STAR HardProbes PWG

[Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>]

Hello PAs,

Glad to see this analysis at this stage.
I tried to go through the paper draft and analysis note.
I know this paper draft will go through multiple review process (hp 
pwg-GPC-Collab) in coming days and my comments are probably zero-th 
stage now.

Please find my comments on your paper draft and AN below.

Paper draft:

$pp$ -> $p+p$ make consistent thought out the paper as $p$+A

L18-20: "These include high-pT hadrons and, in the case of this 
publication, jets (refer to Section II)." It reads awkward in this 1st 
para. Better to introduce the topic with out mentioning "…n the case of 
this publication, jets (refer to Section II)."
L26: "…with other matter 
throughout …" -> you have not discussed yet what is matter?
L24-30: Too big and complicate complicate sentence. Please break it.
L32: "measurements of √sNN = 200GeV d+Au collisions have provided an 
important connecting role …" Here it reads like we are measuring "√sNN = 
200GeV d+Au collisions". That is not true. Rephrase like "At STAR, jet 
measurements at √sNN = 200 GeV in d+Au collisions provide important 
information of cold nuclear matter …"  something like this.
L36-39: "In this publication, we present measurements from √sNN = 200 
GeV p+Au collisions provided by RHIC in 2015 and measured at STAR."   
Unclear and redundant sentence.
L39: Specifically,  -> No needed.
L41: high-η -> so far "η" is not defined ; same for φ_{}
2nd para: "we present…" and "we report" are used in multiple instants. 
Please try to rephrase at then end what "we present/report …" in this 
paper.
L52: "To first order, hard scatterings result in azimuthally 
 back-to-back, pT-balanced dijet pairs. " It reads this is a collection 
of words; please make a sentence. 
L54-60: This sentence needs work. 
Syntax doesn't read well.
L63-67: Rephrase this sentence and provide reference to PHENIX, ATLAS, 
ALICE, CMS measurements.
L67-68 and all bullets: No need to summarize what we observed in 
p/d/He^3 collisions. It would be better to emphasize what we try to 
measure in this publication and what is our current understanding 
pertaining to it.

Overall, I think this introduction section needs work to  be precise and 
coherent.
At the end of this section, we need a paragraph mentioning a brief 
overview of other sections.

Section- II.A

L89: "…provided sNN = 200GeV p+Au collisions…" -> …provided p+Au 
collisions data at sNN = 200 GeV in 2015." (No need to write May and 
June)
L91: "This publication reports collisions measured by STAR (Solonoid 
Tracker at RHIC). Events were selected and measured using the following 
STAR sub-detectors." -> Make it one sentence. Otherwise drop it as it is 
not adding any info here.
L100:	(> 30 GeV/c)…(poor pT resolution),-> better to avoid this style of 
writing. Explicitly mention this in one sentence.
L107: "…20 hits in the TPC …" -> "…charged-tracks with at least 20 
hits…"
L113-115: "The BEMC calorimeter measures principally photons from π0 
decays and, in less abundance, interactions from charged hadrons." -> 
"The BEMC calorimeter measures the energy deposition of 
electromagnetically interacting particles."
L115-118:"Only calorimeter hits with transverse energy projections (ET) 
within the selected pT range ([0.2,30] GeV) were considered in this 
analysis."  Not sure what  does it want to say.  
L118-121: For reader, 
what are "bad online" and "hot towers" ?
L122:" …tracks and towers are combined …" -> "…tracks and towers are 
clustered …" ; "R = 0.4 resolution parameter." -> a resolution parameter 
R=0.4.
L136: "STAR selected minimum bias (MB) collision events triggered online 
by the Vertex …" -> "The minimum bias (MB) events are selected using the 
Vertex …"
L141: "…at least 2.5 GeV. " ->  is  the BHT1 or BHT0 trigger used in 
this analysis?
L143: "HT events is raised to 4GeV as an offline event cut"  -> however 
In "main_AN_v0.pdf"  L196, offline cut is used ET > 8 GeV and In 
"AN_vv_v0.pdf" L24: ET>4 GeV is used. Please make it consistent or 
explain.
L146: "STAR’s interaction point, " -> is it center of the TPC? [same for 
L164]
L154: "(PU)…(tracks not resulting from particles involved in the 
collision being measured) " this is important for this paper so mention 
it in a separate sentence.
L162: "triggered collision" what is triggered collisions?
L165: "Second, Vz was required… VPD… to the TPC" Please mention why we 
need this second condition for selecting events? For example to reduce 
pile up events, … etc.
L170: "reports on measurements from 3.7 mil- lion MB and 135 million HT 
collisions. " -> This sentence doesn't mention what do we report?  What 
observables and why?

L173: "High-backward rapidity " provide eta range.
L195:  φUE  and  φlead are not defined.
L193: "…   .       in MB events, however, …" -> "…in MB events. However, …"

Section-II.B

L202: "Detector track efficiency and acceptance are …" -> "The TPC 
tracking efficiency within a given acceptance is …" 
L215: "using pp 
relative weightings is small" -> mention what is that number is ?
L219-222: "After correcting for the tracking efficiency, the average 
number of tracks in the TPC increases by about 0.5 tracks (…)" -> 
"Increase by about 0.5 tracks " depending on EA or lumi.  not 
clear.
L222: "This increase is attributed to pileup tracks …" why it is 
the only possibility? Due to high lumi, efficiency drops that doesn't 
mean due to pileup tracks. Am I misunderstood? 

