<br><br><div class="gmail_quote">On Tue, Oct 26, 2010 at 9:46 PM, David Flay <<a href="mailto:flay@jlab.org">flay@jlab.org</a>> wrote:<br><blockquote class="gmail_quote">
Hi all,<br>
<br>
So I've spent some time coming up with a modest fit to parameterize<br>
R^{np}, which will influence how we estimate R = F_2^n/F_2^{3He}.<br>
<br>
Attached is my (initial) result. I initially wanted to go with a<br>
polynomial fit, but I was able to achieve a \chi^2/ndf ~ 1 using the form<br>
I display in the plot -- a linear combination of a gaussian and an<br>
exponential. The reasoning for the gaussian was to try to get a nice fit<br>
to the region for x ~ 0.1, where we see R^{np} ~ 1, and from there on out,<br>
I wanted the exponential to take care of the rest (that is, after x ~<br>
0.22, and hence why p_1 = 0.22). This didn't necessarily work, but<br>
because the \chi^2/ndf came out pretty good, I decided to keep this form.<br>
The parameters p_0, p_2, and p_3 were arbitrary.<br><br></blockquote><div><br></div><div>I just realized my choice of p_1 = 0.22 should've been 0.1, as 0.22 centers the gaussian portion on the wrong spot... changing p_1 to 0.1 doesn't change the fit by much at all. In any case, the fit I display is pretty good for an estimation. </div>
</div><br clear="all"><br>-- <br>-----------------------------------------------------------<br>David Flay<br>Physics Department<br>Temple University<br>Philadelphia, PA 19122 <br><br>office: Barton Hall, BA319<br>phone: (215) 204-1331<br>
<br>e-mail: <a href="mailto:flay@jlab.org">flay@jlab.org</a> <br> <a href="mailto:flay@temple.edu">flay@temple.edu</a><br><br>website: <a href="http://www.jlab.org/%7Eflay">http://www.jlab.org/~flay</a><br>
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