I try to digest results obtained for Outer to Inner (sub) sector alignment using Cosmic data from run X (day 159). The method I have described in my previous post.

I made more soft selection for track segments in Inner and Outer sectors : I require more than 5 hits per track segment in each sub sector.Fit parameters are shift (x, y, z) and rotation (alpha around X, beta around Y and gamma around Z axises) Outer sub sector with respect to Inner one. The coordinate system is so called StTpcLocalSector i.e. in coordinate natural for sector 12 with flipped Z axis (== drift distance).  

The fit procedure is same as was used for SVT/SSD alignment. Below the result of fit the above parameters versus sector are  presented. The red line correspond to alignment parameters obtained in May 2000 (i.e. what we have in DB for "2000-05-01 00:00:05") (http://www4.rcf.bnl.gov/~fisyak/star/Tpc/Alignment/F/AlignmentResultsPassF.png)

    Conclusions:

• x and gamma: In general DB parameters have the same trends as for the fitted ones with exception sector 20.
• y:for sector 20 there is a big offset ( ~3mm) (?)
• z: there are some offsets which could be associated with "Tpc effective geometry" i.e. accounting drift time in region between Gating Grid and Anode wires.
• alpha and beta: There is strange offsets for sector 24 (?)

This is what I can conclude for the moment. Comments and ideas are welcome.