STAR Flow, Chirality and Vorticity PWG

[Sooraj Radhakrishnan <skradhakrishnan AT lbl.gov>]

Hi Subhash, Nu, All,

   Zuowen's comment is true only about the relative contributions to proton flow. Because the contribution from transported protons decreases with energy, at higher energies the negative contribution from the tilted expansion wins out, even if the overall magnitude of the anti-flow from the tilted expansion is decreasing. 

The tilt of the source and the anti-flow from it do indeed decrease with collision energy 

thanks

Sooraj

On Wed, Dec 6, 2023 at 7:19 PM subhash via Star-fcv-l <star-fcv-l AT lists.bnl.gov> wrote:

Dear Zuowen, Nu, All,

Also in Bozek's paper (PhysRevC.81.054902) it is mentioned: "The
directed flow is expected to decrease with the collision energy for two
reasons. With increasing kinematic range of rapidities the tilt of the
source goes down, also the contribution of binary collisions to the
Glauber Model density is believed to increase with the energy, with a
similar consequence"

The suggested sentence from Nu is good. Can you make the modifications
at lines 64 and 87.

Thanks and regards,
Subhash


On 2023-12-07 06:45 AM, Nu Xu wrote:
> Hi Zuowen, Subhasis and All,
>
> ’Tilted expansion’: If I understand it correctly, the ‘tilted
> source’ is the combined effects of the hot overlapped region,
> compression region as you mentioned,  and the projectiles. At higher
> collision energy, the mid-rapidity region is stretched in the
> z-direction, the projectiles are further away from the mid-rapidity,
> so the ’tilted region’ becomes weaker, as Subash mentioned. As a
> reference, it is discussed in Ref._Phys.Rev.Lett._ 84 (2000) 2803-2805
>   nucl-ex/9908001 [1].
>
> "The v1 slopes of all particles (π±, K0 , and Λ) decrease in
> magnitude as collision energy increases.’ implying a weaker titled
> source at mid-rapidity, in my view.
> I have not yet read ref. [12].
>
> Regards,
>
> Nu
>
>> On Dec 6, 2023, at 6:44 AM, Zuowen Liu via Star-fcv-l
>> <star-fcv-l AT lists.bnl.gov> wrote:
>>
>> Dear Subhash,
>>
>> Thank you for the reply, I understand the question now.
>>
>> It's just my naive thought after reading the reference
>> (PhysRevC.81.054902):
>> The v1 strength is affected by the interplay between initial
>> compression and tilted expansion. As the collision energy increases,
>> the initial compression might be stronger, and the tilted expansion
>> should also be stronger. By this way, the tilted expansion can
>> “overcome” the compression at some energy, and lead to observed
>> anti-flow at higher energy (e.g. 14.6 GeV).
>>
>> Thanks and Best regards,
>> Zuowen
>> ------------------ Original ------------------
>> From:  "subhash"<subhash AT rcf.rhic.bnl.gov>;
>> Date:  Tue, Dec 5, 2023 06:14 PM
>> To:  "Zuowen Liu"<liuzw AT mails.ccnu.edu.cn>; Subject:  Re:
>> [Star-fcv-l] STAR presentation by Zuowen Liu for Quark Matter 2023
>> submitted for review
>> Dear Zuowen,
>>
>> What you wrote in your proceedings is "It implies that there is
>> stronger
>> tilted expansion [9] at higher collision energy", which implies
>> stronger
>> tilt at larger collision energies.
>> But according to the theory calculation tilt angle of the
>> participants
>> should be smaller at higher energies. So my question was from what
>> context or reference you draw this conclusion, which is opposite to
