[b1_ana] Statistics using Positive Polarization Only

[Patricia SOLVIGNON]

Yes I agree with Oscar. By using N/2 instead of N in the equation means that we are going to spend Time/2 on unpolarized target and Time/2 on polarized target.

Patricia

-- 
Patricia SOLVIGNON
Staff Scientist
Jefferson Lab

Current address : 
Jefferson Lab
Suite 6, MS. 12H4                               Room C121 (Cebaf Center)
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On May 2, 2013, at 2:15 PM, "O. A. Rondon" <or at virginia.edu> wrote:

> Hi,
> 
> I think that the errors don't change, if N = Np + Nu. What changes is
> the time, which it would then be the sum of Np time plus Nu time. It's
> like this:
> 
> eq. (25b) dAzz = 2/sqrt(N) = 2/sqrt(2*Nu) = sqrt(2/Nu)
> 
> the error is the same, but of course, it takes twice as long to collect
> Nu + Np, than just Nu or Np.
> 
> In summary, other than the extra sqrt(2) in the numerator, all numbers
> should be the same.
> 
> Cheers,
> 
> Oscar
> 
> Dustin Keller wrote:
>> Hi Elena,
>> why before eq 25 you use Np=Nu=N/2, why not just have
>> Np=Nu=N?
>> 
>> On Thu, 2 May 2013, Elena Long wrote:
>> 
>>> Good afternoon,
>>> 
>>> I've re-run the statistics using the method we decided on yesterday. The 
>>> results can be seen here: 
>>> https://hallcweb.jlab.org/wiki/index.php/Elong-13-05-01-Azz-Method-2#Plots_with_using_Azz_Method_2_Calculations
>>> 
>>> Please note that they have grown by a factor of two compared to the previous 
>>> assumption, where we had both positive and negative polarization. The 
>>> calculations for the new method are formalized in 
>>> https://hallcweb.jlab.org/wiki/index.php/Elong-13-05-01-Azz-Method-2#Azz_Formalism_-_Method_2
>>> 
>>> Oscar has been mentioning that the code was missing a sqrt(2), which was 
>>> true. The other sqrt(2) on top of it comes from the assumption before 
>>> equation 25, which brings the total uncertainty a factor of two larger than 
>>> was projected with the old method.
>>> 
>>> Take care,
>>> Ellie
>>> 
>>> -- 
>>> Elena Long, Ph.D.
>>> Post Doctoral Research Associate
>>> University of New Hampshire
>>> elena.long at unh.edu
>>> ellie at jlab.org
>>> http://nuclear.unh.edu/~elong
>>> (603) 862-1962
>>> 
>>> 
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