Study: add SV prong and V0 output

Signed-off-by: Felix Schlepper <felix.schlepper@cern.ch>

Author: f3sch

Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/TrackMCStudy.h

@@ -20,7 +20,7 @@ namespace o2::trackstudy
 {
 
 /// create a processor spec
-o2::framework::DataProcessorSpec getTrackMCStudySpec(o2::dataformats::GlobalTrackID::mask_t srcTracks, o2::dataformats::GlobalTrackID::mask_t srcClus, bool checkSV);
+o2::framework::DataProcessorSpec getTrackMCStudySpec(o2::dataformats::GlobalTrackID::mask_t srcTracks, o2::dataformats::GlobalTrackID::mask_t srcClus, bool checkSV, bool useCCDBParams, bool enableCasc, bool enable3body);
 
 } // namespace o2::trackstudy
 

Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/TrackMCStudyConfig.h

@@ -13,6 +13,7 @@
 #define O2_TRACKING_STUDY_CONFIG_H
 #include "CommonUtils/ConfigurableParam.h"
 #include "CommonUtils/ConfigurableParamHelper.h"
+#include <vector>
 
 namespace o2::trackstudy
 {
@@ -33,9 +34,13 @@ struct TrackMCStudyConfig : o2::conf::ConfigurableParamHelper<TrackMCStudyConfig
   int nOccBinsDrift = 10; // number of bins for TPC max drift time, where we integrate the occupancies
   int nTBPerOccBin = 48;  // number of TB per occ bin
   float rejectClustersResStat = 0.1;
-  float maxTPCRefExtrap = 2;                   // max dX to extrapolate the track ref when extrapolating track true posions
-  int minITSClForITSoutput = 7;                // create special ITS otput only for long enough tracks
-  int decayPDG[5] = {310, 3122, 411, 421, -1}; // decays to study, must end by -1
+  float maxTPCRefExtrap = 2;                         // max dX to extrapolate the track ref when extrapolating track true posions
+  int minITSClForITSoutput = 7;                      // create special ITS otput only for long enough tracks
+  std::vector<int> decayPDG = {310, 3122, 411, 421}; // decays to study, matched on |PDG|
+  std::vector<int> selectMCPDG = {};                 // if non-empty, only MC tracks with exactly these PDG codes are collected
+  bool checkSVertexerCuts = true;                    // replay the SVertexer V0 selection on the prongs of decays
+  bool storeRecSV = true;                            // store all reconstructed V0s with the MC origin of their prongs
+  float recSVSamplingFrac = 1.f;                     // fraction of combinatorial reconstructed V0s to store, true decays are always kept
   O2ParamDef(TrackMCStudyConfig, "trmcconf");
 };
 } // namespace o2::trackstudy

Detectors/GlobalTrackingWorkflow/study/include/GlobalTrackingStudy/TrackMCStudyTypes.h

@@ -19,6 +19,7 @@
 #include "CommonConstants/LHCConstants.h"
 #include "CommonDataFormat/TimeStamp.h"
 #include "ReconstructionDataFormats/PrimaryVertex.h"
+#include "ReconstructionDataFormats/V0.h"
 #include "SimulationDataFormat/TrackReference.h"
 #include <array>
 #include <vector>
@@ -320,5 +321,77 @@ struct MCVertex {
   ClassDefNV(MCVertex, 2);
 };
 
