Run 17 TPC T0

 First look, using prompt TPC hits in the file st_physics_18063014_raw_2000009. With significant pile-up, I had to fit for background+signal and used the form: p0 + p1*z + p2*exp(p3*(z-p4)*(z-p4)). I report in this table the prompt peak z position values of p4:

Prompt peak z positions [cm] East West
Outer sectors -209.590 ± 0.007 209.187 ± 0.007
Inner sectors -209.396 ± 0.010 208.977 ± 0.010

Below are the hit z distributions and fits used to determine these values. The values from east and west are no longer symmetric with the New TPC alignment, and are within half a millimeter (0.05 cm) of what was found for Run 12 UU TPC T0 with new alignment, so I think all is as expected and there is no reason to alter the T0s for Run 17.

Hit z distributions [cm] East West
Outer sectors
Inner sectors


-Gene