[G12] GFlux
Michael C. Kunkel
mkunkel at jlab.org
Fri Mar 28 17:15:05 EDT 2014
Greetings,
If I understood Eugene correctly, then what I did was plot the beam
energy in 6 MeV bins for all events from the pi0.
I also did this for the Glux, by creating a histogram of the output of
Johann's glfux calculator.
I am attaching the results, but saving judgment until my mistakes are
pointed out.
BR
MK
On 3/28/14 4:27 PM, Eugene Pasyuk wrote:
> reaction does not matter, pi0 or anything else
>
> -Eugene
>
> ------------------------------------------------------------------------
>
> *From: *"Michael C. Kunkel" <mkunkel at jlab.org>
> *To: *"Eugene Pasyuk" <pasyuk at jlab.org>
> *Cc: *"g12" <g12 at jlab.org>, "Johann Goetz" <theodore.goetz at gmail.com>
> *Sent: *Friday, March 28, 2014 4:22:52 PM
> *Subject: *Re: [G12] GFlux
>
> 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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