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Re: problem with dluex-doc-1300






Hi Andrei,

What is plotted is the maximum number (not the sum) in one of the four
cells in the first layer. It is to find the channel that has the maximum
signal. It may not always be the same segment, but we know that at least
one segment has that much energy.

Cheers, Elton.

Elton Smith
Jefferson Lab MS 12H5
12000 Jefferson Ave
Suite # 16
Newport News, VA 23606
elton@jlab.org
(757) 269-7625
(757) 269-6331 fax

On Tue, 14 Jul 2009 semenov@jlab.org wrote:

> Elton:
>
> What did you plot in the figure 9 of the gluex-doc-1300 note?
>
> The caption says that it's "maximum number of photoelectrons detected in
> the first layer". What's that?
>
> If you meant the sum of photoelectrons in the four cells of the first
> layer, the spectra you show looks strange: with your 23 pe/MeV conversion
> factor, the means of your downstream and upstream spectra are 34.25 and
> 95.19 (respectively) that is significantly bigger values than we have in
> our report for 45 pe/MeV conversion for the sum of four cells of the first
> layer (24.56 and 55.81 respectively, see Figs.27 and 23 of gluex-doc-1301
> or the attachment to this e-mail). Because you used the ntuple that were
> produced by Irina, your numbers must be SMALLER than ours by the factor
> (23/45).
>
> Most probably, you used wrong variables from the ntuples. I did not check
> it, but you might have the same problem with your figures 10,11,12 also.
>
> Another issue is that for photoelectrons you can not just scale the
> spectra is you use another MeV-to-pe conversion factor. Irina will prepare
> the correct figures for you tomorrow.
>
> Sorry,
> Andrei
>
>
>
>
> >
> > Dear collaborators,
> >
> > I have uploaded a new version of the cover document, including a summary.
> > Please send me any feedback by noon JLab time, so I can place final
> > documents on the web site for reviewers.
> >
> > Thanks, Elton.
> >
> > Elton Smith
> > Jefferson Lab MS 12H5
> > 12000 Jefferson Ave
> > Suite # 16
> > Newport News, VA 23606
> > elton@jlab.org
> > (757) 269-7625
> > (757) 269-6331 fax
> >
>