[Frost] [Clas_hadron] Baryons 2013 Talk for Stuart Fegan

[Franz Klein]

Stuart,
Ken gave already good suggestions ... here one more:

slide 6: observables in green=requiring polarised beam+target: keep 
small sigma (Xsection) and P (recoil) blue!

... and 2 comments (let's keep that within the group!):

slide 13+14: the plots show a strong K+ (and K+Lambda) signal from 
carbon. For the original frost proposal I used a simple parametrisation 
based on the Ciofi model and hardly got any K+Lambda from carbon (K+,p 
detected, pi- via cut in missing mass). However, g9a had this strong 
signal - thus I assumed that my simulation was wrong! But the g9b data 
show very little K+Lambda, K+Sigma0 yield from the carbon target. In 
different words: most of the K+Lambda yield from carbon came from 
superinsulation and/or ice on the carbon target. I don't think 
carbon-yield subtraction can be used for K+Lambda in g9a.

slides 20+21: I recommend to use the fit of the phi distribution only to 
discuss possible systematics and use an event-based likelihood or moment 
method instead (the phi method has some intrinsic problems itself!) - 
having that said, I hope that we soon can fix the phi dependence of the 
missing mass because otherwise the moment method can get a bias. Note 
that for the event-based likelihood method we will need relative 
acceptances, i.e. MC data.
Actually, if I remember correctly: Craig showed that for extracting 
Sigma from g8b (fit of phi distribution) he needed simulated data as 
well because not only the K+ detection was required but also the proton. 
Don't we need MC data then for Sigma and G as well? (though it might be 
that he needed simulated data only for beam-recoil observables?!)


On 06/22/2013 11:29 AM, Stuart Fegan wrote:
> Hi Everyone,
>
> Sorry for the short notice, I was waiting until after my hadron
> spectroscopy talk yesterday before sending my Baryons slides, you will
> now find them on the g9 secure page;
> http://www.jlab.org/Hall-B/secure/g9/sfegan/SFegan_Baryons2013.pdf
>
> The talk will give an overview of my work towards measuring the G
> polarisation observable for the strangeness channels K Lambda and K
> Sigma, showing preliminary results for both the beam polarisation
> observable and G, one of the beam-target observables, for K Lambda.
>
> Unlike my aforementioned talk at the hadron spectroscopy meeting, my
> Baryons talk should be a lot clearer, as I will not be showing the
> original thesis results, whose comparison to my latest analysis was a
> central theme of my talk to the working group.
>
> Comments and/or suggestions are welcome.
>
> Cheers,
> Stuart
>

-- 
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                   Franz J. Klein, Associate Professor
                   CUA, Department of Physics
                   Washington, DC 20064
   office: Hannan Hall 206          phone: 202-319-6190
   or: Jefferson Lab,CC F-243       phone: 757-269-6672
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