PROBLEM REMAINS with gluex-doc-1300

[semenov@jlab.org]

Elton:

This explanation does not work. The problem is the figures I sent to you
contain the sum of numbers from the four cells of the 1st layer (viz., the
maximal signal + all 3 other "not-maximal" signals), and the numbers in
the spectra I sent to you are MUCH SMALLER than yours. Also, with
selection of the "maximal" signal, you can not go away from the big
zero-channel spike: if the sum of four signals is close to zero => the
maximal signal is close to zero too.

I still think that your figures made using not correct values from the
ntuples.

Sorry,
Andrei



>
>
> 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
>> >
>>
>