[Halld-cpp] [EXTERNAL] Re: How much amorphous data should we take?

[Sean Dobbs]

Hi Elton,

Another thing we use the amorphous data for is to evaluate instrumental
asymmetries.  This may be something to be concerned about since you're
looking at tracks at small angles, but I also agree that for this you
probably need less data than we have been taking.

Cheers,
Sean

On Wed, Jun 22, 2022 at 5:05 PM Curtis A. Meyer <cmeyer at cmu.edu> wrote:

> Hi Elton,
>
>     I think we have used the amorphous data to also check systematics when
> we analyze data away from the coherent peak. My guess is you probably need
> less than GlueX.
>
> Curtis
>
>
> Curtis A. Meyer | MCS Associate Dean for Research
> The Otto Stern Professor of Physics
> cmeyer at cmu.edu | 412 260 6290
> Carnegie Mellon University
> Department of Physics, Wean Hall 8410
> 5000 Forbes Ave., Pittsburgh PA, 15213
> www.curtismeyer.com
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>
>
>
>
>
> On Jun 22, 2022, at 16:57, Elton Smith <elton at jlab.org> wrote:
>
> Dear Hovanes, Mike, and others,
>
> The CPP experiment has been considering how much data should be taken with
> the amorphous radiator and wanted to get your input. As you know, for GlueX
> we collected about 10% of the triggers on the amorphous radiator.
>
> As, I understand it, the main arguments for collecting data with an
> amorphous radiator  are a) to be able to normalize the coherent spectrum
> and b) check systematics of the polarization. We need very little data for
> a), but  how much data we need to address b)? Also, if there are other used
> for the amorphous radiator data, please send us feedback.
>
> We have already started taking data that can be considered production and
> all of it was taken using polarized beam. We will want to make a plan
> regarding how much amorphous radiator data we take so that it is
> interspersed with diamond radiator data. At the moment, we do not
> anticipate using the amorphous radiator data in the physics analyzes for
> CPP nor NPP.
>
> Thanks, Elton.
>
>
> ------------------------------------
> Elton Smith
> Jefferson Lab MS 12H3
> 12000 Jefferson Ave STE 4
> Newport News, VA 23606
> (757)269-7625
>
>
>
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