STAR Flow, Chirality and Vorticity PWG

[subhash <subhash AT rcf.rhic.bnl.gov>]

Dear Shinichi, All,

If you check slide#21, you will see that the parameter C_B is 
controlling the baryon diffusion. C_B=0 and 1 is roughly the extreme 
cases with and without baryon diffusion.

Thanks and regards,
Subhash

On 2024-12-02 09:19 PM, EsumiShinIchi wrote:
> Dear Sooraj and Muhammad
> Thank you very much for the information.
> Could you please tell me what is the difference between CB=0
> and CB=1 at the page 36-39 of Muhammad’s paper proposal
> slide on 13/Nov/2024?
> Best regards, ShinIchi
>
> > 2024/12/02 16:06、Sooraj Radhakrishnan
> > <skradhakrishnan AT lbl.gov>のメール:
> >
> > Hi Shinichi, Prithwish,
> > Thanks for the slides and comments
> >
> > Regarding the v1 difference and hadro comparisons, there are a
> > couple of points to note
> >
> > 1) The difference in v1 between protons and anti-protons is
> > explained using different initial tilted distributions for the bulk
> > and for transported protons. There is no independent constraint on
> > this and the tilts are tuned to data. In other words, the difference
> > in the final state v1 is carried over to the difference in initial
> > distributions - but without an independent constraint. So doesnt
> > have much predictive power or helps explaining the v1 difference we
> > see. Please find some more details here
> > https://arxiv.org/pdf/2211.15659 [2]
> >
> > 2) What is interesting though is that the centrality dependence is
> > explained through baryon diffusion. As you can see on S.37 here
> https://drupal.star.bnl.gov/STAR/system/files/FCV_Comments_Measurement%20of%20system%20size%20dependence%20of%20directed%20flow%20of%20protons%20%28anti-protons%29%20at%20RHIC_2.pdf,
> > its the baryon diffusion that makes the difference go negative in
> > peripheral collisions. The initial tilt difference is such that the
> > proton v1 gets a positive contribution compared to anti-proton v1.
> > Without the diffusion the difference doesnt go negative. Not sure,
> > but I think its possible, constraints on the baryon diffusion can be
> > checked with other measurements, for example on spectra or v2
> >
> > In short its the baryon inhomogeneity coupled with baryon diffusion
> > that produced negative delta v1 in hydro calculations. Thought that
> > is useful to point out
> >
> > Best,
> > Sooraj
> >
> > On Sun, Dec 1, 2024 at 6:41 PM EsumiShinIchi
> > <esumi.shinichi.gn AT u.tsukuba.ac.jp> wrote:
> >
> > > Dear Prithwish and Diyu
> > > Thank you very much for the suggestions, ALICE D0-D0bar are
> > > already included.
> > > Let’s discuss whether we want to move this to Friday or not.
> > > I’ll try to include
> > > the Lambda results.
> > > Best regards, ShinIchi
> > >
> > > > 2024/12/02 10:48、Diyu Shen <dyshen AT fudan.edu.cn>のメール:
> > > >
> > > > 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
> > > [1]
> > > > > > > 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
> >
> > --
> >
> > Sooraj Radhakrishnan
> >
> > Research Scientist,
> > Department of Physics
> >
> > Kent State University
> > Kent, OH 44242
> >
> > Physicist Postdoctoral Affiliate Nuclear Science Division
> > Lawrence Berkeley National Lab
> > MS70R0319, One Cyclotron Road
> > Berkeley, CA 94720
> > Ph: 510-495-2473 [3]
> >
> > Email: skradhakrishnan AT lbl.gov
>
>
>
> Links:
> ------
> [1] 
> https://drupal.star.bnl.gov/STAR/system/files/v1split_bes2star_Esumi_2024Dec04.pdf
> [2] 
> https://urldefense.com/v3/__https://arxiv.org/pdf/2211.15659__;!!P4SdNyxKAPE!DeQFNclXH4GbLXJ1rhi2DLiNsmhQGY7esZCvfplVqI46p7yGVkd5Gs24ya0Zo28C6fHVy2tmKIvGxXqM6NGBrlu2fk9bTTc5xWNCy4iaRLk$
> [3] tel:%28510%29%20495-2473