STAR HardProbes PWG

[Nihar Sahoo <nihar AT rcf.rhic.bnl.gov>]

Hello Rosi, Peter, Raghav, and all,

Thank you for this discussion and inputs so far.
Certainly we can discuss more on this topic today.

I would like to point out one thing is that this discuss is not all 
about including which results or plots in the presentation or slides. We 
are discussing what are the main physics messages from HF and jet 
measurements in a larger picture we can draw from STAR published results 
and ongoing measurements since last LRP, how our STAR BUR can be 
benefited from it and also future road map and proposal in heavy-ion 
collisions (QGP/hot-dense/cold QCD matter) can be envisioned.
I think this is what Helen and Lijuan were asking to know from our 
HP-pwg.
We can discuss more on it.

Regards
Nihar



On 2022-08-24 23:06, Raghav Kunnawalkam Elayavalli via Star-hp-l wrote:
> Hi Nihar, all
>
> Thanks for preparing the slides. I was unable to join the discussion
> on monday since i was at the vet with my cats most of the morning. I
> would point out that there are two programs within STAR on the jet
> side that are very prominant and relevant for the larger LRP
> community. The first one is on the transport parameters of the QGP and
> the other on fundamental QCD and the transition to np-QCD.
> For the former - i will argue to include our recent published paper on
> the opening angle dependence which is a DOE science highlight (which i
> believe Rosi also mentioned here previously)
> For the latter - This is more related to a growing area of interest in
> using the jet shower to study the non-perturbative nature of particle
> production within jets and we have many measurements on this topic
> such as the differential substructure from Monika and the
> multi-dimensional unfolding from Youqi and also the formation time
> measurements which will be used in AuAu in the future. We don’t need
> to show everything from here, but i think it is important to showcase
> this direction.
>
> Cheers
> Raghav
>
> **************************************
> First Name - Raghav
> Last Name - Kunnawalkam Elayavalli
> email - raghav.ke AT vanderbilt.edu
> website - https://www.raghavke.me [4]
>
> RHIC/AGS UEC member
> Assistant Professor of Physics
> Stevenson Center 6410
> Physics & Astronomy Department
> Vanderbilt University
> Nashville, TN 37235-1807
> <he/them>
> **************************************
>
> > On Aug 24, 2022, at 10:53 AM, Rosi Reed via Star-hp-l
> > <star-hp-l AT lists.bnl.gov> wrote:
> >
> > Hi Peter,
> > I'm surprised that you're surprised given how long a discussion we
> > had on this result when it was a new preliminary.  I completely
> > agree that the experimentalist should report all of her experimental
> > biases and assumptions, whether this is done properly or not in all
> > papers is a discussion for another time.  In any case, in heavy-ion
> > collisions there is always an additional bias that can be attributed
> > to either the fragmentation and/or the geometry by whatever
> > hard-process selection criteria that we use, whether this is a
> > hard-core jet or a leading constituent requirement.  The nuclear
> > modification factor is a particular observable, that the community
> > largely interprets as a measure of suppression (RAA<1), enhancement
> > (RAA > 1) or a canceling of various effects (RAA = 1).  When you
> > have different kinematic requirements in the numerator and the
> > denominator, you construct a variable that can have RAA < 1, even if
> > we could treat the system as an independent superposition of
> > nucleon-nucleon collisions.  I understand that you indicate this
