<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css" style="display:none;"> P {margin-top:0;margin-bottom:0;} </style>
</head>
<body dir="ltr">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Hey everyone,</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
As promised in the morning, yesterday I had done the first fit of the xi=0 GPD, and a<span style="display: inline !important; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="ContentPasted4">s I have told some, I</span> was quite dissatisfied
with the results. The chi^2/dof was 220 when I concluded O(alpha) correction. </div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
I think the issue can be best seen in the inaccuracy of the form factor (z=0 for us). See attached plot of F_1(t)/F_1(0). First the range in t is pretty small we can't fit very meaningful t dependence. Second the point at the lowest |t| is at least 1 sigma
BELOW some points at slightly larger |t|. This undesirable feature is reflected in all the GPD data with z!=0 which lead to terrible fit results where it's supposed to be monotonic. You can see how the GPD fits failed in the App C of
<a href="https://www.overleaf.com/7932724842pjgpxkdxnzsf" id="LPNoLPOWALinkPreview">
https://www.overleaf.com/7932724842pjgpxkdxnzsf</a></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
<span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;"><br>
</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
<span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;">There are some things I will do to move on, but please send any suggestions on these fits above or the next directions below.</span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
First, <span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
<span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;">Colin has given me xi=1 amplitudes which I will begin to look at next. In my notes, I briefly describe how I believe the A_5 amplitude maps to the D term explicitly. Interesting,
if true....</span></span></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0">
<span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof ContentPasted0"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt;"><br>
</span></span></div>
<div class="_Entity _EType_OWALinkPreview _EId_OWALinkPreview _EReadonly_1"></div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="display: inline !important; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="ContentPasted1"><span style="display: inline !important; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="ContentPasted2">Next,<span class="ContentPasted2"> </span></span>Colin
has some xi=0 data with higher pz which I could add to this xi=0 analysis to give better range in nu. I will attempt to get the amplitudes from him. In his famous plot of our data spread in xi and t, there is not a great t coverage at xi=0, so there may not
be much left to do prior to lattice without generating new data to clear up the situation.</span><br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Best,</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Joe</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
PS: Overleaf is failing when I have too many plots (not quite 100). If I can't look at several dozen plots of data and analysis, is it even science? If you wish to see the appendices where I have each (pf,pi) plotted individually<span style="display: inline !important; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="ContentPasted3"><span class="ContentPasted3"> </span>(or
not see or to fix the too many plots error)<span class="ContentPasted3"> </span></span>then you must (un)comment the \iffalse and \if pair which surround the begin{figure} calls.</div>
<div class="elementToProof">
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<br>
</div>
<div id="Signature">
<div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">
<span style="font-family: Arial, Helvetica, sans-serif; font-size: small; text-align: start; display: inline !important; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255);">--</span><br style="font-family: Arial, Helvetica, sans-serif; font-size: small; text-align: start; color: rgb(34, 34, 34);">
<div dir="ltr" data-smartmail="gmail_signature" style="font-family: Arial, Helvetica, sans-serif; font-size: small; text-align: start; color: rgb(34, 34, 34);">
<div dir="ltr">
<div>Joe Karpie</div>
<div>Pronouns: He/His/Him</div>
<div>Postdoctoral Fellow</div>
<div>Theoretical and Computational Physics Center</div>
<div>Jefferson Lab</div>
</div>
</div>
<br>
</div>
</div>
</div>
</div>
</body>
</html>