[ALICE3] Fix usage of mag field in alice3-decayfinder.cxx (#14466)

Author: njacazio

ALICE3/DataModel/A3DecayFinderTables.h

@@ -389,14 +389,16 @@ namespace a3_mc_truth
 DECLARE_SOA_COLUMN(OriginMcRec, originMcRec, int);           //!
 DECLARE_SOA_COLUMN(BHadMotherPtRec, bHadMotherPtRec, float); //!
 DECLARE_SOA_COLUMN(FlagMcRec, flagMcRec, int);               //!
+DECLARE_SOA_COLUMN(ParticleMcRec, particleMcRec, int);       //!
 DECLARE_SOA_COLUMN(OriginMcGen, originMcGen, int);           //!
 DECLARE_SOA_COLUMN(BHadMotherPtGen, bHadMotherPtGen, float); //!
 DECLARE_SOA_COLUMN(FlagMcGen, flagMcGen, int);               //!
 } // namespace a3_mc_truth
 DECLARE_SOA_TABLE(Alice3McRecFlags, "AOD", "ALICE3MCRECFLAG", //!
                   a3_mc_truth::OriginMcRec,
                   a3_mc_truth::BHadMotherPtRec,
-                  a3_mc_truth::FlagMcRec);
+                  a3_mc_truth::FlagMcRec,
+                  a3_mc_truth::ParticleMcRec);
 
 DECLARE_SOA_TABLE(Alice3McGenFlags, "AOD", "ALICE3MCGENFLAG", //!
                   a3_mc_truth::OriginMcGen,