Re: list of assignments for bcal decision

[Alex Dzierba <dzierba@indiana.edu>]

Dear George et al

I ran a MC of gam p --> X(2.0)+ n where X+ -> b1+ pi0 and
b1+ --> omega pi+.  The final state has three charged particles
and 2 pi0's (4 photons).   I assume a min energy of 100 MeV
in FCAL and all charged tracks > 1 degree are accepted
and measured.   Starting with 20 MeV min in BCAL the
overall acceptance is 91%.  If I now change 20 MeV -> 40 MeV
the acceptance is 84% and for 60 MeV the acceptance is
78%.  So this is probably a worse scenario for changing
the min energy in BCAL.

By the way - slightly more than half (54%) of photons end up
in BCAL with a mean energy of 600 MeV and a median energy
of a little less than 400 MeV.

Will do more

Alex

At 11:03 AM -0600 4/13/07, George Lolos wrote:
>Hi Elton:
>
>I did not have time yet to look at your posting, I will do later today.
>I assume you didn't have time to read the draft I sent you yesterday.
>We can address those on Monday.
>
>The threshold of 20 MeV, needs to be investigated particularly so in
>terms of the approximate 2 radiation lengths of cables from the
>chambers.  In  my report, I explicitly mention the 20 MeV threshold in
>terms of the energy deposition in the SciFi's (~2.4 MeV) and the
>resulting numbers of P.E.'s in the SiPM's.
>
>I agree that SensL will not take part in our discussions and I don't
>think they would do this even if we asked them to.  I also think that
>the opportunity for us as a group to invite them to attend a specific
>session, the emphasis is on the invitation and specific session, is
>invaluable for the rest of the working group to hear first hand where
>they are in terms of the R&D and further progress, costs and everything
>we feel it's important for us to know. We therefore have to decide among
>us on Monday when is the optimal time for such session and communicate
>this to SensL.  I would think that the second session on Monday morning
>may be a good time, we would have the first session to get the questions
>together and look at the road map.  Elke's suggestion for the afternoon
>on Monday is also a good alternative, if their travel plans allow it.
>
>George
>


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alex R. Dzierba
Chancellor's Professor of Physics (Emeritus)
Department of Physics / Indiana U / Bloomington IN 47405 / 812-855-9421
JLab Visiting Fellow
Jefferson Lab / 12000 Jefferson Ave / Newport News, VA 23606 / 757-269-7577
Home Phone: 812-825-4063  Cell:  812-327-1881  Fax: 866-541-1263
http://dustbunny.physics.indiana.edu/~dzierba/
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