STAR Flow, Chirality and Vorticity PWG

[Prithwish Tribedy <ptribedy AT rcf.rhic.bnl.gov>]

Hi Fuqiang,
  I think we should avoid model dependent conclusion and concentrate on 
the data from the two analyses. I am happy to use EM-field effects as a 
motivation but not more.

1. The observation from Ashik's analysis is with the increase of 
electric charge (and also strangeness), we see larger v1 slitting. This 
is interesting as we know EM-field driven effects are proportional to 
the electric charge. EM-field has Hall + Faraday + Coulomb -- depending 
on which one dominates, the sign will be either positive or negative.

2. The observation from Diyu's analysis is that with the increase of 
centrality we see a sign change of v1 splitting. This is interesting as 
we know EM-field effects are strongly dependent on centrality. The 
transported quarks can only generate positive v1 splitting. So, in 
peripheral events when we see negative v1 splitting we can say this 
effect may be driven by EM-field (Hall + Faraday + Coulomb).

I don't see a contradiction as in 10-40% we can both have EM-field and 
transport both leading to positive v1 splitting for positive \Delta q 
depending on which effect Hall, Faraday or Coulomb dominates and how 
they change with energy. Model calculations are available but they could 
have limitations.

Best,
Prithwish






On 2022-03-15 18:36, Wang, Fuqiang via Star-fcv-l wrote:
> Hi Ashik, Diyu,
>
> Now I’m confused. Looking at both your results again, I observe:
>
> -        \Delta v1 split is positive for positive \Delta q for
> produced quarks in 10-40% centrality.
>
> -        \Delta v1 split is positive for positive \Delta q also for
> proton – antiproton in the same 10-40% centrality range.
>
> -        However, \Delta v1 for proton – antiproton becomes negative
> in more peripheral collisions.
>
> From Diyu’s presentation, EM-field model calculation is negative v1
> for positive charge, increasing from central to peripheral. So
> Diyu’s interpretation of his data is that the positive transport
> proton v1 is overtaken by the strong negative shift from EM in
> peripheral collisions.
>
> However, what Ashik was saying is that the EM field effect is positive
> v1 for positive charge.
>
> So I do think there’s a contradiction, at least apparently, that
> needs to be sorted out.
>
> First off, the easy question:
>
> Positive v1 is defined to be the direction of spectator nucleons at
> positive rapidity, as I understand it. So positive v1 for transport
> protons makes sense to me. Is Ashik’s positive v1 also defined to be
> the direction of positive-rapidity nucleons?
>
> Best regards,
>
> Fuqiang
>
> From: Star-fcv-l <star-fcv-l-bounces AT lists.bnl.gov> On Behalf Of ASHIK
> IKBAL via Star-fcv-l
> Sent: Tuesday, March 15, 2022 9:49 AM
> To: 申迪宇 <dshen AT rcf.rhic.bnl.gov>
> Cc: Prithwish Tribedy <ptribedy AT icloud.com>; STAR Flow, Chirality and
> Vorticity PWG <star-fcv-l AT lists.bnl.gov>
> Subject: Re: [Star-fcv-l] FCV PWG meeting on 6/Oct/2021 Wed. 9:30AM at
> BNL
>
> Hi Diyu,
>
> Thanks for your email. Regarding the concern you brought to my
> attention, my comments are as follows:
>
> 1. As you have already seen, the analysis is focused on the particles
> containing produced quarks only. We combine particles in such a way
> that the combinations have identical quark content on both sides to
> test the coalescence sum rule. Once this sum rule is valid, we tried
> to find combinations that have a net non-zero charge difference. In
> the combinations, we use the strange baryons along with other produced
> particles. When we combine particles, the combinations must have a net
> strangeness. Similarly, they will also have a net baryon number. This
> is an unavoidable consequence of quark quantum numbers. Here we have
> seen the v1 splitting increases with increasing charge difference
> which is due to the presence of em field. We have shown this splitting
> with strangeness to make a point that the splitting also scales with
> strangeness like it does with charge, since the charge and strangeness
> is correlated here. For the sake of argument, I want to bring up the
> splitting between D0 and D0-bar which is solely driven by the em field
> even if the D0 and D0-bar combination has a net charmness quantum no.
> We do not say that this splitting between D0 and D0-bar is due to the
> net charmness.
>
