[Clascomment] OPT-IN: Electron Beam Energy Reconstruction for Neutrino Oscillation Measurements

[Daniel Carman]

Dear Mariana et al.,

I have read through the draft of your paper on using electron scattering data from
CLAS to impact neutrino oscillation analyses. A nice "outside-the-box" idea and an
ideal application for the Hall B data-mining project. My comments are given below.
If you have any questions, let me know.

Regards,
Daniel
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General:
 - You are not consistent through with handling speed of light units c. I suggest you choose a
   presentation format with c=1.
 - You are not consistent with usage of "quasi elastic", "quasi-elastic", and "quasielastic".
   Please review.
 - You do not list the figures in the order that they are cited in the text.
 - The referencing of the figures in the supplementary section is awkward, e.g. see Fig. Extended
   Fig. 2.
 - You are not consistent throughout with including the atomic number on your different targets.
   I prefer to include the atomic number consistently. This comment is relevant for the text and
   the figure labels/captions.
 - You have units separated from their values over consecutive lines of text. To fix this in
   latex, do the following, e.g. "2~MeV".

Page 1:
 - In the address list, some states are spelled out and other are abbreviations. Be consistent.
 - In the address list, some US addresses have zip codes and some do not. Be consistent.
 - Left column:
   - Paragraph 1:
     - Line 1. Use "... of only a few phenomena ...".
     - Line 2. Use "Standard Model".
     - Line 10. Use "accelerator-based".
     - Line 31. Use "next-generation, high-precision experiments, ..."
   - Paragraph 2:
     - Line 2.
 - Right column:
   - Paragraph 2:
     - Eq. 1. End with a comma for proper punctuation.
     - Line 1 after Eq. 2. Use "... is the neutrino mass difference squared ...".
     - Eq. 1. Your notation is not clear. You have mu and e subscripts and then you switch to
       1, 2, 3 subscripts. It is important that the definitions here are clear.
     - Eq. 2. End with a comma for proper punctuation.
   - Paragraph 4:
     - Line 1 after Eq. 1. Use "cross section".

Page 2:
 - Fig. 1. Both of your 2D plots are unreadable. They need to be enlarged, especially the right-side
   figure that is referenced throughout this paper.
 - Fig. 1. Left-side plot - your capitalization is not consistent in the blue and green areas.
 - Fig. 1 caption.
   - Line 1. Use "(Left)".
   - Line 4. Use "... the way they are analyzed ...".
 - Left column:
   - Paragraph 1:
     - Line 3. Use "... neutrino energies."
   - Paragraph 3:
     - Line 4. Why the quotes on "topologies"?

Page 3:
 - Left column:
   - Paragraph 1.
     - Line 16. Use "... next-generation, high-precision ...".
   - Paragraph 2.
     - Line 2. No comma after "nuclei".
   - Paragraph 3.
 - Right column:
   - Paragraph 1.
     - Line 2. Use "... radiation to the electron-GENIE ...".
   - Paragraph 2.
     - Line 4. The use of the term "unwanted" is not clear.
   - Paragraph 3.
     - Line 7. Use "undetected".
   - Paragraph 6.
     - Line 10. Use "meson-exchange currents".
     - Line 11. Use "... referred to as $2p2h$), ...".

Page 4:
 - Left column:
   - Paragraph 1.
     - Line 1. Use "... were detected, and smeared the ...".
 - Right column:
   - Paragraph 1.
     - Line 4 after Eq. 4. Why "Doppler-broaden" instead of "Fermi-smeared", which is more consistent
       with your terminology later in the paper?
   - Paragraph 2.
     - Line 2. Use "... events that are the most ...".
   - Paragraph 3.
     - The discussion of Fig. 2 is a bit tricky. There is a shift in the QE peak that you do not mention
       here, yet it is one of the first things that I saw. Also, how do we know what the quality of the
       CLAS data reconstruction is? Were momentum corrections done to put the peak in the proper location?
       You never mention which dataset is analyzed in the discussion here.
     - Another aspect in looking at comparing data to models is that the comparison only makes sense if the
       model properly accounts for the CLAS resolution function. This is mentioned a bit tangentially for
       my tastes. It seems that this should be a bit more stressed. The comparison is only as good as this
       accounting. So, how was this done? Did you smear with a resolution function event-by-event? Did
       you use GPP with GSIM (which is entirely inadequate - it works on average, but misses important
       kinematic dependence)? I recommend you mention clear the necessary smearing of the model with the
       CLAS resolution function and provide some more details in the supplementary material.
     - Line 6. Use "cross sections".
   - Paragraph 4.
     - Eq. 5. Add comma at the end of the equation for proper punctuation.
     - Line 3 after Eq. 5. You have not defined "removal energy".
   - Paragraph 5.
     - You capitalize "Carbon" and "Iron". This is not proper.
     - Line 9. Use "... distributions, see Section I.".
     - Line 12. Use "... underestimating it at 2.257 and ...".
   - Paragraph 6.
     - Line 7. Use "... also become significant ...".

