CA: sts QA task: check U/V correlation

CAinputQaSts: check U/V correlation in the hit covariance matrix.

reco/L1/qa/CbmCaInputQaSts.cxx

@@ -251,6 +251,7 @@ void CbmCaInputQaSts::DeInit()
   fvph_hit_dy.clear();
   fvph_hit_du.clear();
   fvph_hit_dv.clear();
+  fvph_hit_kuv.clear();
   fvph_hit_dt.clear();
 
   fvph_n_points_per_hit.clear();
@@ -357,6 +358,9 @@ void CbmCaInputQaSts::FillHistograms()
     double dxHit = pHit->GetDx();
     double dyHit = pHit->GetDy();
 
+    double duvHit = Cxx * cosU * cosV + Cxy * (sinU * cosV + cosU * sinV) + Cyy * sinU * sinV;
+    double kuvHit = duvHit / duHit / dvHit;
+
     // Hit time
     double tHit  = pHit->GetTime();
     double dtHit = pHit->GetTimeError();
@@ -371,6 +375,7 @@ void CbmCaInputQaSts::FillHistograms()
     fvph_hit_dy[iSt]->Fill(dyHit);
     fvph_hit_du[iSt]->Fill(duHit);
     fvph_hit_dv[iSt]->Fill(dvHit);
+    fvph_hit_kuv[iSt]->Fill(kuvHit);
     fvph_hit_dt[iSt]->Fill(dtHit);
 
     fvph_hit_xy[nSt]->Fill(xHit, yHit);
@@ -383,6 +388,7 @@ void CbmCaInputQaSts::FillHistograms()
     fvph_hit_dy[nSt]->Fill(dyHit);
     fvph_hit_du[nSt]->Fill(duHit);
     fvph_hit_dv[nSt]->Fill(dvHit);
+    fvph_hit_kuv[nSt]->Fill(kuvHit);
     fvph_hit_dt[nSt]->Fill(dtHit);
 
     // **********************
@@ -835,6 +841,23 @@ InitStatus CbmCaInputQaSts::InitCanvases()
     fvph_reco_eff[nSt]->DrawCopy("colz", "");
   }
 
+  {
+    auto* canv = MakeQaObject<CbmQaCanvas>("err", "Hit Errors", 1600, 800);
+    canv->Divide2D(6);
+    canv->cd(1);
+    fvph_hit_dx[nSt]->DrawCopy();
+    canv->cd(2);
+    fvph_hit_dy[nSt]->DrawCopy();
+    canv->cd(3);
+    fvph_hit_dt[nSt]->DrawCopy();
+    canv->cd(4);
+    fvph_hit_du[nSt]->DrawCopy();
+    canv->cd(5);
+    fvph_hit_dv[nSt]->DrawCopy();
+    canv->cd(6);
+    fvph_hit_kuv[nSt]->DrawCopy();
+  }
+
   {
     auto* canv = MakeQaObject<CbmQaCanvas>("other", "Other histograms", 1600, 800);
     canv->Divide2D(3);
@@ -1149,6 +1172,7 @@ InitStatus CbmCaInputQaSts::InitHistograms()
   fvph_hit_dy.resize(nSt + 1, nullptr);
   fvph_hit_dt.resize(nSt + 1, nullptr);
   fvph_hit_dv.resize(nSt + 1, nullptr);
+  fvph_hit_kuv.resize(nSt + 1, nullptr);
   fvph_hit_du.resize(nSt + 1, nullptr);
 
   for (int iSt = 0; iSt <= nSt; ++iSt) {
@@ -1203,6 +1227,10 @@ InitStatus CbmCaInputQaSts::InitHistograms()
     sT               = (TString) "Hit position error across back strips" + tsuff + ";dv_{hit} [cm]";
     fvph_hit_dv[iSt] = MakeQaObject<TH1F>(sF + "err/" + sN, sT, kNbins, kRHitDv[0], kRHitDv[1]);
 
+    sN = (TString) "hit_kuv" + nsuff;
+    sT = (TString) "Hit error correlation between front and back strips" + tsuff + ";kuv_{hit} [unitless]";
+    fvph_hit_kuv[iSt] = MakeQaObject<TH1F>(sF + "err/" + sN, sT, kNbins / 2 * 2 + 1, -1.1, 1.1);
+
     sN               = (TString) "hit_dt" + nsuff;
     sT               = (TString) "Hit time error" + tsuff + ";dt_{hit} [ns]";
     fvph_hit_dt[iSt] = MakeQaObject<TH1F>(sF + "err/" + sN, sT, kNbins, kRHitDt[0], kRHitDt[1]);