Home » Groups » STAR Protected

Run 9 200GeV Dijet Cross Section Detector Systematics

Updated on Mon, 2013-09-02 21:09. Originally created by pagebs on 2013-08-21 00:57.

Here I show the systematics due to tracking inefficiency, track pt uncertainty, and tower energy scale uncertainty ...

Figure 1: This figure shows the ratio (Data-Theory)/Theory for CTEQ6M + UEH. The Red curve shows the ratio and the Blue curves show the extent of the theory scale error.

Figure 2: This figure shows the size of the systematics due to track finding inefficiency. The curves show the ratio of the size of the systematic divided by the nominal cross section. The Red curve is for a 4% inefficiency and the Blue curve is for a 7% inefficiency. The unsymmetrized systematic ratio can be seen here. The zoomed-in cross section spectrum can be seen here. 

Figure 3: This figure shows the size of the systematics due to track Pt uncertainty. The curves show the ratio of the size of the systematic divided by the nominal cross section. The Red curve is for a track pt decrease of 1% and the Blue curve is for a track pt increase of 1%. The unsymmetrized systematic ratio can be seen here. The zoomed-in cross section spectrum can be seen here.


Figure 4: This figure shows the size of the systematics due to tower energy uncertainty. The curves show the ratio of the size of the systematic divided by the nominal cross section. The Red curve is for a tower energy decrease of 3.7% and the Blue curve is for a tower energy increase of 3.7%. The unsymmetrized systematic ratio can be seen here. The zoomed-in cross section spectrum can be seen here.

For the track inefficiency, the 4% loss value is used. The systematic is just the size of the deviation between the modified and nominal cross section. For the track pt and tower energy systematics, the size of the systematic is the larger of the deviations between the nominal cross section and the plus or minus modified cross section. The three systematics are added in quadrature and added to / subtracted from the nominal cross section to give the error band in each bin.

Figure 5: This figure shows the quadrature sum of the track inefficiency, track pt, and tower energy systematics divided by the nominal cross section.

Figure 6: This figure is the same as figure 1, but now the black lines show the extent of the systematic errors.

At the Spin meeting, it was suggested that taking the maximum deviation between the + and - modified cross section and the nominal cross section as the systematic was too conservative. Now I am taking the average between the + and - deviations as the systematic.

Figure 7: This figure shows the combined systematic errors using the max error and the average error.

Figure 8: Same as figure 6, but now the data systematic error is taken as the average between the + and - extent in stead of the maximum deviation.

Groups: