Cuts Summary

This page summarizes the effect of each major cut in the 2006 jet+charged pion analysis. Each plot is obtained by applying all other applicable analysis cuts except the one being illustrated.

Figure 1: Black is TPC z-vertex for all BJP1-triggered events, Green is the TPC z-vertex distribution for events in BBC timebins 6-9, and Red is the TPC z-vertex distributions for all charged pion tracks (inclusive, no trigger jet requirement).

It appears at first that the vz distribution of good tracks is broader than the BBC 6-9 distribution, but that’s not actually the case. Here’s the ratio of the red and green histograms from the above plot:

Figure 1b

The following histograms use positively charged pions from any spin state. Black lines are inclusive π+ passing all cuts except the one being shown, green lines are leading π+ opposite a trigger jet, and the filled green histogram shows the π+ accepted for the asymmetry analysis.

Figure 2: |η| < 1.0

Figure 3: |dcaG| < 1.0

Figure 4: nHitsFit > 25

Figure 5: nσ(π). It’s not possible to read off the efficiency from this histo because I actually use a time-dependent cut window based on the results of fill-by-fill fits to the nσ(π) distributions. Ideal world cut shown is nσ(π) [-1,2]

Here’s the ratio of the green and black histograms from that plot. The away-side spectrum has a relative lack of electrons but an increase in the p/K contamination:

Figure 5b

I should also add some more plots here documenting the cuts on jet pT, detector η, and N.E.F.