[PWGHF] Add downsample for real data in Lc derived-data creator (#11914)

Co-authored-by: Vít Kučera <vit.kucera@cern.ch>

Author: Mingyu3360715

PWGHF/TableProducer/derivedDataCreatorLcToPKPi.cxx

@@ -87,7 +87,7 @@ struct HfDerivedDataCreatorLcToPKPi {
 
   HfHelper hfHelper;
   SliceCache cache;
-  static constexpr double mass{o2::constants::physics::MassLambdaCPlus};
+  static constexpr double Mass{o2::constants::physics::MassLambdaCPlus};
 
   using CollisionsWCentMult = soa::Join<aod::Collisions, aod::CentFV0As, aod::CentFT0Ms, aod::CentFT0As, aod::CentFT0Cs, aod::PVMultZeqs>;
   using CollisionsWMcCentMult = soa::Join<aod::Collisions, aod::McCollisionLabels, aod::CentFV0As, aod::CentFT0Ms, aod::CentFT0As, aod::CentFT0Cs, aod::PVMultZeqs>;
@@ -280,6 +280,13 @@ struct HfDerivedDataCreatorLcToPKPi {
               continue;
             }
           }
+        } else {
+          if (downSampleBkgFactor < 1.) {
+            float pseudoRndm = candidate.ptProng0() * 1000. - static_cast<int64_t>(candidate.ptProng0() * 1000);
+            if (candidate.pt() < ptMaxForDownSample && pseudoRndm >= downSampleBkgFactor) {
+              continue;
+            }
+          }
         }
         double ct = hfHelper.ctLc(candidate);
         double y = hfHelper.yLc(candidate);
@@ -318,7 +325,7 @@ struct HfDerivedDataCreatorLcToPKPi {
   {
     rowsCommon.preProcessMcCollisions(mcCollisions, mcParticlesPerMcCollision, mcParticles);
     processCandidates<false, true, false, true>(collisions, candidatesMcSig, tracks, bcs);
-    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, mass);
+    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, Mass);
   }
   PROCESS_SWITCH(HfDerivedDataCreatorLcToPKPi, processMcSig, "Process MC only for signals", false);
 
@@ -331,7 +338,7 @@ struct HfDerivedDataCreatorLcToPKPi {
   {
     rowsCommon.preProcessMcCollisions(mcCollisions, mcParticlesPerMcCollision, mcParticles);
     processCandidates<false, true, true, false>(collisions, candidatesMcBkg, tracks, bcs);
-    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, mass);
+    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, Mass);
   }
   PROCESS_SWITCH(HfDerivedDataCreatorLcToPKPi, processMcBkg, "Process MC only for background", false);
 
@@ -344,7 +351,7 @@ struct HfDerivedDataCreatorLcToPKPi {
   {
     rowsCommon.preProcessMcCollisions(mcCollisions, mcParticlesPerMcCollision, mcParticles);
     processCandidates<false, true, false, false>(collisions, candidatesMcAll, tracks, bcs);
-    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, mass);
+    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, Mass);
   }
   PROCESS_SWITCH(HfDerivedDataCreatorLcToPKPi, processMcAll, "Process MC", false);
 
@@ -368,7 +375,7 @@ struct HfDerivedDataCreatorLcToPKPi {
   {
     rowsCommon.preProcessMcCollisions(mcCollisions, mcParticlesPerMcCollision, mcParticles);
     processCandidates<true, true, false, true>(collisions, candidatesMcMlSig, tracks, bcs);
-    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, mass);
+    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, Mass);
   }
   PROCESS_SWITCH(HfDerivedDataCreatorLcToPKPi, processMcMlSig, "Process MC with ML only for signals", false);
 
@@ -381,7 +388,7 @@ struct HfDerivedDataCreatorLcToPKPi {
   {
     rowsCommon.preProcessMcCollisions(mcCollisions, mcParticlesPerMcCollision, mcParticles);
     processCandidates<true, true, true, false>(collisions, candidatesMcMlBkg, tracks, bcs);
-    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, mass);
+    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, Mass);
   }
   PROCESS_SWITCH(HfDerivedDataCreatorLcToPKPi, processMcMlBkg, "Process MC with ML only for background", false);
 
@@ -394,14 +401,14 @@ struct HfDerivedDataCreatorLcToPKPi {
   {
     rowsCommon.preProcessMcCollisions(mcCollisions, mcParticlesPerMcCollision, mcParticles);
     processCandidates<true, true, false, false>(collisions, candidatesMcMlAll, tracks, bcs);
-    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, mass);
+    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, Mass);
   }
   PROCESS_SWITCH(HfDerivedDataCreatorLcToPKPi, processMcMlAll, "Process MC with ML", false);
 
   void processMcGenOnly(TypeMcCollisions const& mcCollisions,
                         MatchedGenCandidatesMc const& mcParticles)
   {
-    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, mass);
+    rowsCommon.processMcParticles(mcCollisions, mcParticlesPerMcCollision, mcParticles, Mass);
   }
   PROCESS_SWITCH(HfDerivedDataCreatorLcToPKPi, processMcGenOnly, "Process MC gen. only", false);
 };