> > area on the plots with the "biased" vs "unbiased" labels, however,
> > my many discussions with people in other experiments and with
> > theorists has indicated that this isn't appreciated or understood.
> > As no other experiment is constructing their analysis in this
> > manner, it makes it very difficult to compare the STAR nuclear
> > modification results, which will especially be a shame in the era
> > where we have sPHENIX data.  In addition to this more pragmatic
> > approach, I think it blurs together different physics processes in a
> > way that makes interpretation of the data difficult.  Unfortunately
> > I need to run to another meeting, so I will end this discussion
> > here.
> >
> > Cheers,
> > Rosi
> >
> > On Wed, Aug 24, 2022 at 11:25 AM Peter Jacobs <pmjacobs AT lbl.gov>
> > wrote:
> >
> > Hi Rosi,
> >
> > Please see replies below:
> >
> > On Wed, Aug 24, 2022 at 7:52 AM Rosi Reed <rosijreed AT lehigh.edu>
> > wrote:
> >
> > Hi Peter,
> > I agree that this is an important result!  It is somewhat
> > unfortunate that the final result did not have the leading track
> > requirement in the reference, which caused this biased vs unbiased
> > confusion that takes away from the physics message.  I would
> > definitely recommend only including figure 19 which does not show
> > the unbiased points, since it would be somewhat inappropriate to use
> > the plots that are in the AN that did not have this bias.
> >
> > I am surprised by this comment, which I do not think is correct.
> >
> > It is the experimentalist's responsibility to measure and report
> > biases. Unfortunately, many heavy ion jet measurements do not do so
> > - this paper is one of the few exceptions.
> >
> > In this paper we went into detail about the nature of the bias,
> > providing a purely data-driven method to identify where it is
> > negligible. This point is important, because the modeling of bias
> > adds additional uncertainty to theoretical calculations. In JETSCAPE
> > we are comparing to the distributions from this STAR measurement,
> > with the "biased" and "unbiased" regions clearly delineated; see Fig
> > 14 here:
> >
> > https://inspirehep.net/literature/2062342 [1]
> >
> > This I think is exactly as it should be - this approach to bias
> > brings clarity, not confusion.
> >
> > The forthcoming RAA analysis being carried out by Robert (who will
> > provide an update at the collab meeting) will improve the first jet
> > RAA measurement in many aspects, but this approach to the bias will
> > be carried out in exactly the same way. There is no reason to
> > change.
> >
> > There are a number of newer results that should be included too
> > (Raghav's nice jet structure measurements for example), probably
> > what would be good for the conveners to do is to make a list of all
> > papers from the pwg that have been published during this time period
> > to make sure that we don't forget everything.  Once we have that, we
> > can start formulating a succinct and clean message.
> >
> > Regards,
> >
> > Peter
> >
> > Cheers,
> > Rosi
> >
> > On Wed, Aug 24, 2022 at 10:45 AM Peter Jacobs via Star-hp-l
> > <star-hp-l AT lists.bnl.gov> wrote:
> >
> > Hi Convenors,
> >
> > Thanks for the pointer to the slides.
> >
> > I very well appreciate the need for concision, with only a few key
> > results highlighted. However, I think that the STAR paper on
> > inclusive jet RAA also belongs on slide 3 of STARjetLRP.pdf, as one
> > of the significant STAR jet measurements since the last LRP:
> >
> > https://inspirehep.net/literature/1798665 [2]
> >
> > Regards,
> >
> > Peter
> >
