[Frost] [EXTERNAL] Re: Follow up of last FROST meeting
Nicholas Zachariou
nickzachariou at gmail.com
Sat Dec 28 22:26:48 EST 2019
Then in that case it should show up in different dilution factor for the first half of the target as compared to the second half. This should be rather straightforward to show.
If one can argue that the shapes are correct (vertex resolution) one can use these to tailor the z vertex cuts on a bin by bin basis.
Sent from my iPhone
> On 29 Dec 2019, at 02:47, Michael Dugger <dugger at jlab.org> wrote:
>
> Hi,
>
> The same problem applies for the separation of carbon from butanol. There
> is no way to distinguish the two types of bound content. The neural net is
> making some sort of distinction that, on the face of it, looks reasonably
> good. It looks like there are two gaussian distributions that overlap. The
> problem is that there is no reason to believe that the separation is in
> any way faithful. Part of the carbon tail in the overlap region is
> actually some combination of carbon and butanol and part of the butanol
> tail in the overlap region is actually some combination of carbon and
> butanol. We just do not know the relative amounts. Perhaps the shapes are
> somewhat correct and we could make a good guess as to the proportion of
> each type of events in the overlap?
>
> In short, the separation looks nice but can not be used as representing
> pure samples of carbon (or butanol) in the overlap region.
>
> Take care,
> Michael
>
>> I agree that the classification of free vs bound protons is not possible.
>> What the plot he sent shows (maybe thats just me misreading it) is the
>> classification of events based on target: i.e. butanol vs carbon. If the
>> ML can correctly classify butanol vs carbon events then a vertex cut is
>> not really essential. If he can show that the dilution (ratio of bound to
>> total) is the same between events classified as butanol and events with
>> tight z vertex cuts, that is a first indication that the classification is
>> adequate.
>>
>> I might not be following the discussion or have miss-interpreted things:
>> its 2am here afterall :)
>>
>> Sent from my iPhone
>>
>>>> On 29 Dec 2019, at 00:55, Michael Dugger <dugger at jlab.org> wrote:
>>>
>>> Hi,
>>>
>>> My impression of the machine learning implemented by Chan was that it
>>> was
>>> not able to separate the ice from the carbon.
>>>
>>> The problem is that there is no way to take an event originating from a
>>> free proton (like that in ice) and distinguish that event from one that
>>> originates from a bound proton (like that in carbon). Because of this,
>>> the
>>> two types of events are NOT linearly separable.
>>>
>>> Look at it this way: If Chan could remove the signal coming from ice
>>> from
>>> that of carbon, why not just classify the free proton directly from the
>>> bound content within butanol?
>>>
>>> If machine learning could distinguish free proton from bound, there
>>> would
>>> be no need for a carbon subtraction we would just use machine learning
>>> to
>>> do the separation.
>>>
>>> In the MM-Sq region that is physical, the protons from bound and unbound
>>> have angles and momentum that overlap and can not be distinguished from
>>> one another.
>>>
>>> Take care,
>>> Michael
>>>
>>>> Hi Chan,
>>>>
>>>> I dont know the details of your classification, but my first impression
>>>> is
>>>> yes. If you have a reliable classification then you can (in principle)
>>>> not
>>>> apply z vertex cuts. You can just use your butanol events as chosen by
>>>> the
>>>> classification And your carbon events for establishing the bound
>>>> nucleon
>>>> contributions. This would of course need to be studied in a systematic
>>>> way
>>>> and a classification uncertainty needs to be established. It looks like
>>>> you were also able to remove the ice build up downstream the carbon
>>>> target. Might be good to see the missing masses originating from the
>>>> two
>>>> targets. A quick check for your classification would be to plot the
>>>> missing mass of events coming with z vertex that selects the first half
>>>> of
>>>> your target (any events away from the carbon target ). Then scale this
>>>> and
>>>> see if you can get the missing mass distribution to match the one from
>>>> your classified butanol events. If it does, it means you are correctly
>>>> removing any contributions from the carbon target which would only
>>>> contribute to background. If you fail to match the free proton peak and
>>>> the bound nucleon contributions it means that the classification might
>>>> need some work.
