[Halld-physics] GlueX Note: Orientations of the Photon Beam Polarization

[Alexander Austregesilo]

Dear Colleagues,

I extracted the orientation of the photon beam polarization plane from 
rho decays for the Fall 2018 data set and added the values to the GlueX 
note. In addition, I adapted the entire document to the -45/45 notation. 
Finally, I also repeated the analysis for Spring 2018, as the diamond 
orientation of a few runs was corrected in RCDB in the mean time. The 
change in the values for Spring 2018 was only marginal.

Please find the updated document in DocDB:

https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=3977

Best regards,

Alex


On 6/28/2019 10:12 PM, Alexander Austregesilo wrote:
> Dear Colleagues,
>
> I extended the analysis to the recently completed Spring 2018 data set:
>
> https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=3977
>
> During this analysis, I noticed a mismatch between the data and the 
> orientation in RCDB in 5 instances:
>
> * run 41546 has the polarization plane oriented at 90 degrees, not 135
>
> * run 41206 is 0, not 90
>
> * runs 41250, 41607 and 42386 are polarized 45 degree runs, not amorphous
>
>
> In addition, I changed the sign of the offset from the nominal 
> orientations to facilitate the interpretation. The definition is now 
> consistent with the analysis of pi0/eta/eta' asymmetries.
>
> Thanks to Peter Pauli, Will McGinley and Richard Jones for their 
> useful comments and discussions.
>
> Best regards,
>
> Alex
>
>
>
> On 4/19/19 5:27 PM, Alexander Austregesilo wrote:
>> Dear Colleagues,
>>
>> I submitted a draft of my note 'Orientations of the Photon Beam 
>> Polarization for Spring 2017 from rho(770) Decay Asymmetries' to DocDB:
>>
>> https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=3977
>>
>> Abstract:
>> We use the production of the rho(770) meson to extract the deviation 
>> of the nominal polarization plane of the photon beam, providing an 
>> estimate of the statistical and systematic uncertainties. The results 
>> should be used consistently by all studies, especially for final 
>> states with a limited data set which does not permit to extract these 
>> offsets.
>>
>> In addition to the results, it includes a short introduction of the 
>> method, that shows that the extracted offset psi_0 is exactly 
>> equivalent to the offset phi_0 that appears in pseudoscalar beam 
>> asymmetries.
>>
>> Please let me know if you have any corrections and suggestions.
>>
>> Have a nice weekend,
>>
>> Alex
>>
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