[PWGHF] B+ improve correlated background identification (AliceO2Group#9878)

Author: apalasciano

PWGHF/D2H/DataModel/ReducedDataModel.h

@@ -40,10 +40,10 @@ namespace aod
 {
 namespace hf_reduced_collision
 {
-DECLARE_SOA_COLUMN(Bz, bz, float); //! Magnetic field in z-direction
+DECLARE_SOA_COLUMN(Bz, bz, float);                                              //! Magnetic field in z-direction
 DECLARE_SOA_COLUMN(HfCollisionRejectionMap, hfCollisionRejectionMap, uint16_t); //! Bitmask with failed selection criteria
 // keep track of the number of studied events (for normalization purposes)
-DECLARE_SOA_COLUMN(OriginalCollisionCount, originalCollisionCount, int); //! Size of COLLISION table processed
+DECLARE_SOA_COLUMN(OriginalCollisionCount, originalCollisionCount, int);                                                         //! Size of COLLISION table processed
 DECLARE_SOA_COLUMN(ZvtxSelectedCollisionCount, zvtxSelectedCollisionCount, int);                                                 //! Number of COLLISIONS with |zvtx| < zvtxMax
 DECLARE_SOA_COLUMN(TriggerSelectedCollisionCount, triggerSelectedCollisionCount, int);                                           //! Number of COLLISIONS with sel8
 DECLARE_SOA_COLUMN(ZvtxAndTriggerSelectedCollisionCount, zvtxAndTriggerSelectedCollisionCount, int);                             //! Number of COLLISIONS with |zvtx| < zvtxMax and sel8
@@ -516,6 +516,7 @@ DECLARE_SOA_COLUMN(YProng1, yProng1, float);     //! Rapidity of the track's pro
 DECLARE_SOA_COLUMN(EtaProng1, etaProng1, float); //! Pseudorapidity of the track's prong1
 
 DECLARE_SOA_COLUMN(PdgCodeBeautyMother, pdgCodeBeautyMother, int); //! Pdg code of beauty mother
+DECLARE_SOA_COLUMN(PdgCodeCharmMother, pdgCodeCharmMother, int);   //! Pdg code of charm mother
 DECLARE_SOA_COLUMN(PdgCodeProng0, pdgCodeProng0, int);             //! Pdg code of prong0
 DECLARE_SOA_COLUMN(PdgCodeProng1, pdgCodeProng1, int);             //! Pdg code of prong1
 DECLARE_SOA_COLUMN(PdgCodeProng2, pdgCodeProng2, int);             //! Pdg code of prong2
@@ -533,6 +534,7 @@ DECLARE_SOA_TABLE(HfMcRecRedD0Pis, "AOD", "HFMCRECREDD0PI", //! Table with recon
 // DECLARE_SOA_EXTENDED_TABLE_USER(ExTable, Tracks, "EXTABLE",
 DECLARE_SOA_TABLE(HfMcCheckD0Pis, "AOD", "HFMCCHECKD0PI", //! Table with reconstructed MC information on D0Pi(<-B0) pairs for MC checks in reduced workflow
                   hf_bplus_mc::PdgCodeBeautyMother,
+                  hf_bplus_mc::PdgCodeCharmMother,
                   hf_bplus_mc::PdgCodeProng0,
                   hf_bplus_mc::PdgCodeProng1,
                   hf_bplus_mc::PdgCodeProng2,
@@ -547,6 +549,7 @@ DECLARE_SOA_TABLE(HfMcRecRedBps, "AOD", "HFMCRECREDBP", //! Reconstruction-level
 
 DECLARE_SOA_TABLE(HfMcCheckBps, "AOD", "HFMCCHECKBP", //! Table with reconstructed MC information on B+ candidates for MC checks in reduced workflow
                   hf_bplus_mc::PdgCodeBeautyMother,
+                  hf_bplus_mc::PdgCodeCharmMother,
                   hf_bplus_mc::PdgCodeProng0,
                   hf_bplus_mc::PdgCodeProng1,
                   hf_bplus_mc::PdgCodeProng2,
@@ -687,7 +690,7 @@ DECLARE_SOA_COLUMN(Dca, dca, float);         //! DCA of V0 candidate
 DECLARE_SOA_COLUMN(Radius, radius, float);   //! Radius of V0 candidate
 DECLARE_SOA_COLUMN(V0Type, v0Type, uint8_t); //! Bitmap with mass hypothesis of the V0
 
-DECLARE_SOA_DYNAMIC_COLUMN(Px, px,           //!
+DECLARE_SOA_DYNAMIC_COLUMN(Px, px, //!
                            [](float pxProng0, float pxProng1) -> float { return 1.f * pxProng0 + 1.f * pxProng1; });
 DECLARE_SOA_DYNAMIC_COLUMN(Py, py, //!
                            [](float pyProng0, float pyProng1) -> float { return 1.f * pyProng0 + 1.f * pyProng1; });