>> the
>> expectation.
>>
>> On 2023-12-05 04:21 PM, Zuowen Liu wrote:
>>> Dear Subhash,
>>>
>>> Sorry, I didn't your point. inline below?
>>>
>>> Best,
>>> Zuowen
>>>
>>> ------------------ Original ------------------
>>>
>>> From:  "subhash"<subhash AT rcf.rhic.bnl.gov>;
>>> Date:  Tue, Dec 5, 2023 02:15 PM
>>> To:  "Zuowen Liu"<liuzw AT mails.ccnu.edu.cn>;
>>> Cc:  "star-fcv-l"<star-fcv-l AT lists.bnl.gov>;
>>> Subject:  Re: [Star-fcv-l] STAR presentation by Zuowen Liu for
>> Quark
>>> Matter 2023 submitted for review
>>>
>>> Dear Zuowen,
>>>
>>> Thanks for the modified version. Please see inline below:
>>>
>>> On 2023-12-05 11:10 AM, Zuowen Liu wrote:
>>>> Dear Subhash,
>>>>
>>>> I am very appreciative of your nice suggestions and detailed
>> review.
>>>> I have modified the proceeding, kindly find the updated one by
>> the
>>>> link:
>>>>
>>>
>>
> https://drupal.star.bnl.gov/STAR/system/files/qm23proceeding_Zuowen.pdf
>>>>
>>>> For the question: l#61 & 82: Isn't it the opposite of what you
>>>> mentioned?
>>>> I think they are identical, I just copy the same sentence to the
>>>> summary.
>>>>
>>>
>>> I should have clarify it before. What I mean is we expect a
>> smaller
>>> tilt
>>> of the participants at higher energies not the other way around.
>> Isn't
>>>
>>> it?
>>>
>>>> Thanks and Best regards,
>>>> Zuowen
>>>>
>>>> ------------------ Original ------------------
>>>>
>>>> From:  "subhash"<subhash AT rcf.rhic.bnl.gov>;
>>>> Date:  Mon, Dec 4, 2023 03:11 PM
>>>> To:  "Zuowen Liu"<liuzw AT mails.ccnu.edu.cn>;
>>>> Cc:  "star-fcv-l"<star-fcv-l AT lists.bnl.gov>;
>>>> Subject:  Re: [Star-fcv-l] STAR presentation by Zuowen Liu for
>> Quark
>>>> Matter 2023 submitted for review
>>>>
>>>> Dear Zuowen,
>>>>
>>>> Thanks for considering my suggestions and this version reads
>> better.
>>> I
>>>>
>>>> have a few more listed below:
>>>>
>>>> l#10: Furthermore, we ... (smaller case)
>>>> l#17: contribution, we ...
>>>> l#19: in Fixed Target Au+Au collisions....
>>>> l#43: The above data-model comparisons ...
>>>>
>>>> l#51-53: "In contrast with the partonic collectivity .... and
>> below"
>>>> --> How about the following
>>>> While the existence of partonic collectivity is observed through
>> NCQ
>>>> scaling of v2 at higher BES energies (sNN > 7.7 GeV) [7], the
>>> complete
>>>>
>>>> collapse of NCQ scaling in v2 at √sNN = 3.2 GeV implies that
>>>> hadronic
>>>> interactions play an important role at this energy and below.
>>>>
>>>> l#60: "v1 slopes of all particles ...increasing"
>>>> --> The v1 slopes of all particles (..) decrease in magnitude as
>>>> collision energy increases.
>>>>
>>>> l#61 & 82: Isn't it the opposite of what you mentioned?
>>>>
>>>> l#62-65: "The bottom panel of Fig. 4 show collision energy
>>> dependence
>>>> of
>>>> pT integrated v2, negative v2 turns to positive v2 for all
>> particles
>>>> (π±, K0S, and Λ) within collision energy √ sNN = 3.0 - 3.9
>> GeV,
>>>> that
>>>> indicates the change of out-of-plane to in-plane expansion [10]
>>>> happens
>>>> in √ sNN = 3.0 - 3.9 GeV"
>>>> --> The lower panel in Figure 4 depicts the collision energy
>>>> dependence
>>>> of transverse momentum (pT) integrated v2. It is observed that
>> the
>>>> sign
>>>> of v2 changes from negative to positive for all particles (π±,
>>> K0S,
>>>> and
>>>> Λ) within the collision energy range of √sNN = 3.0 - 3.9 GeV.
