Add fitter in reco and do appropriate handling in mcharm finder

Author: jesgum

ALICE3/TableProducer/OTF/onTheFlyTracker.cxx

@@ -919,7 +919,7 @@ struct OnTheFlyTracker {
           }
         }
 
-        if (nHits[1] < fastTrackerSettings.minSiliconHits || nHits[2] < fastTrackerSettings.minSiliconHits) {
+        if (!isReco[1] || !isReco[2]) {
           tryKinkReco = true; // Lambda outside acceptance, set flag for kink reco to be used if mode 1
         }
 
@@ -1150,12 +1150,27 @@ struct OnTheFlyTracker {
               thisCascade.negativeId = -1;
             }
 
+            int nCand = 0;
+            bool kinkFitter = true;
+            try {
+              nCand = fitter.process(trackedCasc, trackedBach);
+            } catch (...) {
+              kinkFitter = false;
+            }
+
+            if (nCand == 0) {
+              kinkFitter = false;
+            }
+
+            std::array<float, 3> kinkVtx = {-999, -999, -999};
+            kinkVtx = fitter.getPCACandidatePos();
+
             thisCascade.bachelorId = lastTrackIndex + tracksAlice3.size() - isReco.size();
             thisCascade.cascadeTrackId = lastTrackIndex + tracksAlice3.size(); // this should be ok
-            thisCascade.dcaV0dau = -1.f;
-            thisCascade.v0radius = -1.f;
-            thisCascade.dcacascdau = -1.f;            // Fix me
-            thisCascade.cascradius = xiDecayRadius2D; // Fix me
+            thisCascade.dcaV0dau = -1.f;                                       // unknown
+            thisCascade.v0radius = -1.f;                                       // unknown
+            thisCascade.dcacascdau = std::sqrt(fitter.getChi2AtPCACandidate());
+            thisCascade.cascradius = std::hypot(kinkVtx[0], kinkVtx[1]);
             thisCascade.cascradiusMC = xiDecayRadius2D;
             thisCascade.mLambda = o2::constants::physics::MassLambda;
             thisCascade.findableClusters = nCascHits;
@@ -1164,7 +1179,7 @@ struct OnTheFlyTracker {
                                                       std::array{pV0[0], pV0[1], pV0[2]}},
                                            std::array{o2::constants::physics::MassPionCharged, o2::constants::physics::MassLambda});
 
-            tracksAlice3.push_back(TrackAlice3{cascadeTrack, mcParticle.globalIndex(), time, timeResolutionUs, false, false, 1, thisCascade.foundClusters});
+            tracksAlice3.push_back(TrackAlice3{trackedCasc, mcParticle.globalIndex(), time, timeResolutionUs, false, false, 1, thisCascade.foundClusters});
 
             // add this cascade to vector (will fill cursor later with collision ID)
             cascadesAlice3.push_back(thisCascade);

ALICE3/TableProducer/alice3MulticharmFinder.cxx

@@ -200,6 +200,13 @@ struct Alice3MulticharmFinder {
     int nTPCHitsPiCC;
   } thisXiCCcandidate;
 
+  struct ProngInfo {
+    float pt = 1e+10;
+    float eta = 1e+10;
+    float dcaXY = 1e+10;
+    float dcaZ = 1e+10;
+  };
+
   template <typename TTrackType>
   bool buildDecayCandidateTwoBody(TTrackType const& t0, TTrackType const& t1, float mass0, float mass1)
   {
@@ -557,10 +564,6 @@ struct Alice3MulticharmFinder {
       }
 
       uint32_t nCombinationsC = 0;
-      auto bach = xiCand.bachTrack_as<Alice3Tracks>(); // de-reference bach track
-      auto neg = xiCand.negTrack_as<Alice3Tracks>();   // de-reference neg track
-      auto pos = xiCand.posTrack_as<Alice3Tracks>();   // de-reference pos track
-
       if (!BIT_CHECK(xi.decayMap(), kTrueXiFromXiC)) {
         continue;
       }
@@ -822,13 +825,39 @@ struct Alice3MulticharmFinder {
                 picc.hasSigPi(), picc.nSigmaPionRich(),
                 getPdgCodeForTrack(picc));
 
+
+              ProngInfo bachelor, positive, negative;
+              if (xiCand.has_bachTrack()) {
+                auto bach = xiCand.bachTrack_as<Alice3Tracks>(); // de-reference bach track
+                bachelor.pt = bach.pt();
+                bachelor.eta = bach.eta();
+                bachelor.dcaXY = bach.dcaXY();
+                bachelor.dcaZ = bach.dcaZ();
+              }
+              
+              if (xiCand.has_negTrack()) {
+                auto neg = xiCand.negTrack_as<Alice3Tracks>();   // de-reference neg track
+                negative.pt = neg.pt();
+                negative.eta = neg.eta();
+                negative.dcaXY = neg.dcaXY();
+                negative.dcaZ = neg.dcaZ();
+              }
+              
+              if (xiCand.has_posTrack()) {
+                auto pos = xiCand.posTrack_as<Alice3Tracks>();   // de-reference pos track
+                positive.pt = pos.pt();
+                positive.eta = pos.eta();
+                positive.dcaXY = pos.dcaXY();
+                positive.dcaZ = pos.dcaZ();
+              }
+
               multiCharmExtra(
-                bach.pt(), bach.eta(),
-                bach.dcaXY(), bach.dcaZ(),
-                pos.pt(), pos.eta(),
-                pos.dcaXY(), pos.dcaZ(),
-                neg.pt(), neg.eta(),
-                neg.dcaXY(), neg.dcaZ(),
+                bachelor.pt, bachelor.eta,
+                bachelor.dcaXY, bachelor.dcaZ,
+                positive.pt, positive.eta,
+                positive.dcaXY, positive.dcaZ,
+                negative.pt, negative.eta,
+                negative.dcaXY, negative.dcaZ,
                 pi1c.eta(), pi2c.eta(), picc.eta());
             }
           }