<div dir="ltr"><br><div class="gmail_quote">---------- Forwarded message ----------<br>From: <b class="gmail_sendername">Steven P. Wells</b> <span dir="ltr"><<a href="mailto:wells@phys.latech.edu">wells@phys.latech.edu</a>></span><br>Date: Mon, Sep 8, 2014 at 3:51 PM<br>Subject: Re: [Q-weak] First draft of the Qweak elastic transverse asymmetry paper<br>To: Buddhini Waidyawansa <<a href="mailto:buddhini@jlab.org">buddhini@jlab.org</a>><br><br><br>
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<br>
Hi Buddhini,<br>
<br>
Thanks for circulating the draft. I really like the paper,
especially<br>
the tie in to the TPE correction to the MuSE observables. In the
past,<br>
the only motivation for B_n in connection with the TPE calculations
was<br>
either through dispersion corrections to relate the imaginary part
to<br>
the real part, or more generally to test the loop formalism in any<br>
two boson Feynman diagram. That being said, I have a few
comments/corrections,<br>
and I also found some grammar that could be cleaned up. So, here
goes:<br>
<br>
1) In referencing my general comment about the explicit tie in to
the MuSE<br>
corrections, is there room available in the paper to explicitly
write down the<br>
TPE corrections to whatever MuSE measures, to show, like you did in
your<br>
pizza seminar, that the helicity flip amplitudes (I think I remember
F_4 twidle,<br>
F_5 twidle, and F_6 twidle) are only accessible through B_n, and not
some<br>
other observable.<br>
<br>
2) In the paragraph which includes Eq. (1), your statement of <br>
" . . . parity conserving, naively time reversal violating . . ."
should be replaced with<br>
" . . . parity conserving, time reversal odd . . ."<br>
<br>
3) In the paragraph starting "Approximately 54 hours of data . . .",
the second<br>
sentence, "The 150 uA circularly polarized electron beam . . ."
should be replaced with<br>
"The 150 uA longitudinally polarized electron beam . . ."<br>
<br>
4) The paragraph starting "For the purpose of suppressing false
asymmetry contributions . . .", I think it would be more clear if
you added "to the parity violating measurement" after<br>
" . . . suppressing false asymmetry contributions . ."<br>
<br>
5) In Eq. (3), the standard unit vector normal to the scattering
plane is $\hat n$, and<br>
$\hat k$ and $\hat k^{\prime}$ are used for the incoming and
outgoing electron directions.<br>
So, I would replace $\hat k$ in Eq. (3) with $\hat n$, and define
$\hat n$ in the text just<br>
below that equation with <br>
<br>
$$\hat n = {{\vec k \times \vec k^{\prime}}/over{\vert \vec k \times
\vec k^{prime} \vert}}$$<br>
<br>
That's all I had for corrections and/or suggestions, but I did find
some grammar issues:<br>
<br>
1) Paragraph 1, sentence 4, starting "This discrepancy was
empirically shown . . ."<br>
change " . . .amplitude which modify . . ." to " . . . amplitude
which modifies . . ."<br>
<br>
2) Paragraph 2, starting "Even though modern TPE . . .", Sentence 3
starting "However,<br>
the recent disagreement . . ." drop the words "to be" at the end of
that sentence.<br>
<br>
3) Paragraph 2, sentence 4 starting "Furthermore, the value of the
magnetic ratio . . ."<br>
change ". . . agreement with one another and world average . . ." to<br>
" . . . agreeement with one another and the world average . . ."<br>
<br>
4) Paragraph 2, sentence 6 starting "One correction [19] . . ."
change<br>
" . . . accounts for a ~ 11% . . . " to " . . .accounts for
approximately an 11% correction . . ."<br>
<br>
5) Paragraph 3, starting "A beam normal spin asymmetry . . .",
sentence 2 starting<br>
"It is a parity conserving . . .", replace "vanish" with "vanishes"<br>
<br>
6) Paragraph 3, sentence 3 starting "The asymmetry is generated . .
.", replace<br>
" . . . and have the form . . ." with " . . . and has the form . .
."<br>
<br>
7) Paragraph 3, last sentence, replace " . . . are invariant
amplitudes which enters . . ."<br>
with " . . . are invariant amplitudes which enter . . ."<br>
<br>
8) Paragraph 4, first sentence, replace " . . . rely on Eq. (1) and
absorptive part . . ." with<br>
" . . .rely on Eq. (1) and the absorptive part . . ."<br>
<br>
9) Paragraph 5, sentence 2 starting "This measurement is part of . .
.", replace<br>
" . . . to constrain the systematic contribution . . ." to " . . .
to constrain the systematic contributions . . ."<br>
<br>
10) Paragraph 9, sentence 3 starting "The correction determined from
. . ." replace<br>
" . . . for a aluminum background . . ." with " . . . for an
aluminum background . . ."<br>
<br>
11) Paragraph 9, sentence 6 starting "In addition to these dominant
. . .", replace<br>
" . . . was also studied . . ." with " . . . were also studied . .
."<br>
<br>
12) Paragraph 12 starting "Above corrections are applied . . ."
change that to<br>
"The above corrections are applied . . ."<br>
<br>
OK, that's all I found. Good luck pushing this through, and I think
it will be a great<br>
publication.<br>
<br>
Best,<br>
Steve<br>
<br>
P.S. If you are still interested in giving a seminar here at LaTech,
there are plenty<br>
of dates still open.<div><div class="h5"><br>
<br>
<br></div></div></div></div>-- <br><div class="gmail_signature"><div dir="ltr"><font face="georgia, serif">-------------------------------------------------------------------<br>Buddhini Waidyawansa<br></font>Postdoctoral Fellow<br>
C122,<br><div><font face="georgia, serif">12000 Jefferson Ave,</font></div><div><font face="georgia, serif">Newport News, VA 23602.</font></div><div><font face="georgia, serif">TP 757-912-0410</font></div></div></div>
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