+ // histograms
+ TH1D *fDeltaPt; // Histogram for the pt resolution
+ TH1D *fDeltaZ; // Histogram for the cluster z deviation
+ TH1D *fDeltaX; // Histogram for the cluster x deviation
+ TH1D *fDeltaYPos; // Histogram for the cluster y deviation (positives)
+ TH1D *fDeltaYNeg; // Histogram for the cluster y deviation (negatives)
+
+ TH1D *fNPoints; // Histogram for the number of points
+ TH1D *fNGood; // Histogram for the number of good points
+
+ TH2D *fRefSpace; // Histogram for reference space