STAR HardProbes PWG

[Dandan <shendandan AT mail.sdu.edu.cn>]

Dear Isaac, and Yi,

Dear Yi，

      Thank you for reminding me to deal with comments and have a good holiday.

Dear Isaac,

I would like to add a bit more information to my previous email, hopefully, this can help you understand my response better.

The new version has been updated in the link: https://drupal.star.bnl.gov/STAR/presentations/SPIN-2023/Measurement-Jpsi-polarization-and-spin-alignment-RuRu-and-ZrZr-collisions-sq

For your comments:

1、"74. Similarly, this should be "reaction plane" rather than "event plane", right?" 

      Reply: We can not find the reaction plane but can only approximate and this approximated reaction plane is known as the event plane. I chose the second-order case plane of TPC as the event plane. Therefore in this case, ‘event plane’ is more accurate, and we prefer to keep the sentence as it is.

2、"General: It would be good to have an explanation somewhere about why it is not contradictory that the rho_00 deviates from 1/3 significantly, while lambda_theta for example is consistent with zero, despite the simple relation in eq. 3 (which is okay in my understanding because the reference frames are different)."

Reply:"The observed spin alignment is likely due to medium-induced effects, while polarization is often believed to mainly originate from the production process; thus these measurements (HX, CS, and Event-plane frames) are not in contradiction with each other. However, the origin of both effects is still under debate, thus we prefer not to include too much speculation in the proceedings. We prefer to keep the discussion as it is, let us know if this is fine with you."

Thank you very much for your suggestions and happy holidays!