> > On Wed, Aug 24, 2022 at 4:33 AM Nihar Sahoo via Star-hp-l
> > <star-hp-l AT lists.bnl.gov> wrote:
> >
> > Hello All,
> >
> > As you all know, we had meeting—LRP planning for STAR/RHIC—to
> > discuss
> > STAR's achievements/contributions since last Long Range
> > Plan(LRP)-2015
> > on Monday this week. We also discussed possible STAR experiment
> > proposals (and their physics) that could be included for upcoming
> > LRP.
> >
> > We want to present the same slides at our HP-pwg meeting this week
> > to
> > get your inputs and to discuss further on this topic.
> > Those slides can be found here (Highlights for HP both on the jet
> > and HF
> > discussion slides) along with other presentations:
> https://drupal.star.bnl.gov/STAR/event/2022/08/22/LRP-planning-STARRHIC
> > Please join this week to discuss on this important topic.
> >
> > Thank you
> > Barbara, Yi, Sooraj, and Nihar
> >
> > On 2022-08-22 17:51, Nihar Sahoo via Star-hp-l wrote:
> > > Hello All,
> > >
> > > We will have our regular HP-pwg meeting this Thursday (25th Aug)
> > at 10
> > > AM BNL time. Let us know if you want to present and update your
> > > analysis.
> > >
> > > If you want to present or update your analysis at collaboration
> > > meeting, Please let us know.
> > >
> > > HP working group weekly meeting info:
> https://drupal.star.bnl.gov/STAR/pwg/Hard-Probes/Weekly-HP-PWG-meeting
> > > Join ZoomGov Meeting
> https://bnl.zoomgov.com/j/1611419615?pwd=VW1hNm43ZDd5d2EvK2R4aEJsQ2ZNZz09
> > [3]
> > > Meeting ID: 161 141 9615
> > > Passcode: 744968
> > >
> > >
> > > Regards,
> > > Barbara, Yi, Sooraj, and Nihar
> > > _______________________________________________
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> >
> > --
> > Peter Jacobs
> > pmjacobs AT lbl.gov
> >
> > Nuclear Science Division,
> > Lawrence Berkeley National Laboratory,
> > 1 Cyclotron Road,
> > Berkeley, California,
> > U.S.A. 94720
> > Tel. (510)486-5413
> > Cell: (510) 688-0055
> >
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>
> --
>
> Rosi Reed
> RHIC/AGS UEC member
> Associate Professor, Physics Department
> Lehigh University
> (610)758-3907
> 16 Memorial Drive East Office 406
> Bethlehem, PA 18015
> she/her/hers
>
> --
> Peter Jacobs
> pmjacobs AT lbl.gov
>
> Nuclear Science Division,
> Lawrence Berkeley National Laboratory,
> 1 Cyclotron Road,
> Berkeley, California,
> U.S.A. 94720
> Tel. (510)486-5413
> Cell: (510) 688-0055
>
> --
>
> Rosi Reed
> RHIC/AGS UEC member
> Associate Professor, Physics Department
> Lehigh University
> (610)758-3907
> 16 Memorial Drive East Office 406
> Bethlehem, PA 18015
> she/her/hers _______________________________________________
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> Star-hp-l AT lists.bnl.gov
> https://lists.bnl.gov/mailman/listinfo/star-hp-l
>
>
>
> Links:
> ------
> [1] 
> https://urldefense.com/v3/__https://inspirehep.net/literature/2062342__;!!P4SdNyxKAPE!Gipq0tWYua8eVtaFIoPTfkdZtgoNrHeInw1V1RvFrF79PlT7mkVpTTOFWu9ljX4uBRTNDTynuJjg1ObzFZx5AGY5rrAj$
> [2] 
> https://urldefense.com/v3/__https://inspirehep.net/literature/1798665__;!!P4SdNyxKAPE!HQrK3iLzKW2nLhdhLajuW4IgqSUjvezHG9FZ48_WOGvhGIM93munz4MZUyI1Be1RybYYMhF4SLhFEKMIHCXiSB2PNQ$
> [3] 
> https://urldefense.com/v3/__https://bnl.zoomgov.com/j/1611419615?pwd=VW1hNm43ZDd5d2EvK2R4aEJsQ2ZNZz09__;!!P4SdNyxKAPE!HQrK3iLzKW2nLhdhLajuW4IgqSUjvezHG9FZ48_WOGvhGIM93munz4MZUyI1Be1RybYYMhF4SLhFEKMIHCUoFAVKiw$
> [4] 
> https://urldefense.com/v3/__https://www.raghavke.me__;!!P4SdNyxKAPE!CsoP4xITinEy3H-Uii6yNxoIpVZoG1_qWK1KOWIkCNMqx3UUnPLQGUe-Zb9o4G_k2ijDa_Uiok_BSkMVlCXcSPWXsQjtvm-AVw$
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