L232: "zero-bias (randomly triggered) events" -> Not clear if it is 
embedded in "zero-bias" p+p or p+A events?
zero-bias events are not "randomly triggered" event? It is without 
(hence zero) any detector condition.
Question: if it is pp zero-bias, then how do you implement pAu event 
background fluctuations while unfolding the jet spectrum?
L33: PYTHIA6 level particles  -> "Generated level PYTHIA-6 particles…" ; 
"the simulated track and tower responses " -> the GEANT3 level simulated 
track and tower responses …"

Additional comments: please mention what is the jet matching efficiency 
in pAu ? And what about JER and JES.
  
L259-262: "Note that there are no jets in the pT range of the 
reported… unity". Not clear, please rephrase or explain here.


Section: II.D
L277-279: "The shape of the azimuthal distribution between the leading 
and subleading jets" -> Mention how do you normalize this distribution. 
Define what is A_phi? I think it is certainly not "Aφ ≡ |φlead − φsub|) 
"?
L289-290: "This justifies the presentation of detector-level Aφ and AJ 
distribution ratios as meaningful." -> this is true for ratios. For 
Fig.7 and 8, But for upper panel plots the shapes are not corrected and 
may not help for any theory comparison in future study. This is a weak 
point of this paper and Referee/Collaboration will be critic of it.

L323-326: "	While this publication focuses on correlations with EA_BBC, 
given its monotonicity with EA_UE, there is no physical preference for 
one definition of EA over the other. " I think we should give preference 
to one of EA definitions (probably here EA_BBC) and that should be 
decided how well we can discriminate the EA classes. For example in 
centrality definition, we decide based on centrality resolution. 
Similarly we need to mention why we choose EA_BBC and based on what? See 
my comment below on this topic. 

L328: the lowest and highest 30% in MB define the ranges of EALow and 
BBC EA_High , respectively (see Sec. II A 3). And cf. Fig.1 -> 30%, 40%, 
30% labels are not clear. 

In this section.III.A , we need to have a discussion on this EA_BBC 
definition, how well we can discriminate different event classes. i.e. 
is there any overlap of events between EA_BBC^High and EA_BBC^low 
classes?

 
section.III.B:
L341: "…plotted in Fig. 3 for ten ranges of EABBC. " and Fig.3 -> As I 
mentioned above, it is difficult using EA_BBC we can really divide 10 EA 
classes as shown in Fig,3. There must be large fraction of events 
overlapping adjacent EA_BBC bins. 

In this section, it is not clear why we have Fig.3? What do we learn 
from this fig? And why do we have 10 ranges of EA_BBC?

section.III.C:

L352: "while Fig. 3 suggests that the underlying event is 
anti-correlated with increasingly energetic triggers." Not clear how do 
we draw this statement from Fig.3? What I can see that within 
uncertainty all three HT trigger cases are consistent with MB.  Am I 
missed anything?
L363: "i.e. |φtower −φjet | > (180◦ −Rjet ). " Please correct it. 
180-Rjet?

Section.III.D

L402:  and withing -> and within
L405: jets will fall outside -> jets fall outside 
L409 and L411 don't 
say anything about the reason of this suppression. This suppression 
discussion sounds like incomplete and hastily stopped at this point.

Section.III.E

L452: Definition of A_phi is different from phi difference. See Fig.7 
upper panel Y-axis title.


_____
Comments on Figures:
General: Make x-, Y-axis title and label clearly visible and make font 
size of legend/title/label  bigger.
Put  "STAR" in every figure.

Fig-3:  Y-axis title in d^2 , "2" is missing. Please increase this size 
of this figure. 
Fig-7: Make Y-axis log scale so that each data point 
can be visible
Fig.6: Y-axis title, should it be d^2N/dpT dphi?
Fig.6, 7, 8,: Mention System, energy in legend

In Fig7 and 8 caption: "Cuts on the lower bounds of pT,jet and  psub are 
indicated in captions." Not sure what "caption"?


—————
General comment: Can you please add these two analysis notes into one so 
that it would be easy for the reader?

main_AN_v0.pdf

1. Can you please work on the proper alignment of figures in this AN? It 
looks awkward.
2.  Section. 3.2: in p+Au events, eta-distribution is not uniform (flat) 
at mid rapidity. Have you checked the difference between EA_TPC for both 
the configurations like p-going side and Au-going sides 
eta-distributions and what is the difference between EA_TPC?
3. Fig.9 and 10: put Y-axis title;  In caption:"The mean values of each 
EA definition in bins of the other EA definition are also plotted."- > 
This is event-by-event of 2D histogram. Then not sure "the mean value of 
each EA… are also plotted" Can you please clarify?  "Statistical errors 
on the mean are shown." -> No stat. Errors are shown.
4. IN fig 9 and 10: no mean values are plotted, I think. Please use 
correct plots.
5. Section 3.3: "	Correlation Between EA_BBC and EA_TPC " -> But in the 
texts you mention EA_UE. So far you have not introduced EA_UE?
6. Fig.16,18, 20, 37, 38,39,40,43,44,45,46,47,52: No data shown in this 
plot. Please use correct plot. Check also other.


Best
Nihar





> On 2023-04-28 12:10, David Stewart via Star-hp-l wrote:
> > Hi all,
> > This is just a reminder in the middle of the flood of QM work/emails
> > that the draft and analysis notes for our p+Au EA vs UE vs jet paper
> > are posted on the paper webpage here [1] and that we are ready and
> > waiting for GPC formation.
> > Thanks,
> > David Stewart
> >
> > Postdoctoral Fellow | Department of Physics, Wayne State University
> >
> > Links:
> > ------
> > [1] 
> > https://drupal.star.bnl.gov/STAR/blog/djs232/Paper-EA-and-UE-Corrs-High-Q2-Events-pAu-sNN200-GeV-Collisions-STAR
> > _______________________________________________
> > Star-hp-l mailing list
> > Star-hp-l AT lists.bnl.gov
> > https://lists.bnl.gov/mailman/listinfo/star-hp-l