W Tracking Evaluation Studies: I

Here is a first look at comparisons for the tracking evaluation between the different frameworks summarized here, and the data files used are described in Lidia's page (1.1 M st_W stream events from run 9 pp500).  A description of the W reconstruction algo is given in the SN #546, which the results below are based on.

Note: PPV VF is the typical vertex finder for pp500, however these evaluation productions used Minuit VF since PPV uses Sti tracks. 

Figure 1:  Minuit VF rank of highest rank vertex

In PPV we look at all vertices with rank > 0.  For Minuit I don't know the standard cutoff for pp500 (if there is one), but I chose to use any vertex with rank > -2.  The difference in statistics between Sti and StiCA is due to a requirement of 3 or more primary vertices in each event, which ~10% of the Sti events fail... I'm still trying to understand this.

Figure 2:  Zvertex of vertices with rank > -2

We remove vertices with |Zvertex| > 100 cm

Track distributions:

Track cuts applied: flag==301 and pT > 1 GeV

Figure 3:  nHits

Figure 4:  nHits/nPoss

Figure 5:  chi^2

Figure 6:  chi^2 vs eta

Figure 7:  dE/dx vs momentum

Figure 8:  phi vs eta

Sector dependent track distributions are attached below for the evaluation productions Sti, StiCA, Stv, and StvCA.   Sector 20 in the figure above has been removed in the analysis by an eta-phi cut.

Distributions after all W cuts: vast majority are real Ws for ET > 25 GeV

Track cuts applied: nHit > 15, nHit/nPoss > 0.51, firstPoint R > 90 cm, lastPoint R > 160, and pT > 10 GeV.

Other W event selection criteria applied:  distance between electron candidate track and BEMC cluster cut , electron isolation cuts, and awayside energy cut

Figure 7:  Electron ET (measured by BEMC)

Figure 8:  Q/pT (measured by TPC) vs Electron ET (measured by BEMC)