Page 5:
 - Fig. 3. I am confused as to why the QE peaks from GENIE are not Gaussian. If you have convoluted the
   model with the CLAS resolution function, it should be force these peaks to be Gaussian.
 - Fig. 3 caption.
   - Line 9. Use "... data are not shown.".
 - Left column.
   - Table I is not referenced in the text.
   - Paragraph 2.
     - Line 5. Use "... beam energy, which is not possible ...".

Page 6:
 - Fig. 4 caption.
   - Line 1. Use "(Left) The missing ...".
   - Line 4. Use "(Right) The calorimetric ...".
 - Left column.
   - Paragraph 3.
     - Line 2. Use "... distributions, which are not testable ...".
     - Line 4. You reference subfigures of Fig. 4 (a,b,c,d), but you have not put the letters
       on the plots.

Page 7:
 - Right column.
   - Paragraph 4.
     - Line 6. Include a reference to CLAS12. We have just published an 18 paper NIM volume!

References:
 - Do not include preprint numbers for papers that are already published.
 - [9]. Fix format for NOVA.
 - [12]. Here you use "NIM". Elsewhere you use a different format.
 - [15]. Reference incomplete. Fix format for NOVA.
 - [16]. Reference incomplete.
 - [19]. Fix format for MINERVA.
 - [40]. Use "et al." as you do elsewhere.

Page 8:
 - Right column.
   - Paragraph 2.
     - Line 10. Use "CLAS Collaboration".
     - Line 12. Use "e-GENIE".
   - Paragraph 3.
     - Line 1. Use "Reprint and permission information ...".

Page 9:
 - Paragraph 1:
   - Line 1. End bf line with a colon, not a period.
   - Line 5. Use "... protons, and photons, and to ...".
   - Line 15. I suggest "... agreed within the detector resolution with that calculated from the
      particle's momentum ..." (Obviously there must be a resolution factor.) 
   - Line 18. Use "... calorimeter, which implied a ...".
 - Paragraph 2:
   - Line 3. Your subscripts should be "_{\pi^+}" and "_{\pi^-}.
   - Line 8. Use "... and close to 100\%."
 - Paragraph 3:
   - Line 4. Missing GeV units on arc measurement.
 - Paragraph 4:
   - Line 3. Switch order of Eq. number references here, 4 should come before 5.
   - Line 4. Add a comma after "\Delta \epsilon".

Page 10:
 - Left column.
   - Paragraph 1.
     - Line 16. Use "... N_{rot}$, where $N_{rot}$ ...".
   - Paragraph 3.
     - Line 3. Use "... $0\pi$ events, which we ...".
     - Line 4. Use "... event sample, or as ...".
     - Line 5. Use "... sample that we used ...".
     - Line 10. Use "... e'p)$ samples. We then ...".
   - Paragraph 4.
     - Line 6. Use "... with an undetected ...".
     - Line 7. Use "... with a detected $\pi^\pm$ ...".
     - Line 11. Use "... photon event and the effect ...".
 - Right column.
   - Paragraph 2.
     - Line 5. Use "... to use reaction mechanisms as close to $\nu$-GENIE as ...".
   - Paragraph 3.
     - Line 5. Use "... production, which includes ..."
     - Line 9. Use "... $2p2h$ currents), which describes ...
     - Line 10. Use "... $\Delta$ peaks; ...".
     - Line 14. Use "data-driven".
     - Line 16. Use "normalized".
     - Line 17. Use "low-energy data".

Page 11:
 - Left column.
   - Paragraph 2.
     - Line 7. Use "... 4.453~GeV, respectively."
 - Right column.
   - Paragraph 1.
     - Line 1. Use "...2\% for the signal and 5\% ...".

Page 13:
 - Fig. 2. Match the plot sizes for a cleaner look.
 - Fig. 2 caption.
   - Line 2. Use "meson-exchange currents".
 - Fig. 4 caption.
   - Line 2. the left and middle figure reference is swapped in the caption.
   - The caption refers to subfigures (a), (b), (c), but there are no labels on the plots.

Page 14:
 - Fig. 5 caption.
   - Line 5. Use "iron".

Page 15:
 - Fig. 7 caption.
   - The term "feed-down" does not seem appropriate. It is a fractional energy shift relative
     to $E_{true}$.
   - Line 2. Missing energy units for 2.256 and 4.453.
 - Fig. 8 caption.
   - Use "vs.".
   - Use "data".

Page 16:
 - Fig. 10 caption.
   - Line 1. Use "(Left)".
   - Line 2. Use "... Fe$(e,e')$ for (a) events ...".
   - This caption is confusing. You use (Left) but do not have a (Right). You refer to (a) and (b)
     and there are no such corresponding labels on the plots. Please tidy this up.