This is a continuation of my studies of the high pt tail started here. In the previous analysis I isolated the high pt tail events by looking at jets in a certain phase space. That study gave very strong evidence that the high pt tail events were predominantly jets which had a high pt track. Furthermore, the majority of those tracks passed through sector 20 of the TPC in the FF part of the run.

This analysis will focus on the properties of the high pt tracks. For each dijet event, I loop through all tracks in both jets and divide them into tracks with pt >= 30GeV and tracks with pt < 30GeV. I also divide the run into reversed full field (first part of run) and full field (second part of run) samples due to the marked change in behavior I observed between the two periods in the last analysis.

Figure 1: This figure shows track phi vs eta. The left column is for positive tracks and the right column is for negative tracks. The first two rows show events from the RFF (beginning) part of the run and the last two rows show events from the FF part of the run. The first and third rows show the eta phi distribution of tracks with pt >= 30GeV and the second and fourth rows show the eta phi distribution of tracks with pt < 30GeV.

In the above figure we see an obvious increase in the concentration of high pt tracks between phi = 0 and phi = -1 in the FF part of the run. This effect is also more prominent for positive charge tracks than for negative charge tracks. We also see a deficite of tracks for eta > 0 between phi = -1 and phi = -2 in the FF part of the run in the track pt < 30GeV plots. It also appears that the phi positions of the structures in the pt < 30GeV plots shift slightly between positive and negative track charge sign.

Figure 2: This figure shows track phi vs track pt * charge sign, so tracks with negative charge sign are ploted with negative pt. The first two rows show events from the RFF part of the run and the last two rows show events from the FF part of the run. The first and third rows show phi vs pt for tracks with pt >= 30GeV and the second and fourth rows show phi vs pt for tracks with pt < 30GeV.

The above figure shows that in the FF part of the run, the pt distributions are much less smooth as a function of phi than they are in the RFF part of the run. It appears that for many sectors the track pt spectrum is being 'stretched' to higher pt for positive tracks and 'compressed' for negative tracks.

Figure 3: This figure shows the pt spectra of track in TPC sector 20 (roughly phi = -0.2 to phi = -0.8). The top row shows tracks which were in the high pt jet and the bottom row shows tracks which were in the low pt jet. The left column is for positive charge sign tracks and the right column is for negative charge sign tracks. The blue curves are from events in the RFF 'good' sample (first part of run) and the red curves are from events n the FF 'bad' sample (second part of run). The curves in each pannel are normalized by the number of tracks in the RFF and FF runs.

Figure 4: This figure shows track phi vs the number of track hits used in the fit (left column) and the number of possible track hits (right column). Again, the x axis is multiplied by the charge sign of the track. The first two rows show events from the RFF part of the run and the last two rows show events from the FF part of the run. The first and third rows show tracks with pt >= 30GeV and the second and fourth rows show tracks with pt < 30GeV.

Figure 5: This figure shows the ratio nHitsFit/nHitsPossible for the RFF (top) part of the run and the FF (bottom) part of the run. The x axis is multiplied by the charge sign of the track.

Figure 6: This figure shows dcaXY, also known as dcaD. The left column shows dcaXY for positive charge tracks and the right column shows dcaXY for negative charge tracks. The top two rows show runs from the RFF part of the run and the bottom two rows show runs from the FF part of the run. The first and third rows show tracks with pt >= 30GeV and the second and fourth rows show tracks with pt < 30GeV.

Figure 7: This figure shows dcaZ. The left column shows dcaZ for positive charge tracks and the right column shows dcaXY for negative charge tracks. The top two rows show runs from the RFF part of the run and the bottom two rows show runs from the FF part of the run. The first and third rows show tracks with pt >= 30GeV and the second and fourth rows show tracks with pt < 30GeV.

Figure 8: This figure shows track phi vs the Chi2 (left column) and the chi2 probability (right column). The x axis is multiplied by the charge sign of the track. The first two rows show events from the RFF part of the run and the last two rows show events from the FF part of the run. The first and third rows show tracks with pt >= 30GeV and the second and fourth rows show tracks with pt < 30GeV.

Figure 9: This figure shows track phi vs the magnitude of the exit vector. The x axis is multiplied by the charge sign of the track. The first two rows show events from the RFF part of the run and the last two rows show events from the FF part of the run. The first and third rows show tracks with pt >= 30GeV and the second and fourth rows show tracks with pt < 30GeV. NOTE: I assume this is the vector that points from the vertex to the spot where the track stops in the calorimeter (not sure exact depth). If this is true, I'm not sure how to interperet the pattern.

Figure 10: This figure shows the low jet pt vs high jet pt for events which contain a track >= 30GeV (first and third rows) and for events which contain no tracks >= 30GeV (second and fourth rows). The first two rows show events from the RFF part of the run and the last two rows show events from the FF part of the run.

Figure 11: This figure shows the eta (left column) and phi (right column) distributions of the low and high pt jets for events with a track >= 30GeV (first and third rows) and for events without a track >= 30GeV (second and fourth rows). The first two rows show events from the RFF part of the run and the last two rows show events from the FF part of the run.