Re: comments on the resolution floor term

["George Lolos" <George.Lolos@uregina.ca>]

Hi Elton:

While the leakage to the back of the BCAL and KLOE are indeed nearly
identical, during the tests we used one module that allows approximately
2.5-3% leakage from top and bottom (in reality out the sides).  KLOE has
not such problem because in beam tests of single modules they have the
advantage of much bigger modules while from the performance of the KLOE
as a detector, this of course does not play a role.  

I see this as the only difference in conditions that may raise issues. 
The gain matching of the PMT's and the response of the light guides do
not introduce variations that may justify larger floor terms for us.


Cheers,

George
>>> Elton Smith <elton@jlab.org> 05/08/07 12:31 PM >>>

collaborators,

A couple of comments occurred to me after the meeting this afternoon
regarding the resolution floor term. In comparing our results to KLOE we
have been making the implicit assumption that we expect similar
resolution. This should be expected for the shower fluctuations, because
it is dominated by geometry and the GlueX and KLOE calorimeters are very
similar. However, the expectation for the floor term may be different.
This term is dominated by systematic contributions to either the energy
or
the timing. However, most contributions to the floor term (e.g.
electronic
noise, gain non-uniformity, etc) could in fact be quite different
between
the two detectors and we should not make that assumption. [See note 1].

Cheers, Elton.

[note 1] The exception is the shower leakage contribution to the floor
term should be similar because of similar geometry and thickness (about
15X_0).



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