Run 9 200GeV Dijet Correction Test II

Second look at dijet corrections ...

This page continues my investigation of dijet corrections started here. I have made two major changes with respect to what was done before. First, I have placed two new cuts on events I look at: an asymmetric pt cut of (highPtJet >= 8.0 && lowPtJet >= 6.0), I have also placed cuts on the maximum allowed pt a jet can have. The second major change is that I have redefined the topological bins, Bin1 now encompases the entire barrel-barrel region, Bin2 is exclusively barrel-endcap coincedence, and Bin3 is exclusively endcap-endcap. 

Figure 1: This plot shows the distribution of events which are cut by the asymmetric pt requirement.

Figure 2: This plot shows the dijet mass spectrum before (Blue) and after (Red) the max jet pt cuts. The pt cuts are: JP2=45.0, JP1Hi=30.0, UnJP2=40.0, UnJP1Lo=30.0, UnJP1Hi=35.0

Figure 3: This plot shows the dijet mass spectrum before (Blue) and after (Red) both the asymmetric pt cut and the max jet pt cut.

As stated above, I have implemented new topological binnings.

Figure 4: This plot shows the three different topological bins the sample has been divided into. The top four pannels show away vs same side jet detector eta and the bottom four pannels show away vs same side jet physical eta

Figure 5: This plot shows the away vs same side jet pt

Figure 6: This plot compares the old topological binning scheme to the new scheme. Both pannels show the average particle level dijet mass vs the detector level dijet mass. The top pannel compares the old Bin3 which included the barrel-endcap and endcap-endcap coincidences to the new Bin2 and Bin3 which split barrel-endcap and endcap-endcap into different bins. The bottom pannel compares the old Bin1 and Bin2 to the new Bin1 which combines the two old bins. 

Figure 7: This figure shows particle vs detector dijet invariant mass for all triggers for all events (top left pannel) and for the three different topological bins. The upper 4 pannels show the scatter plots along with the average particle mass value for each detector mass bin (the error bars on the points are the RMS spreads). The bottom pannel shows the average points for each topological bin overlayed for comparison.

Figure 8: This plot is the same as the bottom plot in figure 7 except it is from the 12 point jet finder branch instead of the 5 point branch. The seperation between the bins is much more evident in the 12 point branch

Figure 9: This figure shows particle vs detector dijet invariant mass split by trigger combination. The points and error bars have the same meaning as in figure 7. The top eight pannels show the scatter plots and the bottom pannel shows the means from the eight trigger combinations for comparison. Reading from top to bottom, left to right, the trigger combinations are: JP2-JP2, JP2-JP1Lo, JP2-UnJP2, JP1Lo-JP1Lo, JP1Lo-JP1Hi, JP1Lo-UnJP1Lo, JP1Hi-JP1Hi, and JP1Hi-UnJP1Hi. These plots show all topological bins combined.

Figure 10: Same as figure 9 but now showing events in topological bin 1

 
Figure 11: Same as figure 9 but now for events in topological bin 2

Figure 12: Same as figure 9 but now for events in topological bin 3

Figures 9 - 12 seem to show a seperation between dijets containing a JP1Lo jet and those not containing a JP1Lo jet. To get a less cluttered view of this seperation, I have remade the profile plots for bins 1 - 3 using only two colors, one for JP1Lo dijets and another for not JP1Lo dijets. To get a better understanding of how the averages change for the different topological bins, I have fit a 1st order polynomial to the JP2-UnJP2 profile points from Bin 1 and reproduced that line on the plots for Bins 2 and 3.

Figure 13: This figure shows the same profiles as in figures 10 - 12. The 8 trigger combinations have been grouped into two colors with dijets containing a JP1Lo jet in red and dijets not containing a JP1Lo jet in blue. The black line was obtained by fitting the JP2-UnJP2 points from topological bin 1. The line is the same in all three pannels. The first pannel shows topological bin 1, the second pannel shows bin 2, and the third pannel shows bin 3.

From figure 13, it looks like we could condense the divisions into 4 bins: Bin 1 = barrel-barrel topology and trigger combo not containing JP1Lo, Bin 2 = barrel-barrel topology and trigger combo containing JP1Lo, Bin 3 = barrel-endcap and endcap-endcap topology and trigger combo not containing JP1Lo, Bin 4 = barrel-barrel and endcap-endcap topology and trigger combo not containing JP1Lo.

Figure 14: This figure shows the eta-eta jet distribution for all events and the four bins defined above. The top pannels show the eta-eta distribution for detector eta and the bottom pannels show the eta-eta distribution for physical eta.

Figure 15: This figure shows the jet pt vs pt distributions for all events and the 4 bins

Figure 16: This figure shows the Particle vs Detector dijet mass for all events and the four bins. The top pannels are the scatter plots and the bottom pannel shows the averages for the bins overlayed.