[Olympus] comment to paper draft

[Belostotski, Stanislav]

Dear colleagues,
Let me first say  that the Olympus  PhD students did really excellent 
job. OLYMPUS, as it was conceived, would provide a very clean signal due 
to the original idea to work symmetrically at two magnet polarities. 
This was not unfortunately possible  in practice  which seriously 
complicates the TPE extraction. However a thoroughly performed MC with 
RC included helped to extract this tiny effect.
Congratulations!
Now my comments:
1.Table 1.
A couple of items :
-uncertainty due to beam positions and slopes is missing ;
-"geometry". What does geometry mean? Is that alignment imperfection?
"Elastic (event) selection and bgr subtraction".
There is no discussion in text about background which  at large angles 
is mostly related to pion production. Remember, the latter is charge 
asymmetrical. I can assume that the pion contribution is small but at 
least a few lines on pion production is needed.
2.Page 3, left, paragraph "The integrated luminosity...."
These MIE , as stated in this paragraph, are coincidences of small angle 
ep scattering and Moller or BhaBha coincidence events.So they are random 
coincidences(?). Then they must be corrected for the beam intensity 
variations(?). Or this is my ignorance (?).Ref.29 does not help ( "to be 
published").   Why just  small angle ep scattering is not  usable for 
normalization?
I presume similar questions will be put by a referee.
3. It is well known that kinematic constrains used for event selection 
effect strongly on RC contribution. Extraction of net TPE effect from 
the ratio is only possible  if these constrains are strictly identical 
for e+ and e-. On the other hand the e+/e- acceptances are different.In 
a bin in Q**2 this is of course solved applying eq.1. The question is 
still how much false asymmetry can be resulted from imperfections of MC 
simulation. Was the MC model tuned somehow and cross-checked?
I think we need a few lines on that point.
4.page4 with Fig.2.correct misprint at line 4. left   (simulation)
5. My opinion on ranking in the author list is in details in my previous 
mails.

With best regards StanB