add trk res in TOF match chi2

noferini · Apr 22, 2024 · e37249e · e37249e
1 parent d08d21a
commit e37249e
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Showing 2 changed files with 27 additions and 3 deletions.
diff --git a/DataFormats/Reconstruction/include/ReconstructionDataFormats/MatchInfoTOFReco.h b/DataFormats/Reconstruction/include/ReconstructionDataFormats/MatchInfoTOFReco.h
@@ -45,14 +45,21 @@ class MatchInfoTOFReco : public MatchInfoTOF
   float pt() const { return mPt; }
   void setPt(float pt) { mPt = pt; }
 
+  void setResX(float val) { mResX = val; }
+  void setResZ(float val) { mResZ = val; }
+  float getResX() const { return mResX; }
+  float getResZ() const { return mResZ; }
+
   void setTrackType(TrackType value) { mTrackType = value; }
   TrackType getTrackType() const { return mTrackType; }
 
  private:
   TrackType mTrackType; ///< track type (TPC, ITSTPC, TPCTRD, ITSTPCTRD)
   bool mFakeMC = false;
   float mPt = 0;
-  ClassDefNV(MatchInfoTOFReco, 4);
+  float mResX = 1;
+  float mResZ = 1;
+  ClassDefNV(MatchInfoTOFReco, 5);
 };
 } // namespace dataformats
 } // namespace o2

diff --git a/Detectors/GlobalTracking/src/MatchTOF.cxx b/Detectors/GlobalTracking/src/MatchTOF.cxx
@@ -1012,6 +1012,13 @@ void MatchTOF::doMatching(int sec)
       int eventIdTOF;
       int sourceIdTOF;
       for (auto iPropagation = 0; iPropagation < nStripsCrossedInPropagation; iPropagation++) {
+        float padResX2 = 0.52; // (2.5/sqrt(12))^2
+        float padResZ2 = 1.02; // (3.5/sqrt(12))^2
+        float cosangle = TMath::Cos(Geo::getAngles(indices[1], indices[2]) * TMath::DegToRad());
+        float errXinv2 = 1. / (trefTrk.getSigmaY2() + padResX2);
+        float errZinv2 = 1. / (trefTrk.getSigmaZ2() * cosangle + padResZ2); // should be valid only at eta=0
+        // look at getPadDxDyDz to understand how to convert track errors in TOF strip ref system (wip)
+
         LOG(debug) << "TOF Cluster [" << itof << ", " << cacheTOF[itof] << "]:      indices   = " << indices[0] << ", " << indices[1] << ", " << indices[2] << ", " << indices[3] << ", " << indices[4];
         LOG(debug) << "Propagated Track [" << itrk << "]: detId[" << iPropagation << "]  = " << detId[iPropagation][0] << ", " << detId[iPropagation][1] << ", " << detId[iPropagation][2] << ", " << detId[iPropagation][3] << ", " << detId[iPropagation][4];
         float resX = deltaPos[iPropagation][0] - (indices[4] - detId[iPropagation][4]) * Geo::XPAD + posCorr[0]; // readjusting the residuals due to the fact that the propagation fell in a pad that was not exactly the one of the cluster
@@ -1028,7 +1035,7 @@ void MatchTOF::doMatching(int sec)
         if (indices[2] != detId[iPropagation][2]) {
           continue;
         }
-        float chi2 = res; // TODO: take into account also the time!
+        float chi2 = 0.5 * (resX * resX * errXinv2 + resZ * resZ * errZinv2); // TODO: take into account also the time!
 
