[PWGLF] Add selection for systematic (#10577)

Author: skundu692

PWGLF/Tasks/Resonances/phipbpb.cxx

@@ -93,6 +93,7 @@ struct phipbpb {
   Configurable<int> cfgCutOccupancy{"cfgCutOccupancy", 3000, "Occupancy cut"};
   // track
   Configurable<bool> useSP{"useSP", false, "use SP"};
+  Configurable<bool> useDcaSyst{"useDcaSyst", false, "useDcaSyst"};
   Configurable<bool> additionalEvsel{"additionalEvsel", false, "Additional event selcection"};
   Configurable<bool> additionalEvselITS{"additionalEvselITS", true, "Additional event selcection for ITS"};
   Configurable<bool> removefaketrak{"removefaketrack", true, "Remove fake track from momentum difference"};
@@ -358,7 +359,10 @@ struct phipbpb {
   template <typename T>
   bool selectionTrack(const T& candidate)
   {
-    if (useGlobalTrack && !(candidate.isGlobalTrack() && candidate.isPVContributor() && candidate.itsNCls() > cfgITScluster && candidate.tpcNClsCrossedRows() > cfgTPCcluster && candidate.tpcFractionSharedCls() < cfgTPCSharedcluster)) {
+    if (useGlobalTrack && !useDcaSyst && !(candidate.isGlobalTrack() && candidate.isPVContributor() && candidate.itsNCls() > cfgITScluster && candidate.tpcNClsCrossedRows() > cfgTPCcluster && candidate.tpcFractionSharedCls() < cfgTPCSharedcluster)) {
+      return false;
+    }
+    if (useGlobalTrack && useDcaSyst && !(candidate.itsNCls() > cfgITScluster && candidate.tpcNClsCrossedRows() > cfgTPCcluster && candidate.tpcFractionSharedCls() < cfgTPCSharedcluster)) {
       return false;
     }
     if (!useGlobalTrack && !(candidate.tpcNClsFound() > cfgTPCcluster)) {