>>>>
>>>> Sent from my iPhone
>>>>
>>>>>> On 28 Dec 2019, at 21:26, Chan Kim <kimchanwook at gwmail.gwu.edu>
>>>>>> wrote:
>>>>>
>>>>>
>>>>> Thank you for your replies.
>>>>>
>>>>> @Michael,
>>>>> For the z-vertex plot, only p<300MeV particles are removed. I will
>>>>> change the momentum selection region and see how z-vertex resolution
>>>>> changes as soon as I have other steps finished. I kept them for now,
>>>>> so
>>>>> I can compare my asymmetry with and without particles with p=[300,
>>>>> 400]
>>>>> MeV.
>>>>>
>>>>> @Nick,
>>>>> In regards to free polarized proton contributions in carbon vertex
>>>>> (left
>>>>> tail of the carbon distribution), would it be ok to use classification
>>>>> results from machine learning? Below is a plot of separation of
>>>>> butanol
>>>>> and carbon in small angles.
>>>>> https://clasweb.jlab.org/rungroups/g9/wiki/images/0/06/Zvrt_1bin_angle.png
>>>>>
>>>>> Thank you,
>>>>> Chan
>>>>>
>>>>>
>>>>>> On Sat, Dec 28, 2019 at 12:42 PM Nicholas Zachariou
>>>>>> <nickzachariou at gmail.com> wrote:
>>>>>> Dear Chan,
>>>>>>
>>>>>> I have done several studies on this that should be documented in my
>>>>>> analysis note. As Michael said, the difficulty lies in the
>>>>>> determination of the dilution factor. If you are using carbon data to
>>>>>> determine this, then you need to make sure you account correctly for
>>>>>> free polarised proton contributions within your carbon vertex cut
>>>>>> that
>>>>>> actually comes from butanol events (this is different than the ice
>>>>>> built up). If you are using parametrization of the bound nucleon
>>>>>> contributions then the dilution is more straightforward, but you
>>>>>> would
>>>>>> need to think/study free unpolarised proton contributions to butanol
>>>>>> events from the ice built up downstream your carbon target. This can
>>>>>> been done by varying the butanol z vertex cut andcomparing your
>>>>>> determined observable. There are several ways you can do this and we
>>>>>> can chat more if needed.
>>>>>>
>>>>>> Best regard,
>>>>>> Nick
>>>>>>
>>>>>> Sent from my iPhone
>>>>>>
>>>>>>> On 28 Dec 2019, at 16:23, Michael Dugger <dugger at jlab.org> wrote:
>>>>>>>
>>>>>>> Chan,
>>>>>>>
>>>>>>> The variables that are important are polar angle and momentum of the
>>>>>>> identified particle. Did you keep the low momentum protons?
>>>>>>>
>>>>>>> When it comes to choosing the range of vertex selection for each
>>>>>> target,
>>>>>>> the method you use for removing the bound nucleon content might be a
>>>>>>> factor. From the plots you created, you can see the difficulty that
>>>>>> you
>>>>>>> face at low angle.
>>>>>>>
>>>>>>> At low polar angle you have the case that there very well could be
>>>>>> some
>>>>>>> leakage of carbon vertices in your butanol definition. This could
>>>>>> cause
>>>>>>> dilution factors to be messed up.
>>>>>>>
>>>>>>> I would cautiously move forward concentrating on the bins that look
>>>>>> good.
>>>>>>> Once everything was running well for the "good" stuff, I would start
>>>>>>> trying to fix the more difficult bins.
