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TPC Sector 16 time offset
I believe I see Tonko's sector 16 time offset in Run 9 physics data (using data from days 147-152). For the 11ns that Tonko sees, one should see 11ns * (5.5 cm/us) ~= 0.06 cm (600 microns).
Plotted here are the z DCA [cm] of tracks to the primary vertex vs. phi (think of it as a z residual at the primary vertex). West is on the left, and East is on the right. Top is the 2D plot, middle is a profile (mean of the phi bins), and bottom is the mean of Gaussian fits over [-0.5,0.5cm]. Each sector has 2 bins in these plots.
On the east, sector 16 is at phi~= 3.4 - 3.9. I think the sinusoid that appears in the rest of the east sectors is from the compensation of the vertex fit to this timing misalignment.
On the west side, there are some other notable features. Sectors 4 and 11 are missing their inner RDOs (padrows 1-8) and it appears to be causing havoc with their z projections, perhaps because (as Tonko has stated), RDO 2 is offset in time too, so the track fit goes awry and isn't brought back via RDO 1 hits. Sector 4 is at phi~= 5.5-6.0, while Sector 11 sits at phi~=1.8-2.3.
It'll be valuable to see these after Tonko's calibration.
-Gene
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