>>> This
>>>> shift
>>>> signifies the transition from out-of-plane to in-plane expansion
>>> [10],
>>>>
>>>> occurring specifically within the mentioned energy range.
>>>>
>>>> l#66: The JAM calculations of Λ are shown by colored bands,
>> where
>>>> blue,
>>>> red, and black bands stand for cascade mode, baryonic mean field
>>> mode,
>>>>
>>>> and mean field mode without spectators, respectively"
>>>> --> The JAM calculations for Λ are represented by colored bands,
>>> with
>>>>
>>>> blue, red, and black bands corresponding to cascade, baryonic
>> mean
>>>> field, and mean field without spectators modes, respectively.
>>>>
>>>> l#68: "Baryonic mean field enhances v1 slope of Λ in √sNN =
>> 3.0
>>>> -3.9
>>>> GeV, it indicates there is strong mean field [11] at high baryon
>>>> density
>>>> region"
>>>> --> The comparison of Λ v1 between the data and model
>> calculations
>>>> suggests the presence of a strong baryon mean field [11] in the
>> high
>>>> baryon density region.
>>>>
>>>> l#69-71: "For pT integrated v2, only mean field mode with
>> spectators
>>>> shows sigh change of v2, implies that the spectator shadowing
>>>> plays important role in √sNN = 3.0 - 3.9 GeV"
>>>> --> Furthermore, the comparison between the measured
>> pT-integrated
>>> v2
>>>> and model calculations indicates the significant influence of
>>>> spectator
>>>> shadowing in the sNN = 3.0 − 3.9 GeV range.
>>>>
>>>> l#83: And negative v2 turns to positive v2, indicates that the
>>> change
>>>> of
>>>> ...
>>>> --> And the sign change in v2 indicates that the change of ....
>>>>
>>>> Thanks and regards,
>>>> Subhash
>>>>
>>>> On 2023-11-30 04:20 PM, Zuowen Liu wrote:
>>>>> Dear Subhash,
>>>>>
>>>>> Thanks a lot for your nice suggestions.
>>>>> I have implemented all of them into the proceeding.
>>>>> For the typos, I checked again and fixed them.
>>>>>
>>>>> Kindly find the updated proceeding by the link:
>>>>>
>>>>
>>>
>>
> https://drupal.star.bnl.gov/STAR/system/files/qm23proceeding_Zuowen.pdf
>>>>> Thanks again for your great help.
>>>>>
>>>>> Best regards,
>>>>> Zuowen
>>>>>
>>>>> ------------------ Original ------------------
>>>>>
>>>>> From:  "subhash"<subhash AT rcf.rhic.bnl.gov>;
>>>>> Date:  Wed, Nov 29, 2023 04:47 PM
>>>>> To:  "Zuowen Liu"<liuzw AT mails.ccnu.edu.cn>;
>>>>> Cc:  "star-fcv-l"<star-fcv-l AT lists.bnl.gov>;
>>>>> Subject:  Re: [Star-fcv-l] STAR presentation by Zuowen Liu for
>>> Quark
>>>>> Matter 2023 submitted for review
>>>>>
>>>>> Dear Zuowen,
>>>>>
>>>>> Nice proceedings. Please consider running a latex spell checker
>> to
>>>>> spot
>>>>> the typos. In general, at several places sentences are not
>>> formatted
>>>>> properly. I tried to correct. Please get it proof read by a
>>>> colleague
>>>>> in
>>>>> your group to check if my interpretations are proper. The
>>> followings
>>>>> are
>>>>> a few suggestions for your consideration:
>>>>>
>>>>> l#1: you may consider adding "at RHIC" for completeness
>>>>>
>>>>> l#5: In this proceeding, --> In these proceedings,
>>>>>
>>>>> l#5,6: may be: transverse momentum dependence of the rapidity
>> slope
>>>> of
>>>>>
>>>>> directed flow (dv1/dy|y=0) for π+ and K0S in Au+Au ... and 3.9
>>> GeV.
>>>>>
>>>>> l#7: Both π+ and K0S show negative
>>>>>
>>>>> l#8: "spectator shadowing could result in anti-flow at low pT "