>>>>>>>
>>>>>>> Take care,
>>>>>>> Michael
>>>>>>>
>>>>>>>> Hello Michael,
>>>>>>>>
>>>>>>>> The pi0 mass shifting from 125MeV (slide 2) to 134MeV (slide 6)
>>>>>> happened
>>>>>>>> simply due to a change in number of bins. On slide 6, I tried to
>>>>>> have the
>>>>>>>> same binning for both ELOSS and ELOSS+momentum correction
>>>>>>>> distributions,causing inaccurate peak locations. After momentum
>>>>>>>> correction,
>>>>>>>> the mmsq distribution has much sharper peaks. So, 125MeV is the
>>>>>> correct
>>>>>>>> value of mmsq after ELOSS distribution, but for ELOSS + momentum
>>>>>>>> correction, I will redo the calculation. Sorry for the confusion.
>>>>>>>>
>>>>>>>> I have another question regarding the z-vertex resolution in
>>>>>>>> angles.
>>>>>> Below
>>>>>>>> is a plot that Eugene suggested to make (Z-vertex position in bins
>>>>>> of
>>>>>>>> photon energies and angle bins).
>>>>>>>> https://clasweb.jlab.org/rungroups/g9/wiki/images/a/ac/Zvrt_select_lab.png
>>>>>>>>
>>>>>>>> As you can see, the z-vertex resolution is very poor in small
>>>>>> scattering
>>>>>>>> angles, unable to clearly distinguish the butanol and carbon
>>>>>>>> region.
>>>>>> do
>>>>>>>> you
>>>>>>>> have any suggestions in choosing the selection ranges for small
>>>>>> angles..?
>>>>>>>>
>>>>>>>> Thank you,
>>>>>>>> Chan
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>> On Thu, Dec 26, 2019 at 4:53 PM Michael Dugger <dugger at jlab.org>
>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> Chan,
>>>>>>>>>
>>>>>>>>> It is probably a good idea to try and keep the low momentum
>>>>>>>>> events,
>>>>>> but
>>>>>>>>> I
>>>>>>>>> would start out by removing them. Once you feel like you have
>>>>>> everything
>>>>>>>>> else under control, then you add in the p < 400 MeV/c events.
>>>>>>>>>
>>>>>>>>> You can see if the momentum cut makes the pi0 mass closer to the
>>>>>> nominal
>>>>>>>>> value. Essentially, you just recreate slides 2 and 6 from your
>>>>>> December
>>>>>>>>> 18
>>>>>>>>> update:
>>>>>>>>>
>>>>>>>>> https://clasweb.jlab.org/rungroups/g9/wiki/images/9/94/FROST_2019_12_18.pdf
>>>>>>>>>
>>>>>>>>> Note: On slide 2 you have pre-ELOSS mass of pi0 = 196 MeV and
>>>>>> post-ELOSS
>>>>>>>>> mass of pi0 = 125 MeV. BUT on slide 6 you have post-ELOSS mass of
>>>>>> pi0 =
>>>>>>>>> 134 MeV!! How did that happen? Then after ELOSS + momentum
>>>>>> correction
>>>>>>>>> the
>>>>>>>>> pi0 mass = 89 MeV. You want to get that all straightened out with
>>>>>> the p
>>>>>>>>>>
>>>>>>>>> 400 MeV/c events. You mass of the pi0 after the ELOSS and momentum
>>>>>>>>> corrections should be the correct value. The momentum correction
>>>>>>>>> is
>>>>>>>>> designed to bring the pi0 mass to the correct value.
>>>>>>>>>
>>>>>>>>> Take care,
>>>>>>>>> Michael
>>>>>>>>>
>>>>>>>>>> Hello Michael,
>>>>>>>>>>
>>>>>>>>>> Yes, I now understand what you are saying about the momentum
>>>>>>>>> acceptance
>>>>>>>>>> varying rapidly between 300 and 400 MeV around scattering angle
>>>>>>>>>> of
>>>>>>>>> 35deg.
