[G12] Multiple Photon Efficiency correction

[Michael C. Kunkel]

Greetings,

He had been asking me for the multiple photon corrections. I had assumed 
it was because he uses multiple photons.
With that being said, if he is using multiple photons (beam photons), 
and is using the old efficiency corrections (corrections for tracks with 
one photon chosen), then his cross sections will be ~5% higher then if 
he used the correct ones.

The reason is quite clear from the fact that with multiple photons you 
have a higher data yield, which deceases the "over efficiency" of the MC 
simulations.

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 11/3/15 8:03 PM, Volker Crede wrote:
> Dear Michael,
>
> Can you elaborate on why new track efficiency corrections for events with multiple photons should affect Zulkaida's ω cross section? I would like to understand the connection and what has actually "improved" …
>
> - Volker
>
>
> On Nov 3, 2015, at 11:01 AM, Michael C. Kunkel <mkunkel at jlab.org> wrote:
>
>> Greetings,
>>
>> I have finished the track efficiency corrections for events with multiple photons. I will present this at the next meeting.
>> Over all, it seems the new corrections decrease the spectrum by 5%, which was what Lei and I had originally calculated.
>>
>> I would ask Zulkaida to please use these new corrections for his omega Xsection and compare to g11, I think the agreement will be better now.
>>
>> https://jlabsvn.jlab.org/svnroot/clas/users/mkunkel/clas/g12_corrections/All_Corrections/
>>
>> or
>>
>> https://github.com/mckunkel/G12_Corrections
>>
>> use:
>>
>>     double g12_trackEfficiency(double Vz, double P_Ptot_fit, double P_Phi_fit, double P_Theta_fit, double Ep_Ptot_fit,double Ep_Phi_fit, double Ep_Theta_fit, double Em_Ptot_fit, double Em_Phi_fit, double Em_Theta_fit, TString DEG_or_RAD, bool MultPhoton){
>>
>> Set MultPhoton = 1 for multiple photon track efficiency
>>
>> -- 
>> 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
>>
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