>>>>> --> spectator shadowing may lead to anti-flow at low pT.
>>>>>
>>>>> "Furthermore, Number of Constitute Quark (NCQ) scaling of v2 at
>> √
>>>>> sNN =
>>>>> 3.2 GeV was observed which is completely broken"
>>>>> --->
>>>>> Furthermore, we observe a complete breaking of Number of
>> Constitute
>>>>> Quark (NCQ) scaling of elliptic flow (v2) at √sNN = 3.2 GeV.
>>>>> It implies that the dominance of hadronic degrees of freedom
>> occurs
>>>> at
>>>>>
>>>>> √sNN = 3.2 GeV and below.
>>>>>
>>>>> l#12: At last, --> Finally,
>>>>>
>>>>> "and physical implications are discussed."
>>>>> --> and the implications in the context of highly dense baryonic
>>>>> matter
>>>>> are discussed.
>>>>>
>>>>> l#16: In this contribution, we present the most recent
>> measurements
>>>>> ...
>>>>> in Au + Au collisions at √sNN = 3.0 - 3.9 GeV in STAR Fixed
>>> Target
>>>>> mode
>>>>>
>>>>> l#18:  For identification of π±, K±, and p, a combination of
>>> Time
>>>>> Projection Chamber (TPC) and Time of Flight (TOF) is used
>>>>>
>>>>> l#20-23: Suggest:
>>>>> The left panel of Fig. 1 illustrates the rigidity (p/q: particle
>>>>> momentum divided by charge) dependence of ionization energy loss
>>>>> (dE/dx)
>>>>> in the TPC. The dashed line represents the theoretical
>> ionization
>>>>> energy
>>>>> loss curve for particles passing through the TPC. Particle
>>>>> identification by TOF is based on the particle mass square (m^2)
>>>>> distribution, which can be obtained from the particle velocity
>>> (β).
>>>>>
>>>>> l#24-26: suggestion:
>>>>> Moreover, the Kalman Filter (KF) particle package [3], where the
>>>>> covariance matrix of reconstructed tracks is taken into account,
>> is
>>>>> employed to reconstruct weak decay particles (KS0 and Lambda).
>>>>>
>>>>> l#26-28: suggestion:
>>>>> An example of reconstructing the invariant mass using the KF
>>>> particle
>>>>> package is demonstrated with the KS0 meson in the right panel of
>>>> Fig.
>>>>> 1.
>>>>>
>>>>> l#30:  kaon --> Kaon
>>>>>
>>>>> l#31-33:
>>>>> The anti-flow of kaons was first observed  .....  6 A GeV. It
>> was
>>>>> attributed to the repulsive potential associated with the
>> strange
>>>>> quark
>>>>> in K0S.
>>>>>
>>>>> l#33-36: suggestion:
>>>>> We have observed anti-flow behavior in kaons and pions for pT <
>> 0.6
>>>>> GeV/c in mid-central Au + Au collisions at 3.0, 3.2, 3.5, and
>> 3.9
>>>> GeV
>>>>> using the fixed target data from STAR.
>>>>>
>>>>> l#37-43: suggestion:
>>>>> The hadronic transport model JAM [5] calculations are compared
>> with
>>>>> experimental data at 3.9 GeV. The JAM model in hadronic cascade
>>> mode
>>>>> (blue band) can successfully capture the anti-flow pattern at
>> low
>>> pT
>>>>> for
>>>>> π+ and K0S, even without the inclusion of a kaon potential [4].
>>>>> However,
>>>>> the JAM model with baryonic mean field (red band) tends to
>>>>> overestimate
>>>>> the v1 slope for π+ and K0S. Additionally, the JAM mean field
>>>> without
>>>>>
>>>>> spectator contribution (black band) exhibits a larger v1 slope
>>>>> compared
>>>>> to the one with spectators. The data-model comparisons above
>>> suggest
>>>>> that the shadowing effect [6] from the spectator may also play a
>>>>> significant role in generating anti-flow at low pT.
>>>>>
>>>>> l#45-48: suggestion
>>>>> The left and right panels of Fig. 3 illustrate the number of
>>>>> constituent
