Discussion of sPHENIX note sPH-cQCD-2017-001

[Joern Putschke <joern.putschke AT wayne.edu>]

Dear Authors,

let me first congratulate for this very comprehensive and complete document. 
In my opinion it is very well written and certainly extends concerning 
details and breadths what I assume is required concerning an Letter of Intent 
at this stage.
I also want to apologize that given the tight schedule and memorial day 
weekend most people did not had the time to go through this comprehensive 
document in every detail (so much of the comments are focused on Chap 1 and 
2). Nonetheless, please consider the following comments/suggestions:

A)  English/Style/Formatting 

Executive summary: l 9 : glimpses —> to explore 

p1 l3: considered —> broadly divided (?)
p2 l16: whatever system —> the potential unique properties (maybe not exactly 
that formulation, but whatever sounds a bit funny)
p2 l37: —> can be uniquely 
p4 l11: here and also later in the text: "off of" appears and should be 
changed accordingly
p4 l41: “lack thereof” sounds a bit harsh (maybe that is intended), maybe 
more like given the present uncertainties/ambiguities 
p5 l20: The can —> They can
p5 l27: hadron in-jet sounds funny, but if this the accepted term then of 
course course it should stay. Otherwise I would suggest to reformulate.
p5 l11: “off of”
p11 l1” “off of”
p12 l10: remove “a” in front of normal 
p13 l5: “learn a great deal” —> to significantly enhance our understanding 
utilizing measurements …
p14 l5: intensive —> comprehensive
p15 l3: widely —> with large rapidity separation
p27 l14: “eta” —> latex symbol
p32 l20: capably (sounds quite weak) —> is well suited to 

B) Everything else …

Executive summary:
- I would suggest to explicitly add that these updates will significantly 
increase the physics case of sPhenix (it is implied, but I would make it make 
concrete)
- In sec 2.6 there is a nice summary of how these upgrades could form a base 
EIC detector, I was wondering if it would be good to also explicitly mention 
this in the executive summary?

p1: here and in the later chapter concerning QCD systems over a range of next 
baryon densities. This indeed is an interesting angle, but I think one should 
mention the BES program and should point out that this would be an important 
complementary approach, but I think omitting the BES seems funny, unless I 
miss some very important line of argumentation?

p13: Sec 1.2: While there are still a lot of unknowns, I think one should 
weaken a bit the statement: “extremely little”.

p18 l27: While I think I would agree that the process should be 
nonpertupative,  I think the statement must be w/o further explanation is a 
bit strong. I any case, I think adding one or two more sentences expanding on 
that physics aspect would help to significantly strengthen this section.

p21: Sec 1.3.2: Again I think “extremely little” seems a bit extreme and I 
would encourage the authors to consider changing/weakening a bit these 
statements and rather try to formulate “positive” in a sense that w/o 
diminishing past accomplishments that there are extremely interesting 
opportunities for sPhenix.

End of Chapter 1: Maybe this is overkill since there is an intro in Chap 1 
and an exec summary, but I was wondering if broadly summarizing in bullet 
form would help the reader before switching to Chap 2?

p53 l29-30: The meaning of the last sentence is unclear? Maybe end with 
connecting back to the physics case and similarity with the WMAP analogy? 
Somehow it would be good to end this section with a clearer 
physics/feasibility statement.

Again, I apologize that given the time constraints not the whole document was 
commented on in detail, but I hope that the above comments/suggestions will 
be considered helpful. 

Thanks

Joern on behalf of Wayne State University