[Clascomment] OPT-IN: A search for baryon- and lepton-number violating decays of Lambda hyperons using the CLAS detector at Jeff erson Laboratory

[Daniel Carman]

Dear Mike and Matt,

I have read through your draft of the "rare" Lambda decay branching ratios based on the draft
of May 26. I have enjoyed watching this analysis proceed from your Working Group presentations,
especially as this is definitely a bit of a novel idea and not one of our "usual" CLAS papers.
My comments are included below. If you have any questions, let me know.


					        Regards,
						
						Daniel

************************************************************************************
Physics/Presentation Comment.
 - The title of this paper is "... baryon- and lepton-number violating decays". The "BNV" aspects
   are quantified and discussed, but the "LNV" aspects are not mentioned after the first page.
   In my reading I found this lack of discussion of lepton-number violation problematic given the
   title and the introduction. I think this needs some attention both in the analysis discussion 
   and in the summary/conclusions section.

General.
 - Your color figures should have "(Color Online)" in the caption.
 - You have tense issues throughout. What I mean is that the analysis steps tend in your manuscript
   to be discussed in the present tense when the past tense is most appropriate. For example, you
   use "For this analysis we make use of the CLAS drift chambers ..." when it is more appropriate
   to use "For this analysis we made use of the CLAS drift chambers ...". The tense issues began
   in Section II and continued through the analysis/results section.

Page 1.
 - Abstract. Line 2. I suggest "... using the CLAS detector at Jefferson Laboratory."
 - Line 14. I think you mean "conception" not "inception".
 - Line 18. Here you use Refs.[4,5] (publication dates in 2004 and 1976) as data that motivated
   Sakharov's work in Ref.[6] published in 1967. This violates causality.
 - Line 26. Use "... interactions that violate ...".
 - Line 48. Use "... calculations that constrain ...".
 - Line 79. Use "... \bar{\Lambda}$), which then undergoes ...".

Page 2.
 - Line 135. Use "... decays, the expected backgrounds ...".
 - Line 148. Use "... by CEBAF (Continuous ...".
 - Line 160. Use "4 m".
 - Line 166. Use "... can be found in [28]." If there are other references that are relevant for the reader
   beyond [28], list them explicitly.

Page 3.
 - Line 183. 3e6 MC events seems too small for a reasonable study by a factor of 10 to 50 in my opinion for
   such a large phase space. Why such a small number?
 - Line 183. Use "... \Lambda$ events, and weighted ...".
 - Line 191. Use "... model the CLAS acceptance, ...".
 - Line 213. I suggest "... through the magnetic field of CLAS) ...".
 - Line 216. I suggest "... $d$ is the path length of the track from the vertex to the TOF system, ...".
 - Eq.(3). Use a period after this equation, not a comma.
 - Line 228. Use "... Monte Carlo events is shown ...".

Page 4.
 - Line 237. Use "... hyperons that include ...".
 - Line 239. Use "... apply geometrical fiducial ...".
 - Line 257. For your number $N_{rec}$, what is the relevant photon energy range for the analysis? Seems like
   this should be listed here with the mention that it is a brem spectrum.
 - Line 266. Use "... and kinematics, we separate ...".
 - Line 281. Use "... MM^2$, as well as ...".

Page 5.
 - Line 288. Use "... for a potentially small ...".
 - Line 300. Use "We have tuned our cuts ...".
 - Line 302. Use "... plots that would ...".
 - Line 305. Use "... of all of our data points until ... of the analysis cuts, ...".
 - Line 311. Use "... to the measured ...".
 - Line 326. I suggest "... order as the dimensions of CLAS and ...".

Page 6.
 - Fig. 4. Your x-axis labels overlap the axis values. Also the axis values at the ends of the plots
   overlap and are partially cut off.
 - Fig. 4 caption. Line 1. Use "... boundaries of the PID ..."
 - Eq.(10). Wrong units.
 - Line 396. I suggest "... there are significant numbers of ...".

Page 7.
 - Fig. 5 caption. Line 4. Use "... of the optimal cuts, ...".

Page 8.
 - Line 447. Missing units on $w_2$.
 - Line 450. Use "... to identify the signal.".
 - Line 456. Missing units on $w_2$.
 - Line 462. Use "... of the background in the signal ...".
 - Line 469. 5e5 again seems way too low of a number of generated events.

References:
 - Problem with formatting of nearly all references as there are no spaces between the different
   parts of the journal names (e.g. Phys.Rev.Lett. vs. Phys. Rev. Lett.).
 - I would have liked to have seen the inclusion of a recent reference for the M/AM ratio based on
   data.
 - I would have liked to have seen a more recent reference instead of [7] which is from 1985. Surely
   there is something from your lifetime.
 - For published papers, do not include the preprint numbers.
 - Ref.[20]. With a long author list, use first author and then "et al.".
 - Ref.[21] has some kind of problem. Who is S.-K. Collaboration?
 - Ref.[22] is incomplete.
 - Ref.[27] is not a CLAS Collaboration paper. First author is "B.A. Mecking".
 - Ref.[28]. First author only and then "et al.".
 - Ref.[30]. I have no idea what eConf C030908 MODT002 is. This reads like some kooky hexadecimal code!