PWGHF/D2H/TableProducer/candidateCreatorBplusReduced.cxx

@@ -200,8 +200,8 @@ struct HfCandidateCreatorBplusReduced {
           }
         }
       } // pi loop
-    }   // D0 loop
-  }     // end runCandidateCreation
+    } // D0 loop
+  } // end runCandidateCreation
 
   void processData(HfRedCollisionsWithExtras const& collisions,
                    soa::Join<aod::HfRed2Prongs, aod::HfRed2ProngsCov> const& candsD,
@@ -297,6 +297,7 @@ struct HfCandidateCreatorBplusReducedExpressions {
         filledMcInfo = true;
         if constexpr (checkDecayTypeMc) {
           rowBplusMcCheck(rowD0PiMcRec.pdgCodeBeautyMother(),
+                          rowD0PiMcRec.pdgCodeCharmMother(),
                           rowD0PiMcRec.pdgCodeProng0(),
                           rowD0PiMcRec.pdgCodeProng1(),
                           rowD0PiMcRec.pdgCodeProng2());
@@ -306,7 +307,7 @@ struct HfCandidateCreatorBplusReducedExpressions {
       if (!filledMcInfo) { // protection to get same size tables in case something went wrong: we created a candidate that was not preselected in the D0-Pi creator
         rowBplusMcRec(0, -1, -1, -1.f);
         if constexpr (checkDecayTypeMc) {
-          rowBplusMcCheck(-1, -1, -1, -1);
+          rowBplusMcCheck(-1, -1, -1, -1, -1);
         }
       }
     }

PWGHF/D2H/TableProducer/dataCreatorCharmHadPiReduced.cxx

@@ -651,7 +651,9 @@ struct HfDataCreatorCharmHadPiReduced {
           auto particleProng1 = vecDaughtersB[1].mcParticle();
           auto particleProng2 = vecDaughtersB[2].mcParticle();
           // b-hadron hypothesis
-          std::array<int, 3> bHadronMotherHypos = {Pdg::kBPlus, Pdg::kB0, Pdg::kBS};
+          std::array<int, 4> bHadronMotherHypos = {Pdg::kBPlus, Pdg::kB0, Pdg::kBS, Pdg::kLambdaB0};
+          // c-hadron hypothesis
+          std::array<int, 5> cHadronMotherHypos = {Pdg::kDPlus, Pdg::kDS, Pdg::kDStar, Pdg::kDSStar, Pdg::kLambdaCPlus};
 
           for (const auto& bHadronMotherHypo : bHadronMotherHypos) {
             int index0Mother = RecoDecay::getMother(particlesMc, particleProng0, bHadronMotherHypo, true);
@@ -667,12 +669,33 @@ struct HfDataCreatorCharmHadPiReduced {
                 pdgCodeProng0 = particleProng0.pdgCode();
                 pdgCodeProng1 = particleProng1.pdgCode();
                 pdgCodeProng2 = particleProng2.pdgCode();
+                // look for common c-hadron mother among prongs 0, 1 and 2
+                for (const auto& cHadronMotherHypo : cHadronMotherHypos) {
+                  int8_t depthMax = 2;
+                  if (cHadronMotherHypo == Pdg::kDStar || cHadronMotherHypo == Pdg::kDSStar) { // to include D* -> D π0/γ, D* -> D0 π, and Ds* -> Ds π0/γ
+                    depthMax += 1;
+                  }
+                  int index0CharmMother = RecoDecay::getMother(particlesMc, particleProng0, cHadronMotherHypo, true, &sign, depthMax);
+                  int index1CharmMother = RecoDecay::getMother(particlesMc, particleProng1, cHadronMotherHypo, true, &sign, depthMax);
+                  if (index0CharmMother > -1 && index1CharmMother > -1) {
+                    if (index0CharmMother == index1CharmMother) {
+                      // pdgCodeCharmMother =
+                      //   Pdg::kDPlus (if D+ is the mother and does not come from D*+)
+                      //   Pdg::kDPlus + Pdg::kDStar (if D+ is the mother and D*+ -> D+ π0/γ)
+                      //   Pdg::kDStar (if D*+ is the mother and D*+ -> D0 π+)
+                      //   Pdg::kDS (if Ds is the mother and does not come from Ds*)
+                      //   Pdg::kDS + Pdg::kDSStar (if Ds is the mother and Ds* -> Ds π0/γ)
+                      //   Pdg::kLambdaCPlus (if Λc+ is the mother)
+                      pdgCodeCharmMother += std::abs(particlesMc.rawIteratorAt(index0CharmMother).pdgCode());
+                    }
+                  }
+                }
                 break;
               }
             }
           }
         }
-        rowHfD0PiMcCheckReduced(pdgCodeBeautyMother, pdgCodeProng0, pdgCodeProng1, pdgCodeProng2);
+        rowHfD0PiMcCheckReduced(pdgCodeBeautyMother, pdgCodeCharmMother, pdgCodeProng0, pdgCodeProng1, pdgCodeProng2);
       }
       rowHfD0PiMcRecReduced(indexHfCandCharm, selectedTracksPion[vecDaughtersB.back().globalIndex()], flag, flagWrongCollision, debug, motherPt);
     }

PWGHF/D2H/Tasks/taskBplusReduced.cxx

@@ -148,6 +148,7 @@ DECLARE_SOA_TABLE(HfRedBpMcCheck, "AOD", "HFREDBPMCCHECK", //! Table with MC dec
                   hf_cand_bplus_lite::Pt,
                   hf_cand_bplus_lite::MlScoreSig,
                   hf_bplus_mc::PdgCodeBeautyMother,
+                  hf_bplus_mc::PdgCodeCharmMother,
                   hf_bplus_mc::PdgCodeProng0,
                   hf_bplus_mc::PdgCodeProng1,
                   hf_bplus_mc::PdgCodeProng2);
@@ -640,6 +641,7 @@ struct HfTaskBplusReduced {
             ptCandBplus,
             candidateMlScoreSig,
             candidate.pdgCodeBeautyMother(),
+            candidate.pdgCodeCharmMother(),
             candidate.pdgCodeProng0(),
             candidate.pdgCodeProng1(),
             candidate.pdgCodeProng2());