PWGJE: Implementation of a tree creator for b-jets (AliceO2Group#6208)

* Implementation of a code for b-jet analysis

* Updating the code

* Removing jet substructure part

Author: hahassan7

PWGJE/Core/JetTaggingUtilities.h

@@ -30,6 +30,7 @@
 #include "TF1.h"
 #include "Framework/Logger.h"
 #include "Common/Core/RecoDecay.h"
+#include "Common/Core/trackUtilities.h"
 #include "PWGJE/Core/JetUtilities.h"
 
 enum JetTaggingSpecies {
@@ -149,7 +150,7 @@ int jetParticleFromHFShower(T const& jet, U const& particles, typename U::iterat
 {
 
   int origin = -1;
-  for (auto& particle : jet.template tracks_as<U>()) {
+  for (const auto& particle : jet.template tracks_as<U>()) {
     origin = RecoDecay::getCharmHadronOrigin(particles, particle, true);
     if (origin == 1 || origin == 2) { // 1=charm , 2=beauty
       hfparticle = particle;
@@ -213,7 +214,7 @@ int mcdJetFromHFShower(T const& jet, U const& tracks, V const& particles, float
  * @param dRMax maximum distance in eta-phi of initiating heavy-flavour quark from the jet axis
  */
 
-template <typename T, typename U, typename V>
+template <typename T, typename U>
 int mcpJetFromHFShower(T const& jet, U const& particles, float dRMax = 0.25)
 {
 
@@ -282,6 +283,46 @@ int jetOrigin(T const& jet, U const& particles, float dRMax = 0.25)
   return 0;
 }
 
+/**
+ * return the jet flavor: 0 for lf-jet, 1 for c-jet, 2 for b-jet
+ *
+ * @param AnyJet the jet that we need to study its flavor
+ * @param AllMCParticles a vector of all the mc particles stack
+ */
+template <typename AnyJet, typename AllMCParticles>
+int16_t getJetFlavor(AnyJet const& jet, AllMCParticles const& mcparticles)
+{
+  const int arraySize = 99;
+
+  std::array<int, arraySize> countpartcode;
+  int count = 0;
+
+  for (auto& mcpart : mcparticles) {
+    int pdgcode = mcpart.pdgCode();
+    if (TMath::Abs(pdgcode) == 21 || (TMath::Abs(pdgcode) >= 1 && TMath::Abs(pdgcode) <= 5)) {
+      double dR = jetutilities::deltaR(jet, mcpart);
+
+      if (dR < jet.r() / 100.f) {
+        if (TMath::Abs(pdgcode) == 5) {
+          return 2; // Beauty jet
+        } else {
+          if (count > arraySize - 1)
+            return 0;
+          countpartcode[count] = pdgcode;
+          count++;
+        }
+      }
+    }
+  }
+
+  for (int ij = 0; ij < count; ij++) {
+    if (TMath::Abs(countpartcode[ij]) == 4)
+      return 1; // Charm jet
+  }
+
+  return 0; // Light flavor jet
+}
+
 /**
  * return geometric sign which is calculated scalar product between jet axis with DCA (track propagated to PV )
  * positive and negative value are expected from primary vertex

PWGJE/Tasks/CMakeLists.txt

@@ -152,4 +152,9 @@ if(FastJet_FOUND)
                         SOURCES jetChCorr.cxx
                         PUBLIC_LINK_LIBRARIES O2::Framework O2Physics::PWGJECore O2Physics::AnalysisCore
                         COMPONENT_NAME Analysis)
+    o2physics_add_dpl_workflow(bjet-tree-creator
+                        SOURCES bjetTreeCreator.cxx
+                        PUBLIC_LINK_LIBRARIES O2::Framework O2Physics::PWGJECore O2Physics::AnalysisCore
+                        COMPONENT_NAME Analysis)
+
 endif()