>>>>>>>>>>
>>>>>>>>>> Would it be a bad idea to apply different low momentum cuts for
>>>>>>>>> particles
>>>>>>>>>> under 35deg and above 35deg? So, 400MeV for particles with angle
>>>>>>>>>> <
>>>>>>>>> 35deg
>>>>>>>>>> and 300MeV for particles with angle >35deg.
>>>>>>>>>> Because for higher energy photon events (photon energy > 1 GeV),
>>>>>> it
>>>>>>>>> looks
>>>>>>>>>> like there are lots of events in p = [350, 400] MeV region.
>>>>>>>>>>
>>>>>>>>>> Thank you,
>>>>>>>>>> Chan
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Tue, Dec 24, 2019 at 3:50 AM Michael Dugger <dugger at jlab.org>
>>>>>>>>> wrote:
>>>>>>>>>>
>>>>>>>>>>> Chan,
>>>>>>>>>>>
>>>>>>>>>>> For these sorts of plots it is interesting to make an additional
>>>>>> MM^2
>>>>>>>>>>> cut.
>>>>>>>>>>> If you make a missing mass cut near the mass of the pion, you
>>>>>>>>> restrict
>>>>>>>>>>> the
>>>>>>>>>>> events to have the kinematics of
>>>>>>>>>>>
>>>>>>>>>>> gamma p -> p pi0 .
>>>>>>>>>>>
>>>>>>>>>>> As it currently stands, you are showing the theta versus
>>>>>>>>>>> momentum
>>>>>>>>>>> distribution for all possible reactions. This is not a bad thing
>>>>>> and
>>>>>>>>> the
>>>>>>>>>>> plots have interesting features.
>>>>>>>>>>>
>>>>>>>>>>> The depletion stripes are probably bad time-of-flight paddles.
>>>>>> You
>>>>>>>>> can
>>>>>>>>>>> see
>>>>>>>>>>> from the depletion stripes how the magnetic field is bending the
>>>>>> path
>>>>>>>>> of
>>>>>>>>>>> the charged particles as a function of momentum.
>>>>>>>>>>>
>>>>>>>>>>> The enhancement stripes are probably from the reaction gamma p
>>>>>>>>>>> ->
>>>>>> p
>>>>>>>>> pi0
>>>>>>>>>>> (compare to
>>>>>>>>> https://userweb.jlab.org/~dugger/pi0PphaseSpacePlotNew.png
>>>>>>>>>>> ).
>>>>>>>>>>>
>>>>>>>>>>> You can clearly see the acceptance in polar angle and momentum.
>>>>>> For
>>>>>>>>>>> angle
>>>>>>>>>>> above 35 degrees, it looks like the momentum acceptance is
>>>>>> rapidly
>>>>>>>>>>> changing between 300 and 400 MeV/c. This is probably the
>>>>>>>>>>> clearest
>>>>>>>>>>> evidence
>>>>>>>>>>> that a cut at 400 MeV/c is appropriate. For angles below ~35
>>>>>> degrees
>>>>>>>>> the
>>>>>>>>>>> momentum acceptance issue is being caused by a bad
>>>>>>>>>>> time-of-flight
>>>>>>>>>>> paddle.
>>>>>>>>>>>
>>>>>>>>>>> Take care,
>>>>>>>>>>> Michael
>>>>>>>>>>>
>>>>>>>>>>>> Hello All,
>>>>>>>>>>>>
>>>>>>>>>>>> Here is a plot of momentum vs lab angle in bins of photon
>>>>>> energies.
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>> https://clasweb.jlab.org/rungroups/g9/wiki/images/2/2e/Low_mome_select_p_abs_theta.png
>>>>>>>>>>>>
>>>>>>>>>>>> Thank you,
>>>>>>>>>>>> Chan
>>>>>>>>>>>>
>>>>>>>>>>>> On Mon, Dec 23, 2019 at 3:47 PM Chan Kim
>>>>>>>>> <kimchanwook at gwmail.gwu.edu>
>>>>>>>>>>>> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> Hello Michael,
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thank you for your suggestion! I should have been more clear
>>>>>> about
>>>>>>>>>>> the
>>>>>>>>>>>>> plots. The mmsq distribution I sent out yesterday was prior to
>>>>>> any
>>>>>>>>>>> event
>>>>>>>>>>>>> selections.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I have two quick questions..
