[G12] g11 correction factpr

[Johann Goetz]

I got the 6% from what Marco and Rafaella called the Delta t correction
which was directly tied to the start counter. We had gotten an efficiency of
about 95% for the start counter per track so this seemed reasonable since it
was not already done by gsim.

I noticed in the CMU report that they said the error on the flux reported by
gflux was due to an incorrect live time in the TGRS bank. This was fixed
according to them by the replacement of a trigger supervisor module that
happened before g12 but after g11. This does not seem related to the
intensity dependent efficiency of the CLAS though. I would however, like
some verification that this problem was fixed in gflux otherwise we'll have
to make corrections (the live reported prior to the fix was the square-root
of the actual live time apparently)

As you say, the trigger efficiency feature was absent in g12 and so I
ignored it. Furthermore, the agreement between the (K+ K+) and (K+ K+
proton) events shows that the "3 track" events give the same excitation
function as the "2 track" events for my case.

Also, to the g12 group as a whole, If anyone has any concerns, I urge you to
bring them up to me in the next couple days. I have moved on to the last
part of my thesis which concerns the penta quarks which I am now calling
"iso-exotics"

On Thu, Oct 7, 2010 at 11:47 AM, Valery Kubarovsky <vpk at jlab.org> wrote:

> Hi Johann,
>
> I am not sure about 6% start counter efficiency per track. As I
> remember we had no such
> correction factor. We had trigger efficiency correction for 2 tracks
> events.
> This correction is absent when you have 3 particles in the event. The g12
> trigger has no such a feature.
>
> As concerning current-dependent correction factor, we had it. And it is
> about
> 16% as you pointed out in your paper.
>
> The comparison g11-g12 cross sections looks much more better now.
>
> Good luck,
> Valery
>
>
> 2010/10/6 Johann Goetz <jgoetz at ucla.edu>:
> > Hi Valery,
> > So Nefkens told me to just use the results from the g11 study and be done
> > with it. So that's what I'm going to do so I need some verification that
> the
> > values I use are valid. Could you please look at my thesis starting on
> the
> > bottom of page 110? I have added this correction to all the plots (though
> > the tables do not reflect the change yet).
> >
> > here is the updated version:
> > http://www.jlab.org/~goetz/thesis_draft5.7.pdf<http://www.jlab.org/%7Egoetz/thesis_draft5.7.pdf>
> >
> > what are you opinions on this? Thank you,
> > Johann.
> >
> >
> > 2010/10/6 Johann Goetz <jgoetz at ucla.edu>
> >>
> >> OK. im working on it right now. I'll email g12 when it is finished
> >> (probably tonight)
> >>
> >> On Wed, Oct 6, 2010 at 12:55 PM, Valery Kubarovsky <vpk at jlab.org>
> wrote:
> >>>
> >>> I don't know what is tripfixer. It looks like this factor is connected
> >>> with trips.
> >>> The correction that i am talking about is due to the high occupancy in
> >>> DC.
> >>> I believe that this factor is very close in g12.
> >>>  Page 6 Current dependent correction .
> >>> We can easily to check it out, if you will compare the normalized yield
> >>> at low anf high beam curent.
> >>> vk
> >>>
> >>> 2010/10/6 Johann Goetz <jgoetz at ucla.edu>:
> >>> > 35% vs 27% seems like a lot of room for error in this estimate.
> >>> >
> >>> > But the question I have is this: does this "tripfixer" program do the
> >>> > same
> >>> > thing as the flux corrections use by g11?
> >>> >
> >>> > The trigger and delta-t (ST efficiency) have not been taken into
> >>> > account so
> >>> > I can include them in this analysis
> >>> >
> >>> > 2010/10/6 Valery Kubarovsky <vpk at jlab.org>
> >>> >>
> >>> >> All in all we had about 50% correction factor.
> >>> >> See the page 13 of [37] presentation. And you cross section will be
> >>> >> the same as g11 I believe.
> >>> >> vk
> >>> >>
> >>> >>
> >>> >>
> >>> >>
> >>> >>
> http://clasweb.jlab.org/rungroups/e1-dvcs/wiki/index.php/Elastic_scattering
> >>> >>
> >>> >> At the bottom of the page you will find this:
> >>> >>
> >>> >>
> >>> >> [37] Test of normalization procedure made by Marco Battaglieri and
> >>> >> Rafaella de Vita for g11 data set.
> >>> >>
> >>> >> - Page 6 Current dependent correction - 15-20 % at 60-65 nA,
> >>> >> extrapolation to zero current.
> >>> >>
> >>> >> - Page 10. Trigger efficiency study. Comparison of open (1 sector
> >>> >> trigger) and production trigger (2 sectors trigger) shows possible
> >>> >> problems of trigger inefficiency depending on the number of tracks
> ->
> >>> >> possible problem with L1 trigger. No trigger inefficiency was
> observed
> >>> >> for the events with at least 3 tarcks. Trigger bit word found to be
> >>> >> wrong: 10% of the recorded events in production runs have only 1
> >>> >> sector bit set. Applied correction factor for 2 tracks topology is
> >>> >> about 15%.
> >>> >>
> >>> >> - page 13. List of all g11 corrections: Flux 19%, trigger 15%.
> >>> >>
> >>> >>
> >>> >> [38] CMU group analysis of the g11 normalization procedure.
> >>> >>
> >>> >> - Page 11. ρ and ω yield as a function of the beam current.
> Correction
> >>> >> at I=65 nA is 27%.
> >>> >
> >>> >
> >>> >
> >>> > --
> >>> > Johann Goetz
> >>> > jgoetz at ucla.edu
> >>> > UCLA Dept. Physics & Astronomy
> >>> > Nefkens Group
> >>> >
> >>
> >>
> >>
> >> --
> >> Johann Goetz
> >> jgoetz at ucla.edu
> >> UCLA Dept. Physics & Astronomy
> >> Nefkens Group
> >
> >
> >
> > --
> > Johann Goetz
> > jgoetz at ucla.edu
> > UCLA Dept. Physics & Astronomy
> > Nefkens Group
> >
>



-- 
Johann Goetz
jgoetz at ucla.edu
UCLA Dept. Physics & Astronomy
Nefkens Group
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