[d2n-analysis-talk] Fwd: helium A1, d2

[Diana Parno]

Hi all,

Here's Wally's recent email. One of you will probably have better  
ideas than I about the nuclear corrections to d2.

Best,
Diana

Begin forwarded message:

> From: Wally Melnitchouk <wmelnitc at jlab.org>
> Date: June 21, 2012 12:52:52 PM PDT
> To: Diana Parno <dparno at uw.edu>
> Cc: Zein-Eddine Meziani <meziani at temple.edu>, Jacob Ethier <jethier at jlab.org 
> >
> Subject: helium A1, d2
>
> Hi Diana,
>
> Can you please remind me what value(s) of Q^2 you need the estimates
> of nuclear effects in d2(Q^2) at?  We can compute these as a function
> of Q^2, say from 0.5 to 6 GeV^2, but can also evaluate it at your
> experimental Q^2.
>
> I understand the Q^2 range over which you would like to see the  
> nuclear
> effects as a function of x are 1 to 6 GeV^2.
>
> Also, what do you intend to do with the quasi-elastic contribution to
> d2(3He)?  Will you be subtracting this from your data before  
> extracting
> d2(n), and if so, which model for the nuclear corrections will you be
> using?
>
> We are making good progress on the calculations with my summer  
> student,
> Jacob Ethier, and should hopefully have some results next week.
>
> Cheers
> Wally
>
>
> On Tue, 17 Apr 2012, Diana Parno wrote:
>
>> Hi Wally,
>>
>> Thanks for your email and the update. I've just gotten back from a  
>> long and derailing trip to Germany and was thinking of emailing you!
>>
>> Yes, your contribution over the next couple of months will still be  
>> useful for our analysis, though sooner is better. We have made a  
>> great deal of progress over the last few months on understanding  
>> our remaining large dataset, although there are still a few more-or- 
>> less minor questions we need to answer. We are close to formulating  
>> a correction for the asymmetry in our pion contamination (not  
>> large, I think). Still remaining are a similar correction for pair- 
>> produced electrons (as opposed to scattered electrons) in our  
>> sample; radiative corrections; and a better calculation of our  
>> target polarization (currently a leading source of systematic error).
>>
>> My very rough estimate is that we are now about one and a half to  
>> two months from having A_1^{3He} with confidence. We are hoping to  
>> have an in-person collaboration meeting in the next few weeks to  
>> clarify a plan for getting between point A and point B. I will keep  
>> you updated. At the very least, I think there are solid grounds for  
>> hope that we'll be ready experimentally to compute A_1^n by mid- 
>> July, and then proceed from there to paper-writing.
>>
>> Best,
>> Diana
>>