fix index for bkg candidates and do not skip them to avoid jump in invariant mass distribution

Author: Chiara De Martin

PWGLF/TableProducer/Strangeness/cascadeflow.cxx

@@ -1552,15 +1552,15 @@ struct cascadeFlow {
         histos.fill(HIST("hLambdaCandidate"), 2);
         if (v0.mLambda() > V0Configs.MinMassLambda && v0.mLambda() < V0Configs.MaxMassLambda && v0.mAntiLambda() > V0Configs.MinMassLambda && v0.mAntiLambda() < V0Configs.MaxMassLambda) {
           histos.fill(HIST("hLambdaCandidate"), 3);
-          continue; // in case of ambiguity between Lambda and AntiLambda, I skip the particle
+          continue; // in case of ambiguity between Lambda and AntiLambda, I skip the particle; checked to be zero in range 1.105 - 1.125
         }
         if (v0.mLambda() > V0Configs.MinMassLambda && v0.mLambda() < V0Configs.MaxMassLambda)
           chargeIndex = 0;
         else if (v0.mAntiLambda() > V0Configs.MinMassLambda && v0.mAntiLambda() < V0Configs.MaxMassLambda)
           chargeIndex = 1;
         else {
+	  chargeIndex = 2; //these are bkg candidates
           histos.fill(HIST("hLambdaCandidate"), 4);
-          continue; // in case of ambiguity between Lambda and AntiLambda, I skip the particle
         }
       }
       if (!isSelectedV0[0] && !isSelectedV0[1])
@@ -1601,10 +1601,14 @@ struct cascadeFlow {
         pzs2Lambda = cosThetaStarProton[0] * std::sin(2 * (v0.phi() - psiT0C)) / lambdav2::AlphaLambda[0] / meanCos2ThetaProtonFromLambda;
         cos2ThetaLambda = cosThetaStarProton[0] * cosThetaStarProton[0];
         cosThetaLambda = cosThetaStarProton[0] / cascadev2::AlphaLambda[0] / meanCos2ThetaProtonFromLambda;
-      } else {
+      } else if (chargeIndex ==1) {
         pzs2Lambda = cosThetaStarProton[1] * std::sin(2 * (v0.phi() - psiT0C)) / lambdav2::AlphaLambda[1] / meanCos2ThetaProtonFromLambda;
         cos2ThetaLambda = cosThetaStarProton[1] * cosThetaStarProton[1];
         cosThetaLambda = cosThetaStarProton[1] / cascadev2::AlphaLambda[1] / meanCos2ThetaProtonFromLambda;
+      } else { //I treat these bkg candidates as Lambdas for the purpose of calculating Pz
+        pzs2Lambda = cosThetaStarProton[0] * std::sin(2 * (v0.phi() - psiT0C)) / lambdav2::AlphaLambda[0] / meanCos2ThetaProtonFromLambda;
+        cos2ThetaLambda = cosThetaStarProton[0] * cosThetaStarProton[0];
+        cosThetaLambda = cosThetaStarProton[0] / cascadev2::AlphaLambda[0] / meanCos2ThetaProtonFromLambda;
       }
 
       histos.fill(HIST("hv2CEPvsFT0C"), coll.centFT0C(), v2CEP);