[Olympus] [Olympus-lumi] SYMB/12 Degree Ratio Plots

[Michael Kohl]

Hi, 
this is a lot (>20%) different from the MWPC/SYMB ratio included in Doug's 
draft 'answers' slides for the closed session. Having missed today's 
meeting, I am wondering if the MWPC/SYMB ratios on Doug's slides 35+36 are 
coincidentally in better agreement than what is realistic. Unclear to me 
what went into either of the simulations for MWPC and SYMB.

The important points are the stability and the difference between e+ and 
e- in the 12deg/symb ratios, which is the aspect that is similar between 
Brian's plots in those from Yury/Denis in Doug's slides.

Best regards
   Michael


On Tue, 22 Apr 2014, Brian S. Henderson wrote:

> Hello all,
>
> As a first note, I have updated all of my 12 degree plots on the Wiki to make 
> sure they are in order.  I have added two new ratio plots for the left side 
> in which I have made a rough "elastic" cut on the accepted events in both the 
> MC and the data by requiring that the track originate from the target cell 
> and that the missing energy (as predicted by the reconstructed angle) is 
> within 400 MeV of zero (which includes the main peak in the missing energy 
> distribution with the current resolution while cutting some tail).  In 
> general, this changes the 12 degree/slow control by ratio by a few percent 
> for each tracking method but the answers are still in the same ballpark.
>
> I have attached two plots showing the ratio of SYMB luminosity to 12 degree 
> luminosity as requested in today's meeting, using my numbers (with the 
> elastic selection discussed above) and the table provided by Roberto for the 
> SYMB (which is available on the Wiki: 
> https://olympus-docu.hiskp.uni-bonn.de/dokuwiki/lib/exe/fetch.php?media=lumigems:symb_data_feb2014.txt). 
> As you can see, the SYMB shows a luminosity considerably lower than that of 
> my 12 degree estimate, but it is perhaps encouraging that the ratio seems 
> stable over these runs (and the species switch). The uncertainties shown on 
> these plots are statistical errors (which are dominated by the 12 degree arm 
> by several orders of magnitude).
>
> At this time, I do not know what assumptions went into the MC used to 
> generate the SYMB result, so perhaps Roberto can provide some information on 
> that.  Please let me know if I can provide any further information.
>
> Brian
>
>

+---------------------------------------------------------------------
| Dr. Michael Kohl, Associate Professor and Staff Research Scientist
| Physics Department, Hampton University, Hampton, VA 23668
| Jefferson Lab, C117, 12000 Jefferson Avenue, Newport News, VA 23606
| Phone: +1-757-727-5153 (HU), +1-757-269-7343 (Jlab)
| Fax:   +1-757-728-6910 (HU), +1-757-269-7363 (Jlab)
| Email: kohlm at jlab.org, Cell: +1-757-256-5122 (USA)
+---------------------------------------------------------------------