add best knowldge of collision time in tof matching info (#14615)

Author: noferini

DataFormats/Reconstruction/include/ReconstructionDataFormats/MatchInfoTOF.h

@@ -86,6 +86,14 @@ class MatchInfoTOF
                       hasT0_1BCbefore = 0x1 << 8,
                       hasT0_2BCbefore = 0x1 << 9 };
 
+  void setFT0Best(double val, float res = 200.)
+  {
+    mFT0Best = val;
+    mFT0BestRes = res;
+  }
+  double getFT0Best() const { return mFT0Best; }
+  float getFT0BestRes() const { return mFT0BestRes; }
+
  private:
   int mIdLocal;                      // track id in sector of the pair track-TOFcluster
   float mChi2;                       // chi2 of the pair track-TOFcluster
@@ -106,7 +114,10 @@ class MatchInfoTOF
   float mTgeant = 0.0;        ///< geant time in MC
   double mT0true = 0.0;       ///< t0true
 
-  ClassDefNV(MatchInfoTOF, 8);
+  double mFT0Best = 0.0;     //< best info for collision time
+  float mFT0BestRes = 200.0; //< resolution (in ps) of the best info for collision time
+
+  ClassDefNV(MatchInfoTOF, 9);
 };
 } // namespace dataformats
 } // namespace o2

Detectors/GlobalTracking/src/MatchTOF.cxx

@@ -1581,6 +1581,8 @@ void MatchTOF::doMatchingForTPC(int sec)
 //______________________________________________
 int MatchTOF::findFITIndex(int bc, const gsl::span<const o2::ft0::RecPoints>& FITRecPoints, unsigned long firstOrbit)
 {
+  const auto& FT0Params = o2::ft0::InteractionTag::Instance();
+
   if ((!mHasFillScheme) && o2::tof::Utils::hasFillScheme()) {
     mHasFillScheme = true;
     for (int ibc = 0; ibc < o2::tof::Utils::getNinteractionBC(); ibc++) {
@@ -1598,6 +1600,10 @@ int MatchTOF::findFITIndex(int bc, const gsl::span<const o2::ft0::RecPoints>& FI
   const int distThr = 8;
 
   for (unsigned int i = 0; i < FITRecPoints.size(); i++) {
+    const auto& ft = FITRecPoints[i];
+    if (!FT0Params.isSelected(ft)) {
+      continue;
+    }
     const o2::InteractionRecord ir = FITRecPoints[i].getInteractionRecord();
     if (mHasFillScheme && !mFillScheme[ir.bc]) {
       continue;
@@ -1702,8 +1708,8 @@ void MatchTOF::BestMatches(std::vector<o2::dataformats::MatchInfoTOFReco>& match
     matchingPair.setT0true(TOFClusWork[matchingPair.getTOFClIndex()].getT0true());
 
     // let's check if cluster has multiple-hits (noferini)
-    if (TOFClusWork[matchingPair.getTOFClIndex()].getNumOfContributingChannels() > 1) {
-      const auto& tofcl = TOFClusWork[matchingPair.getTOFClIndex()];
+    const auto& tofcl = TOFClusWork[matchingPair.getTOFClIndex()];
+    if (tofcl.getNumOfContributingChannels() > 1) {
       // has an additional hit Up or Down (Z-dir)
       matchingPair.setHitPatternUpDown(tofcl.isAdditionalChannelSet(o2::tof::Cluster::kUp) ||
                                        tofcl.isAdditionalChannelSet(o2::tof::Cluster::kUpLeft) ||
@@ -1719,6 +1725,19 @@ void MatchTOF::BestMatches(std::vector<o2::dataformats::MatchInfoTOFReco>& match
                                           tofcl.isAdditionalChannelSet(o2::tof::Cluster::kDownRight) ||
                                           tofcl.isAdditionalChannelSet(o2::tof::Cluster::kUpRight));
     }
+
+    // estimate collision time using FT0 info if available
+    ULong64_t bclongtofCal = (matchingPair.getSignal() - 10000) * o2::tof::Geo::BC_TIME_INPS_INV;
+    double t0Best = bclongtofCal * o2::tof::Geo::BC_TIME_INPS; // here just BC
+    float t0BestRes = 200;
+    if (FITRecPoints.size() > 0) {
+      int index = findFITIndex(bclongtofCal, FITRecPoints, mFirstTForbit);
+      if (index > -1 && FITRecPoints[index].isValidTime(1) && FITRecPoints[index].isValidTime(2)) { // require A and C
+        t0Best += FITRecPoints[index].getCollisionTime(0);
+        t0BestRes = 15;
+      }
+    }
+    matchingPair.setFT0Best(t0Best, t0BestRes);
     matchedTracks[trkTypeSplitted].push_back(matchingPair); // array of MatchInfoTOF
 
     // get fit info

Detectors/GlobalTrackingWorkflow/src/tof-matcher-workflow.cxx

@@ -114,9 +114,9 @@ WorkflowSpec defineDataProcessing(ConfigContext const& configcontext)
     }
   }
 
-  if (!writecalib) {
-    useFIT = false;
-  }
+  //  if (!writecalib) {
+  //    useFIT = false;
+  //  }
 
   LOG(debug) << "TOF MATCHER WORKFLOW configuration";
   LOG(debug) << "TOF track inputs = " << configcontext.options().get<std::string>("track-sources");