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Dear SoLID and Positron supporters:</div>
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I am happy to share the report from the SoLID collaboration review on the new Ae+e- proposal. The proposal was reviewed during the SoLID collaboration meeting on June 10-11 and as you can see from the report, that "<font style="font-size:12pt" size="3">The
SoLID Collaboration endorses this proposal for conditional approval.". Subsequently, the Hall A Collaboration Committee informed me/us that the proposal was approved for "</font><font style="font-size:12pt" size="3"></font><font style="font-size:12pt" size="3"></font>Hall
A Collaboration Status". <br>
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I have attached the report here. There are quite a few suggestions regarding the technical side of the experiment (the last point is physics-y as well). If anyone is interested in leading and/or contributing to the following topics, please contact me:</div>
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1) field/mechanical stability study of SoLID magnet;</div>
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2) stability in detector efficiency, acceptance, and DAQ;</div>
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3) beam current monitor after the target (previously used in "transitional PV" experiments);<br>
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4) Analysis or re-analysis of PREX-II with the goal of (a) forming helicity-asymmetries but with h+ and h- data coming a certain time apart; and (b) study long-term stability of asymmetry itself and set bounds on violation of Lorentz invariance, as described
for example on page 209 of <a href="https://arxiv.org/pdf/2007.14491.pdf"><font size="3">https://arxiv.org/pdf/2007.14491.pdf</font></a>:<font size="3"><span style="font-weight:normal"> "Lorentz violation in the weak vector-boson sector can be studied in ep
scattering via a Fourier analysis of PVDIS asymmetry" $B"*(B see <a href="https://arxiv.org/pdf/1610.08755.pdf">
1610.08755</a> (HERA analysis) and <a href="https://arxiv.org/pdf/1909.10627.pdf">
1909.10627</a> (projection for FCC+LHeC). Note that while PVDIS is mentioned, PVES in general can be used.<br>
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5) Possible analysis of upcoming MOLLER and SoLID PVDIS data with the same goal as 4 above.<br>
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Now a tough but necessary request for the positron team:</div>
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<span style="font-size:12pt"></span>6) Can we switch between e- and e+ beams more frequently than "once during the experiment"? For example once a week or every other week (as in CERN experiment)?</div>
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<span style="font-size:12pt">The timeline for the above tasks will not be "urgent", as none of the topics listed can be done instantaneously and some of them may morph into quite interesting long-term projects. But it will be useful to make a plan prior to
the PAC meeting (week of July 19th). <br>
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<span style="font-size:12pt">I'd also like to mention that the <b>PAC presentation
</b>for this proposal is scheduled to be at 12:30pm EDT on Tuesday July 20th. I am contacting JLab management to see whether and how collaborators can call in.<br>
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Lastly, this single sentence in the review report: "<font style="font-size:12pt" size="3">Nothing like this has ever been attempted before", sums up the challenges of the experiment.
</font>As I already mentioned in an earlier email: we expect to receive theory and technical reviews -- possibly lot of them -- in early July. Until then, for those of you in the US, enjoy your July 4th week!</div>
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Best regards,<br>
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Xiaochao<br>
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