[PWGDQ] Fill vertexing chi2PCA for triplets (#11472)

Author: sigurdnese

PWGDQ/Core/HistogramsLibrary.cxx

@@ -1034,6 +1034,7 @@ void o2::aod::dqhistograms::DefineHistograms(HistogramManager* hm, const char* h
         hm->AddHistogram(histClass, "LxyProj_Mass_Pt", "", false, 50, 2.0, 4.0, VarManager::kMass, 10, 0.0, 20.0, VarManager::kPt, 1000, -1.0, 1.0, VarManager::kVertexingLxyProjected);
         hm->AddHistogram(histClass, "LzProj_Mass_Pt", "", false, 50, 2.0, 4.0, VarManager::kMass, 10, 0.0, 20.0, VarManager::kPt, 1000, -1.0, 1.0, VarManager::kVertexingLzProjected);
         hm->AddHistogram(histClass, "CosPointingAngle", "", false, 200, -1.0, 1.0, VarManager::kCosPointingAngle);
+        hm->AddHistogram(histClass, "VtxingChi2PCA", "", false, 100, 0.0, 10.0, VarManager::kVertexingChi2PCA);
       }
 
       if (subGroupStr.Contains("kalman-filter")) {

PWGDQ/Core/VarManager.h

@@ -3979,6 +3979,7 @@ void VarManager::FillTripletVertexing(C const& collision, T const& t1, T const&
     values[VarManager::kVertexingProcCode] = procCode;
     if (procCode == 0) {
       // TODO: set the other variables to appropriate values and return
+      values[kVertexingChi2PCA] = -999.;
       values[kVertexingLxy] = -999.;
       values[kVertexingLxyz] = -999.;
       values[kVertexingLz] = -999.;
@@ -4013,6 +4014,11 @@ void VarManager::FillTripletVertexing(C const& collision, T const& t1, T const&
       o2::dataformats::VertexBase primaryVertex = {std::move(vtxXYZ), std::move(vtxCov)};
       auto covMatrixPV = primaryVertex.getCov();
 
+      if (fgUsedVars[kVertexingChi2PCA]) {
+        auto chi2PCA = fgFitterThreeProngBarrel.getChi2AtPCACandidate();
+        values[VarManager::kVertexingChi2PCA] = chi2PCA;
+      }
+
       double phi = std::atan2(secondaryVertex[1] - collision.posY(), secondaryVertex[0] - collision.posX());
       double theta = std::atan2(secondaryVertex[2] - collision.posZ(),
                                 std::sqrt((secondaryVertex[0] - collision.posX()) * (secondaryVertex[0] - collision.posX()) +
@@ -4279,9 +4285,10 @@ void VarManager::FillDileptonTrackVertexing(C const& collision, T1 const& lepton
         covMatrixPCA = fgFitterThreeProngFwd.calcPCACovMatrixFlat();
       }
 
-      auto chi2PCA = fgFitterThreeProngBarrel.getChi2AtPCACandidate();
-      if (fgUsedVars[kVertexingChi2PCA])
+      if (fgUsedVars[kVertexingChi2PCA]) {
+        auto chi2PCA = fgFitterThreeProngBarrel.getChi2AtPCACandidate();
         values[VarManager::kVertexingChi2PCA] = chi2PCA;
+      }
 
       double phi = std::atan2(secondaryVertex[1] - collision.posY(), secondaryVertex[0] - collision.posX());
       double theta = std::atan2(secondaryVertex[2] - collision.posZ(),