[G12] My multiple beam photon study

Thu Apr 2 21:42:03 EDT 2015

Greetings,

My plots per run number show that the normalization can differ by as 
much as 3% depending on the run number.

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 7:49 PM, Lei Guo wrote:
> We only need one normalization (as a function of egamma)  for the 
> whole running period, which I think you already have! What you are and 
> Rafael is showing is consistent. Maybe FSU did not show that for the 
> entire range.
>
> Lei
> 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 Apr 2, 2015, at 11:47 AM, Michael C. Kunkel <mkunkel at jlab.org 
>> <mailto:mkunkel at jlab.org>> wrote:
>>
>> 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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>

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