<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle19
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;
color:windowtext;}
span.doi-field
{mso-style-name:doi-field;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">In trying to understand Fig. 1 of <a href="https://arxiv.org/abs/1912.01735">
https://arxiv.org/abs/1912.01735</a>, I plotted the PRad final normalized results from
<a href="https://wiki.jlab.org/pcrewiki/index.php/PRad_Results">https://wiki.jlab.org/pcrewiki/index.php/PRad_Results</a> along with the model of Alarcon and Weiss
<a href="https://doi.org/10.1103/PhysRevC.99.044303">https://doi.org/10.1103/PhysRevC.99.044303</a> for a radius of 0.84 and 0.88fm. (i.e. no free parameters, no re-normalization, no non-sense).
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I also added the result of Mainz’s spline fit from <a href="https://doi.org/10.1103/PhysRevC.99.044303">
https://doi.org/10.1103/PhysRevC.99.044303</a>. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As far as I can tell, Marko fixed the radius and the value of the first derivative of his fit function and then did a regression. This seems like a lot of extra work (and several extra parameters) as Alarcon and Weiss provide a full functional
form which is a function of a single variable, the charge radius. In any case, the final results are nearly the same (shown in ComparisionLinear.pdf and ComparisionLog.pdf).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">One can again see that PRad’s GE results are systematically higher than the Mainz results (represented by the spline) though in agreement with the conventional nuclear physics model with the CODATA-2018 radius. Interestingly the Mainz
results seem to run parallel to the conventional model out to larger Q2 (shown in the ComparisionLinearMore.pdf).<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sincerely,<o:p></o:p></p>
<p class="MsoNormal">Douglas<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="color:black"><o:p></o:p></span></p>
<div>
<p class="MsoNormal"><span style="font-size:12.0pt;color:black"><o:p> </o:p></span></p>
</div>
</div>
</body>
</html>