Target X vs run, for DDC tracks
Target X vs. run number, according to DDC tracks extrapolated upstream
K. Kainz and
W. J. Llope
This page was last updated on January 11, 2000.
The x coordinate of the target was inferred by extrapolating DDC
tracks upstream to z = 253. Dependence of target x upon run number
was obtained by using 12 different Au98 runs, ranging from run 2402 to
2957. The results for all tracks, positive tracks, and negative
tracks are summarized in the plot below.
[Postscript version]
For this study, the current, non-rotated DDC wiremap was used.
Although the x-coordinate centroids for positive and for negative
tracks are separated by about 0.5 cm, their dependences upon the run
number appear to agree.
The trend seen in the charged-particle-extrapolation data above is at
least qualitatively similar to that seen in the projection of neutral
vertices to the target:
Target X (and Y) given by projected v0s to target -- S. Kelly 11/23/1999
