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Re: calorimeter document
Elke,
The most efficient way to deal with some of these questions you have
on the simulation section now is just to talk by phone. Are you
available for a phone call this evening. We at least talk about some
of the more detailed simulation questions. This is much faster than
typing. I will be up at least until 1-2 this evening working so just
send me a phone number if you want to chat briefly.
-Matt
On Feb 6, 2008, at 10:07 PM, Elke-Caroline Aschenauer wrote:
>
> Dear all,
>
> I have not read every line, but I would like to share some high level
> observations with you.
>
> Cheers elke
>
>
> 1. Introduction.
>
> Alex i think it would be nice if possible to replace the colored
> plots in
> fig 2 with the ones you did today for your talk with the bar at the
> side
> showing the relations between the colors.
>
> 2. BCAL + Appendix
>
> I see no mentioning of electronics at all. Neither TDC nor FADC.
> Should there not be at least a small paragraph on what requirements on
> resolution and dynamic range we have to the electronics?
> No mentioning of assembly or so, this is different to the FCal
> section.
> It is okay to do this, but looks a bit strange. We could refer to the
> pre-brief material drawings on the BCal assembly.
>
>
> SiPMTs:
> =======
>
> what ever we write the test should not immediately suggest to the
> reader
> that we are still far away from a final solution especially this is
> a 100%
> design review. This opinion can be easily created reading this some
> of the
> sections from the report testing this first arrays. I think we have to
> check this again carefully.
> Carl, some of the remarks made in your talk by Elton, George and me
> should
> maybe incorporated in the write-up. I think the plots from Elton
> showing the
> trade off between dark current and pde to reach the desired low energy
> threshold should appear somewhere.
>
>
> One more remark of caution here. Regina and JLab have a agreement of
> disclosure with Sensl are we allowed to show all we are showing in
> this
> report taking into account this disclosure agreement? Just something
> to
> think about.
>
> 3. Fcal:
>
> okay here I don't know the version on the www is the last one. but
> don't
> we want to show rates for the inner blocks? Maybe even a plot
> showing the
> difference between the old FDC material and the new one.
>
> For the FCAl we mention electronics and holding structures.
>
> 4. Simulation.
>
> section 2.1: does noise not also influence your lower photon
> threshold.
> It is not mention not a super big deal but important. In
> the
> worst case say just say still under study.
>
> section 2.2: just a remark the current SiPMTs would not allow a
> 100ns gate width. Actually if the plots from Elton on pde
> vs dark rate appear in the document, it would be good to
> check
> the current thresholds are close to the numbers from
> this study. I think they are.
>
> section 3.4
>
> I think it would be helpful to label the peaks to show which one comes
> from which part in the detector. I like a lot the plots on photon
> conversion beni does always z vs r. they give an idea where the
> problem
> areas are. I would include one in addition to figure 10.
>
> section 3:
>
> I think it would be really nice to have a summary table showing the
> energy
> and time resolution you get fro the simulations of both calorimeters
> and
> compare it with the once we get from beam and cosmic tests.
>
> section 4:
>
> fig 12 and 13 show the combination of all photons in an event to
> either
> give a pi0 or a eta. You show also the chi^2 for the fit confidence
> level.
> Does the result for the chi^2 not depend strongly on your
> assumptions for
> the constrained mass fit. I think it would be good to list which
> constrains have been assumed and what happens if you vary them.
>
> One more question how are this plots looking if you just assume that
> the
> single photon energies are the same in some error.
>
> Is it obvious why the background shapes for the different pi0 and eta
> combinations (FCAL, FCAL+BCAL, and BCAL) change?
>
> section 4.2
> I have to ask unfortunately the same question again I asked already
> during
> the collab meeting.
> Pythia generates everything which is can be produced by a 9 GeV
> photon.
> It has no signal events in. Now you run your generator which is able
> to
> generate exotic waves, with all their special properties.
> You mix this to event classes with some ration like 10:1 Pythia to
> exotic
> or 1:1 or ....
> than you run your analysis and see you find your exotic wave. If yes
> wonderful if not you can set a limit on your sensitivity.
>
> Why are you allowed to remove signal like events from the Pythia
> background. In real life / data you can not tell what are signal
> events
> and what comes from QCD photo-production (I don't want to say exotics
> are not QCD).
>
> The section describing the eta-pi0 analysis on page 18
> bottom and page 19 is a bit dense to really follow in detail. As it is
> a very important analysis a bit more explanation would be helpful. I
> can
> explain in more detail on the phone or ... what i think would be
> needed.
>
>
>
>
>
>
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> | `, Elke-Caroline Aschenauer =
> \,_ `-/ -
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