Best regards,

Dandan

From: "Mooney, Isaac via Star-hp-l" <star-hp-l AT lists.bnl.gov>
Date: 2023-12-22 06:03:30
To:  STAR HardProbes PWG <star-hp-l AT lists.bnl.gov>
Cc:  "Mooney, Isaac" <isaac.mooney AT yale.edu>,"webmaster AT star.bnl.gov" <webmaster AT star.bnl.gov>
Subject: Re: [Star-hp-l] STAR presentation by Dandan Shen for SPIN 2023 submitted for review>Hi Dandan,
>
>The proceedings are looking really good at this stage. Good job especially synthesizing the polarization and spin alignment results. Please find some small comments from me below, mostly on grammar.
>
>Thanks,
>Isaac
>
>7.
>        "Using the high-statistics Ru+Ru..."
>        "Secondly"
>        "observables"
>        "these proceedings" (and throughout)
>
>21. "To date,..."
>
>44. "evolution."
>
>48. There seems to be a redundancy here. "...of the angular distribution of the two decay products", and "the angular distribution of the decayed leptons".
>
>70. This seems contradictory or inconsistent. The z-axis is defined relative to "the event plane" but also is "perpendicular to the reaction plane, which is estimated by the event plane." Please think about how to make it more clear.
>
>74. Similarly, this should be "reaction plane" rather than "event plane", right?
>
>Fig. 1. Should this be "The black closed circles depict a fit..."? And I'm not sure depict is the right word here. Maybe "are plotted along with a fit using a crystal ball..."
>
>81. It feels like there is some text missing here. I don't see the transition between the previous page and this equation.
>
>115. "evaluated by unfolding the single electron efficiency through Monte Carlo (MC)" reads unclearly to me.
>
>Fig. 2. The caption to the figure should be a bit more standalone. The "from the last iteration" and "the simultaneous fit" should be given a bit more description. E.g. "from the final iteration of the correction procedure for efficiency and acceptance" and "the simultaneous fit of corrected yield distributions in \cos\theta and \phi."
>
>136. Remove "are".
>
>Fig. 3. I would be a bit more clear that the first "left" and "right" refer to the plots while the second left and right refer to panels within the plots. E.g. "as a function of pT (left plot)..." and "In the left panel of each plot, the polarization...". Alternatively, to make it easier on yourself, you could add an (a) and (b) to the left and right plot respectively, and refer to that.
>        Also, it would be good to explicitly mention the centrality integrated point to the right of the dashed line.
>
>161. Remove "is" before "measured”.
>
>General: It would be good to have an explanation somewhere about why it is not contradictory that the rho_00 deviates from 1/3 significantly, while lambda_theta for example is consistent with zero, despite the simple relation in eq. 3 (which is okay in my understanding because the reference frames are different).
>
>> On Dec 18, 2023, at 2:15 PM, Nihar Sahoo via Star-hp-l <star-hp-l AT lists.bnl.gov> wrote:
>>
>> Hello Dandan,
>>
>> Please find my comments on your nice proceedings.
>>
>> Abstract:
>> 1. "The large scale set by the charm mass means the heavy quark pairs are produced early…" -> "The heavy quark pairs are produced early…"
>> 2. Because of this, J/psi -> "The J/psi…"
>> 3.  "In Ru+Ru and Zr+Zr… contributions, respectively." -> Too long and complicated sentence, break it.
>> 4. we will present -> we present
>> 5. in the mid-rapidity -> at mid-rapidity
>> 6. the Collins-Soper frame ;  "and with respect to the event plane." -> "and also with respect to the event plan."
>>
>> L9: a new perspective -> a new insight
>> L12: "STAR collaboration observed, for the first time, that the  meson exhibits a global spin alignment " -> "STAR collaboration reported for the first time global spin alignment of  meson."
>>
>> L14: "the observed polarization of / " -> the J/psi polarization sensitive …"  [see L22, you mentioned "no observation yet" and also you are are measuring in this proceeding]
>> Why do you discuss phi meson spin alignment and J/psi polarization in the same para? Make it two separate para. They are two different topics.
>>
>> L20: experimental measurements ->  / polarization measurement is
>> L21:  it can have an impact on the polarization of  -> it contributes to the J/psi polarization.
>> L24: The presence of QGP will affect / polarization. -> The QGP could affect / polarization in heavy-ion collisions.
>> L25:  the inclusive / component differs -> Not clear what is that "component"?
>> L29:  meson, , between  ->meson between [you introduced later]
>>
>> Eq.1:  W(cos theta, phi) -> make "cos" roman. [check other places]
>> L59: xz plane -> xz-plane
>> L60:  and of the decaying particle itself.  -> and the decaying particle itself.
>> L65: in both HX and CS frames -> in both the HX and CS frames
>> L74:  Bring the relationship between polarization …distribution function -> Not a clear sentence.
>> Secondly, chnage "polarization density matrix" to "spin density matrix";
>> Recall we had a discussion before, we should not mix "polarization" and "spin alignment".
>>
>>
>> L79: "where ∗ is the polar angle between the z-axis …" ->Here you need to mention what is z-axis? As you have already mention HX, CS frame. So you must mention how do you assign z-axis in the spin-alignment analysis?
>>
>> Fig.1 caption: invariant mass spectrum for unlike-sign -> invariant mass spectrum for the same event unlike-sign…
>>
>> L85: −1 <  < 1 and a full azimuthal angle (− <  < ) -> |eta| < 1 and within full azimuthal angle.
>> L97: extracting data from 7 cos bins spanning from -1 to 1 -> extracting data from the seven bins of cos theta spanning from -1 to 1
>> [similarly for L99]
>>
>> L100: Fig.  2 -> Fig. 2 [no gap] same for other cases like L130, L127, and also Eqs.   (5) and …
>>
>> L106: elaborate "     from gamma conversions "
>> L108: by unfolding
>> L109:the correct input distributions in MC are not known a priori  -> Not clear, we do know inout distribution in embedding. Do you mean the "true distribution of J/psi or its decayed electron" ? If yes, please mention it clearly.
>>
>> L131: to obtain the rho_00
>> This procedure is repeated for different centrality and Npart selections. -> Remove it, not needed.
>>
>> L133: "The / polarization parameters ( and )….complete Run 2018 isobar data sample." -> remove it. Not needed. You already discussed.
>> Fig.3 caption: "as a function of " -> is this J/psi pT? If yes, then mention it. And change x-axis title to " p_{\rm T}^{J/\psi}" because you have used the same notation in the text.
>> L137: "               consistent with zero in both the HX and CS frames " -> does this imply that "J/psi polarization is zero" ?
>>
>> L138: a slight indication of non-trivial -> an indication of non-trivial
>> "but overall, there is …" -> Remove it, you already mentioned it in L137 ; meaning is the same.
>> L140: agreement with the uncertainties with… -> agreement, within the uncertainty, with …
>> L141:                 GeV,[4].  ->            GeV [4].
>>
>> L142-143: "Furthermore, the analysis of the / …. as demonstrated in the right panel of Fig. 3." -> The same repetition you discussed in the previous section. Remove it. Directly mention what you observed and conclusion.
>> L147: in the 0.3 < … -> in the range of 0.3 <…
>> L147: The results obtained are visually represented -> The results are presented in Fig. 4.
>> L149: < 0.6 -> …< 0.6 GeV/c
>>
>> L154: polarization and / spin alignment  -> polarization and spin alignment
>> L155: heavy-ion collisions completed at RHIC energy -> heavy-ion collisions at RHIC energy
>> L157:                 Ru+Ru Zr+Zr -> Ru+Ru and Zr+Zr
>> L158: from -> range
>>
>> L157-159: "The J/psi polarization …CS frames" -> Sloppy writing. Break this sentence.
>> L160: ",confirming the reliability of the results " -> Remove this. All our measurements are reliable. Don't you have confidence?
>>
>> L160-162: "/ global spin alignment …" -> the same Sloppy writing.
>>
>> L164: "…are very welcome and crucial to understanding the physics." -> "Theory calculations are needed to explore the underlying physics."
>>
>>
>> Best
>> Nihar
>>
>>
>> On 2023-12-13 07:55, webmaster--- via Star-hp-l wrote:
>>> Dear Star-hp-l AT lists.bnl.gov members,
>>> Dandan Shen (shendandan AT mail.sdu.edu.cn) has submitted a material for a
>>> review, please have a look:
>>> https://drupal.star.bnl.gov/STAR/node/66258
>>> ---
>>> If you have any problems with the review process, please contact
>>> webmaster@http://www.star.bnl.gov/
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>>> Star-hp-l mailing list
>>> Star-hp-l AT lists.bnl.gov
>>> https://lists.bnl.gov/mailman/listinfo/star-hp-l
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