[Sane-analysis] Wiki update Re: Next meeting Aug 11th at 4:30 in L210

[Oscar Rondon]

I have updated my wiki section on global fits to SANE and SLAC A1 and A2
data, especially A2

https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Fits_to_A1_and_A2

It now has several sections:

- Fits to SLAC data showing points for each spectrometer. The A1 data of
the SLAC 10.5 deg. spectrometer make the  fit's chi-squared
significantly worse. I propose we exclude those data. In any case we
don't need them to get d2 from A2.

- Global fits to SLAC and 2015 preliminary SANE data. Although the SANE
data have changed since then, the fits illustrate what is to be expected
 for A2(W,Q^2) in the final version.

- The draft TN on the method to get d2 from A2, which enhances the
dependence of this matrix element on our measured asymmetry.

- examples of d2(Q^2) calculated from Cornwall-Norton and Nachtmann
moments of the global fits.

- Older results showing attempts to include resonance data in the fits.
The resonance data could be included by applying global duality to A2
which works very well for g1 for Q^2 >= 1.8 GeV^2, see slide 10 here
https://twist.phys.virginia.edu/~or/duality/UVA-dual-15k3.pdf

Global duality obtains for F1 and g1 above some Q^2, so it should also
work for the twist-2 part of g2, which depends only on g1. The
assumption would be that the twist-3 piece of g2 won't spoil duality for
A2 = gamma*gT/F1 = gamma*(g1 + g2)/F1.

But local duality probably fails for g2, from our SANE HMS 1 results
compared to RSS (this is another interesting topic to explore, since we
have DIS g2 data at the same Q^2 for BETA and HMS, and some DIS HMS data
at RSS kinematics).

Cheers,

Oscar





Mark Jones wrote:
> The next SANE meeting will be Aug 11th at 4:30 in L210.
> I will try and remember to send out the reminder the day before.
> 
>          Cheers,
>                 Mark
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