[MUON] use track time in global muon matching

Added option for using the track time when selecting the MFT candidates
to be matched with a given MCH track.
This helps to reduce the number of candidates when the MCH track is
already matched with MID and therefore has a precise timing.
In this case the number of MCH tracks that need to be combined with
MFT tracks from two adjacent ROFs is strongly reduced.

Author: aferrero2707

Detectors/GlobalTracking/include/GlobalTracking/MatchGlobalFwd.h

@@ -339,6 +339,7 @@ class MatchGlobalFwd
   o2::itsmft::ChipMappingMFT mMFTMapping;
   bool mMCTruthON = false;      ///< Flag availability of MC truth
   bool mUseMIDMCHMatch = false; ///< Flag for using MCHMID matches (TrackMCHMID)
+  bool mUseTrackTime = false;   ///< Flag for using the MCH or MCHMID track time information to select the MFT ROF(s)
   int mSaveMode = 0;            ///< Output mode [0 = SaveBestMatch; 1 = SaveAllMatches; 2 = SaveTrainingData; 3 = SaveNCandidates]
   int mNCandidates = 5;         ///< Numbers of matching candidates to save in savemode=3
   MatchingType mMatchingType = MATCHINGUNDEFINED;

Detectors/GlobalTracking/include/GlobalTracking/MatchGlobalFwdParam.h

@@ -39,6 +39,7 @@ struct GlobalFwdMatchingParam : public o2::conf::ConfigurableParamHelper<GlobalF
   bool MCMatching = false;                                ///< MFT-MCH matching computed from MCLabels
   double matchPlaneZ = -77.5;                             ///< MFT-MCH matching plane z coordinate
   bool useMIDMatch = false;                               ///< Use input from MCH-MID matching
+  bool useTrackTime = false;                              ///< Use the MCH or MCHMID track time information to select the MFT ROF(s)
   Int_t saveMode = kBestMatch;                            ///< Global Forward Tracks save mode
   float MFTRadLength = 0.042;                             ///< MFT thickness in radiation length
   float alignResidual = 1.;                               ///< Alignment residual for cluster position uncertainty

Detectors/GlobalTracking/src/MatchGlobalFwd.cxx

@@ -65,6 +65,9 @@ void MatchGlobalFwd::init()
   mUseMIDMCHMatch = matchingParam.useMIDMatch;
   LOG(info) << "UseMIDMCH Matching = " << (mUseMIDMCHMatch ? "true" : "false");
 
+  mUseTrackTime = matchingParam.useTrackTime;
+  LOG(info) << "Use track time = " << (mUseTrackTime ? "true" : "false");
+
   mSaveMode = matchingParam.saveMode;
   LOG(info) << "Save mode MFTMCH candidates = " << mSaveMode;
 
@@ -216,8 +219,8 @@ bool MatchGlobalFwd::processMCHMIDMatches()
       LOG(debug) << " MCHId: " << MCHId << " --> mMCHID2Work[MCHId]:" << mMCHID2Work[MCHId];
       const auto& IR = MIDMatch.getIR();
       int nBC = IR.differenceInBC(mStartIR);
-      float tMin = nBC * o2::constants::lhc::LHCBunchSpacingMUS;
-      float tMax = (nBC + 1) * o2::constants::lhc::LHCBunchSpacingMUS;
+      float tMin = (nBC - 1) * o2::constants::lhc::LHCBunchSpacingMUS;
+      float tMax = (nBC + 2) * o2::constants::lhc::LHCBunchSpacingMUS;
       thisMuonTrack.setMIDTrackID(MIDId);
       thisMuonTrack.setTimeMUS(MIDMatch.getTimeMUS(mStartIR).first);
       thisMuonTrack.tBracket.set(tMin, tMax);
@@ -435,6 +438,7 @@ void MatchGlobalFwd::ROFMatch(int MFTROFId, int firstMCHROFId, int lastMCHROFId)
 {
   /// Matches MFT tracks on a given ROF with MCH tracks in a range of ROFs
   const auto& thisMFTROF = mMFTTrackROFRec[MFTROFId];
+  const auto& thisMFTBracket = mMFTROFTimes[MFTROFId];
   const auto& firstMCHROF = mMCHTrackROFRec[firstMCHROFId];
   const auto& lastMCHROF = mMCHTrackROFRec[lastMCHROFId];
   int nFakes = 0, nTrue = 0;
@@ -464,6 +468,12 @@ void MatchGlobalFwd::ROFMatch(int MFTROFId, int firstMCHROFId, int lastMCHROFId)
   // loop over all MCH tracks
   for (auto MCHId = firstMCHTrackID; MCHId <= lastMCHTrackID; MCHId++) {
     auto& thisMCHTrack = mMCHWork[MCHId];
+
+    // If enabled, use the muon track time to check if the track is correlated with the MFT ROF
+    if (mUseTrackTime && (thisMFTBracket.isOutside(thisMCHTrack.tBracket))) {
+      continue;
+    }
+
     o2::MCCompLabel matchLabel;
     for (auto MFTId = firstMFTTrackID; MFTId <= lastMFTTrackID; MFTId++) {
       auto& thisMFTTrack = mMFTWork[MFTId];