[Sane-analysis] Reminder of Sane meeting at 3:00pm Wed Jan 25th in L210A

[Oscar Rondon]

Hi Whit,

It looks like a good approach. One thing to keep in mind is that the
moments and related matrix elements only have a Q^2 dependence so the
assumption is that the structure functions are taken at constant Q^2, so
they are effectively functions of only x. But the data do have both W
and Q^2 dependencies.

It would be great to have lots of data at fixed Q^2, so the fitting
could be done in x at constant Q^2, which would be equivalent to doing
it only in W instead of in x.

One option might be to separate the Q^2 and W dependences, by first
fitting only the Q^2 dependence and then evolving the data from the
measured to the desired fixed Q^2 values using the Q^2 fit, and then do
the x dependent fit on the evolved data. This should be the same as
fitting in W and Q^2, with the difference that the fitting function in x
could be better physics motivated, like your examples.

Unfortunately the above approach works only for DIS, because the
resonances have a resonance's mass (i.e. W) dependent Q^2 behavior, see
for example the \kappa_i terms in the RSS fit, in the proton PRL online
appendix http://arxiv.org/pdf/nucl-ex/0608003 . But it could be good to
try it for SANE DIS (BETA and HMS) and SANE + world DIS. It would be
similar to what was done for the SLAC data analysis.

One minor comment is to keep in mind that there are two massless limits,
one is massless quarks, which is discussed in Bluemlein and Tkabladze's
 appendix, and the other is when nucleon M<<Q^2, to avoid ambiguity.

Cheers,

Oscar

Whitney R. Armstrong wrote:
> Hi Everyone,
> 
> Sorry I got the time messed up today and showed up an hour late.
> I have attached a discussion of the fits (which is a work in progress)  
> that I wanted to show today.
> 
> Cheers,
> Whit
> 
> 
> 
> On Wed, Jan 25, 2017 at 12:04:29PM -0500, Mark Jones wrote:
>> Reminder of Sane meeting at 3:00pm Wed Jan 25th in L210A
>>
>>
>> https://bluejeans.com/240199984
>>
>> I will be able to attend.
>>
>>
>>
>> Cheers, Mark
>> _______________________________________________
>> Sane-analysis mailing list
>> Sane-analysis at jlab.org
>> https://mailman.jlab.org/mailman/listinfo/sane-analysis
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Sane-analysis mailing list
> Sane-analysis at jlab.org
> https://mailman.jlab.org/mailman/listinfo/sane-analysis