>>>>>>>>>>>>> 1. For momentum ranges of [0.31, 0.39] GeV, the mmsq
>>>>>> distribution
>>>>>>>>>>> (ones
>>>>>>>>>>>>> I
>>>>>>>>>>>>> sent yesterday) look like a gaussian distribution centered
>>>>>>>>>>>>> near
>>>>>> 0,
>>>>>>>>>>> plus
>>>>>>>>>>>>> a
>>>>>>>>>>>>> bump at 1GeV. Are these events bad because of these bumps at
>>>>>> 1GeV?
>>>>>>>>>>>>>
>>>>>>>>>>>>> 2. Are events with backward scattering angles not good because
>>>>>>>>> they
>>>>>>>>>>>>> don't
>>>>>>>>>>>>> have information from DC?? since the drift chamber only covers
>>>>>>>>> from
>>>>>>>>>>> 8deg
>>>>>>>>>>>>> to
>>>>>>>>>>>>> 142deg???
>>>>>>>>>>>>>
>>>>>>>>>>>>> Regards,
>>>>>>>>>>>>> Chan
>>>>>>>>>>>>>
>>>>>>>>>>>>> On Mon, Dec 23, 2019 at 3:33 PM Michael Dugger
>>>>>> <dugger at jlab.org>
>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> Hi,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The last plot was for pion lab-momentum and lab-angles and
>>>>>>>>>>>>>> the
>>>>>>>>>>>>>> center-of-mass angle definitions were also messed up :(
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> I have a new plot at
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> https://userweb.jlab.org/~dugger/pi0PphaseSpacePlotNew.png
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> The above plot shows that the momentum values below 400 MeV
>>>>>> ARE
>>>>>>>>>>>>>> important
>>>>>>>>>>>>>> for MANY kinematic bins.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> However, even with the knowledge that we would be killing a
>>>>>> bunch
>>>>>>>>> of
>>>>>>>>>>>>>> bins,
>>>>>>>>>>>>>> we may have to remove events with momentum below 400 MeV due
>>>>>> to
>>>>>>>>> our
>>>>>>>>>>>>>> possible inability to reconstruct the missing pi0 at low
>>>>>>>>> momentum.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Sorry about any confusion my previous plot may have caused.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Take care,
>>>>>>>>>>>>>> Michael
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Eugene,
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Thanks for catching that. I think I have pion angles instead
>>>>>> of
>>>>>>>>>>>>>> proton.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> I am going to back over the code to fix this.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Take care,
>>>>>>>>>>>>>>> Michael
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> Mike,
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> The vertical axis can't be right. The proton can't go
>>>>>>>>> backwards
>>>>>>>>>>> in
>>>>>>>>>>>>>> the
>>>>>>>>>>>>>>>> lab
>>>>>>>>>>>>>>>> system
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> -Eugene
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> -----Original Message-----
>>>>>>>>>>>>>>>>> From: Frost <frost-bounces at jlab.org> On Behalf Of Michael
>>>>>>>>> Dugger
>>>>>>>>>>>>>>>>> Sent: Monday, December 23, 2019 14:07
>>>>>>>>>>>>>>>>> To: Stuart Fegan <s.fegan.glasgow at gmail.com>
>>>>>>>>>>>>>>>>> Cc: frost at jlab.org
>>>>>>>>>>>>>>>>> Subject: Re: [Frost] [EXTERNAL] Re: Follow up of last
>>>>>>>>>>>>>>>>> FROST
>>>>>>>>>>> meeting
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Hi,
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Chan is just trying to answer questions raised about a
>>>>>>>>> possible
>>>>>>>>>>>>>>>>> momentum
