Hi Nevzat,
I looked quickly through your slides and a have a number of comments.
First, I have a question, what is the allocated time of the talk?
=> General comment 1: Perhaps you want to get inspired by some earlier
talks given by Sebastian, Gail, Peter, Yelena, and others. Sebastian
gave a nice lecture series at Hall B meetings: You can get the links at:
http://clasweb.jlab.org/group_meeting_minutes/Physics/2008/Minutes_2008_9_29.html
=> General comment 2: Please use consistent capitalization of words,
e.g. on slide 16: "Pion and pair symmetric background corrections."
You often use mixed lower case and upper case in one sentence. Also,
often you have Sin and Cos, should be sin and cos., also you often use
A1, A2, \Gamma1, Q2, q2 and g1, this should be A_1, A_2, \Gamma_1, Q^2,
q^2, and g_1.
=> General comment 3: Your introduction, especially in slides 6-9 on
"Scaling in 2D", is for my taste too elementary and pedagogical. You
don't need to explain energy and momentum conservation in a conference
talk. Your intro can be shortened. see some of the other talks.
Now, here are some quick comments:
General: I suggest to use some of Sebastian's graphs from his lecture
series at Hall B:
1) slide 1: change EG1B data -> CLAS/EG1B data.
2) slide 2: I believe the quark helicity contribution is nowadays more
like 30-35%
3) slide 4: you should also mention photon virtuality Q^2 (or 4-momentum
transfer) not only energy transfer. Both together probe the spin
distribution versus distance scale.
4) I made already general comment on introduction in slides 6-9, which I
find, in parts, too elementary,
slide 10: 1/2 and 3/2 don't refer to "spin" but helicity, i.e. spin
projections on the momentum. The photon can excite any spin, e.g. high
spin resonances, but their projections are always only +/-1/2 or +/-3/2.
5) slide 15: don't give #files, but maybe integrated charge, or #
inclusive electron
6) slide 16: Dilutian -> Dilution
7) slide 17/18: Exctration -> Extraction
8) slide 19: A1A2 => A_1+\eta A_2
9) slide 20/21: What is Q^2 range: [0.05,0.05] ?, why do you highlight
lowest Q^2 bin with poorest statistics?, what do the green systematic
error bands mean in areas where there are no data points?
10) slide 22: Limit Q^2 range to where there are CLAS data. At 6 GeV^2
the CLAS contribution to Gamma_1 is = 0!
This brings up the question how the DIS corrections are traeted in terms
of error contributions. The data poins before corrections have the same
error bars as the ones after corrections, that means the DIS corrections
have no errors. I know this is an old debate, but it may raise questions
if the CLAS contribution is zero, and the DIS contribution comes fully
from "model". Maybe the senior folks in eg1 should discuss how to deal
with this. The same question for Gamma_3 and Gamma_5. Here the CLAS
contribution is more significant because of the higher moment in x_B
that favors lower W contributions. Perhaps we should have different
ranges for Gamma_1, Gamma_3, and Gamma_5. In previous papers we have
used a cut in Q^2 where the minimum contribution by CLAS is 50%.
11) The neutron part I would put into the "Outlook". There is too little
information on details.
12) I think the summary should be extended. What are the main results
so far?, Analysis of other energies?, Separation of A_1 and A_2?
Otherwise, a good effort !
Volker
nguler@jlab.org wrote:
> Hello,
> I uploaded my talk to:
> http://www.jlab.org/Hall-B/secure/eg1/EG2000/nevzat/Spin2008/
> Best regards,
> - Nevzat
>
>
>> Dear EG1ers (what's left of them),
>>
>> we have our regular meeting this Wednesday, October 1, at 11:00 a.m., in
>> F224/5. As always, send me your phone # if you want to be called.
>>
>> I propose to spend at least part of the meeting with a dry run for Nevzat's
>> talks (one next week at SPIN2008, then one at the DNP meeting). I'd also like
>> to give a brief update on models and maybe discuss any other items that you
>> may have.
>>
>> - Sebastian
>>
>>
>
>
>