Skip to Content.
Sympa Menu

star-fcv-l - Re: [Star-fcv-l] Glauber fit in CME paper

star-fcv-l AT lists.bnl.gov

Subject: STAR Flow, Chirality and Vorticity PWG

List archive

Chronological Thread  
  • From: "Wang, Fuqiang" <fqwang AT purdue.edu>
  • To: James Dunlop <dunlop AT bnl.gov>, "STAR Flow, Chirality and Vorticity PWG" <star-fcv-l AT lists.bnl.gov>
  • Cc: Star-Cme-Focusgroup-L <star-cme-focusgroup-l AT lists.bnl.gov>
  • Subject: Re: [Star-fcv-l] Glauber fit in CME paper
  • Date: Tue, 2 Nov 2021 13:23:09 +0000

Hi Jamie, Chunjian,

Then it is indeed strange. I don't know why we need to scale the Glauber
model to match the integral of the multiplicity range 50-500. The Glauber is
already a fit to the data, and it is presumably matched to the data but not
necessarily strictly in terms of the integral.

In addition, if the multiplicity distributions are normalized per event, then
I don't understand why the right panel ratio plot is not significantly above
unity. The cross-section is dominated by low multiplicity events, and we do
see a lower than unity ratio of the Ru/Zr data, so the mid-centrality region
should be above unity.

I think there're problems with the centrality figure. The centrality group
needs to step in to clarify it. If indeed there's issue with the figure, we
can still correct it when addressing referee's comment before too late.

Best regards,
Fuqiang



> -----Original Message-----
> From: James Dunlop <dunlop AT bnl.gov>
> Sent: Monday, November 1, 2021 12:13 PM
> To: Wang, Fuqiang <fqwang AT purdue.edu>; STAR Flow, Chirality and Vorticity
> PWG <star-fcv-l AT lists.bnl.gov>
> Cc: James Dunlop <dunlop AT bnl.gov>; Chunjian Zhang <chun-
> jian.zhang AT stonybrook.edu>; Star-Cme-Focusgroup-L <star-cme-focusgroup-
> l AT lists.bnl.gov>
> Subject: Re: [Star-fcv-l] Glauber fit in CME paper
>
> I don't think there is any ambiguity in what was done.
>
> The paper says:
>
> The P (N offline ) distributions shown in Fig. 2 for data are normalized by
> the
> number of events. The same is also applied for the Glauber distributions.
> However, the Glauber distributions are further scaled by an additional
> factor
> equal to the ratio of the integrals from Noffline = 50 to 500 taken between
> the
> data and Glauber distributions.
>
> --J
>
> > On Nov 1, 2021, at 11:51 AM, Wang, Fuqiang via Star-fcv-l <star-fcv-
> l AT lists.bnl.gov> wrote:
> >
> > Hi Chunjian,
> >
> > My understanding is the following:
> > 1) Glauber is just a fit to data. The two can scale up and down
> simultaneously, for each system, depending on how the data normalization is
> done. That’s not a problem.
> > 2) When plotting the ratio of the Ru/Zr data, there’s a scaling. I
> > don’t
> remember what exactly the scaling was; one choice could be that the
> multiplicity distributions of Ru and Zr are both normalized to 1 (per
> event) and
> then the ratio is taken.
> > 3) The same scaling is applied to the Glauber fit Ru/Zr ratio. There
> > isn’t an
> arbitrary scaling here, i.e. the relative Glauber vs data in each system is
> fixed
> from the fit.
> >
> > Best regards,
> > Fuqiang
> >
> >
> > From: Chunjian Zhang <chun-jian.zhang AT stonybrook.edu>
> > Sent: Monday, November 1, 2021 10:49 AM
> > To: Wang, Fuqiang <fqwang AT purdue.edu>
> > Cc: Chirality and Vorticity PWG STAR Flow <star-fcv-l AT lists.bnl.gov>;
> > Star-Cme-Focusgroup-L <star-cme-focusgroup-l AT lists.bnl.gov>; Grigory
> > Nigmatkulov <nigmatkulov AT gmail.com>
> > Subject: Re: [Star-fcv-l] Glauber fit in CME paper
> >
> > Dear Fuqiang,
> >
> > Hi. Thank you for your comments. Yes. In the vertical axis, what’s the
> > actual
> value of the scale factor? Would not we let the audience know this in the
> paper
> clearly?Even in the talk, nobody mention this. I would not say let’t the
> audience
> guess there is no any “tricky” process.
> >
> > Also, please find the similar recent study in slides 4
> https://drupal.star.bnl.gov/STAR/system/files/nuclear%20deformation%20and%
> 20neutronSkin_isobar_FCV1026_CZhang.pdf. It must have one value around
> 0.99 or 0.98 to something else scaling.
> >
> > Best regards
> > Chunjian
> >
> >
> > On Nov 1, 2021, at 10:35 AM, Fuqiang Wang <fqwang AT purdue.edu> wrote:
> >
> > Hi Chunjian,
> >
> > Do you mean the scaling in the vertical axis?
> > I think it’s just a plotting convenience.
> >
> > The Glauber is fit to the data in the range of Nch>50 I believe.
> >
> > Best regards,
> > Fuqiang
> >
> > —————————
> > Fuqiang Wang
> > Professor of physics
> > Purdue University
> >
> >
> >
> > On Nov 1, 2021 at 10:06 AM, <Chunjian Zhang via Star-fcv-l> wrote:
> >
> > Dear experts,
> >
> > Hi. Based on our recent study, I have one comment on the CME paper Glauber
> fit.
> >
> > I could not find any hints that the Glauber fit was scaled by a factor to
> > match
> the STAR multiplicity trend. To me, it’s a misleading that I would like to
> believe
> and be surprised that the case3 describe the tend so well. (I believe the
> outside
> people will also have the same opinion as mine) I do think the CME author
> and
> experts need to consider mention this in the revised CME paper when you
> comment on the referee reports.
> >
> > Thank you and best regards
> > Chunjian
> > _______________________________________________
> > 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
>
> --
> He/Him/His
> Please do not feel obligated to respond to this message outside of your work
> hours.
> James C Dunlop Ph.: (631) 344-7781
> Building 510A Cell: (631)316-8153
> P.O. Box 5000 Fax: (631) 344-4206
> Brookhaven National Laboratory
> Upton, NY 11973
> dunlop AT bnl.gov




Archive powered by MHonArc 2.6.24.

Top of Page