[PWGHF,Trigger] Add option to select only signal in MC and improve MC matching (AliceO2Group#9801)

Author: fgrosa

EventFiltering/PWGHF/HFFilterPrepareMLSamples.cxx

@@ -55,7 +55,7 @@ struct HfFilterPrepareMlSamples { // Main struct
   Produces<aod::HFTrigTrain3P> train3P;
 
   // parameters for production of training samples
-  Configurable<bool> fillSignal{"fillSignal", true, "Flag to fill derived tables with signal for ML trainings"};
+  Configurable<bool> fillOnlySignal{"fillOnlySignal", true, "Flag to fill derived tables with signal for ML trainings"};
   Configurable<bool> fillOnlyBackground{"fillOnlyBackground", true, "Flag to fill derived tables with background for ML trainings"};
   Configurable<float> downSampleBkgFactor{"downSampleBkgFactor", 1., "Fraction of background candidates to keep for ML trainings"};
   Configurable<float> massSbLeftMin{"massSbLeftMin", 1.72, "Left Sideband Lower Minv limit 2 Prong"};
@@ -78,6 +78,10 @@ struct HfFilterPrepareMlSamples { // Main struct
 
   void init(InitContext&)
   {
+    if (fillOnlySignal && fillOnlyBackground) {
+      LOGP(fatal, "fillOnlySignal and fillOnlyBackground cannot be activated simultaneously, exit");
+    }
+
     ccdb->setURL(url.value);
     ccdb->setCaching(true);
     ccdb->setLocalObjectValidityChecking();
@@ -268,7 +272,15 @@ struct HfFilterPrepareMlSamples { // Main struct
 
       // D0(bar) → π± K∓
       bool isInCorrectColl{false};
-      auto indexRec = RecoDecay::getMatchedMCRec(mcParticles, std::array{trackPos, trackNeg}, o2::constants::physics::Pdg::kD0, std::array{+kPiPlus, -kKPlus}, true, &sign);
+      auto indexRec = RecoDecay::getMatchedMCRec<false, false, false, true, true>(mcParticles, std::array{trackPos, trackNeg}, o2::constants::physics::Pdg::kD0, std::array{+kPiPlus, -kKPlus}, true, &sign);
+
+      if (fillOnlySignal && indexRec < 0) {
+        continue;
+      }
+      if (fillOnlyBackground && indexRec >= 0) {
+        continue;
+      }
+
       if (indexRec > -1) {
         auto particle = mcParticles.rawIteratorAt(indexRec);
         flag = RecoDecay::getCharmHadronOrigin(mcParticles, particle);
@@ -355,32 +367,39 @@ struct HfFilterPrepareMlSamples { // Main struct
       int8_t channel = -1;
 
       // D± → π± K∓ π±
-      auto indexRec = RecoDecay::getMatchedMCRec(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kDPlus, std::array{+kPiPlus, -kKPlus, +kPiPlus}, true, &sign, 2);
+      auto indexRec = RecoDecay::getMatchedMCRec<false, false, false, true, true>(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kDPlus, std::array{+kPiPlus, -kKPlus, +kPiPlus}, true, &sign, 2);
       if (indexRec >= 0) {
         channel = kDplus;
       }
       if (indexRec < 0) {
         // Ds± → K± K∓ π±
-        indexRec = RecoDecay::getMatchedMCRec(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kDS, std::array{+kKPlus, -kKPlus, +kPiPlus}, true, &sign, 2);
+        indexRec = RecoDecay::getMatchedMCRec<false, false, false, true, true>(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kDS, std::array{+kKPlus, -kKPlus, +kPiPlus}, true, &sign, 2);
         if (indexRec >= 0) {
           channel = kDs;
         }
       }
       if (indexRec < 0) {
         // Λc± → p± K∓ π±
-        indexRec = RecoDecay::getMatchedMCRec(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kLambdaCPlus, std::array{+kProton, -kKPlus, +kPiPlus}, true, &sign, 2);
+        indexRec = RecoDecay::getMatchedMCRec<false, false, false, true, true>(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kLambdaCPlus, std::array{+kProton, -kKPlus, +kPiPlus}, true, &sign, 2);
         if (indexRec >= 0) {
           channel = kLc;
         }
       }
       if (indexRec < 0) {
         // Ξc± → p± K∓ π±
-        indexRec = RecoDecay::getMatchedMCRec(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kXiCPlus, std::array{+kProton, -kKPlus, +kPiPlus}, true, &sign, 2);
+        indexRec = RecoDecay::getMatchedMCRec<false, false, false, true, true>(mcParticles, arrayDaughters, o2::constants::physics::Pdg::kXiCPlus, std::array{+kProton, -kKPlus, +kPiPlus}, true, &sign, 2);
         if (indexRec >= 0) {
           channel = kXic;
         }
       }
 
+      if (fillOnlySignal && indexRec < 0) {
+        continue;
+      }
+      if (fillOnlyBackground && indexRec >= 0) {
+        continue;
+      }
+
       bool isInCorrectColl{false};
       if (indexRec > -1) {
         auto particle = mcParticles.rawIteratorAt(indexRec);