> I think the theoretical calculations you are talking about here is the
> splitting between a particle and its antiparticle (e.g., p-pbar,
> pi+-pi-, K+-K-) where there are transported quarks. For our case, the
> difference is not simply between a particle and its antiparticle
> rather a group of produced (anti-)particles. You can notice that we
> also have the theoretical calculations (transport model calculations,
> PHSD) presented in the paper that have the same pattern as we found in
> the experiment. I think the pattern we found is consistent with the
> transport model calculations.
>
> 2. Regarding the fitting of  \Delta v1 slope with \Delta q within a
> constant \Delta S is a good idea indeed, but it is not feasible here.
> This is because we only have 2 independent data points having the same
> \Delta S and among them one has large uncertainty. From only 2 data
> points it is really difficult to conclude anything. We discussed all
> these points many times during my presentations within the PWG.
>
> Please let me know if you have any further concerns.
>
> Best,
>
> Ashik
>
> On Tue, Mar 15, 2022 at 4:15 AM 申迪宇 <dshen AT rcf.rhic.bnl.gov>
> wrote:
>
> > Hi, Ashik and all,
> >
> > As both of us are interested in the v1 splitting, and we all got
> > some interesting results, I want to bring out a discussion here.
> >
> > Your analysis focus on the produced quarks via kinds of combinations
> > of hadrons, you see violations of NCQ scaling and this violation
> > increases with charge difference(\Delat q) and strangeness
> > difference(\Delta S).
> >
> > I have no doubt about your analysis, but I want to discuss a little
> > about the interpretations.
> >
> > Although you given a sentence in the paper draft that \Delta q and
> > \Delta S are inevitably correlated, but you imply the \Delta q is
> > the dominate effect and trying to explain it by EM-field.
> >
> > When you do so, you imply the EM-field will introduce positive
> > \Delta v1 slope between positive charges and negative charges, while
> > the theoretical prediction is negative.
> >
> > On another hand, our measurement shows the \Delta v1 slope between
> > proton and anti-proton is negative, which is qualitatively
> > consistent with theoretical calculations.
> >
> > So there is an apparent conflict, which should be avoided and
> > understood before the publication.
> >
> > From my point of view, if you want to argue the positive \Delta v1
> > slope is introduced by EM-field(\Delta q), you should fit \Delta q
> > within a constant \Delta S.
> >
> > Best,
> >
> > Diyu
> >
> > On Mar 14, 2022, at 7:42 AM, ASHIK IKBAL via Star-fcv-l
> > <star-fcv-l AT lists.bnl.gov> wrote:
> >
> > Dear Conveners,
> >
> > We would like to request for GPC of the analysis on "Electric charge
> > and strangeness dependent directed flow splitting of produced quarks
> > in Au+Au collisions".  We replied to all comments from FCV-PWG and
> > PWGC. There are very minor updates of the results as per the
> > comments from PWGC:
> >
> > 1. Lower pT/nq cut is shifted from 0.1 to 0.13 GeV/c to get proton
> > identification right.
> >
> > 2. Only 5 independent combinations are shown in the plot of delta-v1
> > slope vs charge and delta-v1 slope vs strangeness.
> >
> > Here are the details of the analysis, replies and the paper draft:
> >
> > 1. Paper draft:
> https://drupal.star.bnl.gov/STAR/system/files/v1spliting_data_paper_ver1.pdf
> > 2. Analysis note:
> https://drupal.star.bnl.gov/STAR/system/files/AN_CoalescenceQuarkFlow_ver1.pdf
> > 3. Replies to PWGC comments:
> https://drupal.star.bnl.gov/STAR/system/files/Reply_PWGCPreviewComments_Aug27_2021.pdf
> > 4. Webpage:
> https://drupal.star.bnl.gov/STAR/blog/ashik/quark-coalescence-and-directed-flow-auau-collisions
> > If there are no further comments/suggestions from the PWG, we wish
> > to request for GPC.
> >
> > Thanks,
> >
> > Ashik (for the PAs')
> >
> > On Wed, Oct 6, 2021 at 1:25 PM ASHIK IKBAL <ashikhep AT gmail.com>
> > wrote:
> >
> > Hi Prithwish, Shinilchi, all,
> >
> > We were discussing at the FCV today about the STAR presentation
> > (from FCV) for the upcoming DNP21 conference and I was told to share
> > the agenda. Here is the information on the talks (by me, Niseem and
> > Chunjian) from FCV group:
> >
> > Time-table: https://meetings.aps.org/Meeting/DNP21/Session/EE [1]
> >
> > Room name: Park.Scollay
> >
> > Zoom link: https://mit.zoom.us/my/Park.Scollay [2]
> >
> > Password: MITDNP21
> >
> > Best,