>>>>>>>>>>>>>>>>> cut. I suggested that he look at where his events are in
>>>>>>>>> terms
>>>>>>>>>>> of
>>>>>>>>>>>>>>>>> kinematic
>>>>>>>>>>>>>>>>> bins he will report on. My idea was to see if pushing up
>>>>>> the
>>>>>>>>>>>>>> momentum
>>>>>>>>>>>>>>>>> cut
>>>>>>>>>>>>>>>>> to perhaps 400 MeV would cause any issues within his
>>>>>>>>> kinematic
>>>>>>>>>>>>>> binning.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I just made a plot that can be found at
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> https://userweb.jlab.org/~dugger/pi0PphaseSpacePlot.png
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> that shows the lab angle versus lab momentum for protons
>>>>>>>>> coming
>>>>>>>>>>>>>> from
>>>>>>>>>>>>>>>>> the
>>>>>>>>>>>>>>>>> reaction gamma p -> p pi0. The black curves are for
>>>>>> constant
>>>>>>>>>>> photon
>>>>>>>>>>>>>>>>> energy
>>>>>>>>>>>>>>>>> and the blue curves are for constant proton center-of-mass
>>>>>>>>>>> cosine
>>>>>>>>>>>>>>>>> values.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> The above plot would have to be verified but it looks like
>>>>>>>>> there
>>>>>>>>>>> is
>>>>>>>>>>>>>> no
>>>>>>>>>>>>>>>>> need to
>>>>>>>>>>>>>>>>> worry about low momentum protons.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> The idea I had was for Chan to produce this type of
>>>>>>>>> information
>>>>>>>>>>>>>> using
>>>>>>>>>>>>>>>>> real
>>>>>>>>>>>>>>>>> data, but I did a poor job of explaining what I meant.
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> I was trying to make life easier, but perhaps did not
>>>>>>>>> accomplish
>>>>>>>>>>>>>> that
>>>>>>>>>>>>>>>>> :(
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Take care,
>>>>>>>>>>>>>>>>> Michael
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Hi Chan,
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> I'm going to chuck my two cents in, and reply to the
>>>>>>>>>>>>>>>>>> FROST
>>>>>>>>>>> list,
>>>>>>>>>>>>>>>>>> because I missed the meeting last week. Given the
>>>>>>>>> pion
>>>>>>>>>>> is
>>>>>>>>>>>>>>>>>> reconstructed from the proton missing mass, what's the
>>>>>>>>>>> motivation
>>>>>>>>>>>>>> for
>>>>>>>>>>>>>>>>>> looking at proton momenta below the threshold where it
>>>>>>>>>>>>>>>>>> can
>>>>>>>>>>>>>> reliably
>>>>>>>>>>>>>>>>>> reconstructed in CLAS as a proton? Is this to tune
>>>>>>>>> the
>>>>>>>>>>> cut,
>>>>>>>>>>>>>> perform
>>>>>>>>>>>>>>>>>> systematic studies, or is there a physics motivation here
>>>>>>>>> that
>>>>>>>>>>>>>> I'm
>>>>>>>>>>>>>>>>> missing?
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Cheers,
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> Stuart
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> On 23/12/2019 11:47, Michael Dugger wrote:
>>>>>>>>>>>>>>>>>>> Chan,
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> It is a bit of a data dump.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> What is your binning going to by for the analysis? Are
>>>>>> you
>>>>>>>>>>>>>> really
>>>>>>>>>>>>>>>>>>> going to report values for E_gamma near 400 MeV?
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> On slide 3 you show MM^2 and state that MM^2 for p < 280
>>>>>>>>>>> MeV/c
>>>>>>>>>>>>>> don't
>>>>>>>>>>>>>>>>>>> look like the others. I'm not convinced that you can say
>>>>>>>>> much
>>>>>>>>>>>>>> about
>>>>>>>>>>>>>>>>>>> the MM^2 shown above p = 280 MeV/c.
