. apriory probability to be the particle of the given sort is the same for all sorts)
+
+  AliPID ppp; //needed
+  Double_t pid[AliPID::kSPECIES],h[AliPID::kSPECIES];
+   
+  for(Int_t iTrk=0;iTrk<pESD->GetNumberOfTracks();iTrk++){//ESD tracks loop
+    AliESDtrack *pTrk = pESD->GetTrack(iTrk);// get next reconstructed track
+    if(pTrk->GetHMPIDsignal()<=0){//HMPID does not find anything reasonable for this track, assign 0.2 for all species
+      for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++) pid[iPart]=1.0/AliPID::kSPECIES;
+      pTrk->SetHMPIDpid(pid);
+      continue;
+    } 
+    Double_t pmod = pTrk->GetP();
+    Double_t hTot=0;
+    for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++){
+      Double_t mass = AliPID::ParticleMass(iPart);
+      Double_t cosThetaTh = TMath::Sqrt(mass*mass+pmod*pmod)/(AliHMPIDParam::Instance()->MeanIdxRad()*pmod);
+      if(cosThetaTh<1) //calculate the height of theoretical theta ckov on the gaus of experimental one
+        h[iPart] =TMath::Gaus(TMath::ACos(cosThetaTh),pTrk->GetHMPIDsignal(),TMath::Sqrt(pTrk->GetHMPIDchi2()),kTRUE);      
+      else             //beta < 1/ref. idx. => no light at all  
+        h[iPart] =0 ;       
+      hTot    +=h[iPart]; //total height of all theoretical heights for normalization
+    }//species loop
+     
+    Double_t hMin=TMath::Gaus(pTrk->GetHMPIDsignal()-4*TMath::Sqrt(pTrk->GetHMPIDchi2()),pTrk->GetHMPIDsignal(),TMath::Sqrt(pTrk->GetHMPIDchi2()),kTRUE);//5 sigma protection
+    
+    for(Int_t iPart=0;iPart<AliPID::kSPECIES;iPart++)//species loop to assign probabilities
+      if(hTot>hMin)  
+        pid[iPart]=h[iPart]/hTot;
+      else                               //all theoretical values are far away from experemental one
+        pid[iPart]=1.0/AliPID::kSPECIES; 
+    pTrk->SetHMPIDpid(pid);
+  }//ESD tracks loop
+}
+//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++