+/// State of one prong of a MC decay with respect to the SVertexer seeds pool.
+/// A prong which was reconstructed but never made it into the pool can never form a V0,
+/// whatever the pair cuts do, so this has to be checked before interpreting SVCheck::rejV0.
+struct SVProngInfo {
+  o2::dataformats::VtxTrackIndex gid; // reco track used as this prong, unset if not reconstructed
+  int32_t poolEntry = -1;             // entry in the SVertexer seeds pool, -1 if not seeded
+  int8_t poolSide = -1;               // SVertexer::POS / SVertexer::NEG
+  int32_t vBrMin = -1;                // vertex bracket of the seed
+  int32_t vBrMax = -1;
+  float minR = -1.f;   // lowest radial point of the seed, used by the causality cut
+  uint8_t seedRej = 0; // SVertexer::SeedRej, why the track never entered the pool
+  int8_t nITSclu = -1;
+  bool hasTPC = false;
+
+  bool isReconstructed() const { return gid.isSourceSet(); }
+  bool isSeeded() const { return poolEntry >= 0; }
+
+  ClassDefNV(SVProngInfo, 1);
+};
+
+/// Why a MC decay was or was not reconstructed as a V0 by the SVertexer.
+/// stage says how far the decay got, and only if it reached CutRejected is rejV0 meaningful.
+struct SVCheck {
+  enum Stage : int8_t {
+    NotChecked = -1,  // SV checking disabled or decay not eligible
+    NoProngs,         // at least one prong has no reconstructed track at all
+    NotSeeded,        // a prong was reconstructed but rejected before the seeds pool, see prong seedRej
+    SameCharge,       // prongs did not end up as one positive and one negative seed
+    NoBracketOverlap, // seeds share no primary vertex, so the pair is never even tried
+    CutRejected,      // the pair was tried and rejected, see rejV0
+    Found             // the pair passes the SVertexer selection
+  };
+  std::array<SVProngInfo, 2> prongs{};
+  int foundSVID = -1;           // reconstructed V0 matched to this decay by MC labels, -1 if none
+  int8_t stage = NotChecked;    // Stage
+  uint8_t rejV0 = 0;            // SVertexer::V0Rej, only if stage == CutRejected
+  bool pairInReco = false;      // the reconstruction built a V0 out of exactly the two prongs replayed
+  bool replayConsistent = true; // false if the replay verdict differs from pairInReco
+
+  bool isReconstructed() const { return foundSVID >= 0; }
+
+  bool isFound() const { return stage == Found; }
+  bool bothProngsReconstructed() const { return prongs[0].isReconstructed() && prongs[1].isReconstructed(); }
+  bool bothProngsSeeded() const { return prongs[0].isSeeded() && prongs[1].isSeeded(); }
+
+  ClassDefNV(SVCheck, 1);
+};
+
+/// A reconstructed V0 together with the MC origin of its prongs, to study the composition of
+/// the sample: which V0s are real decays and which are combinatorial.
+struct RecSVInfo {
+  enum Kind : int8_t {
+    Unknown = -1,     // MC information unavailable for at least one prong
+    TrueDecay,        // both prongs are daughters of the same MC mother
+    DifferentMothers, // prongs come from unrelated MC particles, i.e. combinatorial
+    FakeProng         // at least one prong track has a fake MC label
+  };
+  o2::dataformats::V0 v0;
+  o2::dataformats::V0Index v0ID{};
+  std::array<o2::MCCompLabel, 2> prongLbl{};
+  std::array<int, 2> prongPDG{0, 0};
+  int mcMotherPDG = 0;       // PDG of the common mother, 0 if there is none
+  int mcMotherEntry = -1;    // entry in the decays pool of mcMotherDecID, -1 if not checked
+  int8_t mcMotherDecID = -1; // which decay type the pool of mcMotherEntry refers to
+  int8_t kind = Unknown;     // Kind
+
+  bool isTrueDecay() const { return kind == TrueDecay; }
+  bool isCheckedDecay() const { return mcMotherEntry >= 0; }
+
+  ClassDefNV(RecSVInfo, 1);
+};
+
 } // namespace o2::trackstudy
 #endif

Detectors/GlobalTrackingWorkflow/study/src/GlobalTrackingStudyLinkDef.h

@@ -43,6 +43,13 @@
 #pragma link C++ class o2::trackstudy::ITSHitInfo + ;
 #pragma link C++ class std::vector < o2::trackstudy::ITSHitInfo> + ;
 
+#pragma link C++ class o2::trackstudy::SVProngInfo + ;
+#pragma link C++ class std::vector < o2::trackstudy::SVProngInfo> + ;
+#pragma link C++ class o2::trackstudy::SVCheck + ;
+#pragma link C++ class std::vector < o2::trackstudy::SVCheck> + ;
+#pragma link C++ class o2::trackstudy::RecSVInfo + ;
+#pragma link C++ class std::vector < o2::trackstudy::RecSVInfo> + ;
+
 #pragma link C++ class o2::checkresid::Point + ;
 #pragma link C++ class std::vector < o2::checkresid::Point> + ;
 #pragma link C++ class o2::checkresid::Track + ;