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> For your previous presentation:
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>> https://clasweb.jlab.org/rungroups/g9/wiki/images/9/94/FROST_2019_12_
>>>>>>>>>>>>>>>>>>> 18.pdf
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> on slide 2 you had a nice fit to the MM^2 distribution
>>>>>>>>> where
>>>>>>>>>>> you
>>>>>>>>>>>>>>>>>>> pulled off a pi0 mass. Are you able to do that for the
>>>>>> low
>>>>>>>>>>>>>> momentum?
>>>>>>>>>>>>>>>>>>> Is it possible that you can not pull out any pi0 from
>>>>>>>>>>>>>>>>>>> the
>>>>>>>>> low
>>>>>>>>>>>>>>>>>>> momentum data? I just do not see any pi0. Am I missing
>>>>>>>>>>>>>> something?
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> Take care,
>>>>>>>>>>>>>>>>>>> Michael
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> Dear FROST run group,
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> Hello, below is a link to my slides for follow up of
>>>>>> last
>>>>>>>>>>> FROST
>>>>>>>>>>>>>>>>>>>> meeting(12/19):
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>> https://clasweb.jlab.org/rungroups/g9/wiki/images/e/ed/FROST_2019_12
>>>>>>>>>>>>>>>>>>>> _22.pdf
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> 1. Distributions of kinematics (MMSQ, dt, d\beta) for
>>>>>>>>>>> particles
>>>>>>>>>>>>>> in
>>>>>>>>>>>>>>>>>>>> lower momentum ranges are plotted to see whether lower
>>>>>>>>>>> momentum
>>>>>>>>>>>>>>>>>>>> particles are of any use for my asymmetry calculation.
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> 2. Proton selection, using beta difference, was revised
>>>>>>>>> to a
>>>>>>>>>>>>>>>>> simpler
>>>>>>>>>>>>>>>>>>>> version where static cuts on beta diff are applied at
>>>>>> +/-
>>>>>>>>>>> 0.06
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> Thank you,
>>>>>>>>>>>>>>>>>>>> Chan
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>>>>>> Frost mailing list
>>>>>>>>>>>>>>>>>>>> Frost at jlab.org
>>>>>>>>>>>>>>>>>>>> https://mailman.jlab.org/mailman/listinfo/frost
>>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>>>>> Frost mailing list
>>>>>>>>>>>>>>>>>>> Frost at jlab.org
>>>>>>>>>>>>>>>>>>> https://mailman.jlab.org/mailman/listinfo/frost
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> --
>>>>>>>>>>>>>>>>>> Dr Stuart Fegan
>>>>>>>>>>>>>>>>>> Honorary Research Associate
>>>>>>>>>>>>>>>>>> Nuclear Physics Group
>>>>>>>>>>>>>>>>>> University of Glasgow
>>>>>>>>>>>>>>>>>> (Currently at the University of York)
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> E-mail: s.fegan.glasgow at gmail.com
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>>>> Frost mailing list
>>>>>>>>>>>>>>>>>> Frost at jlab.org
>>>>>>>>>>>>>>>>>> https://mailman.jlab.org/mailman/listinfo/frost
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>>>>> Frost mailing list
>>>>>>>>>>>>>>>>> Frost at jlab.org
>>>>>>>>>>>>>>>>> https://mailman.jlab.org/mailman/listinfo/frost
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>>>> Frost mailing list
>>>>>>>>>>>>>> Frost at jlab.org
>>>>>>>>>>>>>> https://mailman.jlab.org/mailman/listinfo/frost
>>>>>>>>>>>>>>
>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> _______________________________________________
>>>>>>>>>>> Frost mailing list
>>>>>>>>>>> Frost at jlab.org
>>>>>>>>>>> https://mailman.jlab.org/mailman/listinfo/frost
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Frost mailing list
>>>>>>> Frost at jlab.org
>>>>>>> https://mailman.jlab.org/mailman/listinfo/frost
>>>>
>>>
>>>
>>
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