STAR Flow, Chirality and Vorticity PWG

[Diyu Shen <dyshen AT fudan.edu.cn>]

Hi Prithwish and ShinIchi,

I think for this topic it is necessary to include all the results in 
heavy-ion experiment, not only from STAR but also from ALICE.
So I would suggest to discuss D meson splitting observed by ALICE after point 
5.

Say D-Dbar results show 2.8 sigma splitting, despite D’s have no electrical 
charge — challenges naive EM-field explanation.

Best,
Diyu


> On Dec 2, 2024, at 05:05, Prithwish Tribedy <ptribedy AT rcf.rhic.bnl.gov> 
> wrote:
> 
> Hi ShinIchi and all,
> Thank you for the excellent compilation! Should we consider moving your v1​ 
> talk to Friday? This would allow you to include both public and STAR 
> internal results, providing more flexibility to address key issues that 
> support or challenge EM-field explanations. I list a few points for you to 
> consider on both support and apparent challenge to EM-field explanations:
> 
>    1. Proton results change sign with centrality across all energies -- 
> supports naive EM-field expectations
>    2. Kaon results follow proton trends but are weaker -- supports EM-field 
> if we assume strange quark behave differently
>    3. Pion results align with protons/kaons at low energies, 
> pion-proton-kaon all showing same trend -- challenging transport-only 
> explanations.
>    4. Above (#3) may not be the case for 200 GeV, it's unclear if pion 
> results change sign like protons at 200 GeV -- points to something is 
> missing in our understanding
>    5. Net-ΛΛ results are almost on top of protons, despite Λ's have no 
> electric charge -- challenges naive EM-field explanation
>    6. Splitting increases with ΔqΔq, ΔBΔB, and ΔSΔS, if you assume NCQ 
> scaling holds for produced particles -- supports both EM-field & has been 
> explained by hydro models with baryon inhomogeneity
>    8. NCQ scaling -- crucial but is hard to verify, attempt made for 
> produced quarks only with limited significance, but there are proof that it 
> does not hold for mixture of produced & transported quarks
>    7. Hydro models explain proton data without EM fields -- challenging EM 
> explanations
>    8. Hydro models has not demonstrated that they can explain all PID data 
> -- incompleteness to hydro models that challenge EM-field explanations
>    9. Other models such as mean field -- I am not an expert but it's worth 
> touching.
> 
> Overall, this is a fascinating topic that deserves lengthy discussion, so 
> having it as the last talk of the day may not be ideal.
> 
> Let me know your thoughts!
> 
> Best,
> Prithwish
> 
> 
> On 2024-12-01 12:40, EsumiShinIchi wrote:
>> Dear Rich, Subhash, Prithwish and all
>> I send you the draft of my talk on v1 splitting with materials that
>> are already in public,
>> if you have any suggestions, please let me know. Thank you very much
>> in advance.
>> Best regards, ShinIchi
>> https://drupal.star.bnl.gov/STAR/system/files/v1split_bes2star_Esumi_2024Dec04.pdf
>>> Hi Everyone
>>> I like Subash’s suggestion
>>> To be clear it is now
>>> Sooraj - v1, v2 (and v3?) of light and strange hadrons and
>>> implications
>>> Chengdong Han - light and hyper nuclei flow
>>> Xingrui Gou - Global and local polarization in BES-II COL (note that
>>> we intend to make FXT-polarization a separate talk)
>>> Zhiwan Xu - Chiral effects (CME related) in BES-II and 200GeV
>>> Shinichi - v1 splitting and possible interpretations
>>> Pretty good. Hope we can fit it all in. I think at least Sooraj and
>>> Shinichi’s talks should be in the open session with the theorists
>>> -Rich
>>>> Dear Sooraj, ShinIchi, Richard and Prithwish,
>>>> My understanding is that we were looking for candidates whose
>>>> talks could present an unbiased perspective on topics such as the
>>>> onset of partonic collectivity (bringing together all viewpoints)
>>>> and the electromagnetic field (covering both electromagnetic and
>>>> non-electromagnetic scenarios). However, we did not reach a
>>>> consensus on the EM-talk.
>>>> Therefore, may I suggest having ShinIchi give a summary talk on
>>>> the experimental results of v1-splitting from STAR (if possible
>>>> and if you agree), followed by a theorist? I would recommend
>>>> Sandeep Chatterjee to discuss v1 with hydrodynamics. He is an
>>>> expert on v1 splitting due to EM (predicted D-meson v1 splitting)
>>>> and non-electromagnetic scenario with baryon. This talk could be
>>>> part of an open session, as most of our v1 results are public.
>>>> Although I don't see much space in agenda to accommodate
>>>> v1-splitting theory speaker,  I’m cc’ing ShinIchi here to get
>>>> his opinion on this.
>>>> The followings are rest of the talks from FCV:
>>>> Sooraj - Summarizing v1, v2 of light and strange hadrons
>>>> Chengdong Han - light and hyper nuclei flow
>>>> Xingrui Gou - Global and local polarization in BES-II COL (note
>>>> that we intend to make FXT-polarization a separate talk)
>>>> Zhiwan Xu - Chiral effects (CME related) in BES-II and 200GeV
>>>> Thanks and regards,
>>>> Subhash