sPHENIX is a new detector at RHIC.

[Martin Purschke <purschke AT bnl.gov>]

Hi Emma and PPG03ers,

Congratulations to this nice paper! Great to see these key results 
coming out.

I have some comments, first a more substantial suggestion for the 
paragraph starting at line 194 about the reweighting. We describe a 
parade of reweighting steps that is somewhat hard to follow. Maybe we 
could add a figure (with a few panels as in fig 3) that shows the effect 
of this reweighting, step by step? This is a central piece of the 
analysis. Not sure if it's easy to do.

More minor comments -

L 6 - "per unit pseudorapidity" -> per unit of pseudorapidity

L 23 - the full repetition of "at the Relativistic Heavy Ion Collider 
(RHIC)", already in line 8, seems unnecessary.

Lines 7,26,46 and other places - homogenize the typesetting style of the 
\sqrt{S_{NN}} = 200 GeV

L 40 check this sentence - The dET /dη     measurement is a key for 
benchmark the sPHENIX calorimeter performance... "for benchmarking" or 
"a key benchmark for.."?

L 60 available in Ref. [20]  -> "available here [20]" ?

L 87 - This sounds a bit awkward with the "voltage" - The light from the 
scintillating fibers is collected by a light guide and processed into 
voltage signals using silicon photo-multipliers (SiPMs).
Maybe "The light from the scintillating fibers is collected by light 
guides [plural] and measured with silicon photomultipliers (SiPMs)."

L 88 the next sentence should be split up a bit. The numbers' meaning is 
a bit ambiguous for a non-RHIC user (and "beam clock" is not a good 
term, IMHO). 9.4MHz is the bunch crossing rate, and we digitize at 6x 
that, at about 56.4MHz. Maybe "The analog signals from these SiPMs are 
digitized with 14-bit ADCs at a sampling frequency of 56.4MHz, which is 
six times the RHIC bunch crossing rate." [Also avoiding the word 
"precision".] And also, this goes for all calos including the ZDC, not 
just the EmCal, so maybe we can move that out of the EmCal section to 
cover all 3. We should also stress more that we are measuring an actual 
waveform, like "For all but the zero-suppressed channels, we record a 
full 12-sample waveform. Channels are zero-suppressed if [the 2-sigma 
algo etc]. In this case we retain only 2 summary samples." This makes 
the subsequent discussion about the template fitting clearer.

L 130 "complete trigger and offline event selection efficiency" sounds 
odd - can we quantify this?

L 134 / 135 time samples from the calorimeter electronics  were fit to a 
waveform template
 -> the signal waveforms were [fit ->] fitted to a template derived...

L 158 makes a sudden jump to simulated data and back to real data. This 
narrative could be made clearer. "We simulated the detector response to 
cosmics to  using....   to derive the offline cuts to apply to the data..."

Fig 2 - Panel (b) illustrate -> illustrates
... comparing that in cosmic-ray data-taking (points) and in a geant-4 
simulation of cosmic-ray muons from EcoMug (histogram) ->
"comparing cosmic-ray data from the detector (points) and  from GEANT4 
simulation using EcoMug (histogram)"

Line 205 "same.... analysis chain as the [real] data."

Line 256 varying by over a factor of ten  -> more than a factor of 10

Fig 3 since the y axes are the same, can we gain more viewing space by 
combining the 3 into one block (eliminate the repeated y axis space)?


Ok, that's what I have. Again, great work!

Best,

     Martin



On 3/8/25 09:11, Emma Grace McLaughlin wrote:
> Dear sPHENIX collaborators,
>
> We are very excited to announce the first internal circulation of 
> PPG03: "Measurement of dETdeta in Au+Au Collisions at √s_NN = 200 GeV 
> with the sPHENIX detector" for collaboration review. The intended 
> journal for this paper is Physical Review C.
>
> The paper draft can be found here: 
> https://sphenix-invenio.sdcc.bnl.gov/records/s87xy-nd113
>
> The internal analysis note can be found here: 
> https://sphenix-invenio.sdcc.bnl.gov/records/8sark-8re40
>
> We look forward to comments from the collaboration on this paper 
> draft. Please use the invenio conversation tab location on the paper 
> draft to include comments for ease in documentation of collaboration 
> comments and PPG responses.
>
> Thank you,
> PPG03: Emma McLaughlin, Joseph Clement, Skaydi Grossberndt, Hanpu 
> Jiang, Shuhang Li, Sam Liechty, Dan Lis, Jaebeom Park, Blair Seidlitz, 
> Stefan Bathe, Jamie Nagle and Bill Zajc
>
> IRC03: Huan Huang (chair), Derek Anderson and Virginia Bailey

--
Martin L. Purschke, Ph.D.        ;   purschke AT bnl.gov
                                 ;   http://www.phenix.bnl.gov/~purschke
                                 ;
Brookhaven National Laboratory   ;   phone: +1-631-344-5244
Physics Department Bldg 510 C    ;   fax:   +1-631-344-3253
Upton, NY 11973-5000             ;   skype: mpurschke
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