sPHENIX is a new detector at RHIC.

[Nathan Grau <ngrau AT augie.edu>]

Hi all,

I realize I'm probably a few minutes late with these suggestions. I'm hoping you can still consider them. FIrst off, congratulations on the measurement. It is impressive to see the comparison of these results from earlier RHIC measurements. I have a few comments on the current draft. I provide them in order they appear in the text.

Thanks,

Nathan

1) Lines 39-43. The first couple of sentences in this paragraph is rather specific to the analysis and would better be incorporated at the beginning of Section 3 on Data Selection. Then the paragraph could start with "This paper presents measurements..." and is a nice concluding paragraph for the introduction.

2) Line 78: spell out $X_0$

3) Lines 87-88: The sentence about the reuse of the BBC seems completely unnecessary. I would remove it.

4) Line 95: IP needs to be spelled out on first use.

5) Line 104: Why are the cuts on the north and south charge so asymmetric. Why is that necessary? What does it accomplish?

6) Line 118: define $N_{part}$ on first use.

7) Lines 184, 100: say "on the order of" instead of $\mathcal{O}$.

8) Lines 185-186: The parenthetical definition of trackles offset by the commas is redundant and can be removed. 

9) Figure 3 and Figure 4 need appropriate units on the axes.

10) Figure 3 caption needs to have further details such as naming the two different distributions and give the punchline. I don't see the point simply from the legend.

11) Line 260: 0.5 is missing units. I'm presuming it is cm.

12) Section 5. In one case you give the size of the uncertainty but not in others. I know it can be redundant to have them in both the text and the table. But my preference is to have them in both places so that I can compare the relative importance of the many different uncertainties as I'm reading the text. Alternatively you could refer to Table 1 before defining all of the uncertainties.

13) Section 5 and 6. It was not clear from the text if these systematic uncertainties are Type A, B, or C. There are at least some of A and B given your averaging of the two different analyses and the statements in lines 345-353. In Figures 5-6 it would appear that all of the uncertainties are correlated as they are only given a single box for the systematic. But that also seems inconsistent with the text.

14) Table 1: Does it make sense to refer to such small values i.e. 1.0x10^-4? I don't know if sPHENIX has a way to say that this is effectively 0. But it is, no? Also, do the systematic uncertainties vary with eta? or centrality? or both? That also affects the interpretation of Figures 5 and 6.

On Thu, Mar 13, 2025 at 9:01 PM SATO Susumu <susumu.sato AT j-parc.jp> wrote:

Dear PPG02 colleague 

Sorry to post this in the list, but not in the Invenio.

 (Though I have consulted with Anne et al. (incl. Dave and John) 

  about current situation where no connectivity to the ppg02's Invenio 

  entries, the situation seems to be not-yet fixed).

The followings are the comments for the PPG02 first release,

--- --- Comments, for ppg02 first release --- ---

[[ Type-I, substantial-type ]]

(1) Fig.5 and related places.

Does this paper have (,and then will this paper make) 

 any interpretation for the systematically-larger mean 

 value (e.g. in Fig.5 Left) for the "closest-match" method 

 than for the "combinatoric" method (, especially much larger 

 at larger abs(eta)?

 

 In other words, (after combining the "combinatoric" and the "closest-match" methods,) 

 is the the concave shape (e.g. in Fig.5 right, especially for central events) 

 at mid-pseudorapidity (= around zero eta),  (to be stated) significant ?

 Or, In much-other words, 

 does the " '1.6 (or the coming larger number)' reduction 

 in uncertainty (stated in the abstract and the conclusion)", 

 make clearer statement (in Fig.5) for the concave shape at abs(eta)<0.3 ? 

 I am asking because this shape (the concave (,or if in contrast, convex)) 

 would related to

 the Baryon stopping at this energy (with these centralities). 

 And this might (probably minorly) change the increasing 

 slope (at larger centralities) in Fig.6 (both the right and the left figures).     

[[ Type-II, editorial-type]]

(2) L3

The title contains the _expression_ "at 200 GeV", but it's better to be "at sqrt(s_NN) =200GeV" 

(3) LL282-338 and Table 1

The main text is itemized by "black dot (L288, L292, L297, L300, L303, L306, L310, L317, and L323",

but it's better to be itemized in "numbered" or in "alphabet-ized", each of which 

is ALSO better shown in Table 1. For the general readers, it is convenient to have easy correspondences between

explanation (shown in the main text) and extracted value (shown in Table 1)   

(4) L421

"S^(1/2)" should be well Tex-formatted.

(5) LL49-99

Are not there any figure to pictorially-show the sPhenix detector ? 

--- --- End of Comments, for ppg02 first release --- ---

Sincerely,

Susumu SATO.

----- Original Message -----
From: Cheng-Wei Shih <cwshih0812 AT gmail.com>
To: sphenix-l AT lists.bnl.gov
Cc: sphenix-ppg02-l AT lists.bnl.gov,sphenix-irc02-l AT lists.bnl.gov,"Shih, Cheng Wei" <cshih AT bnl.gov>
Hao-Ren Jheng <hrjheng AT mit.edu>,Cameron Dean <ctdean AT mit.edu>,Itaru Nakagawa <itaru AT riken.jp>
Date: 2025-03-10 13:01:39
Subject: [[Sphenix-l] ] First circulation of PPG02: Charged hadron multiplicity measurement in Au+Au Collisions at √s_NN = 200 GeV

Dear sPHENIX Collaborators,

PPG-02 would like to announce the first collaboration circulation and review of the paper, targeted for submission to the Journal of High Energy Physics: “Measurement of Charged Hadron Multiplicity in Au+Au Collisions at 200 GeV with the sPHENIX Detector.”

The Invenio entry for the paper draft is: https://sphenix-invenio.sdcc.bnl.gov/records/aga48-gv870

The Invenio entry for the internal analysis note is: https://sphenix-invenio.sdcc.bnl.gov/records/ajtz6-bfe57

We note the following regarding the current results in the paper draft, which are marked in red and described in the footnotes:

- They were obtained using HIJING simulation samples with an older version of the MVTX geometry. The impact of different MVTX geometries is expected to be minimal.

- Two sources of systematic uncertainty have yet to be included: 1) variations due to different event generators/models, and 2) the uncertainty from secondary particles originating from weak decays. These uncertainties are not expected to be dominant compared to the existing ones, and their inclusion should not affect the key physics results or the main conclusions of the paper.

PPG will incorporate these remaining components once the centrality divisions for EPOS and AMPT are available and the analysis is fully processed with the requested simulation samples. PPG has coordinated with the IRC, conveners, and PCs, who have agreed to proceed with the first circulation based on the current status. The outstanding elements will be incorporated before the second circulation.

Best regards,

PPG-02 Analysis Team

IRC: Stefan Bathe (IRC Chair), Xiaochun He, Greg Ottino

--

Nathan Grau (he/him/his)

Professor and Chair

Department of Physics

Augustana University

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Sioux Falls, SD 57197
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