> >
> > Ashik
> >
> > On Wed, Oct 6, 2021 at 9:10 AM ASHIK IKBAL <ashikhep AT gmail.com>
> > wrote:
> >
> > Hello all,
> >
> > Please find my slides here:
> https://drupal.star.bnl.gov/STAR/system/files/FCVmeeting-Oct062021-ashik.pdf
> > Thanks,
> >
> > Ashik
> >
> > On Wed, Oct 6, 2021 at 1:20 AM pdixit via Star-fcv-l
> > <star-fcv-l AT lists.bnl.gov> wrote:
> >
> > Dear all,
> > I would like to give a short update on our analysis of the elliptic
> > and
> > triangular flow of multistrange hadrons in Au+Au collision at 54.4
> > GeV.
> > Please add me to the agenda.
> > Link to my slides:
> https://drupal.star.bnl.gov/STAR/system/files/FCV_meeting_06102021.pdf
> > Thanks and regards,
> > Prabhupada
> > On 2021-10-04 19:22, ASHIK IKBAL via Star-fcv-l wrote:
> > > Dear conveners,
> > >
> > > I would like to give an update on “Coalescence and quark
> > flow”.
> > > Please add me to the agenda. I will post my slides ASAP.
> > >
> > > Thanks,
> > > Ashik
> > >
> > > On Mon, Oct 4, 2021 at 6:21 AM ShinIchi Esumi via Star-fcv-l
> > > <star-fcv-l AT lists.bnl.gov> wrote:
> > >
> > > > Dear FCV PWG colleagues
> > > >
> > > > We will have our weekly FCV PWG meeting on this Wednesday morning
> > > > 6/Oct/2021
> > > > 9:30AM in BNL (NY time zone) at our usual time and place. So if
> > you
> > > > have anything to
> > > > present, please let us know and please post your slide by
> > Tuesday.
> > > > The zoom room link,
> > > > ID and pass for the FCV PWG meeting are in our usual drupal
> > agenda
> > > > page below.
> > > >
> > > > Please also keep in mind that all the preliminary plots should
> > have
> > > > already been there
> > > > in the summary area below. Please prepare, if yours are not
> > there...
> > > > Best regards, Jiangyong, Prithwish and ShinIchi
> > > >
> > > > Meeting agenda page with zoom link :
> > > > https://drupal.star.bnl.gov/STAR/blog/jjiastar/bulkcorr
> > > > Preliminary page :
> https://drupal.star.bnl.gov/STAR/pwg/bulk-correlations/bulkcorr-preliminary-summary
> > > > _______________________________________________
> > > > Star-fcv-l mailing list
> > > > Star-fcv-l AT lists.bnl.gov
> > > > https://lists.bnl.gov/mailman/listinfo/star-fcv-l
> > > --
> > >
> > > Ashik Ikbal
> > >
> > > Research Associate
> > > Kent State University
> > > Department Of Physics
> > >
> > > Kent, OH 44242, USA
> > >
> > > Contact no.s: +1 631-504-7647 (USA)
> > >
> > > +91 8250216234 (India)
> > >
> > > Alternate e-mails: asheikh2 AT kent.edu
> > > ashik AT rcf.rhic.bnl.gov
> > > ashik.ikbal.sheikh AT cern.ch
> > > _______________________________________________
> > > 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
> >
> > --
> >
> > Ashik Ikbal
> >
> > Research Associate
> >
> > Kent State University
> >
> > Department Of Physics
> >
> > Kent, OH 44242, USA
> >
> > Contact no.s: +1 631-504-7647 (USA)
> >
> > +91 8250216234 (India)
> >
> > Alternate e-mails: asheikh2 AT kent.edu
> >
> > ashik AT rcf.rhic.bnl.gov
> >
> > ashik.ikbal.sheikh AT cern.ch
>
> --
>
> Ashik Ikbal
>
> Research Associate
>
> Kent State University
>
> Department Of Physics
>
> Kent, OH 44242, USA
>
> Contact no.s: +1 631-504-7647 (USA)
>
>                       +91 8250216234 (India)
>
> Alternate e-mails: asheikh2 AT kent.edu
>
>                              ashik AT rcf.rhic.bnl.gov
>
>                              ashik.ikbal.sheikh AT cern.ch
>
> --
>
> Ashik Ikbal
>
> Research Associate
>
> Kent State University
>
> Department Of Physics
>
> Kent, OH 44242, USA
>
> Contact no.s: +1 631-504-7647 (USA)
>
>                       +91 8250216234 (India)
>
> Alternate e-mails: asheikh2 AT kent.edu
>
>                              ashik AT rcf.rhic.bnl.gov
>
>                              ashik.ikbal.sheikh AT cern.ch
>
> _______________________________________________
> Star-fcv-l mailing list
> Star-fcv-l AT lists.bnl.gov
> https://lists.bnl.gov/mailman/listinfo/star-fcv-l [3]
>
> --
>
> Ashik Ikbal
>
> Research Associate
>
> Kent State University
>
> Department Of Physics
>
> Kent, OH 44242, USA
>
> Contact no.s: +1 631-504-7647 (USA)
>
>                       +91 8250216234 (India)
>
> Alternate e-mails: asheikh2 AT kent.edu
>
>                              ashik AT rcf.rhic.bnl.gov
>
>                              ashik.ikbal.sheikh AT cern.ch
>
> Links:
> ------
> [1] 
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> [2] 
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