         if (res < mSpaceTolerance) { // matching ok!
           LOG(debug) << "MATCHING FOUND: We have a match! between track " << mTracksSectIndexCache[type][sec][itrk] << " and TOF cluster " << mTOFClusSectIndexCache[indices[0]][itof];
@@ -1037,6 +1044,8 @@ void MatchTOF::doMatching(int sec)
           int eventIndexTOFCluster = mTOFClusSectIndexCache[indices[0]][itof];
           mMatchedTracksPairsSec[sec].emplace_back(cacheTrk[itrk], eventIndexTOFCluster, mTOFClusWork[cacheTOF[itof]].getTime(), chi2, trkLTInt[iPropagation], mTrackGid[sec][type][cacheTrk[itrk]], type, (trefTOF.getTime() - (minTrkTime + maxTrkTime - 100E3) * 0.5) * 1E-6, trefTOF.getZ(), resX, resZ); // subracting 100 ns to max track which was artificially added
           mMatchedTracksPairsSec[sec][mMatchedTracksPairsSec[sec].size() - 1].setPt(pt);
+          mMatchedTracksPairsSec[sec][mMatchedTracksPairsSec[sec].size() - 1].setResX(sqrt(1. / errXinv2));
+          mMatchedTracksPairsSec[sec][mMatchedTracksPairsSec[sec].size() - 1].setResZ(sqrt(1. / errZinv2));
         }
       }
     }
@@ -1337,6 +1346,12 @@ void MatchTOF::doMatchingForTPC(int sec)
           if (detId[ibc][iPropagation][1] != indices[1] || detId[ibc][iPropagation][2] != indices[2]) {
             continue;
           }
+          float padResX2 = 0.52; // (2.5/sqrt(12))^2
+          float padResZ2 = 1.02; // (3.5/sqrt(12))^2
+          float cosangle = TMath::Cos(Geo::getAngles(indices[1], indices[2]) * TMath::DegToRad());
+          float errXinv2 = 1. / (trefTrk.getSigmaY2() + padResX2);
+          float errZinv2 = 1. / (trefTrk.getSigmaZ2() * cosangle + padResZ2); // should be valid only at eta=0
+          // look at getPadDxDyDz to understand how to convert track errors in TOF strip ref system (wip)
 
           LOG(debug) << "TOF Cluster [" << itof << ", " << cacheTOF[itof] << "]:      indices   = " << indices[0] << ", " << indices[1] << ", " << indices[2] << ", " << indices[3] << ", " << indices[4];
           LOG(debug) << "Propagated Track [" << itrk << "]: detId[" << iPropagation << "]  = " << detId[ibc][iPropagation][0] << ", " << detId[ibc][iPropagation][1] << ", " << detId[ibc][iPropagation][2] << ", " << detId[ibc][iPropagation][3] << ", " << detId[ibc][iPropagation][4];
@@ -1360,7 +1375,7 @@ void MatchTOF::doMatchingForTPC(int sec)
           }
 
           LOG(debug) << "resX = " << resX << ", resZ = " << resZ << ", res = " << res;
-          float chi2 = mIsCosmics ? resX : res; // TODO: take into account also the time!
+          float chi2 = mIsCosmics ? resX : 0.5 * (resX * resX * errXinv2 + resZ * resZ * errZinv2); // TODO: take into account also the time!
 
           if (res < mSpaceTolerance) { // matching ok!
             LOG(debug) << "MATCHING FOUND: We have a match! between track " << mTracksSectIndexCache[trkType::UNCONS][sec][itrk] << " and TOF cluster " << mTOFClusSectIndexCache[indices[0]][itof];
@@ -1369,6 +1384,8 @@ void MatchTOF::doMatchingForTPC(int sec)
             int eventIndexTOFCluster = mTOFClusSectIndexCache[indices[0]][itof];
             mMatchedTracksPairsSec[sec].emplace_back(cacheTrk[itrk], eventIndexTOFCluster, mTOFClusWork[cacheTOF[itof]].getTime(), chi2, trkLTInt[ibc][iPropagation], mTrackGid[sec][trkType::UNCONS][cacheTrk[itrk]], trkType::UNCONS, trefTOF.getTime() * 1E-6 - tpctime, trefTOF.getZ(), resX, resZ); // TODO: check if this is correct!
             mMatchedTracksPairsSec[sec][mMatchedTracksPairsSec[sec].size() - 1].setPt(pt);
+            mMatchedTracksPairsSec[sec][mMatchedTracksPairsSec[sec].size() - 1].setResX(sqrt(1. / errXinv2));
+            mMatchedTracksPairsSec[sec][mMatchedTracksPairsSec[sec].size() - 1].setResZ(sqrt(1. / errZinv2));
           }
         }
       }