[g13] g13a timing problems

[Paul Mattione]

For file cooked_053600.A05.B00, I've studied the timing problem that  
we've seen between the "Start Time" and Tagger from the anahist plots  
(~0.5 ns):

Anahist, 2D: http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/h3115.gif
Anahist, 1D: http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/h3112.gif

Looking through the ana package code, what is actually being plotted  
is the TGPB.dt variable, which is still unclear as to what it actually  
means.

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Also, for the same cooked file I've computed the start time of every  
track from: SCPB, STPB, and HEVT (copied).  I've then compared all of  
these times against each other, and also against the time of all of  
the photons in the TAGR bank, propagated to the interaction (EVNT.z)  
vertex.  The plots may be find in the directory below:

http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/

The Good:
TAGR & SCPB are lined up:
http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/dh_KStarZero_TDiffs_1D_0.gif

TAGR & HEVT are lined up:
http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/dh_KStarZero_TDiffs_1D_2.gif

SCPB & HEVT are the same (by definition):
http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/dh_KStarZero_TDiffs_1D_4.gif


The Bad:
SCPB & STPB are off by 139 ps:
http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/dh_KStarZero_TDiffs_1D_3.gif

STPB & HEVT are also off by 139 ps (by definition (SCPB = HEVT)):
http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/dh_KStarZero_TDiffs_1D_5.gif

TAGR & STPB are off by 126 ps:
http://www.jlab.org/Hall-B/secure/g13/pmatt/tdiffs/dh_KStarZero_TDiffs_1D_1.gif

However, this is nowhere near as bad as the 0.5 ns that the anahist  
plots are showing.  Thoughts?

  - Paul