t0 reconstruction

Add a task CbmRecoTzero for reconstruction of the event t0. The current implementation just reads the time from the CbmTzdDigi in the event and fills the respective field in the CbmEvent class. In case there is no TzdDigi, the time is set to -1.; if there are more than one, the time is set to -2. These values are to be regarded as error codes.

The new task is added to the run_reco macro for the event-by-event case. If no TzdDigi branch is found, the task will be inactive.

core/data/CbmEvent.h

@@ -137,6 +137,13 @@ public:
    **/
   double GetStartTime() const { return fTimeStart; }
 
+
+  /** Get t0
+   ** @value Reconstructed t0 [ns]
+   **/
+  double GetTzero() const { return fTzero; }
+
+
   /** Set event number
    ** @value Event number
    **/
@@ -160,6 +167,12 @@ public:
   void SetStartTime(double startTime) { fTimeStart = startTime; }
 
 
+  /** Set t0
+   ** @param tZero  T0 measurement [ns]
+   **/
+  void SetTzero(double tZero) { fTzero = tZero; }
+
+
   /** Set the STS track index array
    ** @brief Sets the index array for STS tracks.
    ** Old content will be overwritten.
@@ -204,12 +217,13 @@ public:
 
 private:
   /** Event meta data **/
-  int32_t fNumber;      ///< Event number
-  double fTimeStart;    ///< Event start time [ns]
-  double fTimeEnd;      ///< Event end time [ns]
-  int32_t fNofData;     ///< Number of data objects in the event
-  CbmVertex fVertex;    ///< Primary Vertex
-  CbmMatch* fMatch;     ///< Match object to MCEvent
+  int32_t fNumber   = -1;        ///< Event number
+  double fTimeStart = 0.;        ///< Event start time [ns]
+  double fTimeEnd   = 0.;        ///< Event end time [ns]
+  double fTzero     = -999999.;  ///< T0 of event for TOF PID [ns]
+  int32_t fNofData  = 0;         ///< Number of data objects in the event
+  CbmVertex fVertex = {};        ///< Primary Vertex
+  CbmMatch* fMatch  = nullptr;   ///< Match object to MCEvent
 
   /** Arrays of indices to data types **/
   std::map<ECbmDataType, std::vector<uint32_t>> fIndexMap;