>>>>> quarks (nq) scaled elliptic flow (v2/nq) as a function of
>>> transverse
>>>>> kinetic energy ((mT − m0)/nq) for particles (π+, K+, K0S, p,
>> and
>>>>> Λ) and
>>>>> antiparticles (π−, K−, and K0S), respectively.
>>>>>
>>>>> l#48-52: please re-format to clarify the sentence.
>>>>>
>>>>> Thanks and regards,
>>>>> Subhash
>>>>>
>>>>> On 2023-11-25 12:05 PM, Zuowen Liu wrote:
>>>>>> Dear Subhash,
>>>>>>
>>>>>> Kindly find the updated proceeding by the link:
>>>>>> https://drupal.star.bnl.gov/STAR/node/65884
>>>>>> Thank you.
>>>>>>
>>>>>> Best regards,
>>>>>> Zuowen
>>>>>>
>>>>>> ------------------ Original ------------------
>>>>>>
>>>>>> From:  "Zuowen Liu"<liuzw AT mails.ccnu.edu.cn>;
>>>>>> Date:  Fri, Nov 24, 2023 04:41 PM
>>>>>> To:  "star-fcv-l"<star-fcv-l AT lists.bnl.gov>;
>>>>>> Cc:  "subhash"<subhash AT rcf.rhic.bnl.gov>;
>>>>>> Subject:  Re: [Star-fcv-l] STAR presentation by Zuowen Liu for
>>>> Quark
>>>>>> Matter 2023 submitted for review
>>>>>>
>>>>>> Dear Subhash,
>>>>>>
>>>>>> Thank you for the kind reminder.
>>>>>> I would short it to four.
>>>>>>
>>>>>> Best regards,
>>>>>> Zuowen
>>>>>>
>>>>>> ------------------ Original ------------------
>>>>>>
>>>>>> From:  "subhash via Star-fcv-l"<star-fcv-l AT lists.bnl.gov>;
>>>>>> Date:  Wed, Nov 22, 2023 04:15 PM
>>>>>> To:  "star-fcv-l"<star-fcv-l AT lists.bnl.gov>;
>>>>>> Cc:  "subhash"<subhash AT rcf.rhic.bnl.gov>;
>>>>>> Subject:  Re: [Star-fcv-l] STAR presentation by Zuowen Liu for
>>>> Quark
>>>>>> Matter 2023 submitted for review
>>>>>>
>>>>>> Dear Zuowen,
>>>>>>
>>>>>> Thanks for posting your proceedings.
>>>>>> I guess there are page limits on the proceedings. It supposed
>> to
>>> be
>>>>>> 4-page including references, you have 5-pages now.
>>>>>> Can you please check and shorten it to fit the limit.
>>>>>>
>>>>>> Thanks and regards,
>>>>>> Subhash
>>>>>>
>>>>>> On 2023-11-10 05:14 PM, webmaster--- via Star-fcv-l wrote:
>>>>>>> Dear star-fcv-l AT lists.bnl.gov members,
>>>>>>>
>>>>>>> Zuowen Liu (liuzw AT mails.ccnu.edu.cn) has submitted a material
>> for
>>>> a
>>>>>>> review,
>>>>>>> please have a look:
>>>>>>> https://drupal.star.bnl.gov/STAR/node/65884
>>>>>>>
>>>>>>> ---
>>>>>>> If you have any problems with the review process, please
>> contact
>>>>>>> webmaster AT www.star.bnl.gov
>>>>>>> _______________________________________________
>>>>>>> Star-fcv-l mailing list
>>>>>>> Star-fcv-l AT lists.bnl.gov
>>>>>>> https://lists.bnl.gov/mailman/listinfo/star-fcv-l
>>>>>> _______________________________________________
>>>>>> Star-fcv-l mailing list
>>>>>> Star-fcv-l AT lists.bnl.gov
>>>>>> https://lists.bnl.gov/mailman/listinfo/star-fcv-l
>> _______________________________________________
>> Star-fcv-l mailing list
>> Star-fcv-l AT lists.bnl.gov
>> https://lists.bnl.gov/mailman/listinfo/star-fcv-l
>
>
>
> Links:
> ------
> [1]
> https://urldefense.com/v3/__https://arxiv.org/abs/nucl-ex/9908001__;!!P4SdNyxKAPE!F-NqGclsgrJ0EbUbrM6Xjtv2Fs2HufCsOCfoTpsZfMYcpXZL-DPT-G9l6EY_4Fcakg0PZpQrFTTD8hoF3cs$
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--

Sooraj Radhakrishnan

Research Scientist,

Department of Physics

Kent State University

Kent, OH 44243

Physicist Postdoctoral Affiliate

Nuclear Science Division
Lawrence Berkeley National Lab
MS70R0319, One Cyclotron Road

Berkeley, CA 94720

Ph: 510-495-2473

Email: skradhakrishnan AT lbl.gov