Properly treat pi0 in matching to MC

Author: fgrosa

PWGHF/TableProducer/candidateCreatorDstar.cxx

@@ -650,15 +650,27 @@ struct HfCandidateCreatorDstarExpressions {
         if (indexRecDstar > -1) {
           // D*± → D0(bar) π± π0
           auto motherParticleDstar = mcParticles.rawIteratorAt(indexRecDstar);
-          if (RecoDecay::isMatchedMCGen(mcParticles, motherParticleDstar, Pdg::kDStar, std::array{+kPiPlus, +kPiPlus, -kKPlus, +kPi0}, true, &signDstar, 2)) {
-            flagDstar = signDstar * (BIT(aod::hf_cand_dstar::DecayType::DstarToD0PiPi0));
+          if (signDstar > 0) {
+            if (RecoDecay::isMatchedMCGen(mcParticles, motherParticleDstar, Pdg::kDStar, std::array{+kPiPlus, +kPiPlus, -kKPlus, +kPi0}, false, &signDstar, 2)) {
+              flagDstar = signDstar * (BIT(aod::hf_cand_dstar::DecayType::DstarToD0PiPi0));
+            }
+          } else {
+            if (RecoDecay::isMatchedMCGen(mcParticles, motherParticleDstar, -Pdg::kDStar, std::array{-kPiPlus, -kPiPlus, +kKPlus, +kPi0}, false, &signDstar, 2)) {
+              flagDstar = signDstar * (BIT(aod::hf_cand_dstar::DecayType::DstarToD0PiPi0));
+            }
           }
         }
         if (indexRecD0 > -1) {
           // D0(bar) → π± K∓ π0
           auto motherParticleD0 = mcParticles.rawIteratorAt(indexRecD0);
-          if (RecoDecay::isMatchedMCGen(mcParticles, motherParticleD0, Pdg::kD0, std::array{+kPiPlus, -kKPlus, +kPi0}, true, &signD0)) {
-            flagD0 = signD0 * (BIT(aod::hf_cand_dstar::DecayType::D0ToPiKPi0));
+          if (signD0 > 0) {
+            if (RecoDecay::isMatchedMCGen(mcParticles, motherParticleD0, Pdg::kD0, std::array{+kPiPlus, -kKPlus, +kPi0}, false, &signD0)) {
+              flagD0 = signD0 * (BIT(aod::hf_cand_dstar::DecayType::D0ToPiKPi0));
+            }
+          } else {
+            if (RecoDecay::isMatchedMCGen(mcParticles, motherParticleD0, -Pdg::kD0, std::array{-kPiPlus, +kKPlus, +kPi0}, false, &signD0)) {
+              flagD0 = signD0 * (BIT(aod::hf_cand_dstar::DecayType::D0ToPiKPi0));
+            }
           }
         }
       }