GlueX-doc-926

[Elton Smith <elton@jlab.org>]

Hi George,

I have a question about your report on Si PMs regarding Fig 11. It seems
that you have taken the middle spectrum and subtracted the fitted shape of
the pedestal from the top spectrum to produce the bottom spectrum. The
resulting spectrum shows a displacement from the origin. But this is not
the way one should subtract pedestals. These need to be subtracted event
by event (not in a distribution) and the result will be a spectrum
identical to the middle one but with the peak (currently approximately in
channel 90) centered on zero. This distribution does not show a clear
separation of signal from pedestal.

Am I missing something?

Thanks, Elton.




Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave
Suite # 16
Newport News, VA 23606
elton@jlab.org
(757) 269-7625