[Clas_hadron] talk for HYP-X

[Mike Williams]

Hi Kei,

Looks really good to me...lots of good work here.  I hope you have at 
least 30 minutes ;-) Just a few minor comments below.

Cheers,

Mike

general: I'm wondering if it makes sense to reverse the order of the main 
topics, i.e. do the spin-parity stuff first.  It isn't as interesting as 
the lineshapes, but it *should* be less controversial/easier to understand 
and you *should* be 
able to get through it w/o too much debate (hopefully).  The way it's put 
together now, the spin-parity stuff almost seems like an after-thought.

sl 4: The Feynman diagrams need to have thicker lines and larger labels 
(at least, I can barely see them even when zoomed in on the pdf).

sl 11: I can't tell the Sigma(1385) MC (red) and the Sum of MC (magenta) 
apart.  Maybe you should switch the color scheme so that one of these is 
green (which currently just oscillates close to zero...well away from any 
other markers).

sl 13: Have you tried iterating this procedure? I.e. taking the lineshapes 
you get out and then regenerating your Lambda(1405) MC using these shapes, 
then re-doing the fits to see if there's any signifcant effects. I realize 
this would be time consuming.  A quick test could be to weight your 
Lambda(1405) MC events by the ratio of the lineshapes 
(extracted/generated).  It looks like you have enough statistics that this 
would give you a decent idea what kind of affect using a different 
lineshape 
at this stage can have.  I could see this being a *very* useful backup 
slide.

sl 15: Is dashed line "nominal" line shape? Also, I'm not convinced by 
looking just at these 3 plots (especially the 2nd two) that the Sigma+ pi- 
decay mode is narrower 
than Sigma0 pi0.  Can you defend this quantitatively? Perhaps you could 
quote the RMS's (since the lineshapes aren't Gaussian or BW)?



On Sun, 6 Sep 2009, Kei Moriya wrote:

>
> Dear Spectroscopists,
>
> I will be giving a contributing talk
> at the HYP-X conference to be held on
> Sep. 14-18 in Japan.
>
> My talk is available at:
> http://www.jlab.org/Hall-B/secure/hadron/presentations/2009/Moriya_HYPX.pdf
>
> The talk shows the results on the Lambda(1405)
> research I have been doing with the g11a data set.
> The main results are the lineshapes and differential
> cross sections, and also a spin-parity analysis.
> It has been a while since I showed the spin-parity
> analysis to the collaboration, but the main results
> have not changed; the conclusion is that the Lambda(1405)
> has J^P = 1/2- and is produced polarized.
>
> Comments and suggestions are very welcome
> and should be sent to clas_hadron at jlab.org
>
> For those of you in the US,
> have a happy Labor Day weekend,
>
> 	Kei Moriya
> 	Carnegie Mellon University
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