Re: systematic contributions to time-of-flight resolution

[Matt <bellis@ernest.phys.cmu.edu>]

Hi Simon,

    Is this a study of resolution of TOF? Or a study of the resolution on how we will reconstruct the path length? The time-of-flight will just be the time-of-flight as calculated from the start time (accelerator RF) and the stop time from some detector (BCAL/forward TOF), independent of what path it took to get there. Resolution on the TOF will be dependent on those quantities as well. 

    Isn't it more accurate to say this study is looking at the resolution of our swimming routine and the path length that it returns. I might be too picky...I wasn't sure if this was for the review or just some internal study. Or perhaps I missed something.

Matt B.

On Tue, Mar 25, 2008 at 9:06 AM, Simon Taylor <staylor@jlab.org> wrote:

Hi, everyone.

I have started looking at the contribution to the time-of-flight
resolution due to the momentum resolution, path length variations, and
z-vertex position variations.  I have attached a plot of
resolution in the difference between the true flight time to either the BCAL
or the TOF (as determined from the MC truth points) and the reconstructed
flight time using the path length derived from swimming the reconstructed
track from the vertex position to either the first TOF plane or the inner
BCAL radius.  I threw 1.0, 2.0, and 3.0 GeV/c pions from the center of the
target uniformly in phi and flat in theta from 126 degrees to ~0.5
degrees.  I find that the time resolution does not depend on the momentum
in the barrel region but does for tracks that would hit the TOF.
Comments welcome.

Simon

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Matt Bellis
Carnegie Mellon University
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(cell) 412-310-4586
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