[PRad] Fwd: we talked

[Douglas Higinbotham]

The only question of note I got after Weizhi's very nice APS talk was a question about the highest Q2 PRad points disagreeing with the Mainz results.

As far as Tony Thomas’s question, Jerry Miller also had concerns about the range of the PRad data and we should note we passed Miller’s blind test using the techniques presented in Xuefei’s paper with pseudo points binning like the PRad data .   (i.e. not only did we publish our fitting functions ahead of time, we have also passed a blinded validation test against two more realistic G_E functions)

Here is the new open access paper that I presented at APS:
https://journals.aps.org/prc/abstract/10.1103/PhysRevC.99.044303<https://gcc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fjournals.aps.org%2Fprc%2Fabstract%2F10.1103%2FPhysRevC.99.044303&data=02%7C01%7C%7C7e40dcf00f0d438a5a0f08d6c4bae50d%7Cb4d7ee1f4fb34f0690372b5b522042ab%7C1%7C0%7C636912704315399567&sdata=UtHiuRJY%2FsGeUEfeAHkbb%2FEMTE68ZhF%2BLZoe8teWp44%3D&reserved=0>

That work goes is of course very model dependent as it uses the shape of G_E at high Q2 data to extract the radius.

NOTE: As I would hope is clear to everyone (though it doesn’t seem to be) is that the PLB by Y. Ze et al.  fixed the radius to the current CODATA value: https://doi.org/10.1016/j.physletb.2017.11.023<https://gcc01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdoi.org%2F10.1016%2Fj.physletb.2017.11.023&data=02%7C01%7C%7C7e40dcf00f0d438a5a0f08d6c4bae50d%7Cb4d7ee1f4fb34f0690372b5b522042ab%7C1%7C0%7C636912704315409572&sdata=q2gR6%2F1Rz%2Bf7C9SWhztvfyBfe0qT1LPcoRHcMsKi6Us%3D&reserved=0>.   What we did in the PRC is repeat that fit with the radius to all plausible values and then compared to theory with the radius also fixed to those same values.

Best Wishes,
Douglas



From: PRad <prad-bounces at jlab.org> on behalf of Haiyan Gao <gao at phy.duke.edu>
Date: Thursday, April 18, 2019 at 10:02 PM
To: prad <prad at jlab.org>
Subject: [PRad] Fwd: we talked


Dear PRad colleagues:

I am sending you a report from John Ralston and his student related to the proton charge radius puzzle.

I also like to report that our PRad result generated great interest in the community at the hadron meeting that I reported as well as Weizhi's APS talk. The questions I received following my talks:

1. how much better will PRad do re reducing our uncertainties? This is something I hope we can discuss and address in our DRad proposal. The question was asked by Jen-Chieh Peng

2. Tony Thomas asked a question about fitting concerning the Q^2 range used for the fit, which we addressed in Xuefei's paper

I think these are the two important questions I remembered. Thanks,

Best, Haiyan




-------- Forwarded Message --------
Subject:

we talked

Date:

Wed, 17 Apr 2019 11:42:07 -0500

From:

John Ralston <ralston at ku.edu><mailto:ralston at ku.edu>

To:

H. Gao <gao at tunl.duke.edu><mailto:gao at tunl.duke.edu>

CC:

John Craig Martens <j671m042 at ku.edu><mailto:j671m042 at ku.edu>



Hello Haiyan

it was good to see you at GHP.

When we talked, I mentioned that
the history of decisions of CODATA have excluded data, leading to a wrong
perception that the muonic lamb shift
data was "inconsistent". The paper attached (invited book chapter) shows there is no proton
size problem... especially with the value
reported by PRAD. The fundamental constants
are all coupled and cannot be determined by
piecemeal fits. The proton size and Rydberg in electronic hydrogen spectra are exceedingly correlated, contradicting
claims that either would be highly determined, or over-determined.

Our first accomplishment is that r_p =0.84+small is perfectly consistent with world data. Our second
accomplishment makes it possible for anyone
to find the fundamental constants with their
own assumptions. Just type numbers into a website ...which is almost
ready for you or your students to play with!

all the best

JP
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