[G12] GFlux
Michael C. Kunkel
mkunkel at jlab.org
Fri Mar 28 16:22:52 EDT 2014
Greetings,
I am wondering if Johann's trip program takes into account the tagger
hit status to be 7 or 15 as well as does the GFlux calculator when using
the "good" option take this into account?
Also, Eugene, when you wrote to look at the flux and yield and
normalized yield per E-bin, would the yield of pi0 suffice?
BR
MK
On 3/28/14 4:13 PM, Eugene Pasyuk wrote:
> The other thing is to make sure when you select your events and match
> them to the tagger you use tagger hits with status 7 or 15 only.
>
> -Eugene
>
> ------------------------------------------------------------------------
>
> *From: *"Eugene Pasyuk" <pasyuk at jlab.org>
> *To: *"Michael C. Kunkel" <mkunkel at jlab.org>
> *Cc: *"g12" <g12 at jlab.org>, "Johann Goetz" <theodore.goetz at gmail.com>
> *Sent: *Friday, March 28, 2014 4:04:41 PM
> *Subject: *Re: [G12] GFlux
>
> The way to figure out is to look at the flux and yield and
> normalized yield per E-bin, that is the finest binning. If they
> are consistent, the the problem is in re-binning procedure. If
> they are not, then we have to look further. Technically speaking
> there is not unusual that you may have holes on photon spectrum,
> that would just indicate that some of the counters are dead.
>
> -Eugene
>
> ------------------------------------------------------------------------
>
> *From: *"Michael C. Kunkel" <mkunkel at jlab.org>
> *To: *"Eugene Pasyuk" <pasyuk at jlab.org>, "Johann Goetz"
> <theodore.goetz at gmail.com>
> *Cc: *"g12" <g12 at jlab.org>
> *Sent: *Friday, March 28, 2014 3:55:45 PM
> *Subject: *Re: [G12] GFlux
>
> Greetings,
>
> I am wondering where we are at with the flux issue?
> Meaning, what is going on with the flux in the 3.5 GeV region?
>
> I feel that the flux is in error for a few reasons.
> First when I bin flux in 15 MeV, I see 0 flux at 3.515 - 3.53.
> Second, when I bin flux in 50 MeV binning I see a drop in flux
> at 3.5 MeV
> Here is the output
> //
> 3.45 3.5 1.06825209003e+12
> 3.5 3.55 470202243457.0
> 3.55 3.6 1.69234003548e+12
> //
>
> Third reason is that if you look at my attached pdf, I show
> the pi0 cross section for various energies, if you were to go
> to compare the cross sections around 3.5 GeV to the
> neighboring Egamma bins, you will notice a sizable
> discrepancy. See G12_XSection_ALL.pdf
>
> Fourth reason, if I were to compare the pi0 cross section in
> unit of dsigma/dt and compare it other experiments at 4 and 5
> GeV, our cross section is off by a factor of 2, see
> t_vs_dsigdt_Compare.pdf
>
> In order for any g12 papers to be published, we need
> verification of cross sections, which as of this moment I do
> not believe we have.
>
> BR
> MK
>
>
>
>
> On 3/25/14 10:16 PM, Eugene Pasyuk wrote:
>
> This is not quite correct, especially when bins are small
> and comparable with the width of E-bin.
> Just imagine, You energy bin is 3.000-3.015 GeV. E-bin
> let's say covers 3.0121-3.0181 GeV. The center of E-bin
> will be 3.01505 GeV. When you enter this into the
> histogram it will fall to 3.015-3.030 bin then. However,
> this E-bin should be split between two adjacent bins in
> new binning scheme. There are two possible ways of doing
> this. Either randomize energy within the width of the
> E-bin before you enter it to th ehistogram, or split it
> between adjacent bins using weight which depends on how
> the bin boundary splits E-bin and have two entries to the
> histogram with sum of the weights equal one. You can
> imagine, if the bin width is chosen to be less than the
> widths of E-bin, then you will get completely empty bins
> in resulting histogram.
>
> -Eugene
>
> ------------------------------------------------------------------------
>
> *From: *"Johann Goetz" <theodore.goetz at gmail.com>
> *To: *"Eugene Pasyuk" <pasyuk at jlab.org>
> *Sent: *Tuesday, March 25, 2014 9:12:49 PM
> *Subject: *Re: [G12] GFlux
>
> I consider the beam energy to be the center of the
> energy paddle and fill the histogram at that energy
> with the number if counts in the gflux file. Is that
> wrong?
>
> On Mar 25, 2014 5:59 PM, "Eugene Pasyuk"
> <pasyuk at jlab.org <mailto:pasyuk at jlab.org>> wrote:
>
> I see four numbers in each row in this file. I
> figured the first one is E-bin number. What are
> the other three? I guess the second and the fourth
> are some energies. What is the third number which
> is integer and varies a lot.
> When you say you "histogram" does it mean you take
> one fixed number for each E-bin (beam centroid?)
> and put it in the histogram, or something else?
>
> -Eugene
>
> ------------------------------------------------------------------------
>
> *From: *"Johann Goetz"
> <theodore.goetz at gmail.com
> <mailto:theodore.goetz at gmail.com>>
> *To: *"g12" <g12 at jlab.org <mailto:g12 at jlab.org>>
> *Sent: *Tuesday, March 25, 2014 5:40:42 PM
> *Subject: *Re: [G12] GFlux
>
> The output of gflux includes a file that has
> the energies of the individual energy paddles
> and the counts. These files are then used to
> fill a histogram in the g12-gflux script where
> the range and bins are specified on the
> command line. The energies are slightly
> "corrected" to the ones found in the following
> file:
> /group/clas/parms/pcor/g12/tagger_energies.dat
> But, the correction is very small and averaged
> over the whole run period (i.e. not one a
> run-by-run basis).
>
> And before you ask, the the summing of the
> flux is valid to at least 4 figures -
> probably 5.
>
> -- Johann
> <https://sites.google.com/site/theodoregoetz/>
>
>
> On Tue, Mar 25, 2014 at 4:28 PM, Michael C.
> Kunkel <mkunkel at jlab.org
> <mailto:mkunkel at jlab.org>> wrote:
>
> Greetings,
>
> If the data shows a hole at beam energies,
> how does the gflux for this
> energy have events?
> Below is a table of Gflux for 15MeV
> binning, which is to fine for
> analysis but great for illustrating this
> question.
>
> Also, notice the 0 entries at 3.5 GeV, and
> low events in neighbors.
> FORMAT: Emin:Emax:Flux
>
>
>
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