[G12] My multiple beam photon study

Thu Apr 2 13:47:02 EDT 2015

Greetings,

So does this mean normalization is dependent on run?

BR
MK
----------------------------------------
Michael C. Kunkel, PhD
Forschungszentrum Jülich
Nuclear Physics Institute and Juelich Center for Hadron Physics
Experimental Hadron Structure (IKP-1)
www.fz-juelich.de/ikp

On 4/2/15 7:22 PM, Rafael Badui wrote:
> Hi,
>
> To answer Lei’s question on how my results compares with MK’s, I have 
> attached my results and MK’s for run 56669. I did not use error bars 
> but the results look the same, nonetheless.
>
> I wanted to post this on the wiki page, but it seems that my jlab 
> password does not work anymore. Is anyone else having this issue?
>
>
> Best regards,
>
>
> Rafael
>
>
>
>
>
>
>
>> On Apr 1, 2015, at 7:57 AM, Michael C. Kunkel <mkunkel at jlab.org 
>> <mailto:mkunkel at jlab.org>> wrote:
>>
>> Greetings,
>>
>> I to was curious to know why FSU and myself did not agree, so I 
>> looked at the entire run range in which had the lepton trigger set, 
>> also the MorB configuration was the same.
>>
>> https://clasweb.jlab.org/rungroups/g12/wiki/index.php/TAGR_code#April_1
>>
>> I noticed an overall difference of 3% from when I used earlier runs. 
>> So I decided to look run by run and I noticed there was a dependence 
>> on run.
>>
>> For instance compare run 56726 to run 57195 using this
>> https://www.jlab.org/Hall-B/secure/g12/mkunkel/MULTIPLE_PHOTONS/Plot_1.pdf
>>
>> BR
>> MK
>> ----------------------------------------
>> Michael C. Kunkel, PhD
>> Forschungszentrum Jülich
>> Nuclear Physics Institute and Juelich Center for Hadron Physics
>> Experimental Hadron Structure (IKP-1)
>> www.fz-juelich.de/ikp
>> On 31/03/15 20:51, Lei Guo wrote:
>>> Hi, MK and Michael,
>>>
>>> In general I agree with Michael what you are showing is reasonable. 
>>> The 1-photon-only probability plot shows basically the percentage 
>>> (for Egamma > 3.6GeV) is about 86.6%+-1% (eyeballing). What Will 
>>> showed from his ppbar channel is about 87%+-1% (also eyeballing, and 
>>> he starts from 3.9GeV). There is no difference here. The two plots 
>>> (you and will) looks dramatically different because of the energy 
>>> range (x-axis), and because of will shows on the Y-axis from 0 to 
>>> 100%, and you zoomed in from 80% to 90%. It tells exactly the same 
>>> story.
>>>
>>> For the low energy part (Egamma <3.6 GeV), I think Michael’s 
>>> explanation is probably right — although I won’t call it trigger 
>>> efficiency or inefficiency. It’s only inefficient when a event that 
>>> should have triggered and been recorded did not get registered.
>>> But even if you compare these two ranges, it’s really a only 1.5% 
>>> difference. Do you think our systematic uncertainty on the 
>>> normalization is less than 1.5%? I think in the big picture, we are 
>>> fine.
>>>
>>> But I do agree with MK that his picture is different from FSU, 
>>> particularly in the low energy part, since it showed opposite trend.
>>>
>>> How does Rafael’s results compare with you, particularly for the low 
>>> energy part?
>>>
>>> Is it possible that again this is due to you and FSU are not showing 
>>> the data from exactly the same set of runs?
>>>
>>>
>>>
>>>
>>>
>>> Lei Guo
>>> Assistant Professor
>>> Physics Department
>>> Florida International University
>>> Miami, FL
>>>
>>> email: leguo at fiu.edu <mailto:leguo at fiu.edu> or lguo at jlab.org 
>>> <mailto:lguo at jlab.org>
>>> Office:305-348-0234
>>>
>>>> On Mar 31, 2015, at 2:31 PM, Michael Paolone <mpaolone at jlab.org 
>>>> <mailto:mpaolone at jlab.org>> wrote:
>>>>
>>>> Hi MK, All,
>>>>
>>>> This looks reasonable, and I think I can explain the energy 
>>>> dependence.
>>>> The key is that all events have to fire a trigger whose efficiency is
>>>> dependent on the momentum and angle of the tracks created from the
>>>> reaction which itself IS photon energy dependent.
>>>>
>>>> Look at the 1 photon probability plot and ask how likely is it that 
>>>> that
>>>> photon is the one that created the trigger.  For very low energy 
>>>> photons
>>>> the overall trigger efficiency drops, and since we see an event at 
>>>> all, it
>>>> becomes more likely that another higher energy photon in the same beam
>>>> bucket generated the reaction that triggered the event.
>>>>
>>>> The sharp jump at 3.6 GeV shows that the event is now more likely to
>>>> trigger with just that photon (since that's where the primary trigger
>>>> starts).
>>>>
>>>> The downward slope after 3.6 GeV might again be a trigger efficiency
>>>> effect, where it becomes more likely that we lose small angle 
>>>> tracks down
>>>> the beam hole which could have fired the trigger.
>>>>
>>>> -Michael
>>>>
>>>>> Greetings,
>>>>>
>>>>> I did not want to show this last night because I thought there was 
>>>>> a bug
>>>>> in my code. But I do not think I have a bug in my code, so I want to
>>>>> show you what I concluded.
>>>>>
>>>>> First of all, my result does not agree with the values found by FSU or
>>>>> FIU. I actually see a strange dependence on energy. What I am 
>>>>> depicting
>>>>> are plots of the probability of multiple photons within the same 
>>>>> bucket
>>>>> as clasEvent choose Â±1.002 ns, meaning the photon energy on the 
>>>>> X-axis
>>>>> of the plots are of clasEvent chosen, which was the best timed beam
>>>>> photon compared to the average _of_ start times.
>>>>>
>>>>> The data used for this is only the 566* runs, which is 
>>>>> approximately 7%
>>>>> of the data.
>>>>> Please see:
>>>>> https://clasweb.jlab.org/rungroups/g12/wiki/index.php/TAGR_code#March_31
>>>>>
>>>>> --
>>>>> BR
>>>>> MK
>>>>> ----------------------------------------
>>>>> Michael C. Kunkel, PhD
>>>>> Forschungszentrum JÃ¼lich
>>>>> Nuclear Physics Institute and Juelich Center for Hadron Physics
>>>>> Experimental Hadron Structure (IKP-1)
>>>>> www.fz-juelich.de/ikp
>>>>>
>>>>> _______________________________________________
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>>>>
>>>>
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